污水处理的英文文献翻译

Oxidize the ditch craft in dirty water handle of application and developmentCaiZhi一jun(Foshan City Shunde District Environmental EngineeringBranch Foshan Guangdong 528000)【Abstract 】Setanaerobic, naoxic section Carrous oxidation ditch with biologicla nitrogen and phosphoru sremoval capabilitie, is curren dythe mainstream of city life process of sewage treatme nt, This article descirbes the structure of Carrousel oxidation ditch, porcess and design problems d uring the oper-ation and the corresponding solutions．【Keywords】Carrousel；Oxidationditch；Phosphorusnadnitrogenremoval；Structure；Mechanism1. ForewordOxidize the ditch( oxidation ditch) again a continuous circulation spirit pond( Continuous loop r eactor), is a live and dirty mire method a kind of to transform.Oxidizing the dirty water in ditch ha ndles the craft be researched to manufacture by the hygiene engineering graduateschool of Hollan d in the 50'sof20centuriessuccess.Since in 1954 at Dutch throw in the usage for the velY first nme .secause its a water fluid matter good, circulate the stability and manage convenience etc. techniqu e characteristics, already at domestic and international and extensive application in live the dirty w ater to is dirty to manage aquecustv with the industy[1].Current application than oxidize extensively the ditch type include:The ( Pasveer) oxidizes the ditch, the (Carrousel) oxidizes the ditch, ( Orbal) oxidizes the ditch, the type of T oxidizes the ditc h( three ditch types oxidize the ditch), the type of DE oxidizes the ditch to turn to oxidize the ditch with the Integral whore.these oxidize the ditch because of the difference of esse in construction wi th circulating, therefore each characteristics[2].This text will introduce construction, mechanism, e xistent problem and its latest developments that Carrousel oxidize ditches primarily.2. The Carrousel oxidizes the construction of the ditchThe Carrousel Oxidize the ditch to be researched to manufacture by Dutch DHV company deve lopment in 1967.0xidize the last the companyofDHVinfou ndationoftheditchin theoriginal Carrous el to permited specially the company EIMCO to invent again with its patent in the United States C arrousel 2000 system realizes the living creature of the higher request takes off the nitrogen with d ividedbythefunctionof.Therehasbeen in the world up to now more than 850 Carrousels oxidize the ditch with the Carrousel 2000 system are circulating From diagram therefore[3].The Carrousel oxidizes the ditch the usage the spirit of that definite direction control with shak e up the device, face to mix with the liquid deliver the level speed, from but make drive the liquid of admixture that shake up is in oxidize ditch shut match outlet circulate nowrnererore oxidize the ditch have the special hydraulics flows the ,current complete mix with the characteristics of the ty pe reactor, have the characteristics that push the flow type reactor again, the ditch inside exsrts obviously of deliquescence oxygen density steps degree.Oxidizing the ditch cross section is rectangle or trapezoids, the fiat surface shape is many for oval, the ditch internal water is deep general for2.5 -4 .5 m , the breadth is deep compare for 2:1, also have the deep wate r amount to 7 ms of, ditch inside average speed in water current is 0.3 mS/ s.ostorze ditch spirit admixture equipments cont ain surface spirit machine, the spirit of turn to brush or turn the dish and shoot to flow the spirit m achine, pipe type spirit machine with promote take care of type spirit machine etc., match with in r ecent years usage still contain underwater push machine[4~6].3. The Carrousel oxidizes the mechanism of the ditch3.1 The Carrousel oxidizes the ditch handles dirty and aqueous principleThe at the beginning common Carrousel oxidizes the dirty water In inside In craft of the ditch di rect with dirty mire In reflux together enteroxidize theditch system.The surface spiritmachinemake sfuse In the liquid of admixture the density of the oxygen DO increases about 2 the 3 mgsl t.uncer this kind of well the term of the oxygen, the microorganism gets the enough deliquescence oxygen comes and go to divided by the BOD;At the same time, the ammonia were too oxidized nitrate wi th second nitrate, this time, mix with the liquid be placed in the oxygen appearance.In the spirit ma chine downstream, after water current be become by the swift flow appearance of the spirit Distric t oP even flow the appearance, the water current maintainsin theminim umcurrentvelocity,guarante eingthe liveand dirty mire be placed in the floats the appearance.( average current vercctvs-o.a msl s)Oxldlze microbially the process consumed to fuse theoxygenin thewater,until thevalueofDOdecl inesforzero, mixing with the liquid report the anoxia appearance.versa nitric that turn the function through anoxia area, mix with the liquid enter to have the oxygen area, completing once circulatin g.That system inside, the BOD declines the solution is a continuous process, the nitric turns the fu nction to turn with the versa nitric ~e function ta ke place in same pond.Because of structural restri ct, this kind of oxidize the ditch although can then valid whereabouts BOD,divided by the phosph orus take off the nitrogenous ability ltmrtedt".3.2 The Carrousel oxidizes the ditch divideds by the phosphorus takes off the nitrogenous inf luence factor.Affecting the Carrousel oxidizes the ditch divideds by the phosphoric factor is dirty mire, nitrat e density and quality densities primarily.The research expresses, being total and dirty mire as 11% that a hour biggest phosphorus 4% with deal is its fuck dirty mire deal within live and dirty mire, k eep for the the germ physical endowment measures, but when dirty mire over 15 d hour dirty mire the Inside is biggesttocontain theobviousdescentindealIn phosphorus,canning not reach the biggest divideding by the result of phosphorus on the contrary.Therefore, prolong persistently the dirty mi re (for example 20ds,25ds,30ds) is to have no necessary, proper choose to use within the scope of 8~ 15 d.At the same time, high nitrate density with low quality density disadvantage in divided by the process of phosphorus .4. The Carrousel oxidizes problem and solution methods of the ditch esse.Though the Carrousel oxidizes the ditch has a water fluid matter good, the anti-pounds at the b urthen ability strong, divided by the phosphorus take off the nitrogen efficiency. But, in physically of movement process, still exstts a series of problem.4.1 Dirty mire inflation problemWhen discard the aquatic carbohydrate more, the N, P contains the unbalance of deal, the pH value is low, oxidizing the dirty mire in inside in ditch carries high, fuse the oxygen density the shor tage, line up the mire not etc. causes easily dirty mire ingerm in form in silk inflatlon;Not the dirty mire in germ in form in silk inflation takes place primarily at the waste water water temperature is lower but the dirty mire carries higher hour.The microbial burthen is high, the germs absorbed the large quantity nourishment material, is low because of the temperature, metabolism the speed is sl ower, accumulating the rises large quantity is high to glue sexual and many sugar materials, makin g the surface of the live and dirty mire adhere to the water to increase consumedly, SVI the value i s very high, becoming the dirty mire inflation.Cause that aim at the dirty mire inflation, can adopt the different counterplan:From the anoxia, water temperature high result in of, can enlargement tolerance or lower into the water measures to alleviate burthen, or the adequacy lowers the MLSS( control dirty mire reflux measure), making n eed the oxygen measures decrease.It the dirty mirecarrieshigh, can increaseMLSS, toadjusttheburt hen, necessity4.2 Foam problemBecauseentering totakethe greaseoflarge quantityinthewater, handling system can't completely and availably its obviation, parts of greases enriches to gather in in the dirty mire, through turn to brush the oxygen agitation, creation large quantity foam;The mire is partial to long, the dirty mire is aging, and also easy creation toam.Sprav topourthewaterordivided bywiththesurfacetheof do aw ay with the foam, in common use divided by the an organism oil, kerosene, the oil of stncon, thro w deal as 0.5~ 1.5 mgsl L.Pass to increase dirty mire in pond in spirit in density or adequacies let up the tolerance of ,also can control the foam creation effectively.When contain the live materia! i n surface in the waste water more, separate with the foam easily and in advance method or other m ethods do away with.Also can consider to increase to establish a set of dlvideding by the oil device moreover.But enhance most importantly the headwaters manage, reducing to contain the oil over t he high waste water and other poisonous waste water of into[llJ.4.3 Float the problem on the dirty mireWhen contain in the waste water the oil measures big, whole system mire quality become light , can't like to control very much in operate process its at two sink the pond stop over time, resultin g in the anoxia easily, producing the corrupt and dirty mire ascend to float;When spirit time over l ong, take place in pond the high degree nitric turn the function, making nitrate density high, at two sink the versa nitric in easy occurrence in pond turn the function, creation nitrogen spirit, make di rty mire ascend f1oat;Moreover, contain the oil in the waste water?Take place thedirtymire ascendafterfloating should pauseenter water, broke off or dirty mire in clearance, judge the clear reason, adjust the operation.The dirty mire sinks to decline the sex bad, can throw to add of oagulate or sloth materials, the improvement precipitates the sex;Suchas entert he watercarries big let upintothe water measures or the enlargement reflux measures.Sucn as the di rty mire grain small lower the spirit machine turn soon.If discovers versanitricturning,shouldletup thetolerance,enlarge the reflux or row the mire measures;1f discover the dirty mire is corrupt, shou ld enlargement tolerance, the clearance accumulates the mire, and try the ameliorative pond intern al water dint term!':"4.4 Current velocity is not all and the dirty mire sinks to accumulate the problemIn Carrousel oxidize ditch, for acquiring its special admixture with handles result, mix with liq uid must with certain current velocity is in ditch circulate flow.Think generally, the lowest current velocity should should attain for an average current velocity for, doing not take place sinking acccmutetmq 0.3~0.5 msl s.The spirit equipments that oxidize the ditch is general to turn to brush for t he spirit of to turn the dish with the spirit of , turning to brush of immerse to have no depth for 25 0 ~300 mms, turn the dish immerse to have no depth for 480"'530 mms.With oxidize the ditch wat er the deep(3.0~3.6 ms) comparing, turn to brush occupied the deep 1 / 1 0~ in water 1/12, turned t he dish to also occupy the 1/6'" only 1/7, therefore result in to oxidize the ditch upper part current velocity bigger{ roughly 0.8"'1.2 ms, even larger}, but the bottom current velocity is very small( e specially at the water is deep 2/3 or 3/4 below, mix with the liquid has no current velocity almost), causing ditch bottom large quantity accumulate the mire( sometimes accumulate the mire thicknes s amount to a 1.0 ms), the valid capacity that reduced to oxidize the ditch consumedly, lowered to handle result, affected a water fluid matter[13].Moreover, pass in the spirit on board swim to establish the underwater push machine can also t urn to the spirit of the liquid of admixture that brush the bottom low speed area circulates to flow t o rise positive push function, from but the solution oxidizes the problem that low and dirty mire in current velocity in bottom in ditch sink accumulates,Establish the underwater push machine useds for exclusivelythe push mixs withtheliquidcan make movementmethod that oxidize the ditch much more vivid, this for economy energy, lift the high-efficiency having the very important meaning[14].5. The Carrousel oxidizes the development of the ditchBecause the dirty water handles standard inside to divided by the phosphorus take off the nitro genous request more and more strict, the development that Carrousel further oxidized the ditch to also get.Current, the research and application includes morely below two category type:Tiny bore spirit type Carrousel 2000 systems, Carrousel 3000 system.5.1 TIny bore spirit type Carrousel 2000 systemTiny bore spirit type Carrousel 2000 tiny bore in adoption in system spirit( provide oxygen equi pments as the drum breeze machine), the tiny bore spirit machine can produce the diameter of larg e quantity as a surface for or so and small spirit steeping, this consumedly increases spirit bubble a ccumulates, undering the certain circumstance in capacity in pond make the oxygen transfer the gr oss measures aggrandizement.( if deep increment in pond, its spread the quality efficiency will be higher)Produce the technique ability of the factory house according to the current drum breeze ma chine, the valid waterof thepond is deepbiggestamountingtoa8 ms, therefore can select by examina tions according to the different craft request the fit water is deep.The tradition oxidizes the ditch p ushes to flow is to make use of to turn to brush, turn a disc or pour the umbrella type form machin e realizes of, its equipments utilization is low, the motive consumes big.TIny bore spirit type Carro usel 2000 systems then adopted the underwater pushes the way that flow, rises to dive the propelle r the leaf the motivation that round creation the direct function namely in the of water, at push to fl ow the function to can keep dirty mire from sinking to decline effectively again at the same time.A s a result, the adoption dives the propeller since lower the motive consume, making mire water got again to mixs with adequately.5.2 Carrousel 3000 systemCarrousel 3000 systems are in the Carrousel 2000 systems are ex-to plus a living creature the c hoice the area.That living creature choice area is a craft to make use of high organism carries to sie ve germ grow, repress silk form germ increase, increase each pollutant do away with the rate, after ward principle together Carrousel 2000 syste m.Carrousel 3000 system of bigger increases to express at:An is to increased the pond deep, can a mount to 7.5"'8 ms, united at heart circle type, the pond wall uses totally, reducing to cover the are a, lowering to build the price to increases to bear the low temperature ability at the same time;( ca n amount to 7 'C )Two is the liquid of admixture that spirit equipments that skillful design, the for m machine descends to install to lead to flow ,the anoxia of take out, adopt the underwater propell er solution current velocity problem;Three is to used the advanced spirit controller QUTE.( it adop t the much aer kind of changing the deal control mode)f our is to adopt the integral whole turn the design, starting from the center, Including below wreath form consecuuon craft unu.eoter the well of waterwiththecent watermachine thatused for the liveand dirty mire in reflux;Difference from fo ur-part the choice pond that cent constitute with !X oxygen pond.This outside is a Carrousel to hav e three spirit machine with a prepare versa nitric turn the pond 2000 system.( such as figure 2 sho w)Five is tube line that the design that the circular integral whole turn to make oxidize the ditch do not need additionally, can immediately realize dirty mire in reflux allotment in different craft unit[ [17].6. ConclusionThe Carrousel oxidizes the ditch because of having the good a phosphorus takes off the nitroge n ability, anti-pounds at the burthen ability with circulate to manage the convenience etc. the adva ntage, having got the extensive application.But because of technological development with social advance, that craft is necessarily will exaltation getting further.The author thinks:The carrousel oxi dizes the future research direction of the ditch will now of main below several aspects.1 Combination living creature method, research with develop the living creature model carrouse l oxidize the e this can not only increases the microorganism gross of the unit reactor meas ures, from but increases the organism carries, but also living creature oneself the inside that have p laces the AI the system of 0 enhances to take off the nitrogen result[[18].2 Increases continuously the Carrousel oxidize the microbial activity in Inside in crtcn.scr exa mple throw to add the EM in oxidize ditch with single mind the germ grow, throws in that the salt of Iron make the microorganism tame the live char in iron, devotion in living creature to become t he torrnation to strengthen the germ gumregiment and increases to bear the toxicity pound at etc..3 Increasing the Carrousel oxidizes the ditch equtpments function with supervise and control the technique.Function that increases form machine, underwater propeller, reduce to maintain the w orkload; Making use of DO, etc. of ORP many targets supervises and control the technique and ch anges the technique of is from now on the carrouseloxidizes ditchsciencecirculatenecessarilyfromi troad.4 Increasing the Carrousel oxidizes the ditch resistant to cold and bear toxicity can, reduce to co ver the area to build the price with the engineering.Theoretical application, deep pond in water po wer term with the research of the craft function is to lowers the engineering builds the price and in creases resistant to cold bear the toxicity can wait to provide the possible direction. 【References】[1] Xia Shibin, Liu Junxin. An innovative integrated oxidation ditch with vertical circle for domestic wastewater treatment. Process Biochemistry, 2004, 39(4):1117[2] X, Hao; Doddema, H. J.; van Groenestijn, J. W. Use of contact tank to enhance denitrification in oxidation ditches. Water Science and Technology, 1996, 34(1-2):195~202.1~1117.[3] 汪大，雷乐成。

污水处理方法的英语作文There are various methods for treating sewage. One common method is the use of primary treatment, where large solids are removed from the sewage through screening and settling processes. This helps to reduce the amount ofsolid waste in the sewage before further treatment.Another method is biological treatment, which involves the use of microorganisms to break down organic matter in the sewage. This process can be carried out in aerobic or anaerobic conditions, depending on the specific requirements of the treatment plant.Chemical treatment is also a widely used method for sewage treatment. This involves the use of chemicals such as chlorine or ozone to disinfect the sewage and remove any remaining pathogens before it is discharged into the environment.Advanced treatment methods, such as membrane filtrationand reverse osmosis, are becoming more popular for treating sewage. These methods can remove even smaller particles and contaminants from the sewage, producing high-quality effluent that can be reused for irrigation or other purposes.In addition to these methods, there are also natural treatment systems, such as constructed wetlands, that can be used to treat sewage. These systems rely on the natural processes of filtration and biological degradation to clean the sewage before it is released into the environment.Overall, there are many different methods for treating sewage, each with its own advantages and limitations. By using a combination of these methods, it is possible to effectively clean sewage and protect the environment from the harmful effects of untreated wastewater.。

污水处理的过程英语作文Wastewater Treatment ProcessWastewater treatment is a crucial process that plays a vital role in maintaining the health and sustainability of our environment. It involves the removal of contaminants from wastewater, ensuring that the discharged water is safe for the ecosystem and human use. The process of wastewater treatment consists of several stages, each designed to address specific types of pollutants and ensure the final effluent meets the required standards.The first stage of wastewater treatment is known as the preliminary treatment. This stage aims to remove large, coarse, and floating materials from the wastewater. This includes items such as rags, sticks, and other debris that could potentially clog or damage the equipment used in the subsequent treatment stages. Preliminary treatment typically involves screening, grit removal, and sometimes oil and grease removal.Following the preliminary treatment, the wastewater undergoes primary treatment. This stage focuses on the removal of suspended solids and organic matter from the wastewater. The primarytreatment process involves sedimentation, where the wastewater is allowed to settle, allowing the heavier solids to sink to the bottom of the tank. The settled solids, known as primary sludge, are then removed and sent to further processing or disposal. The clarified liquid that remains is then ready for the next stage of treatment.The secondary treatment stage is the most crucial step in the wastewater treatment process. This stage is designed to remove the remaining organic matter and nutrients, such as nitrogen and phosphorus, from the wastewater. The secondary treatment typically involves biological processes, where microorganisms are used to break down the organic matter. The most common secondary treatment methods include activated sludge, trickling filters, and rotating biological contactors.In the activated sludge process, the wastewater is mixed with a population of microorganisms, typically bacteria and protozoa, in an aeration tank. The microorganisms consume the organic matter, converting it into carbon dioxide and new cellular material. The resulting mixture of wastewater and microorganisms is then sent to a clarifier, where the treated water is separated from the excess microorganisms, known as activated sludge. The activated sludge is then recycled back to the aeration tank to continue the treatment process.Trickling filters, on the other hand, use a fixed-film biological process. In this method, the wastewater is sprayed over a bed of media, such as rocks or plastic, where a layer of microorganisms grows. As the wastewater trickles through the media, the microorganisms break down the organic matter. The treated water is then collected and sent to the next stage of treatment.Rotating biological contactors (RBCs) are another type of secondary treatment method. RBCs consist of a series of large discs that are partially submerged in the wastewater. The discs are slowly rotated, allowing the microorganisms that grow on the discs to be alternately exposed to the wastewater and the air. This process enables the microorganisms to consume the organic matter in the wastewater.After the secondary treatment, the wastewater may undergo additional treatment steps, such as tertiary or advanced treatment, depending on the specific requirements of the receiving water body or the intended reuse of the treated water. Tertiary treatment can include processes like filtration, disinfection, and nutrient removal to further improve the quality of the effluent.The final stage of wastewater treatment is the sludge treatment and disposal. The sludge generated during the various treatment stages is processed to reduce its volume and stabilize the organic matter. This can involve thickening, dewatering, digestion, and sometimesincineration or landfilling. The treated sludge can then be used as a soil amendment or disposed of in an environmentally responsible manner.The wastewater treatment process is essential for protecting the environment and public health. By removing contaminants and ensuring the treated water meets the necessary standards, wastewater treatment helps to maintain the quality of our water resources, prevent the spread of waterborne diseases, and support the overall sustainability of our ecosystems. As the demand for clean water continues to grow, the importance of efficient and effective wastewater treatment will only become more critical in the years to come.。

污水治理的英语作文Sewage treatment is an important process in maintaining the health and safety of our environment. With the increasing population and industrialization, the amount of sewage produced has also increased, making it crucial to have effective sewage treatment methods in place.There are several methods of sewage treatment, including physical, chemical, and biological processes. In the physical treatment, sewage is passed through screens and grit chambers to remove large objects and debris. Then, it undergoes a process called sedimentation where the heavy solids settle at the bottom, forming sludge, while the lighter solids float on the surface, forming scum. The next step is biological treatment, which involves the use of microorganisms to break down the organic matter in the sewage. This process can take place in either aerobic or anaerobic conditions. In aerobic conditions, microorganisms use oxygen to break down the organic matter, while in anaerobic conditions, they work in the absence of oxygen.Chemical treatment is often used as a final step in sewage treatment to remove any remaining contaminants. Thiscan involve the use of chemicals such as chlorine or ozone to disinfect the water and remove pathogens. Once the sewage has undergone these processes, it can be safely released back into the environment without causing harm to human health or the ecosystem.In addition to these traditional methods, there are also emerging technologies in sewage treatment, such as membrane bioreactors and advanced oxidation processes, which are more efficient and environmentally friendly. These technologies can further improve the quality of treated sewage and reduce the impact on the environment.Proper sewage treatment is essential for protecting public health and the environment. Untreated sewage can contaminate water sources, leading to the spread of waterborne diseases and harming aquatic life. It can also contribute to pollution and eutrophication of water bodies, leading to algal blooms and dead zones. Therefore,investing in effective sewage treatment infrastructure is crucial for sustainable development and the well-being of communities.污水治理是维护环境健康和安全的重要过程。

污水处理流程英文版English:The wastewater treatment process involves several stages to remove impurities and contaminants from the sewage before it is released back into the environment. The first stage is screening, where large objects like sticks, rags, and debris are removed from the sewage using bar screens or fine screens. Then, the sewage goes through the primary treatment stage, where solid materials are settled and removed from the water. After that, the sewage undergoes secondary treatment, which uses biological processes to break down organic matter and remove pathogens. The final stage is disinfection, where chemicals or physical methods like UV radiation are used tokill any remaining bacteria and microorganisms in the water. Oncethe wastewater has gone through all these stages, it can be safely discharged into rivers, lakes, or oceans.中文翻译:污水处理过程包括几个阶段，以在将其排放回环境之前从污水中去除杂质和污染物。

污水处理英语作文Water pollution is a pressing environmental issue that affects communities around the world. Untreated wastewater can contaminate drinking water sources, harm aquatic ecosystems, and pose a threat to public health. Effective wastewater treatment is crucial to mitigate these impacts and ensure a sustainable water supply.One of the primary sources of water pollution is the discharge of untreated or inadequately treated sewage from residential, commercial, and industrial sources. Sewage can contain a variety of pollutants, including pathogens, organic matter, nutrients, heavy metals, and synthetic chemicals. These pollutants can have detrimental effects on the environment and human health if not properly managed.Wastewater treatment is the process of removing contaminants from wastewater to produce an effluent that is safe for discharge into the environment. The treatment process typically involves a series of physical, chemical, and biological processes to remove various pollutants. The specific treatment methods used will depend on the characteristics of the wastewater and the desired level of treatment.The first stage of wastewater treatment is typically the primary treatment, which involves the removal of larger solids and floating debris through screening and sedimentation. This stage helps to reduce the overall organic load and suspended solids in the wastewater. The secondary treatment stage then focuses on the removal of dissolved organic matter and nutrients, such as nitrogen and phosphorus, through biological processes. This is often achieved through the use of activated sludge or trickling filter systems, where microorganisms break down the organic matter and convert the nutrients into less harmful forms.In some cases, tertiary treatment may be required to further purify the wastewater. This can include processes such as disinfection, advanced oxidation, or membrane filtration to remove any remaining contaminants and ensure the effluent meets the necessary water quality standards for safe discharge or reuse.The treated effluent can then be safely released into the environment, such as a river, lake, or ocean, or it can be reused for various purposes, such as irrigation, industrial processes, or groundwater recharge. Proper wastewater treatment not only protects the environment but also conserves valuable water resources and reduces the strain on freshwater supplies.In addition to the treatment processes, proper management and maintenance of wastewater treatment facilities are crucial. This includes regular monitoring of the system's performance, proper disposal of sludge and other byproducts, and the implementation of appropriate safety and emergency protocols.The benefits of effective wastewater treatment are numerous. It helps to protect aquatic ecosystems by reducing the introduction of harmful pollutants, prevents the contamination of drinking water sources, and supports the sustainable use of water resources. Furthermore, the reuse of treated wastewater can alleviate water scarcity in many regions and contribute to a more circular economy.However, the implementation of wastewater treatment systems is not without its challenges. Factors such as the availability of funding, the existing infrastructure, and the level of public awareness and engagement can all impact the effectiveness of wastewater treatment programs. Governments, policymakers, and water management authorities play a crucial role in addressing these challenges and ensuring the widespread adoption of sustainable wastewater treatment practices.In conclusion, wastewater treatment is a vital component of environmental protection and water resource management. By effectively removing contaminants from wastewater, we cansafeguard the health of our water bodies, protect public health, and promote the sustainable use of water resources. Continued investment, technological advancements, and collaborative efforts among stakeholders are essential to address the global challenge of water pollution and ensure a cleaner, more sustainable future for all.。

Application of multi-soil-layer system (MSL) in ruralwastewater treatmentAbstract: with the continuous improvement of living in rural farmers, the water consumption of residents is increasing, rural sewage emissions will continue to increase, if not treat effectively, the water environment in rural areas will be serious deteriorated, and influence the life quality of rural residents. In this case this paper presents a decentralized sewage treatment system, multi-soil-layer system technology (MSL) application in the rural sewage treatment, this paper summarizes the new technology, you can better understand and practice, especially in the developing countries where is in need of this technology. In the foreseeable future, it can protect public health and the sustainable development of the environment, and it also provides a new way for rural sewage treatment.Key words:rural sewage; multi-soil-layering system; distributed1.IntroductionIn recent years, with the continuous development of economy, people's living standards continue to improve, rural economic development is also very rapid, but the rural economic development and environmental development is not synchronized, serious rural water pollution.While high technical sewage treatment plants, such as centralized sewage treatment plants are involved in large investment costs, high operating costs, Because of economic constraints, such systems are less suitable for livestock farms and small communities in rural areas. While the multi-media-soil layer system(MSL) sewage treatment system, this decentralized sewage treatment system, it has less investment, low operating costs, high handling load. Besides, the utility model overcomes the defects of the prior soilpercolation which is easy to be blocked from the space structure. The sewage treatment system is one kind of the purification technology of sewerage treatment soil developed in Japan in twentieth Century, the soil system will be modularized, and the module is set up around the water in the soil layer to avoid clogging, and adding natural organic materials to soil modules can improve the purification ability of the system.The MSL system consists of a Permeable layer (PL) and a soil mixing layer block (SMB),The Permeable layer is usually composed of larger particles fillers such as gravel, pumice, perlite and zeolite.Higher porosity can effectively prevent clogging of the soil water layer.At the same time, the formation of aerobic environment is conducive to organic degradation.The mixed layer soil is mainly packing soil mixed with other 20%-30% other materials such as activated carbon, wood, iron and other material or soil with local resources.The organic material added in the soil mixed layer can improve the biological decomposition and adsorption capacity of the system, and can also improve the supply of hydrogen in the process of nitrogen removal and promote the removal of nitrogen.There are many researches on MSL system treating urbansewage, livestock wastewater and river water at home and abroad. Researchers in China, Ye Hai et al[1] studied the effect of surface load on polluted river water treated by multi-soil-layer system.Song Ying[2]had studied the treatment effect of multi medium soil infiltration system for turtle breeding wastewater.Zou Jun[3]also pointed out that multi-soil-layer material selection will have a certain impact on the domestic sewage treatment efficiency.In foreign countries, especially in Japan, Thailand and Indonesia, MSL systems have been used to handle various types of wastewater, but the domestic of this technology in sewage treatment in rural areas there is no comprehensive study,This article through to the MSL system technology processing rural domestic sewage research, in order to provide some technical support for the MSL system in the practical application of rural sewage treatment.2.1characteristics of rural sewageFor a long time,China's pollution control on rural attention and investment far less than the city,96% of the villages without drainage pipe network and sewage treatmentsystem,The random discharge of domestic sewage has become one of the main reasons for the deterioration of water quality in the basin, and is also an important factor causing the rural water environment pollution and lake eutrophication.At the same time, it seriously affects the safety of production and living in the rural areas, and seriously affects the economic development.The main features of rural sewage in China are:(1)The amount is huge and increases year by year. Statistics show that in 2002.There are 3.205 million tons of national rural domestic sewage daily emissions.The total nitrogen emission is about 283.1t, total phosphorus daily emission is about 56.6t, basically without any treatment directly discharged.(2)Water quality and water quantity fluctuation are huge. Rural sewage water is not stable, different periods have different water quality,generally do not contain heavy metals and toxic and harmful substances, but contains more synthetic detergent and bacteria, viruses.(3)More sources.In addition to human feces, kitchen generated sewage, there are household cleaning, domestic waste landfill leachate generated sewage, which will then enter theriver part of the sewage, will cause greater pollution.(4)Low treatment rate.Part of the system can not run low temperature, rural sewage daily variation coefficient and seasonal variation coefficient, the system a few time high load operation, if there is little sewage, it will stop running [4].(5)Wide and scattered.Scattered geographical distribution of villages caused sewage dispersion and it is difficult to collect.2.2 the main source of rural sewageRural sewage refers to the formation of sewage of the rural areas in the life and production process, including rural production wastewater and rural domestic sewage two aspects. Rural domestic sewage refers to the residents living in the process of toilet discharge of sewage, bath, laundry and kitchen sewage, etc.Rural production sewage refers to livestock and poultry breeding, aquaculture, agricultural products processing and other high concentration of organic wastewater.Because China's rural living is scattered, rural domestic sewage showed a small amount and wide ck of appropriate sewage collection, treatment facilities, domestic sewage without treatment will be free to discharge,the health of rural residents to bring greater harm.At the same time, rural sewage production also poses a greater threat to the rural ecological environment.2.3main technologies of decentralized domestic sewage treatmentBeginning in 1970s, Japan, the United States, Europe and other developed countries on the use of decentralized sewage treatment of rural sewage treatment, has accumulated a lot of experience, achieved good results.The United States since the mid-20th century began the construction of rural sewage treatment facilities, in 1972 promulgated the first complete clean water, then according to the distributed processing technology in 2002 promulgated the decentralized sewage treatment system application manual [5].1987, In Denmark promulgated a decentralized sewage treatment guidelines[6]. Germany from 2003 to implement the decentralized needle infrastructure system project research, use membrane bioreactor purification to treat remote rural sewage[7]. Australia proposed a sewage treatment land use system [8].While research and application of rural sewage decentralized treatment in China began in late 1980s,Compared with developedcountries and regions, there are still many gaps in laws and regulations system, technical standard system and management and service system.In recent years, domestic scholars have done a lot of research on rural domestic sewage,and puts forward some mature processing technology, including aerobic biological treatment, anaerobic biological treatment technology, soil infiltration technique and physical and chemical processing technology etc.There are many scholars in the multi-soil-layer system improvement and application development of the Japanese, it has also done a lot of research, some scholars found through experiments: to earthworm soil infiltration layer can also solve the problem of blockage of MSL system, but also can guarantee the winter operation effect in winter [9-10].2.4 Multi-soil-layer system (MSL) technology2.4.1Structural characteristics of multi-media-soil layer systemMulti-soil-layer treatment (MSL) system is a kind of land sewage treatment system.Mainly composed of Permeable layer (PL) and a soil mixing layer block (SMB),From top to bottom are waterproof layer, gravel layer, soil layer and mixed layer (twoalternately arranged), in addition, the MSL technology has a certain terrain fall from the inlet to the outlet, mainly by the drop let water can automatically flow in the system, at the same time to purify [11].2.4.2Purification mechanism of multi-soil-layer systemWastewater contains high concentrations of BOD, COD, ammonia nitrogen, phosphate ions and organic matter.When the wastewater into the MSL system, the organic matter in wastewater can be adsorbed on the surface of zeolite and soil through physical and chemical effects, followed by decomposition of soil layer in microorganism, and phosphorus removal is mainly through the soil layer of iron is oxidized to ferric hydroxide after the formation of insoluble iron, then adsorption in wastewater the formation of phosphate coprecipitation.Nitrogen removal is mainly through nitrification and denitrification by ammonia ion, and finally reduced to nitrogen discharge system.2.4.3Advantages of multi-soil-layer systemMulti-media-soil layer system is used to treat wastewater from traditional soil infiltration system.It has the disadvantages of low treatment load, large ground, easy toblock nitrogen and phosphorus removal and other shortcomings [12].The MSL system with "soil modular" as the core concept, its unique brick type internal structure can form a plurality of aerobic and anaerobic environment in order to promote the removal of pollutants,Among them, the permeable layer greatly improves the water permeability of the system to prevent clogging, adding natural materials in the soil increases the purification capacity of the system.3.ConclusionsWith the economic reform and development, China's environmental awareness is also improving, water pollution in rural areas have also obtained more and more attention,The MSL system applicable to the small population, scattered in rural areas, the decentralized sewage treatment system can be widely installed and used in the rural society, especially in rural areas of developing countries such as Chinese, Chinese is in need of such technology, sustainable development can protect the public health and the environment.4.Reference[1] Ye Hai Ye et al. Effect of surface load on polluted river water treatedby multi-soil- layer system[J]. China water supply and drainage, 2012,28 (19): 74-77[2]Ying Song et al.Treatment of turtle aquaculture effluent by anmulti-soil-layer system[J].Journal of Zhejiang University ScienceB.2015,16(2):145-154[3]Zou Jun, Chen Xin et al. Effect of material selection ofmulti-soil-layer system on domestic wastewater treatment efficiency[J]. Journal of ecology and rural environment, 2010,26 (1): 14-18[4]Zhang Keqiang et al. Rural sewage treatment technology[M]Beijing:China Agricultural Science and Technology Press, 2006.10[5] Chen Jinming et al.Policy and experience of managing decentralizedwastewater treatment systems in the United States [J]. China water supply and drainage, 2004,20 (6): 104-106[6] Hans B.Danish guidelines for small-scale constructed wetland systemsfor onsite treatment of domestic sewage[C].Proceedings of the 9th International Conference on Wetland Systems for Water Pollution Control, Avignon, France,2004:1-8[7] Li Wushuang, Wang Hongyang. Status and treatment technology of ruraldecentralized domestic wastewater [J]. Tianjin Agricultural Sciences, 2008,14 (6): 75-77[8] Zhang Jiawei, Zhou Zhiqin. Application of decentralized treatmenttechnology for rural domestic sewage [J]. environmental science and management, 2011,36 (1):95-99[9] Wang Xixi, Guo Feihong, et al. A new improved capillary infiltrationditch for domestic wastewater treatment. [J].environmental chemistry,2011,30(3): 721-722[10]Zhang Xiaowei, Li Jianchao, et al. Experimental study on earthwormenhanced land treatment of rural wastewater [J]. Journal of agro environmental science,2009,28 (6): 1225-1229[11]Hu Hongqi, Yang Yong et al. Analysis of practical application of twoefficient rural sewage treatment technologies [J]. Heilongjiang environmental bulletin, 2016, 40 (1): 20-24[12] Xin Chen et al.An introduction of a multi-soil-layering system:anovel green technology for wastewater treatment in rural areas[J].Water and Environment Journal.2009:255-262。

污水处理方法的英语作文Wastewater Treatment Methods。

As the world's population continues to grow, the demand for clean water is becoming increasingly important. However, with the increase in population and industrialization, the amount of wastewater being produced is also increasing. Wastewater is any water that has been used and discarded, and it can contain a variety of pollutants. Therefore, itis essential to treat wastewater before it is released back into the environment. There are several methods fortreating wastewater, including physical, chemical, and biological methods.Physical methods involve the removal of solid materials from wastewater. This can be done through a process called sedimentation, where the wastewater is allowed to sit in a tank, and the solids settle to the bottom. The remaining liquid is then treated further. Another physical method is filtration, where the wastewater is passed through a filterto remove any remaining solids.Chemical methods involve the use of chemicals to remove pollutants from wastewater. One common chemical method is chlorination, where chlorine is added to the wastewater to kill any bacteria or viruses. Another chemical method is coagulation, where a chemical is added to the wastewater to cause the pollutants to clump together, making them easier to remove.Biological methods involve the use of microorganisms to break down pollutants in the wastewater. One common biological method is activated sludge, where microorganisms are added to the wastewater to break down organic matter. The wastewater is then aerated to provide oxygen for the microorganisms to thrive. Another biological method is constructed wetlands, where wastewater is treated by passing it through a wetland area that contains plants and microorganisms.In conclusion, treating wastewater is essential to protect our environment and ensure that we have access toclean water. There are several methods for treating wastewater, including physical, chemical, and biological methods. Each method has its advantages and disadvantages, and the choice of method depends on the type of wastewater being treated and the desired outcome. However, regardless of the method used, the goal is the same – to remove pollutants from wastewater and protect our environment.。

污⽔处理-英⽂⽂献4Desalination 231 (2008) 20–260011-9164/08/$– See front matter ? 2008 Elsevier B.V. All rights reservedat The 4th IWA Conference on Membranes for Water and Wastewater TreatmentMay 15–17, 2007, Harrogate, UK*Corresponding author.Upgrading and retrofitting of municipal wastewater treatmentplants by means of membrane bioreactor (MBR) technologyCh. Brepols a , E. Dorgeloh b , F.-B. Frechen c , W. Fuchs d , S. Haider e , A. Joss f ,K. de Korte g , Ch. Ruiken g , W. Schier c *, H. van der Roest h , M. Wett i , Th. Wozniak jaErftverband, Bergheim, GermanybPrüf- und Entwicklungsinstitut für Abwassertechnik (PIA) an der RWTH Aachen, Germany cDepartment of Sanitary and Environmental Engineering - DESEE, University of Kassel, Germany Tel. +49 (561) 8043817; Fax+49(561)8043642;email:*******************************University of Natural Resources and Applied Life Sciences – Vienna, Department IF A-Tulln,Institute for Environmental Biotechnology, Tulln, AustriaeH2Office Abwassertechnik, Wien, AustriafEAWAG — Swiss Federal Institute of Aquatic Science and Technology, Duebendorf, SwitzerlandgDWR — Dienst Waterbeheer en Riolering, Amsterdam, The Netherlands hDHV —Consultancy and Engineering, Amersfoort, The Netherlands iSüddeutsche Abwasserreinigungs-Ingenieur GmbH, Ulm, Germanyjwws consulting, Reutlingen, GermanyReceived 17 May 2007; accepted revised 20 November 2007AbstractIn the future, upgrading of existing wastewater treatment plants (wwtps) will become the more challenging task than erection of wholly new plants, as most of the plants (e.g. necessary in Germany) do exist already. Since some time, MBR technology has been taken into consideration and has been realised as an alternative for wwtp upgrading.This paper gives an overview about some relevant preconditions, basic upgrading concepts and examples of already upgraded wwtps using MBRtechnology.Keywords: Municipal wastewater treatment; Upgrading; MBR technologydoi:10.1016/j.desal.2007.11.035Ch. Brepols et al. / Desalination 231 (2008) 20–26211. IntroductionMany wwtps suffer from an inadequate level of treatment provided. There are several reasons for the need of retrofittedand/or upgraded equip-ment, such as expiry of lifespan, the increase of wastewater flow or load or higher treatment stan-dards due to a change of legal framework. In gen-eral, no standard solutions for the upgrading of wastewater treatment systems are available and the transfer of a certain measure from one case to another is limited. In fact, the optimum answer in each individual case is largely site-dependent. Accordingly, there is a broad spectrum of mea-sures that might be employed. In most cases it is not a singular action to be taken, but the upgrad-ing will incorporate a set of different interlocking components both at the drainage system and the wastewater treatment plant.The MBR process is an emerging advanced wastewater treatment technology that has been successfully applied at an ever increasing num-ber of locations around the world. It involves a suspended growth activated sludge system that utilizes microporous membranes for solid/liquid separation as a substitute of the conventional sec-ondary clarifier. MBR technology has not only attracted increasing interest for the set up of new wastewater treatment systems but also it has high potential looking at upgrading tasks of already existing wwtps.2. Considerations for the choice of MBR technologySince membrane filtration allows raised sludge concentrations, the activated sludge tank volume can be significantly reduced. In combination with the option to convert the secondary clarifier, that is no longer required as a sedimentation tank, as an additional activated sludge tank, the treatment capacity of the existing plant can be largely ex-tended. That way it is possible to upgrade exist-ing wwtps from simple carbon removal to BNR systems just using the already existing volume.Therefore favourable conditions for the choice of MBR technology are given, where retrofitting of the existing plant by the conventional activated sludge (CAS) process would demand for substan-tial extension of the activated sludge volume. As well, where limitations due to insufficient effi-ciency of the secondary clarification basin exist, particularly however, where both problems have to be solved.MBR technology should also be considered if high effluent criteria such as removal of suspended solids or absence of pathogens have to be met. Examples are discharge into small creaks as well as into bathing water or other sensitive areas.Due to the small space requirement the MBR offers special advantages if the given location holds no or only a limited amount of area in re-serve. Moreover, the small footprint allows a com-plete indoor installation in a building designed to blend in with its surrounding environment and such to address issues of visual amenity, odour or noise.Another distinct advantage of MBR technol-ogy is direct utilisation of the effluent for reuse purposes. The water reuse potential includes irri-gation of agricultural land, recharge of aquifers or river flow replenishment. On several occasions this was the major decision criteria to opt for MBR technology.With the choice of the MBR special attention should be paid to the fact that the investment costs are largely correlated with the hydraulic peak flow. This parameter determines the total membrane surface area which needs to be installed. There-fore, accompanying measures to minimize wet weather flow or to harmonise resultant wastewa-ter largely contribute to cost effectiveness of the MBR approach. One option for dealing with high wet weather peaks is to use the former secondary clarifier as storage volume. Another option is hy-brid systems where the conventional system is used as a backup to treat the inflow volume that exceeds the hydraulic membrane capacity. An al-ready realised hybrid concept designs the MBR22Ch. Brepols et al. / Desalination 231 (2008) 20–26line to treat the dry weather flow at the maximum.The inflow volume beyond dry weather condi-tions is treated conventionally.3. Modification of the operation mode using the MBR approachWith the change of sludge/treated wastewater separation from gravity settling to membrane fil-tration the following process configurations are available:3.1. MBR with or without a separate filtration chamberWith upgrading of wwtp as a pure MBR pro-cess the question is to be cleared whether exist-A: substitution of the sedimentation tank by a separate filtration chamberB: sedimentation tank: change of utilisation as biological volumeC: change of flow scheme and immersed membranes within the biologyinitial Fig. 1. Upgrading variations using MBR technology.ing sedimentation tanks can be included sensibly in the future concept of utilisation. According to the structural state it can be possible to use these tanks as an additional biological volume. Also the suitable installation and operation of the mem-brane modules either in activated sludge tanks or in separated filtration chambers depends on the quality of the respective structural situation. At this point wide engineering space is given. Fig. 1shows some possible variations.3.2. Hybrid systems The combination of the CAS process and the MBR process is understood as the hybrid proce-dure. Fig. 2 shows two basic operation concepts of hybrid processes (among other hybrid systems).Ch. Brepols et al. / Desalination 231 (2008) 20–2623Besides, a fullness of mixing variations is pos-sible. The flow concept of the sludge streams be-tween both biological units at parallel operation mode or serial operation mode can be operated separately or combined according to the local cir-cumstances (grey arrows in Fig. 2). In the latter case possible differences are to be taken into con-sideration concerning the sludge qualities, in par-ticular, the quality of sedimentation and the MLSS concentrations.3.3. Other processesBeside the combination with the CAS process also combinations with other wastewater treat-ment procedures are possible, e.g. with SBR tech-nology [1] or with pond technology. Today SBR technology integrating membrane technology as separation process is used at industrial applica-tions or at package plants. Applications combin-ing pond technology and MBR technology are op-parallelserialFig. 2. Basic operation concepts of the hybrid procedure.erated at wwtp St. Peter ob Judenburg, Austria and at wwtp Ihn, Germany.3.4. MBR process with low MLSS concentration In cases when available sedimentation volume is used as additional biological volume, the amount of total biological volume increases to a degree, that clearly exceeds the usual volume de-mand of a conventional MBR process with ap-propriate MLSS concentrations ranging from 10kg/m3 to 15 kg/m3. Dimensioning the MLSS concentration both the available biological vol-ume and the guarantee of the aerobic SRT have to be taken into consideration. Usually this dimen-sioning ends up with less MLSS concentration in the range of 5–7 kg/m3 [2,3] compared with con-ventional MBR operating circumstances. If such a draught can be realised, the usual disadvantages (sensibility compared to impact load, reduced al-pha value) could be overcome by MBR process24Ch. Brepols et al. / Desalination 231 (2008) 20–26to a great extent. Beside the anyway raised efflu-ent quality other advantages of this upgrading concept can be named: considerable biological reserve capacities for future extension;smaller place consumption compared to a con-ventional upgrading concept.Some manufacturers of membrane modules recommend not falling short of a given MLSS concentration directly at the membrane or within a separated filtration chamber. Thus, the suitabil-ity of the respective membrane modules for the “low MLSS operation mode” is to be clarified. Nevertheless, by the construction of a separate filtration chamber optimal MLSS concentrations at the membrane and within the biological zone can be adapted accordingly.3.5. MBR in combination with anaerobic sludge stabilizationUp to now most municipal MBR plants are dimensioned with aerobic simultaneous sludge stabilization. In principle the MBR process also can be combined with anaerobic sludge stabiliza-tion. Some single studies assume dependence be-tween increasing fouling potential and increasing F/M-ratio or rather decreasing SRT [4–6]. A final statement cannot be met yet. If the MBR process is dimensioned with a short SRT, hence, possible intensified fouling effects have to be considered.If the MBR process is dimensioned with a long SRT, slightly reduced digester gas production can be expected. A possible process variation features the digestion of only primary sludge. Thus, in an upgrading situation the cost intensive new build-ing of digestion volume can be avoided.4. Experiences from full-scale applicationsThe full version of DWA WG KA-7.4 report includes all subsequently mentioned wwtps:?wwtp St. Peter ob Judenburg, Austria ?wwtp Schilde, Belgium ?wwtp Eitorf, Germanywwtp Bergheim-Glessen, Germanywwtp Brescia, Italywwtp Viareggio, Italywwtp Heenvliet, Netherlandswwtp Rietliau, SwitzerlandUpgrading of wwtps by means of MBR tech-nology is not a question of special membrane types. The above mentioned plants are equipped with usual and well known hollow fibre mem-branes as well as with flat sheet membranes.In the following two plants out of the above mentioned are now introduced more detailed. Besides, the German wwtp Bergheim-Glessen is an example for a complete process rearrangement. The Swiss wwtp Rietliau shows a hybrid solu-tion.4.1. wwtp Bergheim-Glessen, GermanyIn the case of the wwtp Bergheim-Glessen MBR technology is used to meet advanced re-quirements caused by the discharge of wastewa-ter to sensitive wetland. Upgrading occurs at the existing location using extensively already exist-ing constructions. Treatment efficiency will be rapidly increased by introducing MBR technol-ogy. Hence, in addition, the wastewater of a neighbouring, smaller wwtp, likewise in the need of upgrading, is led across, treated and afterwards led back. Thus, the wwtp load is raised from 5,000p.e. nowadays to 9,000 p.e. Wastewater quantity to be treated from now on amounts to 900,000 m3/a. Fig. 3 illustrates the flow diagram.The mechanical pre-treatment is completely renewed consisting of three units: screening (gap size 6 mm), aerated grit chamber and grease trap, sieving (mesh geometry, gap size 1 mm). The existing oxidation ditch furthermore will be used as activated sludge volume. SRT should amount about 25 d, MLSS concentration is dimensioned with only 8 kg/m3. In time of maximum inflow HRT amounts to 6 h. The membrane modules are installed in four separated filtration chambers.Ch. Brepols et al. / Desalination 231 (2008) 20–2625Fig. 3. Flow diagram of wwtp Bergheim-Glessen.Sludge treatment and simultaneous precipitation are taken over from the today’s continuance. The plant is scheduled to be commissioned in late 2007.4.2. wwtp Rietliau, SwitzerlandUpgrading was necessary to meet the effluent requirements (DOC: 10 mg/l, BOD: 10 mg/l, P total: 0.2 mg/l, SS: 5 mg/l) especially according parameter SS which was unachievable by the former wwtp concept. An upgrading of the treat-ment capacity from 41,400 p.e. up to 44,000 p.e. also would have been accomplished by depth fil-tration as a fourth treatment step. Caused by small space availability the hybrid solution was evalu-ated as an economically more favourable way. Shortage of space is due to the wwtp location in the midst of the residential area W?denswil, 100m far from the bank of the Lake of Zurich. Fig. 4 shows the flow diagram.Wwtp Rietliau was commissioned in Novem-ber 2005. The treatment process is subdivided into two lines. Each, the MBR line and the conven-tional process line, treat half of the incoming wastewater. Sludge of both treatment lines is not mixed. All wastewater is treated by the existing mechanical pre-treatment units (screen, grit cham-ber and grease trap, primarysedimentation). In addition, the inflow from the primary sedimenta-tion to the MBR line is led through a sieve con-sisting of hole geometry with 1 mm gap size.The MBR line consists of two sub-lines. Aero-bic and anoxic volumes of the MBR process are dimensioned the way, that in times of maximum inflow the minimum HRT within the biological zone prior to the filtration chambers does not fall below30min.Better effluent quality concerning the conven-tional process line also is achieved caused by the less hydraulic load of the secondary clarifiers. Thus, the requirements that have to be met by the mixture of both effluent streams can be guaran-teed.5. ConclusionsThe presented upgrading concepts raise no claim to completeness and thus reveal the wide spectrum of supposable measures. Many of them are under investigation and appropriate findings can be expected to be reported soon. However, the chosen upgrading concept must meet the claim to bedemand-oriented according the wastewater-sided requirements and the load situation,economical in view of annual costs (operating expenses and net debt service).Besides, various other, not only process-re-lated, but also nonmonetary and monetary hardly assessable aspects are to be followed and to weigh in each individual case which do not admit a stan-26Ch. Brepols et al. / Desalination 231 (2008) 20–26conventional activated sludge process Fig. 4. Flow diagram of wwtp Rietliau.dard approach concerning the handling of the planning task.Altogether MBR technology provides several promising perspectives in view of upgrading wwtps. The different options introduced provide an overview of the bunch of possibilities the op-timal solution can be selected from. As with all other upgrading options which in general are in-dividual solutions, special importance lies on the adequate diligence of the planning engineer. Nev-ertheless the increasing number of full scale ap-plications presents a sound and ever growing de-cision basis.References[1]J. Krampe and Kh. Krauth, Das Sequencing BatchReactor-Membranbelebungsverfahren. 4. ATSV, Aachen, 2001.[2]W. Schier, An exemplary approach for the integra-tion of new sizing procedures and new purification technologies for the performance of wwtps, Scripts W ATER ? W ASTEW ATER ? W ASTE of Department of Sanitary and Environmental Engineering —DESEE and Department of Waste Engineering ofthe University of Kassel, issue 22, Kassel Univer-sity Press, 2003.[3] F.-B. Frechen, W. Schier, M. Wett and A. Waldhoff,The non-conventional low MLSS MBR technology, IWA Specialty Conference Water Environment –Membrane Technology (WEMT), Seoul, Korea, 2004.[4] A. Drews, M. V ocks, V. Iversen, B. Lesjean and M.Kraume, Fouling in Membranbelebungsreaktoren: Erfahrungen beim Betrieb mit diskontinuierlichem Schlammabzug, Chemie Ingenieur Technik, 77 (2005) 593–599.[5] A. Pollice, A. Brookes, B. Jefferson and S. Judd,Subcritical flux fouling in membrane bioreactors —a review of recent literature. Desalination, 174(2005) 221–230.[6]M. Wett, Fouling behaviour of a submerged mem-brane bioreactor for domestic waste water and its influence to the process efficiency, Scripts WATER ? W ASTEWATER ? W ASTE of Department of Sani-tary and Environmental Engineering — DESEE and Department of Waste Engineering of the University of Kassel, issue 26, Kassel University Press, 2005.[7]Water Environment Federation, Upgrading and Ret-rofitting Water and Wastewater Treatment Plants, Manual of Practice No. 28, McGraw-Hill, USA, 2004.。

氧化沟工艺在污水处理中的应用和发展摘要:本文主要阐叙了Carrousｅl氧化沟的结构、工艺机理、运行过程中存在的问题和相应的解决办法.最后,介绍了Ｃaｒrouｓel氧化沟的最新的研究进展并指出了未来的主要研究方向。

关键词：Cａｒrｏｕseｌ氧化沟除磷脱氮结构机理1、前言氧化沟又名连续环曝气池,是活性污泥法的一种变形。

氧化沟处理工艺在２０世纪50年代由荷兰卫生工程研究所研制成功的.自从1９５4年在荷兰的首次投入使用以来。

由于其出水水质好、运行稳定、管理方便等技术特点,已经在国内外广泛的应用于生活污水和工业污水的治理。

目前应用较为广泛的氧化沟类型包括:帕斯维尔氧化沟、卡鲁塞尔氧化沟，奥尔博氧化沟、T型氧化沟、DE型氧化沟和一体化氧化沟。

这些氧化沟由于在结构和运行上存在差异,因此各具特点。

本文将主要介绍Carｒousel氧化沟的的结构、机理、存在的问题及其最新发展.2、Caｒrouｓｅｌ氧化沟的结构Cａｒrouseｌ氧化沟是19６7年由荷兰的DHV公司开发研制．在原Ｃarrouｓe氧化沟的基础上DＨV公司和其在美国的专利特许公司EＩＭCO又发明了Caｒrｏusｅｌ20０0系统,实现了更高要求的生物脱氮和除磷功能。

至今世界上已有85０多座Carrousｅl氧化沟和Carrousｅl 2０00系统正在运行。

Carrouｓel氧化沟使用定向控制的曝气和搅动装置,向混合液传递水平速度,从而使被搅动的混合液在氧化沟闭合渠道内循环流动。

因此氧化沟具有特殊的水力学流态,既有完全混合式反应器的特点,又有推流式反应器的特点，沟内存在明显的溶解氧浓度梯度。

氧化沟断面为矩形或梯形，平面形状多为椭圆形,沟内水深一般为2.5~４.5ｍ,宽深比为2：１,亦有水深达7m的,沟内水流平均流速为０．3m/s。

氧化沟的曝气混合设备有表面、曝气转刷或转盘,射流曝气池、导管式曝气器和提升管曝气机等,近年来配合使用的还有水下推动器。

3、Carｒoｕｓel氧化沟的机理3.1Ｃａｒｒousel氧化沟处理污水的机理最初的普通Carrousel氧化沟的工艺中污水直接与回流污泥一起进入氧化沟系统。

废水处理英语作文
Wastewater treatment is really important. It helps to keep our
environment clean and healthy. We need to use different methods to
deal with the dirty water.

Sometimes it can be a difficult job. There are many challenges to
overcome. But we have to keep trying.

There are many technologies available for wastewater treatment. We
should choose the right ones for the specific situation. It takes a lot of
knowledge and expertise.

Everyone should be aware of the importance of wastewater
treatment. We all have a responsibility to protect our water resources.

氧化沟工艺在污水处理中的应用和发展摘要：本文主要阐叙了Carrousel氧化沟的结构、工艺机理、运行过程中存在的问题和相应的解决办法。

最后，介绍了Carrousel氧化沟的最新的研究进展并指出了未来的主要研究方向。

关键词：Carrousel氧化沟除磷脱氮结构机理1、前言氧化沟又名连续环曝气池，是活性污泥法的一种变形。

氧化沟处理工艺在20世纪50年代由荷兰卫生工程研究所研制成功的。

自从1954年在荷兰的首次投入使用以来。

由于其出水水质好、运行稳定、管理方便等技术特点，已经在国内外广泛的应用于生活污水和工业污水的治理。

目前应用较为广泛的氧化沟类型包括：帕斯维尔氧化沟、卡鲁塞尔氧化沟，奥尔博氧化沟、T型氧化沟、DE型氧化沟和一体化氧化沟。

这些氧化沟由于在结构和运行上存在差异，因此各具特点。

本文将主要介绍Carrousel氧化沟的的结构、机理、存在的问题及其最新发展。

2、Carrousel氧化沟的结构Carrousel氧化沟是1967年由荷兰的DHV公司开发研制。

在原Carrouse氧化沟的基础上DHV公司和其在美国的专利特许公司EIMCO又发明了Carrousel 2000系统，实现了更高要求的生物脱氮和除磷功能。

至今世界上已有850多座Carrousel氧化沟和Carrousel 2000系统正在运行。

Carrousel氧化沟使用定向控制的曝气和搅动装置，向混合液传递水平速度，从而使被搅动的混合液在氧化沟闭合渠道内循环流动。

因此氧化沟具有特殊的水力学流态，既有完全混合式反应器的特点，又有推流式反应器的特点，沟内存在明显的溶解氧浓度梯度。

氧化沟断面为矩形或梯形，平面形状多为椭圆形，沟内水深一般为2.5~4.5m，宽深比为2:1，亦有水深达7m的，沟内水流平均流速为0.3m/s。

氧化沟的曝气混合设备有表面、曝气转刷或转盘，射流曝气池、导管式曝气器和提升管曝气机等，近年来配合使用的还有水下推动器。

3、Carrousel氧化沟的机理3.1 Carrousel氧化沟处理污水的机理最初的普通Carrousel氧化沟的工艺中污水直接与回流污泥一起进入氧化沟系统。

Application of multi—soil-layer system （MSL) in ruralwastewater treatmentAbstract:with the continuous improvement of living in rural farmers, the water consumption of residents is increasing, rural sewage emissions will continue to increase，if not treat effectively，the water environment in rural areas will be serious deteriorated，and influence the life quality of rural residents. In this case this paper presents a decentralized sewage treatment system，multi—soil-layer system technology (MSL) application in the rural sewage treatment, this paper summarizes the new technology，you can better understand and practice，especially in the developing countries where is in need of this technology。

In the foreseeable future, it can protect public health and the sustainable development of the environment，and it also provides a new way for rural sewage treatment。

污水处理方法的英语作文1. Sewage treatment is a crucial process that aims to remove pollutants and contaminants from wastewater beforeit is released back into the environment. It involves various methods and technologies that work together to ensure the water is safe and clean.2. One common method used in sewage treatment is called primary treatment. This involves the physical removal of large solids and debris from the wastewater. This can be done through processes such as screening and sedimentation, where the heavier particles settle at the bottom of a tank.3. After primary treatment, the wastewater undergoes secondary treatment. This step focuses on the biological removal of organic matter and nutrients. Microorganisms are introduced into the wastewater to break down the organic matter and convert it into carbon dioxide, water, and biomass. This process, known as activated sludge, helps to reduce the organic load in the water.4. In addition to primary and secondary treatment, some wastewater treatment plants also employ tertiary treatment methods. Tertiary treatment is designed to further purify the water and remove any remaining contaminants. This can involve processes such as filtration, disinfection, and advanced oxidation. These methods ensure that the water meets the required quality standards before it is discharged.5. Another important aspect of sewage treatment is the management of sludge, which is the solid waste generated during the treatment process. Sludge can be treated and reused in various ways, such as being used as fertilizer in agriculture or converted into biogas through anaerobic digestion. Proper sludge management is essential to minimize environmental impact and maximize resource recovery.6. It is worth noting that sewage treatment is not only important for environmental protection but also for public health. Untreated wastewater can contain harmful pathogensand pollutants that can pose significant risks to human health. By treating sewage effectively, we can prevent the spread of diseases and ensure a safe water supply for communities.7. In conclusion, sewage treatment plays a vital rolein maintaining a clean and healthy environment. Through various methods such as primary, secondary, and tertiary treatment, as well as proper sludge management, we can ensure that wastewater is treated effectively and released back into the environment in a safe and sustainable manner.。

African Journal of Biotechnology Vol. 7 (15), pp. 2621-2629, 4 August, 2008Available online at /AJBISSN 1684–5315 © 2008 Academic JournalsFull Length Research PaperPerformance of wastewater treatment plants in Jordanand suitability for reuseAl-Zboon, Kamel1* and Al-Ananzeh, Nada21Environmental Engineering Department, Al-Huson University College, Al-Balqa Applied University, Irbid-Jordan.2Chemical Engineering Department, Al-Huson University College, Al-Balqa Applied University, Irbid-Jordan.Accepted 12 June, 2008There is an increasing trend to require more efficient use of water resources, both in urban and rural environments. In Jordan, the increase in water demand, in addition to water shortage has led to growing interest in wastewater reuse. In this work, characteristics of wastewater for four wastewater treatment plants were determined. Characterization of wastewater was evaluated in terms of measuring BOD, COD, TSS, TDS, NH4, and DO for the influent and the effluent wastewater from the selected plants. The quality of the treated wastewater was compared with Jordanian standards. Results indicate that municipal wastewater in Jordan contains high concentrations of pollutants such as BOD, COD, TSS, and NH4; therefore it is classified as a strong waste. The performance of the four treatment plants was evaluated. Conventional and modified activated sludge show good performance, while low water quality is produced by stabilization ponds. The effluent from activated sludge treatment plants complies with Jordanian standards for restricted use. Before reuse, effluent wastewater needs advanced treatment to prevent its impact on human health and the environment.Key words:Wastewater, treatment plants, water reuse, wastewater characteristics, wastewater treatment, Jordan.INTRODUCTIONJordan population has increased rapidly from 0.58 million in 1950 to more than 5.6 million in 2006. This increase has resulted from the high growth rate of 3.1% annually and the successive immigrations from Palestine in 1948, 1967 and from Kuwait in 1990 (Statistical Department, 2006). Jordan has faced the problem of water scarcity for many years, and improving the efficiency of water use is an important part of its effort to deal with the problem. The total average precipitation volume is about 8.5 x 109 m3/y; however 92% of this quantity is lost via evaporation (Al-Zboon, 2002). Water consumption has increased, as a result of population growth and development projects, while the available sources of water are limited and de-*Corresponding author. E-mail: kalzboon@. Tel: +962-2-7010400. Fax: +962-2-7010379. creasing year after year. In the year of 2000, the demand of water was estimated to be about 1100 millions m3 (MCM), while the available water from all sources (surface and ground water) was less than 850 MCM, indicating a shortage of water of 250 MCM. The shortage of water has affected the individual consumption. For example the water consumption in the year of 1998 was about 160 m3/capita/y and is expected to fall to 90 m3/capita/y in 2020, which is very low in comparison to the international per capita consumption level of 1000 m3/y (Al-Zboon, 2002). The agricultural demand of water is estimated to be 73% of the total water consumption, while 22% of water is used for domestic needs and only 5% is used for industrial sector (WAJ, 2006).This increase in water demand combined with the limi-tation of water resources lead to development of available water resources. Currently, the interest in wastewater reuse in various parts of the world has promoted the2622 Afr. J. Biotechnol.development of wastewater and secondary effluent treat-ment technologies (Janga et al., 2005, Simon, 2006). The main purpose of wastewater treatment is to prevent pollution of the receiving watercourse, and to protect human health and the environment (Metcalf and Eddy, 1991). The reuse of reclaimed wastewater is an interna-tional practice. Reclaimed wastewater is applied on soil, on cultivated as well as marginal areas in various facilities, in irrigation, industry, and for recharge of ground water (Kalavrouziotis and Apostopoulos, 2007; Bushnak, 2003; Salgot et al., 2006; Ernst et al., 2007). The integrated and safe application of the reuse of reclaimed wastewater from wastewater treatment plants (WWTPs) dictates the development of a comprehensive environ-mental plan, which will take into consideration all parameters relative to such reuse, qualitative charac-terization of wastewater as well as examination of physical-chemical and environmental properties of all applications on soil, plants, building installations, and pipes (Kalavrouziotis, and Apostopoulos, 2007; Salgot et al., 2006; Magalha et al., 2005). Due to the more and more pronounced water deficit, the reuse of wastewater in the Middle East countries is part of the strategy for the conservation and development of water resources. Moreover, the experience of these countries in this domain has proved the feasibility of the reuse procedure (Bataineh et al., 2002; Jemali and Kefati, 2002; Alatiri et al., 2002).The characteristic of wastewater depends considerably on the type of sewer collection system (combined or separate), industrial waste entering the sewer, type of wastewater treatment technology, the quality of domestic fresh water, and the standard of living of consumer's community. The degree of required treatment is determined by the beneficial uses of the receiving stream, lake, and reuse for different purposes (Hammer, 1996). Therefore, the investigation of the characteristics of the reclaimed wastewater is necessary for evaluating its suitability for reuse.In Jordan there are twenty three municipal treatment plants, which cover most of the major cities and towns. These plants serve about 56% of the population. The total inflow to these plants is around 216,412 m3/d, of which 186223 m3/d inflow to Asamra wastewater treatment plant (ASTP) (Bataineh et al., 2002; Asa’ad, 2006). Jordanian standards for reclaimed wastewater (JS893/1995) try to regulate both water reuse and environmental discharges. Jordanian standards allow discharging treated waste-water to valleys and streams when it meets the specific criteria for many parameters such as BOD, COD, TSS, Escherichia coli bacteria, and helminthes eggs. In the present time, the reclaimed wastewater is used for restricted agriculture either near the plants or downstream after mixing with natural surface water (Bataineh et al., 2002). More than 70 million m3/year of reclaimed water, around 10% of the total national water supply, is used either directly or mostly indirectly in Jordan and will increases to a share of more than 15% within the next 30 years (Bataineh et al., 2002; Bdour and Hadadin, 2005; McCornick et al., 2007; Ammary, 2007). Therefore, water reuse is considered an attractive option for increasing the available water resources of JordanIn this study, characteristics of wastewater for four wastewater treatment plants, which are Al-Samra (ASTP), Irbid (ITP), Ramtha (RTP), and Wadi Hassan (WTP) were determined. Characterization of wastewater was eva-luated in terms of measuring chemical oxygen demand (COD), biological oxygen demand (BOD), total suspend-ed solids (TSS), total dissolved solids (TDS), and dissolved oxygen (DO) for the influent and effluent from the selected plants. The performance of the four waste-water treatment plants (WWTPs) was evaluated and the quality of the reclaimed wastewater was compared with Jordanian standards to determine its suitability for reuse.MATERIALS AND METHODSThe selected plants treat about 90% of the domestic wastewater in Jordan and serve more than 2 million inhabitants (Bataineh et al., 2002). ASTP utilizes stabilization ponds as the treatment process as shown in Table 2. Because ASTP is the largest plant in Jordan and treat more than 76% of collected municipal wastewater, most of the environmental studies concentrate on the performance of this plant and the possible actions to enhance its efficiency. The plant consists of three parallel trains with total areas of 181 hectare (Asa’ad, 2006). There are two aerobic ponds, four facultative ponds, and four maturation ponds in each train. The effluent from the plant to the Zarqa River represents more than 80% of the total flow in the river during dry weather. River’s water contains high concentrations of organic matter, inorganic minerals, salts, and heavy metals (Al-Zboon, 2002). The other treatment plants, which are ITP, RTP, and WTP, are operated as activated sludge with different modes as shown in Table 2. In order to determine the characteristics of wastewater for the selected plants, representative weekly samples were taken from the inlet and outlet of these plants during June 2005 to march 2006. Samples were analyzed in the environmental laboratory at AL-Huson College according to the Standard Methods (APHA, 1985). BOD and TSS are the most important parameters used to define the characteristics of municipal wastewater.TDS, NH4, and DO are used as indicators for the suitability of wastewater for reuse. Representative samples were collected very carefully to avoid agitation or any contact with air. Glass bottles with 300 ml volume with ground glass stopper and flared mouth were cleaned, dried and then used for samples. Samples were transported to the laboratory and analyzed as soon as possible. If delay before analysis was expected, the samples were preserved and stored according to the recommended proce-dure in the standards methods. After dilution, the BOD samples were incubated at 20o C for 5 days. The change in DO concentration during the incubation period was measured to determine the BOD concentration. Closed reflux method was used to determine COD concentration. Culture tubes were washed and caped with H2SO4.Then the samples tubes were put in a block digester preheated to 150o C and refluxed for 2 h. After digestion period, the samples were cooled to the temperature room and titrated by 0.1Al-Zboon and Al-Ananzeh 2623 Table 1. Wastewater treatment plants in Jordan.No. Plant Hydraulic designcapacity m3/dOperatingcapacity m3/d R**Type oftreatment1 ASTP 68000 224175 330 WSP2 Aqaba19000 6229 69 WSP3 Mafraq 1800 1866 104 WSP4 Ramtha 5400 3492 65 AS5 Ma’an 1600 2644 165 WSP6 Madaba 7600 4584 60 AS7 Irbid 11000 6353 58 TF+AS8 Karak 785 1618 206 TF9 Baqa’a 12000 10978 91 TF10 Tafila 1600 1012 63 TF11 Kufranja 1900 3387 178 TF12 Salt 7700 4322 56 AS13 Jerash 3500 3312 95 AS14 Abu-Nusir 4000 2309 58 AS15 Fuheis 2400 1684 71 AS16 Wadi Musa 3400 1670 49 AS17 Wadi Hassan 1600 1098 69 AS18 WadiArab 22000 9960 45 AS19 Wadi Al-Sir 4000 2718 68 AL20 Aqaba 212000 6952 58 AS**R = Applied hydraulic load/design hydraulic load x 100%.WSP: Waste Stabilization ponds, TF: Biological filter, AS: Activated Sludge, AL: Aerated Lagoon.Table 2. The treatment plants concerned in the study.Plant Treatment process R* Remarks Al-Samra Stabilization ponds (natural aeration, facultative,anaerobic lagoons)330Irbid Screen, grit removal, primary sedimentation, biological process, secondary sedimentation, disinfections 58 Trickling filter +ActivatedsludgeRamtha Screen, grit removal, biological process, secondarysedimentation, Polishing pond, infiltration, disinfections 65 Activated sludge withnitrogen removal techniqueWadi-Hassan Screen, grit removal, biological process, secondary sedimentation, polishing pond, disinfections 69 Activated sludge –Oxidationditch*R = Applied hydraulic load/design hydraulic load x 100%.molarity of Ferric Ammonium Sulfate (FAS) standard. The titration process was continuing until the color of samples changed from blue-green to reddish-brown. In order to determine TSS and TDS concentrations, samples were filtered through a weighed standard glass-fiber filter with 2 µdiameter. The filtrate was evaporated to dryness in a weighted dish and dried at 180o C. The increase in dish weighted represents TDS weight. The residue on the filter was dried at 105o C. The increase in the weight of the filter represents the total suspended solid.RESULTS AND DISCUSSIONThe average values of BOD, COD and TSS concentra- tions for the influent wastewater are 880, 1946, and 795 mg/L, respectively (Table 3). Based on these values, wastewater in Jordan is classified as a strong wastewater where the concentration of pollutants is much higher than the international figures. The ASTP, ITP, RTP, and WTP plants had been designed to receive BOD concentration of 520, 600, 800, and 1000 mg/L respectively (WAJ, 2006). This variation between applied and designed values caused unexpected deterioration in plants performance.Figure 1 shows the effluent BOD values for the selected treatment plants. It can be seen that the BOD value ranges2624 Afr. J. Biotechnol.Table 3. Wastewater characteristics for the plant concerned in the study.Al-Samra Irbid Ramtha Wadi Hassan Average BOD in (mg/L) 705 1030 915 870 880BOD out (mg/L) 140 32 13 12 49BOD removal % 80 97 98 98 93COD in (mg/L) 1890 2205 1980 1710 1946COD out (mg/L) 605 110 70 63 212COD removal % 67.8 95 96 96 89TSS in (mg/L) 591 1040 780 770 795TSS out (mg/L) 117 51 30 2556TSS removal % 80.2 95 96 96.7 92 NH4-N in (mg/L) 90 108 90 118 102 NH4-N out (mg/L) 97 12 1 4 28 NH4-N removal % * 88 99 96.6 95 DO out (mg/L) 1.8 3.9 4.3 5.8 4 *Effluent concentration higher than the influent.23fodder crops, JS4: irrigation parks, JS5: standard for fishponds. JS6: standards forground water recharge. Others: Jordanian standards for other uses.from 140 to 12 mg/L where the highest value is for ASTP. The effluent from ITP, RTP, and WTP complies with Jordanian standards for reclaimed wastewater discharge to streams, ground water recharge, irrigation parks, reuse for irrigation of cocked vegetables, fruits, and trees, and for reclaimed wastewater reuse for fodder crops. Effluent from ASTP does not comply with Jordanian standards for water discharge to streams, ground water recharge, and irrigation parks or for unrestricted irrigation as shown in Figure 1. The effluent from the plant is discharged to Wadi Al-Dhlil which meets Zarqa River at Al-Sukna location. This water is mixed with other tributaries along the river that improve its quality, but in all cases the pollutants concentration remain high and above the allowable limits.A similar behavior to the one that was observed for BOD values is obtained for COD and NH4 values for the effluent from the WWTPs as shown in Figure 2 and Figure 3, respectively. The effluent from ITP, RTP, and WTP complies with Jordanian standards while the effluent from ASTP does not with regard to the obtained COD and NH4value. The effluent from the selected plants has aAl-Zboon and Al-Ananzeh 26251Standard for discharge to streams, JS2: Standard for cocked vegetables. JS3:Standard for fodder crops, JS4: irrigation parks, JS5: standard for fishponds. JS6:standards for ground water recharge. Others: Jordanian standards for other uses.discharge to streams, JS2: Standard for cocked vegetables. JS3: Standard for foddercrops, JS4: irrigation parks, JS5: standard for fishponds. JS6: standards for ground waterrecharge. Others: Jordanian standards for other uses.high concentration of TSS which does not comply with Jordanian standards for fishponds as shown in Figure 4. On the other hand, the concentrations of TSS for the effluent from the four plants comply with Jordanian standards for cocked vegetables, fruits, trees, and fodder crops. With respect to Jordanian standards for discharge to streams, ground water recharge, and irrigation parks, the TSS concentration in the effluent from ITP, RTP, and WTP matches the previous standard while effluent from ASTP does not. Regarding TDS, results shown in Figure5 indicate that the effluent from the studied WWTPs has values smaller than the Jordanian standards for dis-charge to streams, irrigation parks, cocked vegetables, fruits and trees, fodder crops, and ground water recharge. The concentration of DO for the effluents from the studied plants complies with Jordanian standards for fodder crops,2626 Afr. J. Biotechnol.Figure 4. Comparison between effluent TSS and Jordanian standards. JS1: Standardfor discharge to streams, JS2: Standard for cocked vegetables. JS3: Standard forfodder crops, JS4: irrigation parks, JS5: standard for fishponds. JS6: standards forground water recharge. Others: Jordanian standards for other uses.1discharge to streams, JS2: Standard for cocked vegetables. JS3: Standard for foddercrops, JS4: irrigation parks, JS5: standard for fishponds. JS6: standards for ground waterrecharge. Others: Jordanian standards for other uses.for discharge to streams, ground water recharge, irriga-tion of parks, cocked vegetables, fruits, and trees as shown in Figure 6. With respect to Jordanian standards for fishponds, only WTP has a DO concentration that complies with this standard.Effluent from ASTP has a high concentration of BOD, COD, NH4, and TSS as shown in Figures 1, 2, 3, and 4, respectively. This could be related to several possible reasons. ASTP is operated as a stabilization pond and receives an organic load higher than the design capacity see Tables 2 and 3. ASTP was designed to treat 68000 m3/d and started with 57000 m3/d in 1985 m3/d, and reached 186823 m3/d in 2003 that means the present hydraulic load is more than 2.75 times the design value,Al-Zboon and Al-Ananzeh 2627discharge to streams, JS2: Standard for cocked vegetables. JS3: Standard for foddercrops, JS4: irrigation parks, JS5: standard for fishponds. JS6: standards for ground waterrecharge. Others: Jordanian standards for other uses.which decreases the detention period in the basins from 42 days to less than 19 days (Bataineh et al., 2002; Asa’ad, 2006). This type of treatment is influenced by climate, where low temperature and short sunshine period during winter will affect the activity of bacteria and algae as shown in Figures 7 and 8. Also, the influent to the plant has a high strength of organic matter due to the low water consumption by population where the available data indicates that the daily consumption is less than 80 l/capita (Al-Zboon, 2002). Illegal discharge of wastewater from some industries, slaughterhouses, and septic tank participate in increasing the concentration of the organic matter. ASTP plant does not have any facility to remove nitrogen which explains the high concentration of ammonium in the effluent stream. For all the previous reasons, the quality of the effluent treated water declined and the removal efficiency of the plant deteriorated. Therefore, the effluent wastewater would be unsuitable for reuse except for limited purposes. It is important to mention that ASTP will be changed to activated sludge2628 Afr. J. Biotechnol.mode during the next two years. This change will improve reclaimed water quality in Jordan, and increases the available water resources by more than 110 MCM /y (WAJ, 2006).The other studied plants are operated as activated sludge where oxygen is sufficient for biological decom-position, also recycled sludge enhance the activity of bacteria. Activated sludge treatment or mechanical treatment is considered as a flexible operating system where the operator has many alternatives and can maintain many parameters in order to achieve the desirable effluent quality. For this reason the water authority decided to convert many stabilization ponds to the mechanical mode such as RTP and Madaba treatment plant. RTP has a modified technique used to remove nitrogen by nitrification denitrification processes. RTP was constructed in 1987 as stabilization ponds, but as a result of high load, the treated effluent has dete-riorated so it was modified and redesigned as activated sludge-extended aeration process, and it started opera-tion in 2003 (WAJ, 2006). A significant improvement in water quality is obtained as a result of plant modification (WAJ, 2006)Table 1 shows that the ITP, RTP, and WTP plants receive low hydraulic loads compared with ASTP, which ranges between 1098 m3/d for WTP to 6353 m3/d for ITP, therefore these plants have limited importance for water reuse.ConclusionWastewater in Jordan is classified as a strong waste-water. The stabilization ponds treatment plant (ASTP) has low efficiency with regard to BOD, COD, and NH4 removal where they do not comply with Jordanian standards. A better water quality can be achieved by using activated sludge method (ITP, RTP, and WTP). The effluent from activated sludge treatment plants complies with Jordanian standards for restricted use. Discharged wastewater from the selected plants is not suitable for unrestricted irrigation and it needs advanced treatment before reuse. More research needs to be conducted in order to improve the quality of reclaimed wastewater for different purposes and to increase public confidence.REFERENCESAl-Zboon K (2002). Molding of water quality for Zarqa River, PhD dissertation, University of Baghdad.Al-Atiri R, Rezgui F, Aniba B (2002). Wastewater reuse in Tunisia, Wastewater Reuse, in water demand management forum, Amman. Ammary B (2007). Wastewater reuse in Jordan: Present status and future plans, Desalination J. Volume 211, Issues 1-3, 10, pp. 164-176.APHA American Public Health Association (1985). Standard Methods for the Examination of Water and wastewater 16th ed. Prepared and published jointly by: APHA, AWWA and WPCF.Asa’ad S (2006). performance of Alsamra Waste Stabilization Pond, MSc. thesis, university of Jordan.Bataineh F, Najjar M, Malkawi S (2002) Wastewater Reuse in water demand management forum Amman Jordan.Bdour A, Hadadin N (2005). Potentials and Limitations of Wastewater Reuse in Rural Areas in Jordan: The Reuse Options in the Jordan Valley J. Agron. 4: 4.Bushnak AA (2003). Future strategy for water resources management in Saudi Arabia. In proceeding of: A Future Vision for the Saudi Economy Symposium Riyadh.Ernst M, Sperlich A, Zheng X, Ganb Y, Hub J, Zhao X, Wang J, Jekel M (2007). An integrated wastewater treatment and reuse concept for the Olympic Park 2008 Beijing. Desalination J. 202: 3.Hammer MJ (1996). Water and wastewater technol. third edition, Prentice –hall. Inc.Janga N, Rena X, Kimb G, Ahnb C, Choa, J, Kima I (2005). Charac-teristics of soluble microbial products and extra cellular polymeric substances in the membrane bioreactor for water reuse Presented atthe conference of Wastewater Reclamation and Reuse for Sustain-ability (WWRS2005) Korea.Jemali O, Kefati A (2002). Waste water reuse in morocco Wastewater Reuse in water demand management forum Amman. Kalavrouziotis IK, Apostopoulos CA (2007). An Integrated Environ-mental Plan for the Reuse of Treated Wastewater Effluents from WWTP in Urban Areas Building Environ. J. 42: 4.Magalha˜es JM, Silva JE, Castro FE, Labrincha JA (2005). Physical and Chemical Characterization of Metal Finishing Industrial Wastes J. Environ. Manage. 75: 3.McCornick PG, Hijazi A, Sheikh B (2007). Progression of Water Reuse Standards in Jordan. Available online: http://www.idrc.ca/en/ev-68342-201-1-DO_TOPIC.html.Metcalf Eddy (1991). Wastewater treatment disposal and reuse 3rd. Ed., McGraw Hill.Al-Zboon and Al-Ananzeh 2629Salgot M, Huertasa E, Weberb S, Dottb W, Hollenderb J (2006). Wastewater reuse and risk: definition of key objectives Desalination 2006 187: 1.Simon T (2006). Reuse of effluent water-benefits and risks, Agric. Water Manag. J. 80: 3.Statistical Department Population of Jordan (2006). Annual report Jordan.WAJ, Jordan water authority (2006). Annual report.。