下载文档原格式
The influence of temperature on nutrient treatmentefficiency in stormwater biofilter systemsG.-T.Blecken*,Y.Zinger***,T.M.Muthanna**,A.Deletic***,T.D.Fletcher***and M.Viklander* *Urban Water,Department of Civil,Mining and Environmental Engineering,Lulea˚University of Technology, 97187Lulea˚,Sweden(E-mail:godecke.blecken@ltu.se;maria.viklander@ltu.se)**Norwegian Institute for Water Research,Havnegata9,7010Trondheim,Norway(E-mail:tone.muthanna@niva.no)***Department of Civil Engineering,Facility for Advancing Water Biofiltration,Monash University,Victoria 3800,Australia(E-mail:yaron.zinger@.au;Tim.Fletcher@.au;ana.deletic@.au)Abstract Nutrients can cause eutrophication of natural water bodies.Thus,urban stormwater which is an important nutrient source in urbanised areas has to be treated in order to reduce its nutrient loads.Biofilters which use soilfilter media,biofilms and plants,are a good treatment option for nutrients.This paper presents the results of a biofilter column study in cold temperatures(þ28C,þ88C,control atþ208C) which may cause special problems regarding biofilter performance.It was shown that particle-bound pollutants as TSS and a high fraction of phosphorus were reduced well without being negatively influenced by cold temperatures.Nitrogen,however,was not reduced;especially NO x was produced in the columns. This behaviour can be explained with both insufficient denitrification and high leaching from the columns. Keywords Biofilter;cold climate;nutrients;stormwater treatmentIntroductionNutrients can cause eutrophication in receiving natural water bodies(Browman et al., 1979;Pitt et al.,1999;Kim et al.,2003).Stormwater runoff is an important source of nutrients in urbanised areas(Larm,2000;Graves et al.,2004;Taylor et al.,2005),and it should therefore be treated.Stormwater biofiltration,also known as bioretention,is a novel option that might be able to treat nutrients in stormwater in order to prevent eutrophication of recipients.A biofilter consists offilter media placed in a trench or basin that is planted on the top.It has a detention storage on the top(by placement in a depression)and a drainage pipe at the bottom to collect the treated water.Stormwater is treated by mechanical,biological and chemical processes in thefilter media,but also by the plants and biofilms,that develops in the media and on the plant roots(Prince George’s County,2002;Hsieh and Davis,2005).Several studies conducted so far have shown a significant removal of phosphorus, phosphate and ammonium,but with low(and sometimes negative)removal of nitrate (Davis et al.,2001;Lloyd et al.,2001;Henderson et al.,2007).However,biofilters are still a relatively new technology and hence,only limited data of the performance of these systems are available.Particular problems could arise when implementing biofilters in regions with constant or temporary cold temperatures,due to reduced biological activity, shorter growing seasons and a smaller number of adapted plant species.However,these systems may still perform well in these instances,since adequate nutrient removal has been achieved in constructed wetlands in cold subalpine climates(Heyvaert et al.,2006). Biofilter performance in cold temperatures is the deciding factor to their successful implementation in regions with rainfall on non-frozen ground during cold periods Water Science & Technology Vol 56 No 10 pp 83–91 Q IWA Publishing 2007 83doi:10.2166/wst.2007.749(autumn,winter and spring in temperate climate;autumn,later spring and summer in cold climate).This paper presents preliminary results of a study of the performance of biofilters in relation to temperature.The aim was to determine the nutrient treatment performance of stormwater biofilters in low temperatures in order to enable an analysis of whether there is a correlation between temperature and treatment rate.Material and methods Experimental set-up Laboratory tests were conducted on 15biofilter mesocosms (‘biofilter columns’)made of PVC stormwater pipe (inner diameter:377mm,area:0.11m 2,height:900mm).A trans-parent top (height:400mm)allowed water to pond without affecting light availability for plant growth.The inside wall was sandblasted to prevent preferential flow along the wall.A drainage pipe (diameter:58mm)at the bottom discharged to a sampling outlet (Figures 1and 2).The filter media in the columns included four layers (listed from top,Figure 2):(1)sandy loam layer,400mm,medium to coarse sand with 20%topsoil in the upper 100mm,(2)sand layer,400mm,fine to medium sand,(3)transition layer,30mm,coarse sand and (4)underdrain,70mm,fine gravel with embedded drainage pipe.The columns were planted with Carex rostrata Stokes (Bottle sedge)which is wide-spread in the northern hemisphere (Anderberg and Anderberg,2006).The plant density in the columns was 8plants per column,which corresponds to a density of approximately 73plants/m 2.Before they were planted in the columns,the plants were grown for 5weeks outside to develop a substantial root system.Afterwards they were grown in the columns for two month and irrigated with tapwater.Figure 1Biofilter columns in climate roomG.-T.Bleckenetal.84In order to investigate the temperature effect on the biofilter performance,the tests were carried out in three thermostat controlled climate rooms at constant target tempera-tures of þ28C,þ88C,and þ208C (þ35.68F,þ46.48F,and þ688F,resp.).Five columns each were placed in every climate room (Figure 1).The air temperature in the climate rooms was logged at a 15minute interval using one EBI 20-T (88C)and two EBI 2T-112(28C and 208C)temperature loggers (ebro Electronic,Ingolstadt,Germany).All columns were illuminated with high pressure sodium greenhouse lamps (G-Power Agro,400W,55,000Lm)12hours daily.Experimental procedureStormwater .Since natural stormwater was not available in the required quantity and with constant water quality over the time of the experiment,nor could be stored without significant changes to its quality,semi-synthetic stormwater was used.It was made by mixing tap water with gully pot sediment to achieve the required TSS concentration,topped with certain pollutants to achieve the targeted pollutant concentrations,as outlined in Table 1(only for nutrients;heavy metals were added as well,but are not reported in this paper).A new mixture was made for every stormwater application.The water was stored at the respective temperature (28C,88C,208C,resp.)for at least 24hours before dosing the columns in order to have similar water and air temperatures.In Lulea ˚(Sweden)it rains approximately two times per week in September and October (the month with the most rain events in cold temperatures)with a total precipi-tation amount of around 110mm (SMHI,2005).This corresponds to an average of 5.4L/m 2stormwater runoff per rain event from a catchment with 85%impervious surface.It Figure 2Biofilter column configurationG.-T.Blecken et al.85was assumed that the biofilter area represents appr.4%of the catchment area (one col-umn with 0.11m 2for 2.75m 2catchment)(Wong et al.,2006).Therefore every column was dosed with 15L (5.4L/m 2·2.75m 2¼14.85L <15L)of stormwater twice weekly.Sampling .From the stormwater a sample was taken in three replicates before every stormwater application.All outflow water was collected in PE-tanks until the next dosing event,it was stored at þ28C,and a composite sample was taken from each PE-tank,i.e.15samples per each dosing.This paper reports on results of the first four weeks of stormwater dosing (i.e.eight events).Analyses .All samples were analysed for total and dissolved N,ammonium (NH þ4),nitrate/nitrite (NO x ),TSS,and pH.The dissolved samples were filtered,using Whatman ME25membrane 0.45m m pore size filters.Before analysing P and N,the samples were digested with peroxo-disulphate (according to the Swedish standard method SS 028127)and oxidised with peroxisulphate (SS 028131),resp.The analyses were conducted with a continuous micro flow analyser (QuAAtro,Bran þLuebbe,Hamburg,Germany)according to the device-specific methods no.Q-031-04for P,no.Q-003-04for N and NO x and no.Q-001-04for NH þ4.TSS was determined by filtration through Whatman GF/A 1.6m m pore size glass microfibre filters (SS-EN 872)in one replicate.pH was measured with a field pH-meter (pH330,WTW GmbH,Weilheim,Germany).Data analyses Pollutant reduction was calculated as reduction ¼(1-(out/in))·100%.Thus,production of pollutants results in a negative reduction rate.Analysis of variance (ANOVA)was used to test the influence of temperature on outflow concentrations.Furthermore,box plots were created for nitrogen species and phosphorus to compare in-and outflow concen-trations and their evolution over time.All statistical calculations and plots were computed with the software MINITAB w 15.1.Results and discussion The mean temperature in the three different rooms were 1.88C (SD:1.018C),7.48C (SD:0.358C)and 20.38C (SD:1.028C)respectively.Thus,the real temperatures were very near the target temperatures.The mean inflow and outflow pollutant concen-trations (mg/L)as well as reduction rates (%)at the three different temperatures are shown in Table 2.pH .The average pH-value of the stormwater was 6.9.The pH increased in the columns and the outflow pH at all temperatures was around 7.4.Table 1Semi-synthetic stormwater pollutants and their sourcesPollutant Targeted SourcepH6.9H 2SO 4TSS140mg/L Stormwater gully pot sediment (#400m m Phosphorus (total)0.3mg/L KH 2PO 4(potassium dihydrogen phosphate)0.32mg/L nitrate:KNO 3(potassium nitrate)Nitrogen (total) 1.4mg/L 0.24mg/L ammonium:NH 4Cl (ammonium chloride)organic nitrate:C 6H 4NO 2(nicotinic acid)G.-T.Bleckenetal.86TSS .Reduction of TSS was around 97%,and whilst the effect of temperature on this removal was statistically significant (p ¼0.001),it accounted for very little of the observed variation,and was of no practical significance (Table 3,Figure 3).Other factors are clearly influencing TSS removal,although it was high in all cases.The low difference between the columns at different temperatures is not surprising since the TSS removal is mainly a matter of mechanical filtration which itself is not influenced by temperature (unless the soil media soil freezes forming channels).Because of the high TSS removal,a high (and largely temperature independent)removal of particle bound pollutants could be expected.Phosphorus .In the stormwater inflow 85%of the total phosphorus was particle bound.The fraction was slightly different in the outflow at the different temperatures (28C:87%particle bound,88C:84%particle bound and 208C:82%particle bound).A temperature independent removal of about 80%was detected for total phosphorus (p ¼0.933,Table 3).There is a very clear decrease in the outflow concentrations and their variances over time (Figure 4).Dissolved phosphorus was also well removed by the biofilter,with no significant temperature dependence (p ¼0.285,Table 3).However,its reduction rate was slightly higher at cold temperatures.The results make sense,if we assume that physical filtration is the main mechanism for P removal,while biological activity within the soil may cause some leaching of P from media (the higher biological activity occurs at higher temperatures).This leaching is getting smaller with time as the Table 2Pollutant concentrations and removalStormwater (2)all temp.Outflow (3)28C 88C 208CpH 6.90(0.20)7.32(0.13)7.40(0.10)7.46(0.18)TSS concentration 142.7(13.9) 3.6(1.4) 5.1(1.7) 4.6(2.1)mean reduction 97.5%96.4%96.8%N total concentration 1.38(0.16) 1.38(0.29) 1.54(0.25) 4.23(0.68)mean reduction 20.5%211.6%2207.8%N dissolved concentration 1.16(0.08) 1.33(0.26) 1.31(0.15) 3.94(1.02)mean reduction 214.9%213.2%2240%NO x (1)concentration 0.24(0.01)0.72(0.26)0.89(0.13) 3.79(0.57)mean reduction 2198%2265%21461%NH 4(1)concentration 0.32(0.05)0.11(0.05)0.14(0.06)0.15(0.05)mean reduction 64.5%56.2%51.7%P total concentration 0.292(0.018)0.055(0.036)0.058(0.032)0.056(0.030)mean reduction 81.2%80.3%80.7%P dissolved concentration 0.031(0.017)0.007(0.002)0.009(0.004)0.010(0.005)mean reduction 77.5%71.5%69.3%(1)only the first 4events have been analysed (2)three replicates per event analysed (3)mean value of five replicate columns and all events.Table 3One-way ANOVA:p-value of temperature influence on outflow concentrations and R 2(adjusted)of the modelp -value R 2(adj.)TSS 0.0019.0%N total 0.00089.4%N dissolved 0.00080.4%NO x (2)0.00093.7%NH ð2Þ40.065 6.0%P total0.9330.0%P ð2Þdiss :0.285 2.1%G.-T.Blecken et al.87source is depleted,which explains the decreasing outflow concentrations with time in Figure 4.Overall however,mechanical removal of phosphorus is the most important factor and therefore overall P removal is high.Nitrogen .While the biofilters at 28C and 88C showed little or no leaching of total nitrogen,a high production (on average 2208%removal)was observed at 208C (Figure 5,Table 2).No trend over time wasobserved.Figure 3Box plot of in-and outflow TSS concentrations at the 3different temperatures and 8samplings Figure 4Box plots of in-and outflow total phosphorus concentrations at the 3different temperatures and 8samplingsG.-T.Bleckenetal.88The total nitrogen in the synthetic stormwater influent was 84%dissolved,whilst in the treated outflow water 96%,85%and 93%was at 28C,88C and 208C,respectively.The proportion of the nitrogen compounds changed during the treatment in the biofilter.NH þ4was reduced at all temperatures,whilst NO x was produced (Table 2,Figure 6).This means that nitrification in the unsaturated zone of the biofilter was occurring and there-fore NH þ4levels were decreased and NO x levels were increased.Since no denitrification was taking place due to the lack of an anoxic zone and/or a carbon source,levels of NO xFigure 5Box plots of in-and outflow total nitrogen concentrations at the 3different temperatures and 8samplingsFigure 6Box plots of in-and outflow:(a)dissolved NO x ,(b)and dissolved NH þ4concentrations at the 3different temperatures and 8samplings G.-T.Blecken et al.89However,a significant temperature effect was demonstrated for dissolved nitrogen behaviour (p ¼0.000dissolved N and NO x ,Table 3):the higher the temperature the higher the NO 3production due to increasing nitrification with increasing temperatures.More importantly,more nitrogen from the soil leached to the outflow water at higher temperatures.Unfortunately,it is not clear yet whether the leaching will stop over time as plants mature,as has been observed in similar biofilter studies (Zinger et al.,2007).The plants had only 2–3months of establishment,while in Zinger at al ’s experiments they had 5months to establish.It is known that plants (and in particular their roots)play a major role in N removal,since unvegetated biofilters are always demonstrated to leach nitrogen (Hatt et al.,2006;Lee and Schloz,2007),whilst vegetated biofilters do not (Henderson et al.,2007).Conclusion Even in cold climates,it is clear that effective removal of particle-bound pollutants (TSS and particulate phosphorus)can be achieved.This verifies the findings of other cold climate studies (Ba ¨ckstro ¨m,2002;Muthanna et al.,2007).However,the results showed poor overall removal of nitrogen from the stormwater.In particular,there was a very high production of NO x ,which was probably caused by nitrification,and limited denitrifi-cation.Such large net production of nitrogen was not expected as other studies have shown a reduction or at least only minor production of nitrogen even in biofilters without an anoxic zone (Kim et al.,2003;Scholz,2004;Zinger et al.,2007).However,it is possible that the short establishment time of the plants in the presented experiments is the main cause of this.Further research should be conducted to investigate if the removal of N will begin to improve over time.The biofilters showed the best performance for nitrogen (i.e.the lowest production)at the coldest temperatures.A key area of subsequent research is therefore to determine if the addition of an anoxic zone with added carbon source,which has been shown to improve denitrification in biofilters (Kim et al.,2003;Zinger et al.,2007),would remain effective,even in cold temperatures.References Anderberg,A.-L.and Anderberg,A.(2006).Den virtuella floran:Naturhistoriska Riksmuseet.http://linnaeus.nrm.se/flora/(accessed 08October 2007).Browman,M.G.,Harris,R.F.,Ryden,J.C.and Syers,J.K.(1979).Phosphorus loading from urban stormwater runoff as a factor in lake eutrophication -Theoretical considerations and qualitative aspects.J.Environ.Qual.,8(4),561–566.Ba ¨ckstro ¨m,M.(2002).Grassed Swales for Urban Drainage .Doctoral Thesis 2002:06,Division of Sanitary Engineering,Lulea ˚University of Technology,Lulea ˚,Sweden.Davis,A.P.,Shokouhian,M.,Sharma,H.and Minami,C.(2001).Laboratory study of biological retention for urban stormwater management .Water Environ.Res.,73(1),5–14.Graves,G.A.,Wan,Y.and Fike,D.L.(2004).Water quality characteristics of storm water from major land uses in south Florida .J.Am.Water Resour.Assoc.,40(6),1405–1418.Hatt,B.E.,Siriwardene,N.,Deletic,A.and Fletcher,T.D.(2006).Filter media for stormwater treatment and recycling:the influence of hydraulic properties of flow on pollutant removal .Water Sci.Technol.,54(6–7),263–271.Henderson,C.,Greenway,M.and Phillips,I.(2007).Removal of dissolved nitrogen,phosphorus and carbon from stormwater by biofiltration mesocosms .Water Sci.Technol.,55(4),183–191.Heyvaert,A.C.,Reuter,J.E.and Goldman,C.R.(2006).Subalpine,cold climate,stormwater treatment with a constructed surface flow wetland .J.Am.Water Resour.Assoc.,42(1),45–54.Hsieh,C.-H.and Davis,A.P.(2005).Multiple-event study of bioretention for treatment of urban storm water runoff.Water Sci.Technol.,51(3–4),177–181.G.-T.Blecken et al.90Kim,H.,Seagren,E.A.and Davis,A.P.(2003).Engineered bioretention for removal of nitrate from stormwater runoff.Water Environ.Res.,75(4),355–367.Larm,T.(2000).Stormwater quantity and quality in a multiple pond-wetland system:Flemingsbergsviken case study.Ecol.Eng.,15(1–2),57.Lee,B.-H.and Scholz,M.(2007).What is the role of Phragmites australis in experimental constructed wetlandfilters treating urban runoff?Ecol.Eng.,29(1),87–95.Lloyd,S.,Fletcher,T.D.,Wong,T.H.F.and Wootton,R.M.(2001).Assessment of pollutant removalperformance in a bio-filtration system-preliminary results.Paper presented at the Second South Pacific Stormwater Conference,New Zealand.Muthanna,T.M.,Viklander,M.,Blecken,G.-T.and Thorolfsson,S.T.(2007).Snowmelt pollutant removal in bioretention areas.Water Res.,41(18),4061–4072.Pitt,R.,Clark,S.and Field,R.(1999).Groundwater contamination potential from stormwater infiltration practices.Urban Water,1(3),217.Prince George’s County(2002).Bioretention Manual.Lead Author:D.A.Winogradoff.Department of Environmental Resources,Programs&Planning Division,Prince George’s County,Maryland,USA. Scholz,M.(2004).Treatment of gully pot effluent containing nickel and copper with constructed wetlands ina cold climate.J.Chem.Technol.Biotechnol.,79,153–162.SMHI.Swedish Meteorological and Hydrological Institute(2005).Klimatkarta Uppma¨tt nederbo¨rd 1961–1990,ma˚nadsvis.(In Swedish).Taylor,G.D.,Fletcher,T.D.,Wong,T.H.F.,Breen,P.F.and Duncan,H.P.(2005).Nitrogen composition in urban runoff–implications for stormwater management.Water Res.,39(10),1982.Wong,T.H.F.,Fletcher,T.D.,Duncan,H.P.and Jenkins,G.A.(2006).Modelling urban stormwater treatment–A unified approach.Ecol.Eng.,27(1),58.Zinger,Y.,Fletcher,T.D.,Deletic,A.,Bleckenr,G.-T.and Viklande,M.(2007).Optimisation of the Nitrogen Retention Capacity of Stormwater Biofiltration Systems.Paper presented at the NOVATECH 2007,Lyon,France.G.-T. Blecken et al.91。
Unit1水文循环也称为水循环或水循环，描述水在地球表面之上，之下的连续运动。
水可以在水循环中的各个地方在液体，蒸气和固体之间改变状态。
虽然地球上的水平衡保持不变，但是水分子可以进出大气。
通过蒸发，冷凝，降水，渗透，径流和地下流动等物理过程，水从一个水库移动到另一个水库，例如从河流到海洋，或从海洋到大气。
[1]这样做，水经历了不同的阶段：液体，固体和气体。
水循环涉及热能的交换，这导致温度变化。
例如，在蒸发过程中，水分从周围吸收能量，冷却环境。
相反，在凝结过程中，水会向周围环境释放能量，使环境变暖。
水循环在维持地球生命和生态系统方面具有重大意义。
即使每个水库的水都起着重要的作用，水循环给我们这个星球上的水的存在带来了更多的意义。
？通过将水从一个水库转移到另一个水库，水循环净化水，补充淡水，并将矿物运送到全球不同地区。
[2]它还涉及通过侵蚀和沉积等过程来重塑地球的地质特征。
另外，由于水循环也涉及热交换，所以也对气候产生影响。
驱动水循环的太阳加热海洋中的水分。
水分蒸发成水蒸气。
冰雪可以直接升华成水汽。
蒸散是从植物中蒸发出来并从土壤中蒸发出来的。
上升的气流将蒸汽带入大气中，在较冷的温度下，气体凝结成云。
气流使全球各地的水汽移动，云粒子相互碰撞，成长，并由于降水而从天而降。
？一些降水如雪或冰雹，雨雪，可以积蓄成冰盖和冰川，可以储存数千年的冷冻水。
大部分的水回落到海洋中，或者像雨水一样落到地面上，在地表径流时，水流过地面。
一部分径流进入山谷中的河流，河流将水流向海洋。
径流和地下水在湖泊中作为淡水储存。
？并非所有径流都流入河流，大部分径流都渗透到地下渗透。
有些水深入地下，补充含水层，长期储存淡水。
有些渗入物靠近地表，可以渗入地表水体（和海洋）作为地下水排放。
一些地下水在地表上找到开口，并以淡水泉的形式出现。
随着时间的推移，水回到了我们的水循环开始的海洋。
一个水库在水文循环中的停留时间是水分子在该水文循环中花费的平均时间。
There are several species of bacteria that are widely found in the aquatic environment but so not normally cause illness in the immuno-competent. They are not therefore particularly associated with health problems from drinking-water. It is important to be aware of them nevertheless, as they have occasionally been associated with disease where people may already be ill with other conditions or their immune system is reduced and unable to cope (Dufour 1990).They are usually known as environmental bacteria, but I have also come across the terms adventitious or heterotrophic in this context (although heterotrophic strictly means they get their source of energy and cellular carbon from the oxidation of organic material, that is, by feeding on plants or animals-rather than photosvnchesis). Where laboratories carry out plare counts, it is often these bacteria that are cultured. There will be many different types of environmental bacturia but the imporiant ones for drinking-water safety are listed here.AeromonasAeromonas are commonly found in both fresh and salt waters. There are several species, each one favouring a particular environmental niche. Aeromonas bydropbila is found mainly in clean river water, Aeromonas sobria in stagnant water and Aeromonas caviae in marine water. They are so common that people have tried to use them in rivers as indicators of pollution. They are known to cause diarrhoea and infection in soft tissue where damaged skin comes into contact with contaminated river or lake water.Aeromonas caviae is the one most commonly associated with diarrhoea. Diarrhoeal infection is usually mild, although more severe symptoms have occasionally been known, including bloody diarrhoea and chronic colitis (inflammation of the colon).Aeromonas have been found in treated chlorinated water and sometimes, there is re-growth in the distribution pipes. Chlorine only appears to have a temporary effect on them and this may mean that it stops them from reproducing but does not kill them. If left (presumably so they can get their breath back and have a bit of a rest after the chlorine attack) they can continue as normal.有一些种类的细菌在水生环境中被发现,但通常不引起疾病immuno-competent。
大学专业英语阅读教程（给水排水与环境工程）单词总结同济大学出版社－李田编著arlex7577 整理part I Water resource and regi slationunit 1 The Hydrologic Cycle1、hydrol ogy 水文学、水文地理学2、hydrol ogic=hydrol ogical3、hydrol ogic cycle 水文循环4、freshwater 淡水的、河水的5、fresh water 淡水、湖水6、precipitate 沉降、下沉7、evaporate 使蒸发、消失8、dewpoint 结露点9、droplet 小滴10、Ideal Gas Law 理想气体定律11、orographic 山岳的、山形的12、terrane 岩层13、convective 传送的、对流的14、schematic 示意的15、diagram 图表、图解16、hydraulic 水力的、水力学的17、precipitation 降水、降雨量、沉淀18、transpiration 蒸发（物）、植物蒸腾作用19、depict 描述、描写20、diagrammatically 用图解法地21、physical works 实际构筑物22、meterologi st 气象学者23、hydrologist 水文学者24、hail （下）冰雹25、sleet 冰雪、雨加雪26、snowpack 积雪场27、thaw 解冻28、discard 丢弃、放弃29、environmental 环境的、周围的30、marketable 时宜销售的31、isolated 隔离的、孤立的32、Madi son avenue 纽约麦迪逊大街unit 2 The World Fresh Water Resource33、integral 整体的、构成整体所需要的34、ecological 生态学的35、harbor 隐匿、庇护36、aquatic 水的、水生的、水憩的37、ecosystem 生态系统38、species 物种、式样39、aqueduct 沟渠、导水管40、desalinate 去处盐分、海水淡化41、arid 干旱的、贫瘠的42、iceberg 冰山、冷冰冰的人43、reverse 相反、颠倒、相反的、颠倒的44、aquifer （土壤）含水层、蓄水层45、rudimentary 根本的、未发展的46、malaria 疟疾、瘴气47、typhoid 伤寒症、伤寒的48、cholera 霍乱49、wetland 湿地、沼泽地50、habitat （动植物）的生活环境。
CO2与零价铁有压系统处理硝酸盐废水研究Chi-Wang Li*, Yi-Ming Chen, Wei-Shuen Yen摘要：本文提出一种新的反应装置进行硝酸盐的去除，反应器中的Fe0（ZVI）成流化状态，并通过加压CO2来控制系统的PH值。
所采用的CO2有压系统比传统CO2曝气系统的CO2用量少且能更快的使PH稳定下来。
但由于碳酸盐是弱酸性，系统的PH会随着ZVI的氧化和硝酸盐的降解逐渐上升。
随着反应过程中溶液PH的增加，硝酸盐的降解效率不断的下降。
实验结果表明硝酸盐的去除效率随着ZVI的用量和硝酸盐的初始浓度的增加而不断上升，但当ZVI用量超过8.25g/l，或硝酸盐的初始浓度达到100mg/l以后，硝酸盐的去除效率不会发生较大的变化。
与我们曾经研究的通过强酸来控制溶液PH的流化系统不同的是，在本实验中，硝酸盐的去除率接近100%，这说明通过ZVI在不同的PH条件下去除硝酸盐有不同的反应途径。
关键词：加压系统；CO2；硝酸盐降解；化学平衡方程式1.导言用ZVI来处理硝酸盐废水已有不少研究者做了这方面的研究，如： Choe（2000）、 Alowitz and cherer（2002）、Westerhoff（2003）、Westerhoff and James（2003）、Choe 2004）、Su and Puls（2004）、Chen（2005）、Liou（2005） Zhang and Huang（2005）、Ruangchainikom （2006）等等。
在他们发表的论文中，提到了在ZVI反应墙(Furukawa et al., 2002; Wilkin et al., 2003)和滤柱(Westerhoff, 2003; Westerhoff and James, 2003)中硝酸盐降解比较慢的反应动力学以及金属表面的金属氧化膜的阻碍反应进行等问题。
由于硝酸盐在酸性PH下具有较高的去除效率(Alowitz and Scherer, 2002; Choe et al.,2004; Zhang and Huang, 2005),我们在以前的研究中提出了一种地上渗透墙系统来处理水体中的硝酸盐，这种系统与PH控制装置合成一体，系统中的ZVI成流化状态(Chen 2005).在这种流化状态的ZVI系统装置中，通过PH控制装置自动的投加强酸性物质（盐酸），系统的PH可以精确控制在适合硝酸盐降解的水平上。
一种利用蜜糖废水产生PHA的侧流工艺的建立方法摘要试验建立了一种利用蜜糖废水生产聚羟基烷酸脂（PHA）的三阶段过程。
该过程包括（1）糖蜜废水酸酵解，（2）PHA富集菌的筛选，（3）利用富集完毕的污泥和酵解之后的糖蜜废水批次累积PHA。
在发酵阶段，试验评估了PH（5~7）对有机酸型体分布以及产率的影响。
PH较高时乙酸和丙酸为主要产物，然而较低的PH值有利于丙酸和戊酸的产生。
试验评估了利用乙酸盐和发酵糖蜜废水为基质筛选的两类菌群的PHA积累能力。
考察了有机酸型体分布对利用醋酸盐筛选菌群产生的多聚体的组成以及产率的影响。
PHA富集产率在0.37到0.50CmmolHA/Cmmol VFA之间变化。
试验观察到了被利用有机酸的类型和多聚物成分的一种直接关系。
在糖蜜废水中，低氨氮浓度（0.1Nmmol/l）促进了PHA 的储存（0.59 Cmmol HA/Cmmol VFA）。
此外，试验建立了一种控制反应器运行利用发酵糖蜜废水筛选PHA富集菌群的方法。
利用高有机负荷以及低氨氮浓度选择了一种具有稳定储存PHA能力的菌群，富集产率达到0.59Cmmol HA/Cmmol VFA)，这一能力与醋酸盐筛选菌相似。
前言聚羟基烷酸脂被认为是优良的可生物降解塑料的候选者。
这类含有多种单体组分具有热塑性的多聚物是被细菌作为能量和碳储存物质的。
它们的结构特性与聚丙烯的结构性质一致，同时又具有诸多优势：可生物降解、可生物相容、能进一步由可再生碳源产生从而使可持续生产过程成为可能。
然而，PHAs与石化工业衍生的塑料制品在成本上相当大的差异成了这类高聚物部分替代后者的阻碍。
目前，商业可行的PHAs是由纯菌（野生的和基因重组的菌种）和纯底物（通常很昂贵）工业化生产而来。
PHAs的价格主要取决于底物成本，约占总成本的40%（Choi和Lee，1997）。
最近十年来，一系列低成本的碳源基质（例如淀粉、木薯粉水解物、乳清和蜜糖）在纯菌生产PHA过程中得到检验。
《给水排水专业英语》Lesson 1译文：（第一课）给水工程我们知道，水的供应对生命的生存至关重要。
人类需要喝水，动物需要喝水，植物也需要喝水。
社会的基本功能需要水：公共卫生设施的冲洗，工业生产过程耗水，电能生产过程的冷却用水。
在这里，我们从两方面讨论水的供给：）1、地下水供给2、地表水供给地下水是通过打井而得到的重要直接供水水源，也是一种重要的间接供水水源，因为地表溪流（或小河）会经常得到地下水的补给。
在靠近地表的通气层中，土壤孔隙内同时包含着空气和水。
这一地层，其厚度在沼泽地可能为零，在山区则可能厚达数百英尺，蕴涵三种类型的水分。
重力水，是在暴雨过后进入较大的土壤孔隙中的水。
毛细水是在毛细作用下进入较小的土壤孔隙中的水，它能够被植物吸收。
吸湿水是在不是最干燥的气候条件下由于分子间引力而被土壤稳定下来的水。
地表通气层的湿气是不能通过凿井方式作为供水水源的。
位于通气层以下的饱和层，土壤孔隙中充满着水，这就是我们通常所说的地下水。
包含大量地下水的地层称为含水层。
通气层和含水层之间的水面称为地下水位或浅层地下水面，地下水静压力与大气压力相等。
含水层可延伸相当深度）, but because the weight of overburden material generally closes pore spaces（但因为地层负荷过重会压缩（封闭、关闭）土壤孔隙，深度超过600m，即2000英寸，就基本找不到地下水了。
能够含水层中自由流出的水量称为单位产水量。
The flow of water out of a soil can be illustrated using Figure 1（土壤中水流如图1所示）. The flow rate must be proportional to the area through which flow occurs times the velocity（流量与流水面积成比例，流经该土壤面积的流量等于面积与速率成的乘积）, orQ=AvWhere（此式中）Q=flow rate , in m3/sec（流量，单位为m3/s）【cubic meter per second】A=area of porous material through which flow occurs, in m2（渗透性土壤的流水断面，单位为m2）v=superficial velocity, in m/sec（表观流速（表面流速），单位为m/s）表观流速当然不是水在土壤中流动的真实速度，因为土壤固体颗粒所占据的体积大大地降低了水流通过的空间。
大学专业英语阅读教程给水排水与环境工程课后练习题含答案IntroductionEnvironmental engineering is a branch of engineering that focuses on studying the effects of human impact on the environment, and devising ways to reduce that impact. One of the most important aspects of environmental engineering is the field of water supply and sanitation.In this document, we will be presenting a set of practice questions on the topic of water supply and sanitation, with answers provided at the end.Practice QuestionsQuestion 1Which of the following is NOT a typical method of water treatment?A)Coagulation and flocculationB)FiltrationC)ChlorinationD)IncinerationAnswer: D) Incineration. Incineration is not a typical method of water treatment.Question 2What is the purpose of chlorination in water treatment?A)To remove sedimentB)To remove bacteria and virusesC)To remove dissolved solidsD)To remove taste and odorAnswer: B) To remove bacteria and viruses. Chlorination is the process of adding chlorine to water to kill bacteria and viruses.Question 3What is the difference between primary and secondary sewage treatment?A)Primary treatment removes suspended solids, while secondarytreatment removes dissolved solids.B)Primary treatment is a physical process, while secondarytreatment is a biological process.C)Primary treatment is more expensive than secondary treatment.D)Primary treatment produces more sludge than secondarytreatment.Answer: B) Primary treatment is a physical process, while secondary treatment is a biological process. Primary treatment involves physical processes such as screening, sedimentation and flotation to remove large particles, while secondary treatment involves biological processes such as activated sludge and trickling filters to remove dissolved and suspended organic matter.Question 4What is the purpose of aeration in the activated sludge process?A)To remove bacteria and virusesB)To remove dissolved solidsC)To provide oxygen for the growth of aerobic bacteriaD)To produce biogasAnswer: C) To provide oxygen for the growth of aerobic bacteria. Aeration is the process of adding r to the activated sludge tank to provide oxygen for the growth of aerobic bacteria, which break down organic matter in the wastewater.Question 5What is the purpose of a settling tank in the wastewater treatment process?A)To remove suspended solidsB)To remove dissolved solidsC)To remove bacteria and virusesD)To produce biogasAnswer: A) To remove suspended solids. A settling tank is used to allow the solids in the wastewater to settle to the bottom, so that they can be removed from the wastewater.Question 6What is sludge, and how is it disposed of in the wastewatertreatment process?Answer:Sludge is the solid material that is produced during the wastewater treatment process. It contns the organic matter that has been removedfrom the wastewater. Sludge is typically disposed of by either incineration, land application, or landfill.Question 7What is the purpose of a biosolids treatment plant?A)To remove suspended solids from wastewaterB)To remove bacteria and viruses from wastewaterC)To treat the sludge produced in the wastewater treatmentprocessD)To produce biogasAnswer: C) To treat the sludge produced in the wastewater treatment process. A biosolids treatment plant is used to treat the sludge produced in the wastewater treatment process, so that it can be safely disposed of or used as a fertilizer.ConclusionIn this document, we have presented a set of practice questions on the topic of water supply and sanitation. These questions cover topics such as water treatment, sewage treatment, and sludge disposal. By answering these questions, students can test their knowledge of the subject and prepare for exams.。
土木工程给水排水英文文献及翻译-英语论文土木工程给水排水英文文献及翻译Building drainage of water-saving techniquesWith people's quality of life，the quality and quantity of water are constantly expanding. Implement sustainable water use and protection of water resources from destruction. And access to healthy water, recycling of water, has become the government and the broad masses of the people the focus of attention. All this gave to the construction of drainage works on the design of the many new requirements, water supply advanced technology of the urgent need to accelerate the pace. This paper will explore more of the building for drainage of water-saving technology; we hope to arouse the awareness of water conservation to build water-saving city efforts. Construction of a water-saving project, in addition to the water saving should formulate laws and regulations to strengthen the management and day-to-day publicity and education use price leverage to promote water conservation work, but also take effective measures, to ensure that the construction of water-saving work carried out in-depth and comprehensive. We are aware that the water supply network's coverage, the extension of transmission mains and the construction of the building because arising from the difference in height, will be used to increase the water pressure before the end of ways to protect the most disadvantaged water points will be adequate water supply, This will be a large number of regional supply of high pressure water supply is. Therefore accessories before the water hydrostatic head greater than outflow, the flow was greater than the rated flow capacity. Beyond the rated flow capacity of that part of the normal flow did not have the use efficiency is a waste of water. As a result of this water is being wasted is not easy to detect and understand, it could be called a "stealth" wasting water.It has been in a different type of floor, the building 67 water distribution points so the overpressure from the measured flow analysis, Statistical results are 55% of the iron spiral movements - taps (hereinafter referred to as "ordinary water") and 61% of the ceramic valve - leading the flow of water-saving more than their rated flow, the super-flow pressure from the state. Two endings the largest flow out of the rated flow capacity of about three times [1]. This shows that in our existing buildings, water supply system overpressure out-flow phenomenon is widespread and it is a fairly serious. In distribution point pressureAs overpressure flow out of the "invisible" water is not wasted paid enough attention to, So in our existing "building water supply and drainage design" and "construction water supply and drainage design GBJ15-20 00 draft "(hereinafter referred to as" draft "), although the water accessories and home support the greatest pressure certain restrictive provisions in [2], but this is only to prevent water from the high pressure parts will lead to damage to the point of consideration, not prevent excess pressure from the out-flow point of view, the pressure is too lenient restrictions on the flow overpressure no fundamental role. Therefore, in accordance with the water supply system overpressure flow from the actual situation, the pressure on the water supply system to make reasonable limit.1.2 measures taken decompressionWater supply system in a reasonable allocation of decompression device is to control pressure within the limits required to reduce excess pressure from the flow of technical support.1.2.1 Jangled nervesRelief valve is a good decompression device, can be divided into proportional (lower left) of direct action and the type (Photo) The former is based on the ratio of the area to determine the proportion of decompression, which can be set under pressure prior decompression, When the water-stop water, you can also be controlling the vacuum tube pressure is not increased, Decompression can achieve dynamic can achieve static decompression.1.2.2 Decompression orifice and conserving Cypriots1106土木工程给水排水英文文献及翻译Orifice decompression compared with jangled nerves example, the system is relatively simple, less investment, easy management. The practice of some units, water-saving effects are fairly obvious, If Shanghai Jiao tong University in the school bathroom water pipe installation aperture of 5 mm orifice, water-saving about 43%. But decompression orifice only by the dynamic pressure, static pressure can be reduced and the pressure downstream with the upstream pressure and the flow is changed, is not stable enough. In addition, the vacuum orifice plug easy. In better water quality and water pressure more stable, by using [3]. Cutting expenditure and the role of Cypriot advantages and decompression orifice basically are the same. Suitable for the small diameter and accessories installed to use [3].1.3 adopt water-saving leadingA trial showed that the leading Practical water-saving taps and the general state of the full, flow out of the former than the latter out of the flow. That is the same pressure, the leading water conservation has good water saving, water-saving volume in 20% ~ 30% between. And the higher the pressure ordinary tap water from the larger, water-saving is leading the greater the volume of water-saving. Therefore, should the building (especially in the standard water pressure in water distribution points) leading installation of water-saving, reduce water wastage. In 1999 the Ministry of Construction, State Economic and Trade Commission, State Bureau of Building materials apparatuses jointly issued a document "on the elimination of residential buildings behind the products notified" require large and medium-sized cities in new residential prohibit the use of helical-style cast iron nozzle movements, actively adopt "ceramic cartridge faucets" and "common faucet technical conditions of the ceramic cartridge faucets [4]. Since the main building of our school building earlier in the toilet faucet is still an ordinary spiral movement - iron taps. We have often seen leading loosening and tightening the leading difficulty caused by the leakage phenomenon. In fact, there is such a faucet overpressure caused by the "invisible" huge waste of water. Schools should arouse the concern of the relevant departments, from the long-term interests for the use of water-saving new leader, reduce unnecessary losses.2 vigorously develop the construction of water facilities, "watercourse." As the name suggests is not delivered on the waterways clean water is not sullied by sewage contamination. Residents put a wash, bathing, washing clothes and other water washing and flushing water together, after CO., filtration and disinfection, Sterilization, which imported waterway network, for toilet flushing, washing cars, and pouring green, onto the road and other non-drinking purposes. China therefore waterway is also known as miscellaneous water Road. With a watercourse which cubic meters of water, equivalent to the use of one cubic meters of clean water, emit less nearly a cubic meter of sewage and kill two birds with one stone. Water-saving achieved nearly 50% [3]. Therefore, the channel has many of the world's water shortage in cities used extensively.2.1 full use washing wastewater and other quality miscellaneous drainageThe existing water facilities built in most hotels, colleges, and the basic source for the bathroom bathing wastewater. For some small units, smaller than bathing wastewater, and discharge time is too concentrated, Water facilities are not stable and adequate source of water. And washing with water wastewater, the use of time more evenly, water treatment and the advantages of relatively good, as a water source, to be fully exploited.2.2 Develop and implement as soon as possible the return to the new water quality standardsThe current construction of water reused implementation of the existing “life miscellaneous water quality standards.” The total coli form standards and the requirements of "sanitary standard for drinking water," the same, compared to the developed countries and the Chinese water standards apply to the swim-minus III also strict standards. This has led to two problems: First, many of the existing water works is less than the standard; 2 are fulfilled with a certain degree of difficulty, improve the water project investment and processing cost. So should develop appropriate indicators of the value of water works to promote the spread土木工程给水排水英文文献及翻译and popularize. Water Saving water is not limiting, or even prevents the water. But reasonable people to water, efficient use of water and not waste. As long as we pay attention to fit the family's bad habits, we will be able to water-saving around 70% [3]. Water and waste a lot of the habits, such as: flush toilets single wash cigarette butts and broken fine waste; to access a cup of cold water. Many people will not venting water; spend the potatoes, carrots after peeling, washing or after the optional vegetables; when the water stopped (open access customers, answer the phone, change TV channels), not turning off the tap; During the suspension, forget turningoff the tap; toilets, wash, brush, let the water has been flowing; Before sleep, go out, do not check the faucet; equipment leaks, not promptly repaired. From the following table, we can see in many parts of life as long as we interested to note that the conservation of water is very impressive.3 to promote the use of water-saving devicesIn addition to the family of water-saving attention to cultivate good habits of water, using water-saving devices is very important and also the most effective. Some people prefer laissez-faire, but also refused to replace water-saving devices, in fact, so much water is a long time down the uneconomical. Thus vigorously promote the use of water-saving devices is the construction of water-saving important ways and means.3.1Water-saving taps3.1.1 Water Saving leading CeramicsCurrently most of the water-saving taps used Ceramics taps. Such taps compared with ordinary taps, water was typically up to 20% ~ 30%; and other types of water-saving compared to the leading and cheap [3]. Therefore, in the residential buildings of architectural vigorously promote the use of such water-saving lead. We taught thefifth floor of the dormitory building and are used by such leading.3.1.2 Closed since delay tapsSince the delay in the water taps closed after a certain time, shut down automatically to avoid Changliushui phenomenon. Water timing to be in a certain range adjustment, both for the convenience of Health has complied with the water-saving requirements suitable for washing in public places with.3.1.3 Photoelectric controlled tapsClosed since the delay of water-saving taps but water while fixed time and meet the different requirements of the use of the object. Photoelectric controlled taps will be able to overcome the above drawbacks, such as the latest one of the type of infrared device control wash, The first installation will be self-inspection of the device in front of or below the fixed reflectors (for example, vanity) and based on the reflectors adjust their distance from work to avoid the past because of automatic water obstacles closer to the front of regular water, Such intelligent device can wash your hands although below action without washing their hands without water. a long time will wash water and do not have long-term can also regularly flush Water Seal failure to avoid a supply shortage ahead of the police [3].3.2The total water-saving flush3.2.1 Use of small volume cisterns commodeChina is promoting the use of water tanks 6 L fecal water-saving devices, and have flushing water to 4.5 L or even less, stood on the stool available. However, we should also pay attention to the drainage system to ensure the normal work of the use of small volume cisterns commode, otherwise they will be brought to plug the pipeline, not a net wash, and other issues. Two respectively flushing cisterns in urine, flushing water for 4 L (or less); Washing stool, Chong stood at 9 L (or less) [3]. (Map is a two-valve I-Yuan annually to the water tanks, to open the stool below the drain urine when opened above the drain Pictured left is the two-block cisterns switch several forms) Israel's construction regulations require all new buildings to install two respectively wash cisterns. China should also vigorously promoted two respectively cisterns, because one day, the number is far higher than the urine stool frequency. To three homes as an example, per person per day for a meeting of feces, urine four times and the use of existing water tanks L 9, day to 135 L of water; 6 L of water use, 90 L of water a day;土木工程给水排水英文文献及翻译and the use of cisterns two respectively, 75 L of water a day, can be seen using two respectively cisterns 9 L 6 L than using more water-saving cisterns [3]. 6 L Yuan annually to the use of water-saving cisterns better results. The use of tanks in two trances another advantage is not right and the replacement of the total drainage system to carry out reform therefore particularly applicable to existing buildings the total replacement of water tanks.UrinalThe United States launched the Urinal-washing, which is not water, the stench from the toilets without using utensils, In fact, only in one end Urinal add special "trap" devices, but because the economic, health, water effectively, So popular station.control UrinalUrinal photoelectric controls in a number of public buildings installations.3.2.4 Delayed flushing valve closedIt is the use of guide-work principle, water officials directly connected with the water pressure high enough circumstances, can protect the instantaneous flushing commode needs to replace tanks and accessories, installation is simple and easy to use, health, low prices, Water-saving effect of the obvious characteristics [3]. We carpentry center is used for such cleaning.3.3 in hot water systems installed in various forms of water-saving devicesIf installed in public bathrooms limited flow orifice, in the cold, hot water imported pressure balance between the installation of equipment; Installation of low-flow plumbing. Inflatable hot water thermostat and cooling, hot water mixed hydrants. 3.4 to further develop various forms of water-saving devices3.4.1 Development of different water taps outSome countries, in different places with different water out of taps, Singapore provides water for washing vegetables pots 6 L / min, shower water 9 L / min; China's Taiwan Province launched the spray-wash special taps, the flow was 1 L / min. In China, various taps most of the rated flow capacity of 0.2 L / s, that is 12 L / min, excessive [4]. Therefore be reasonable to develop taps the rated flow, and gradually installed in different places different from water taps.3.4.2 Vacuum water-saving techniquesTo ensure that sanitary ware and sewer cleaning effect of vacuum technology can be applied to drainage works Most of the air instead of using water, relying on the vacuum of high-speed gas-water mixture, and rapid disposal of the sewage, dirt-gully clean and save water and drain away the effects of dirty air. A complete vacuum drainage system, including: vacuum valve and with a magnitude of suction devices occupants, the closed aqueduct, vacuum collection containers. Vacuum pumps, control equipment and channels and so on. Together with the vacuum generated 40 ~ 5min the negative pressure of sewage pumped to the collection containers, then will collect sewage pump effluent into the municipal sewer. Different types of construction in the use of vacuum technology, the average water-saving exceed 40%. The use of the office building water-saving will rate-70% [2].3.4.3 Development zone leading to the wash waterIn Japan, many families use with the leading water wash, wash all the wastewater into water tanks for back flushing. If the water tank, they can directly turn on the water faucet open. Irrigation water use, it can not only save water but also reduce the costs. At present, the water in China has sales.土木工程给水排水英文文献及翻译随着人民生活质量的提高，对供水量和质的要求正不断扩展.同时实施水的可持续利用和保护，使水资源不受破坏，并能进入良性的水质、水量再生循环，也已成为政府和广大人民群众关注的焦点。
污水的有机污垢物污染的反渗透膜的污染和清洗摘要：被模拟的混合有机废水污水污染反渗透膜的结垢和随后的清洗已经有了系统的研究。
有机污染研究包括海藻，牛血清白蛋白（BSA），萨旺尼河天然有机物，与辛酸,分别代表多糖、蛋白质、腐殖酸和脂肪酸，在出水有机物中它们是无处不在的。
建立了存在或缺乏钙离子的混合有机污染物的结垢行为和机制后，我们的研究集中在被有机污染物质的混合物污染的渗透膜的清洗机制。
化学清洗剂代理包括碱（氢氧化钠），金属螯合剂（乙二胺四乙酸），阴离子表面活性剂（十二烷基硫酸钠），和浓缩盐溶液（氯化钠）。
具体来说，我们研究清洁剂型，清洁液，清洗时间，和结垢层组成对膜清洗效率的影响。
在有机污染物质的混合物污染的污染膜的的条件下模拟的化学清洗的调查时，粘附力值测量值提供了深入了解化学清洗机制。
结果表明，在单用碱性溶液（氢氧化钠）不能有效的破坏含钙有机污染形成的配合物，较高的pH值会导致有效的清洁，如果有足够的流体剪切力（由横向表面流提供）存在。
表面活性剂（十二烷基硫酸钠），一个强大的螯合剂（乙二胺四乙酸），和盐溶液（氯化钠）可以有效的清洗混合污染的反渗透膜，尤其是如果应用在高pH值和更长的清洗时间。
观察各种清洁剂的清洗效率均符合相关测量–分子间力值值。
此外，我们已经表明，最佳的清洁剂浓度可以从绘制的还原百分比–粘附力的值与清洗剂浓度的对比中推出。
1 景区简介全球范围对饮用水需求的增加，选择水源满足这一需求的方式从传统的来源，如水库、湖泊，转换到较常规来源，如污水二级污水处理。
为生产优质用水，使用膜进行海水淡化和废水回收已应用的更广泛。
膜污染是利用膜技术等应用的一个主要障碍，因为污染是不可避免的。
尽管努力研究开发更好的防污膜[和改进控制方法策略，膜污染仍随时间发生。
因此，长期解决办法是通过化学清洗清除沉积膜。
在废水中，回收为了选择适当的清洁剂和采用有效的化学清洗规程，必须了解废水排放特性的对膜污染的影响。
