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How to Control Air Pollution: A MultifacetedApproachAir pollution has become a pressing issue that poses a significant threat to both human health and the environment. The causes of air pollution are diverse, ranging from industrial emissions to vehicular exhaust and dust particles. The negative impacts of air pollution are also wide-ranging, including respiratory diseases, climate change, and reduced air quality. Given the gravity of the situation, it is imperative to take effective measures to control air pollution.One of the most effective ways to control air pollution is through the adoption of clean energy sources. Transitioning from fossil fuels to renewable energy such as solar, wind, and hydroelectric power can significantly reduce greenhouse gas emissions and air pollution. Governments should provide incentives for individuals and businesses to adopt these clean energy sources, such as tax breaks or subsidies.Another crucial measure is the improvement ofindustrial processes. Manufacturers should be encouraged toadopt pollution control technologies that reduce emissions and waste. Additionally, they should be required to comply with strict environmental regulations to ensure that their operations do not exceed acceptable pollution levels.Vehicle emissions are a significant contributor to air pollution, especially in urban areas. Therefore, promoting the use of public transportation, cycling, and walking can help reduce the number of private vehicles on the road. Governments can also introduce policies such as congestion charges or car-free days to encourage people to use alternative modes of transportation.Urban planning and green infrastructure are also essential in controlling air pollution. By increasing the number of green spaces, such as parks and gardens, cities can absorb carbon dioxide and other pollutants from the air. Furthermore, well-planned urban areas can reduce the needfor long-distance commuting, thus reducing vehicle emissions.Individual actions also play a crucial role in controlling air pollution. Simple actions such as reducing the use of single-use plastics, conserving energy, andrecycling can help reduce the amount of pollution generated. Additionally, individuals can choose to purchase products and food from companies that are environmentallyresponsible and reduce their carbon footprint.In conclusion, controlling air pollution requires a multifaceted approach that involves government policies, industrial reforms, urban planning, and individual actions. By adopting clean energy sources, improving industrial processes, promoting sustainable transportation, enhancing urban green infrastructure, and taking individual actions, we can effectively mitigate the negative impacts of air pollution and protect our health and the environment.**如何控制大气污染：多层面的方法**大气污染已经成为一个紧迫的问题，对人类健康和环境构成了重大威胁。
空气污染防治措施英文作文英文：Air pollution is a serious issue that affects thehealth and well-being of people all over the world. Inorder to combat air pollution, there are several measures that can be taken.Firstly, it is important to reduce emissions from vehicles and industrial sources. This can be achieved through the use of cleaner fuels, such as natural gas or electricity, and the implementation of stricter emissions standards for factories and power plants. For example, inmy city, the government has introduced a policy to encourage the use of electric vehicles by providing subsidies and building more charging stations. This has led to a significant decrease in air pollution from vehicle emissions.Secondly, promoting the use of renewable energy sources,such as solar and wind power, can also help to reduce air pollution. By decreasing our reliance on fossil fuels, we can decrease the amount of harmful pollutants being released into the atmosphere. For instance, in my country, there has been a push towards investing in solar energy infrastructure, and as a result, the amount of air pollution from power plants has decreased significantly.Furthermore, improving public transportation and encouraging people to use it can also play a role in reducing air pollution. By reducing the number of individual cars on the road, we can decrease the overall emissions of harmful pollutants. In my experience, the implementation of a well-connected and efficient public transportation system in my city has led to a decrease in traffic congestion and air pollution.In conclusion, there are several measures that can be taken to prevent and control air pollution, and it is important for governments, businesses, and individuals to work together to address this issue.中文：空气污染是一个严重的问题，影响着全世界人们的健康和福祉。
如何控制大气污染英语作文Controlling Air PollutionAir pollution is a major environmental issue that has been affecting the health and well-being of people around the world. It is caused by a variety of factors, including industrial emissions, vehicle exhaust, and the burning of fossil fuels. In order to control air pollution, it is important to take a comprehensive approach that addresses the sources of pollution and implements measures to reduce emissions.One of the most effective ways to control air pollution is to implement regulations and standards that limit the amount of pollutants that can be released into the atmosphere. This can include setting emissions limits for industrial facilities, requiring vehicles to meet certain emissions standards, and enforcing regulations to limit the burning of fossil fuels. By implementing and enforcing these regulations, it is possible to reduce the amount of pollutants that are released into the air, leading to improved air quality and reduced health risks for the population.In addition to regulating emissions, it is also important to invest in cleaner energy sources and technologies that canhelp to reduce air pollution. This can include promoting the use of renewable energy sources such as wind and solar power, and implementing energy efficiency measures to reduce the amount of energy that is consumed. By transitioning to cleaner energy sources and technologies, it is possible to reduce the emissions of harmful pollutants and improve air quality.Another important aspect of controlling air pollution is to raise awareness and educate the public about the impacts of air pollution and the steps that can be taken to reduce it. This can include providing information about the health risks associated with air pollution, as well as promoting sustainable practices that can help to reduce emissions. By raising awareness and educating the public, it is possible to build support for measures to control air pollution and encourage individuals and businesses to take action to reduce their environmental impact.Overall, controlling air pollution requires a comprehensive approach that addresses the sources of pollution and implements measures to reduce emissions. By regulating emissions, investing in cleaner energy sources and technologies, and raising awareness, it is possible to improve air quality and reduce the health risks associated with air pollution.控制大气污染大气污染是一个严重的环境问题，已经影响了全球人民的健康和福祉。
关于大气污染以及防治措施英文短篇作文Air pollution is a major environmental issue thataffects people's health and quality of life. It is caused by a variety of factors, including industrial emissions, vehicle exhaust, and the burning of fossil fuels. The pollutants released into the air, such as nitrogen oxides, sulfur dioxide, and particulate matter, can have harmful effects on human health, including respiratory problems, cardiovascular disease, and even premature death.In order to combat air pollution, it is important to implement effective measures to reduce emissions and improve air quality. One approach is to promote the use of clean energy sources, such as wind and solar power, which produce minimal air pollution compared to traditionalfossil fuels. Additionally, stricter regulations on industrial emissions and vehicle exhaust can help to reduce the amount of pollutants released into the atmosphere.Another important step in addressing air pollution is to increase public awareness and education about the issue. By educating people about the sources and effects of airpollution, as well as the ways they can reduce their own contribution to it, we can work towards creating a cleaner and healthier environment for everyone.Furthermore, investing in public transportation and promoting the use of electric vehicles can help to reduce the amount of air pollution caused by cars and other forms of transportation. By providing people with more sustainable and environmentally friendly transportation options, we can reduce the overall impact of vehicle emissions on air quality.In addition to these measures, it is also important to monitor air quality and take action to address areas with high levels of pollution. This can involve implementing air quality control measures, such as the installation of air purifiers and the use of green spaces to absorb pollutants.Overall, addressing air pollution requires a multi-faceted approach that involves a combination of regulatory measures, public education, and investment in cleaner technologies. By taking action to reduce emissions and improve air quality, we can create a healthier and more sustainable environment for future generations.空气污染是一项严重的环境问题，影响人们的健康和生活质量。
Title: Safeguarding Our Planet: The Urgent Need for Environmental Protection andPollution ControlIn the 21st century, the call for environmental protection and pollution control has become louder than ever before. The relentless pursuit of industrialization and modernization has taken a heavy toll on our planet, leading to a worsening environmental crisis. The time for action is now, and it is up to each and every one of us to contribute towards sustainable development and a cleaner, greener future.The statistics are alarming. Air pollution, water pollution, soil degradation, and climate change are among the many challenges we face. The relentless burning of fossil fuels and the disposal of waste have led to a significant increase in greenhouse gas emissions, causing global warming and extreme weather events. The impact of these environmental issues is felt across the globe, affecting both human health and the biodiversity of our planet.To address these challenges, we must adopt a holistic approach that encompasses both environmental protection and pollution control. We need to prioritize renewable energy sources, reduce our carbon footprint, and adopt sustainable practices in all aspects of our lives. Governments must implement strict environmental regulations and enforce them effectively to ensure that industries and businesses comply with environmental standards.Moreover, education and awareness are crucial in this effort. We need to raise awareness among the public about the importance of environmental protection and the consequences of pollution. By educating people about these issues, we can inspire them to make eco-friendly choices in their daily lives, such as using public transport orcycling instead of private vehicles, reducing waste, and conserving resources.In addition, technological innovation holds the key to addressing environmental challenges. Green technologies and innovative solutions can help us reduce pollution, improve energy efficiency, and conserve resources. For instance, the development of electric vehicles and renewable energysources can help us reduce our dependence on fossil fuels and lower greenhouse gas emissions.However, it is important to recognize thatenvironmental protection and pollution control are not the sole responsibility of governments or businesses. Each individual has a role to play in this effort. Simpleactions like reducing water waste, composting organic waste, and planting trees can have a significant impact on our environment. By making these changes in our daily lives, we can contribute towards building a more sustainable world.In conclusion, the protection of our environment andthe control of pollution are urgent and necessary for the well-being of our planet and its inhabitants. It is ashared responsibility that requires the collective effortof governments, businesses, and individuals. By adopting sustainable practices, prioritizing renewable energy, and raising awareness about environmental issues, we can create a cleaner, greener, and more sustainable future for ourselves and future generations.**守护地球：环境保护与污染治理的迫切需求**在21世纪，环境保护和污染治理的呼声比以往任何时候都更加响亮。
大气污染防治行动计划英文版内容English:The Atmospheric Pollution Prevention and Control Action Plan is a comprehensive initiative launched by the Chinese government to tackle air pollution in the country. The plan includes specific targets and deadlines for reducing pollutant emissions, increasing the share of non-fossil fuels in the energy mix, improving energy efficiency, and promoting the use of clean transportation. It also emphasizes the need for stricter enforcement of environmental regulations and the development of advanced technologies for pollution control. The plan aims to significantly improve air quality and public health, as well as to support the sustainable development of the economy and the environment.中文翻译:《大气污染防治行动计划》是中国政府为解决国内空气污染问题而推出的一项综合计划。
该计划包括了降低污染物排放、增加非化石能源在能源结构中的比重、提高能源利用效率以及推广清洁交通的具体目标和时间表。
此文档是毕业设计外文翻译成品（含英文原文+中文翻译），无需调整复杂的格式！下载之后直接可用，方便快捷！本文价格不贵,也就几十块钱！一辈子也就一次的事！外文标题：Air Pollution Prevention and Control - An Integrated Designed Approach外文作者：Dr. Akshey Bhargava, M.tech, Ph.D., LLB文献出处：International Journal of Engineering Science and Computing,April 2018,Volume6,Issue No.4(如觉得年份太老，可改为近2年，毕竟很多毕业生都这样做)英文2873单词， 14698字符(字符就是印刷符)，中文4589汉字。
Air Pollution Prevention and Control - An Integrated DesignedApproachAbstract:The Planning, Management and Control of Air Pollution need to be addressed simultaneously to achieve the maximum output. The present paper signify the importance and high light an integrated approach needs to be infused into the system which inter-alia include Source control, Pathway control, and Receptor control . An effort has been made in the present paper to briefly describe Pathway and Receptor control with main emphasis on design of the Air Pollution Control Systems, particularly Bag Filters to control dust emissions and Wet Scrubbers to control gaseous emissionsby way of Throwaway scrubbing processes, Regenerative Scrubbing Processes, Dry Processes and Spray Towers.Key Words: Air Pollution, Integrated Approach, Design of Control Systems.Introduction:The term “Air Pollution” is used to describe substances that are artificially introduced in to the air in the form of gases and airborne particles which, in excess, are harmful to human health, buildings and ecosystems. Air pollution is mainly caused by combustion of fossil fuel, processing of materials and decomposition of organic matters. The main sources of air pollution is from industrial activities, transport sector, house hold fuel burning, and other commercial activities. The present paper high light an integrated approach which inter-alia include Source Control, Pathway control, and Receptor control . An effort has been made in the present paper to briefly describe Pathway and Receptor control with main emphasis on design of the Air Pollution Control Systems, the details of which are as under:Pathway Control:Pathway control is a control system through which the air pollutants are restricted or arrested between a source and receptor through the mechanism of scavenging and filtration.This can be achieved by having a green belt of suitable species between source and receptor. Such a green belt would be able to absorb the air pollution gases and would also act as filtering media for the particulate matter. Sometimes in certain situations, curtains in the form of high walls or other means are also provided between sources and receptor to restrict air pollutants to reach receptors.Receptor Control:Receptor control is governed by an integrated urban and rural planning which should invariably incorporate environmental policy parameters in the form of following:-Atmospheric stability condition-Aerodynamic effects-Albedo-effect-Heat island effect-Ventilation coefficients-Optimization between concreting and non-concreting surface area-Optimization between vertical to horizontal expansion of urban areaIf the above issues are adequately and scientifically addressed, the level of air pollution at the receptor urban area shall be significantly low.Source Control:Main stress is usually laid on source control techniques with the focus on two fronts, one on “transformatio n of waste gasses / materials into usable products” and second on “end of the pipe treatment “. The first approach is gradually coming to fore front with the advancement of research and developmental activities and which has economic value addition. The second approach is cost intensive in which pollution control equipment or devices are installed to restrict air pollution into atmosphere. Source control is also associated with introduction of cleaner technologies, optimization of processes, controlled combustions, use of cleaner raw materials or fuels etc.Design of Air Pollution control systems:A.Particulate Matter control:There are various air pollution control equipment for the control of dust emissions depending upon particle size, minimum loading, desired efficiency, typical velocity, maximum gas pressure drop, and space requirements. These control equipment’s are dry collectors, as well as, wet collectors depending upon the basic characterises of gas and local conditions.The dry collecting devices are:1.Settling chambers2.Baffle chambers3.Lower chambers4.Cyclone chambers5.Multiple cyclones6.Impingement7.Fabric Filters8.Electrostatic precipitatorsThe wet devices are used where in water or scrubbing media is usually used to control emissions. These control devices are1.Gravity spray tower2.Centrifugal Collectors3.Impingement chambers4.Packed tower5.Jet spray scrubbing tower6.Ventury scrubberBag filters design: Introduction:Filtration is among the most reliable, efficient, and rather economical methods by which particulate matter may be removed from gases.∙Such type of filters are represented by various fabric bag arrangements and capable of high dust loading, more than 1gm / m3∙In-depth or bed filters∙Represented by fibrous array, a paper like mat, and occasionally, as a deep packed bed.Packed beds are applied when particulate concentration is much less. Deep packed beds are prepared from crushed stone or bricks, wire screens, or fibers of many types arranged individually or in combinationFabric bag filters:∙Employed to control emissions involving abrasives, irritating chemical dusts, and exhausts from electric furnaces, oil fired boilers, oxygen fed converters for steel making.Principle of operation:Filtration is principally accomplished by the particle layer that accumulates on the fabric surface. Pressure loss increases with accumulated dust layer, thereby gas velocity decreases. Thus, dust dislodging operation is undertaken to have proper filtration. Many fabric bag filters assembled in one unit is called bag house.Classification of filters:∙Fabric or cloth filtersProperties of fiber materials:Design of Bag Filter:Collection efficiency and pressure drop for a single layer or bag filter∆P = (K1+K2*C ma)*V o = (K1+K2*C ma)*Q/A f Where,C ma = mass area concentration in kg/m2 and represents mass of dust present in the dust cake attached tounit area of filter, also proportional to thickness of dust cakeK1, K2 = constants in N-sec/m3 or kg/m2/s Typical values of K1 and K212000 < K1 < 120000 N-s / m310000 < K2 < 130000 s-1The thickness of dust cake increases with time, its growth can be predicted if flow rate and dust concentration are known. The equation is:C ma = Q*C mv*t / A f = V o*C mv*t Where,C mv = mass volume concentrationt = time since filter was last cleanedBag filters and Bag houses:∙Bag filter most commonly used is in the shape of a long cylinder where filter is clamped around a sleeve at the bottom and around a cap at the top.∙The air enters at the bottom, flows through filter along its sides, leaving the dust to form a cake on the inside of the filter, and flows outside the filter to the exit duct.∙Generally, bags diameter ranges from 12.5 to 30 cm with lengths from 2 to 6 meters. Length to diameter ratio should not usually exceed 20 : 1∙Bags in the bag house are sewed to a strap which is fastened to a hanger at the top end of each bag. The hanger is attached to the shaker mechanism.∙Large bag houses are built with several compartments out of which atleast 2 compartmentsshould be off-line, one for cleaning and one for repair or replacement of bagsBags should be arranged within each compartment in such a way as to utilize the space effectively and yet provide access to each individual bag for replacement. This is done by placing the bags close together, about 5 cm apart, while leaving wide spaces of 1/3 to 2/3 meter between every fourth to eighth row of bags.Cleaning cycles for bag houses∙Cleaning is essential whenever the pressure drop across the filter reaches a certain preset value. The length of cleaning cycle, that is, the time period between the start of onecleaning process and the start of next cleaning process needs to be calculated. Followingassumptions are made:n = number of compartments in bag house Q = total flow raten – 1 = active compartments, as one will always be kept for cleaning∆P= pressure drop∆P m = maximum value of pressure dropC mai= weight of dust cake on each filter, where subscript i represents the ithcompartmentt1= length of cleaning cycleQ i= flow rate through i th compartmentA fi= filter area in each compartment which is same for all compartments∆t c= length of cleaning processø1and ǿ1 are the constants, value of ø1 can be obtained from graph drawn between ø1 andQK1/A fi*∆P mǿ1 can be calculated from equation below: ǿ1= ø1 – 2K2*C mv*∆P m*∆tc / K12t1 can be calculated from equation:t1= (A fi*K1/K2*C mv*Q)*(√1+ǿ1+ ø1* (n – 1)-1))Design of Wet Scrubber: Particulate scrubberIn all scrubbers droplets of the scrubbing media are formed, generally much larger than the particles to be collected.∙In most cases, scrubbing media is water,occasionally a different substance is used∙Different types of scrubbing devices employ different means of forming water droplets and different means of ensuring a relative velocity between water droplets and the gas to becleaned∙In all cases the cleaning mechanism involves attachment of particulates to the droplets. The droplets are then collected and drained to a sump.∙Scrubbers in common use are:∙Spray chamber or spray tower∙Centrifugal or cyclone scrubber∙Orifice or self-induced sprayVentury scrubber: Spray tower:∙The scrubbing liquid, usually water for particulate matter removal, is sprayed into the chamber from a series of nozzles located at the top chamber while the air-particle mixtureenters the bottom of chamber and flows upward, encountering the droplets formed from thesprays which fall to the bottom by gravity. The droplets remove the particles by scrubbingaction, the resulting slurry so formed is collected at the bottom and sent for treatment forremoval of collected particles and treated water is recirculated.Collection efficiency of spray tower, using following:L = length of tower D sc= diameter of towerV a= velocity of upward airV d= velocity of dropping dropletsV∞= relative velocity between drops and air Re d= Reynolds number = 10 <Re d > 700D = diameter of droplet ρd= density of dropletρ= density of airμ= viscosity of airn = no of droplets encountered by a group of particlesN d= rate of drop formation in number per secondA sc= area of towerUpward velocity of air in chamber:V a= Q / A sc, which must not exceed drop velocity V d to prevent air from carrying drops outof the top of chamberF = Force acting on the dropF = π*ρd*D3*g / 6 = 5.135* ρd*D3 If spray liquid is water,F = 5135 D3If Reynolds number for the drop motion is between 10 and 700:V∞= (4.8/ρ*D)*√ ((447*μ2)+(ρ*ρd*D3*g/6)) –20.4*μFor standard air as gas and water as spray liquid. The above equation becomes:V∞= (178.3/D)*√(0.7814*10-10+D3) – 1.520*10-3/DThe Reynolds number becomes:Re d = V∞*D / v = 11.50*106*√ (D3+0.7814*10-10) – 98.06If Reynolds number is greater than 700,V∞= (2.4/D)*√ (π* ρd*D3*g/6*ρ) = 5.44*√ (ρd*D/ρ)For standard air and water V∞ = 158 √ D Re d > 700Reynolds number is given by Re d = 1.020*107*D 3/2Since the drop falls with velocity V d Where,V d = V∞ - V a, (particle travel upward with velocity V a)Time period for impaction, diffusion becomes: L / V a + L / V d , and n becomes:n = (N d* π* D2 / 4* A sc)*(L / V a + L / V d)Total drop formation rate is related to mass flow rate of spray fluid as:N d = 6* m s/ π* d3* ρd n becomes,n= (1.5*m s*L / ρd*D)*(1/Q+1/ (A sc*(V∞-V a)) For water as spray fluid,n = (0.0015*m s*L/ D)* (1/Q+1/ (A sc*(V∞-V a)) If spray chamber is circular, thenA sc= π D sc2/4Collection efficiency for a single droplet = ηd, is defined as ratio of no. of particles collected to no. of particles initially contained in the volume swept through by the droplet.∙To predict the behavior of the particles as they flow around and into the droplet, a particle of given diameter and density will strike the droplet if it lies initially within a certain distance y1of the axis of motion of the droplet. If it lies away from axis than this, it will pass by thedroplet and not collected.∙The collection efficiency of the individual droplet due to interception and inertial impaction combined ηdi can be defined as the ratio of the area of circle having radius y1 to the projectedarea of the droplet. This ratio is modified by an attachment coefficient σ.∙From above, efficiency is defined as :ηdi= (π* y12* σ) /(π* D2/4) = 4* σ* y12 / D2, and β = ( 5 / 72 )*( ρp* d2* V t* C / μ* D ) Now considering boundary layer conditions,ηdi= 8.811* σ*√(v/V∞*D) *((y2/∂2)2– 1/6*( y2/∂2)4))When, y2 < ∂2 And,ηdi=7.342* σ*√v/V∞*D, when y2 = ∂2 And,ηdi=7.342* σ*√v/V∞*D+(2* σ)*(y2/D-∂2/D)*(3+6*y2/D+4*(y2/D)2) , when y2 > ∂22. Control of NOx:In general, the main parameters which effect NOX, formation are temperature, residence time, concentration of various species, and extent of mining. From the experimental view point, the factors which control NOX formation include1)Air-fuel ratio 2)Combustion air temperature3)Extent of combustion zone cooling 4)Furnace-burner configurationConsideration of these basic design factors leads to the combustion techniques known as flue-gas recirculation and two stage combustion. Type of fuel is also a major influence on performance.Among the possible removal techniques for oxides of nitrogen are catalystic decomposition, catalytic reduction, absorption and adsorption.In catalytic decomposition the direct decomposition of NO into N2 and O2 would be highly desirable whereas but in catalytic reduction a reaction with another compound reduces NO to molecular nitrogen. Two types of reduction must be considered-selective and non-selective. In selectivereduction, the excess O2 must be consumed first. Selective reduction is too preferred, since it minimizes the amount of reactant required.Selective reduction can be carried out with H2, CO, NH3, or H2S as reactant gas, and with suitable catalyst.2CO + 2 NO 2CO2 + N2 and4CO + 2 NO24CO2 + N2Rather than the combustion reaction 2CO + O22CO2The use of CO has the disadvantage that any amount which is unreacted adds to the general CO pollution of the atmosphere. Using hydrogen is preferable to using CO. However, some catalysts for H2 are not effective in the presence of CO (present from the main combustion reaction). The catalysts found to be most effective are the platinum-type metals.Infect absorption is quite prominent in the reduction of NOx. The oxides of nitrogen can be absorbed by water, hydroxide and molten alkali carbonates and hydroxides. When aqueous alkaline solutions, such as NaOH and Mg OH are used, complete removal requires that one-half of the NO must first be oxidized to NO2 (or NO2 gas added to the gas stream). Best absorption occurs when the NO/NO2 molar ratio is 1:1, which indicated the absorption of the combined oxide, N2O3, is the most favorable. The absorption of NO2 by alkaline solutions has been confirmed during desulfurization of power plant emissions by such solutions. In the desulfurization process, apparently about 10 % of the NO was oxidized to NO2 before the flue gas reached the scrubber.The scrubber then removed about 20% of the total NO2 in equal parts of NO and NO2.Conclusions:Air Pollution is an area where integrated approach needs to be infused into the system of planning, strategy formulation, and technological advancement in the form of cleaner technology, transformation of waste into usable product, process optimization, andinter-linkage of pollution control devices with production. Significant focus needs to be given on Receptor Control coupled with Pathway Control.References:1. Air Pollution Book, by M.N. Rao and H.V.N. Rao, Tata McGraw-Hill Publishing Company Limited, New Delhi, Page No 160-1672. Handbook of Air pollution Prevention and control by Nicholas P. Cheremisinoff, Ph.D., N & P Limited3. Book on Performance criteria of Air pollution control equipment by Sinclair Knight Merz, Final August 2000 International Journal of Environmental Science and Development, Vol. 2, No. 5, October 20114. Shepherd, C. B., and C. E. Lapple. 1939. Air Pollution Control: A Design Approach. InCyclones. 2nd Edition, ed. C. David Cooper, and F. C. Alley, pp 127-139. Illinois: Woveland Press Inc.5. Parker, R., R. Jain., and S. Calvert. 1981. Particle Collection in Cyclone at High Temperature and High Pressure. Environ. Sci. Technol., 15: 451- 458.大气污染的防控–一条综合性的设计方法摘要：为了实现最大效益的产出，大气污染的规划、管理和控制问题需要进行同步解决。
治理空气污染的措施英语作文英文回答：Air pollution is a major environmental problemaffecting cities around the world, posing significanthealth risks to their inhabitants. Implementing effective measures to mitigate air pollution is crucial to improving public health and ensuring a sustainable future.1. Promoting Clean Energy Sources and Energy Efficiency.Switching to clean energy sources, such as solar, wind, and geothermal energy, can significantly reduce airpollution emissions. Promoting energy efficiency measures, such as energy-efficient appliances and insulation, canalso minimize energy consumption and emissions.2. Encouraging Public Transportation and Active Mobility.Reducing reliance on private vehicles by promoting public transportation systems and encouraging walking and cycling can significantly lower transportation-related emissions.3. Implementing Vehicle Emissions Standards and Inspections.Establishing and enforcing strict vehicle emissions standards and conducting regular emissions inspections can ensure that vehicles operate efficiently and produce minimal pollutants.4. Monitoring Air Quality and Enforcing Regulations.Establishing air quality monitoring systems and enforcing regulations that limit emissions from factories, power plants, and other sources is essential for controlling air pollution.5. Promoting Green Infrastructure.Planting trees and creating green spaces can helpabsorb air pollutants, improve air quality, and provide additional environmental benefits.6. Raising Public Awareness and Education.Educating the public about the health risks of air pollution and promoting behavioral changes, such asreducing vehicle idling and using energy-efficient products, can contribute to reducing emissions.7. International Cooperation and Knowledge Sharing.Collaborating with other countries and sharing best practices can accelerate the development and implementation of effective air pollution control measures.中文回答：治理空气污染的措施。
空气污染治理英文作文英文：Air pollution has become a major concern in many parts of the world. It is caused by various factors, including industrial activities, transportation, and agricultural practices. The impacts of air pollution are far-reaching and can affect both human health and the environment.There are several strategies that can be employed to address air pollution. One of the most effective methods is to reduce emissions from industrial sources. This can be achieved by implementing regulations and standards that limit the amount of pollutants that can be released into the air. For example, the United States Environmental Protection Agency (EPA) has implemented the Clean Air Act, which sets standards for six major pollutants and requires industries to reduce their emissions.Another strategy is to promote the use of clean energysources, such as wind and solar power. This can help to reduce the amount of greenhouse gases that are releasedinto the atmosphere, which contribute to climate change. In addition, individuals can take steps to reduce their own carbon footprint by using public transportation, biking or walking instead of driving, and conserving energy at home.Finally, it is important to educate the public about the impacts of air pollution and the steps that can be taken to reduce it. This can be done through public awareness campaigns, school programs, and community events. By working together, we can make a significant impact onair pollution and create a healthier and more sustainable future.中文：空气污染已经成为世界许多地区的主要问题。
治理空气污染英语作文英文回答：Air pollution is a serious issue that affects people's health and the environment. In order to effectively govern air pollution, there are several measures that can be taken. Firstly, the government should implement stricterregulations on industrial emissions. Factories and power plants are major sources of air pollution, so it'simportant to enforce laws that limit the amount of harmful gases and particles they release into the air. Additionally, investing in cleaner technologies and renewable energy sources can help reduce air pollution from these sources.Another important aspect of governing air pollution is reducing vehicle emissions. This can be achieved through promoting the use of public transportation, carpooling, and investing in electric vehicles. For example, in many cities, the government has implemented policies to restrict the use of cars with high emissions in order to improve air quality.Moreover, creating more bike lanes and pedestrian-friendly areas can also encourage people to choose alternative modes of transportation, which can ultimately reduce air pollution.Furthermore, raising public awareness and education about the impacts of air pollution is crucial. People need to understand how their daily activities contribute to air pollution and what they can do to minimize their impact. For instance, educating the public about the importance of reducing energy consumption, properly disposing of waste, and planting trees can all help mitigate air pollution.In addition to government actions, individuals and businesses also play a significant role in governing air pollution. For example, companies can implement eco-friendly practices and technologies in their operations, while individuals can make small changes in their daily lives, such as using energy-efficient appliances and reducing their use of single-use plastics.In conclusion, governing air pollution requires amulti-faceted approach that involves government regulations, public awareness, and individual actions. By taking these measures, we can work towards cleaner air and a healthier environment for future generations.中文回答：空气污染是一个严重的问题，影响着人们的健康和环境。
关于治理空气的英语作文As air pollution becomes an increasingly pressing issue, effective air governance is crucial to protect public health and the environment. In this essay, I will discuss various measures and strategies for governing air quality.Firstly, regulatory measures are essential for controlling air pollution. Governments should enforcestrict emission standards for industries, vehicles, and power plants. These standards can limit the amount of pollutants released into the atmosphere, thereby reducing air pollution. In addition, penalties for non-compliance with these standards should be enforced to ensure that businesses and individuals adhere to regulations.Secondly, investment in clean energy technologies is vital for improving air quality. Renewable energy sources such as solar, wind, and hydroelectric power produce minimal air pollution compared to fossil fuels. Governments should provide incentives for the development and adoption of these clean energy technologies, as well as invest in research and development to make them more affordable and accessible.Furthermore, public transportation and urban planning play a significant role in air governance. Encouraging the use of public transportation, cycling, and walking can reduce the number of vehicles on the road, lessening air pollution. Additionally, well-designed urban areas with green spaces and proper zoning can contribute to better air quality by reducing traffic congestion and promoting sustainable development.Moreover, public awareness and community engagement are crucial for effective air governance. Education campaigns can inform citizens about the health risks associated with air pollution and encourage them to take action to reduce their carbon footprint. Furthermore, involving communities in decision-making processes can lead to the implementation of more effective air governance policies that are tailored to local needs and concerns.In conclusion, governing air quality requires a multi-faceted approach that encompasses regulatory measures, investment in clean energy technologies, public transportation and urban planning, as well as public awareness and community engagement. By implementing thesestrategies, governments can effectively mitigate air pollution and safeguard public health and the environment.治理空气污染已成为一个日益紧迫的问题，有效的空气治理对保护公共健康和环境至关重要。
如何治理空气污染英语作文【中英文实用版】How to Tackle Air Pollution - A Comprehensive EssayAir pollution has become a significant issue affecting our planet.The deteriorating air quality poses a severe threat to both human health and the environment.To effectively address this problem, a multi-pronged approach is essential.治理空气污染已成为影响我们星球的一个重要问题。
日益恶化的空气质量对人类健康和环境都构成了严重威胁。
为了有效解决这个问题，我们需要采取多管齐下的方法。
Firstly, it"s crucial to strengthen legislation and enforce strict regulations on industrial emissions.Factories and power plants should be required to adopt advanced technology to reduce pollution.Additionally, promoting the use of clean energy, such as solar and wind power, can significantly contribute to improving air quality.首先，加强立法并对工业排放实施严格监管至关重要。
工厂和电厂应被要求采用先进技术减少污染。
此外，推广使用清洁能源，如太阳能和风能，对改善空气质量也能起到显著作用。
Secondly, individuals should also take responsibility for reducing air pollution.Encouraging people to use public transportation, carpool, or cycle can help decrease vehicle emissions.Moreover, raising public awareness about the importance of trees in improving air quality can leadto more tree planting initiatives.其次，个人也应承担起减少空气污染的责任。
控制环境污染的措施英语作文Measures to Control Environmental Pollution.Environmental pollution is a global challenge that threatens the sustainability of our planet. With the rapid industrialization and urbanization, the emission of pollutants into the air, water, and soil has increased significantly, posing a grave danger to human health, biodiversity, and the ecological balance. Therefore, it is imperative to take effective measures to control environmental pollution and safeguard our environment.Raising Awareness and Education.One of the fundamental measures to controlenvironmental pollution is raising awareness and educating the public about the importance of environmental protection. Through educational programs, workshops, and campaigns, people can be informed about the causes, consequences, and solutions to environmental pollution. This awareness canmotivate individuals to adopt sustainable practices intheir daily lives, such as reducing waste, conserving energy, and using renewable sources. Additionally, educating policymakers, industrialists, and business leaders is crucial to ensure that environmental considerations are integrated into policymaking and business operations.Implementing Strict Environmental Regulations.Governments play a vital role in controlling environmental pollution by enacting and enforcing strict environmental regulations. These regulations should cover all sectors, including industry, agriculture, transportation, and waste management. By setting standards for emissions, waste disposal, and resource use, governments can ensure that companies and individuals comply with environmental regulations. Violations should be subject to heavy fines and penalties to deter non-compliance. Additionally, governments should provide incentives, such as tax breaks and subsidies, to encourage companies to adopt cleaner technologies and practices.。
大气污染的防治措施英语作文English:To combat air pollution, a multi-faceted approach is essential. Firstly, strict regulations must be implemented to limit emissions from industries, vehicles, and other sources. This includes enforcing emission standards, promoting the use of cleaner fuels, and investing in pollution control technologies. Secondly, public transportation should be improved and encouraged to reduce the number of vehicles on the road. This can be achieved through expanding public transport networks, implementing congestion charges, and providing incentives for using public transport. Additionally, promoting energy efficiency and renewable energy sources can help reduce the reliance on fossil fuels, thereby lowering air pollution levels. Lastly, raising public awareness through education campaigns can foster a sense of responsibility towards the environment, encouraging individuals to take actions to reduce their carbon footprint. Overall, a combination of strict regulations, improved public transportation, promotion of clean energy, and public awareness campaigns is crucial in the fight against air pollution.中文翻译:要想有效防治空气污染，必须采取多管齐下的措施。
怎样减少空气污染的方法英语作文【中英文实用版】How to Reduce Air PollutionAir pollution is a significant issue that affects the environment and our health.It is caused by various factors, including industrial emissions, vehicle exhaust, and burning of fossil fuels.To combat this problem, we need to take collective actions to reduce air pollution.Here are some effective methods to minimize air pollution:e Public Transportation: Opting for public transportation, carpooling, or cycling can significantly reduce vehicle emissions.Encouraging the use of electric vehicles also helps in reducing air pollution.2.Reduce Fossil Fuel Consumption: Limiting the use of fossil fuels by conserving energy at home and work can contribute to a cleaner environment.Switching to renewable energy sources like solar and wind power is a sustainable alternative.3.Plant Trees: Trees absorb carbon dioxide and release oxygen, acting as natural filters for the air.Planting more trees can help in reducing air pollution levels.4.Support Clean Energy Initiatives: Backing policies and initiatives that promote clean energy can lead to a significant reduction in air pollution.Encourage the government and businesses to invest inrenewable energy projects.5.Practice Waste Management: Proper disposal and recycling of waste can prevent the release of harmful pollutants into the air.Avoid burning waste, and support recycling programs in your community.6.Reduce Industrial Emissions: Industries should adopt cleaner production technologies and strict emission control measures.Encouraging the use of eco-friendly practices can minimize air pollution caused by industrial activities.7.Raise Awareness: Educating the public about the causes and consequences of air pollution can lead to behavioral changes.Encourage people to adopt environmentally friendly habits and advocate for clean air policies.8.Support Green Spaces: Preserving and creating green spaces in urban areas can help in improving air quality.Green spaces act as natural filters and provide a breath of fresh air in polluted environments.In conclusion, reducing air pollution requires collective efforts from individuals, communities, industries, and governments.By adopting these methods, we can contribute to a cleaner and healthier environment for future generations.如何减少空气污染空气污染是影响环境和我们健康的一个重要问题。
大气污染的防治措施英语作文【中英文实用版】Title: Measures to Control Air PollutionAir pollution is a significant environmental issue that has detrimental effects on human health, ecosystems, and the planet as a whole.It is caused by various sources such as industrial emissions, vehicle exhaust, and burning of fossil fuels.To combat this pressing problem, stringent measures need to be implemented at both the government and individual levels.Firstly, it is crucial for governments to enforce strict regulations on industrial emissions.Industries should be required to install advanced technology filters and cleaners to minimize the release of harmful pollutants into the air.Moreover, regular monitoring and inspection should be conducted to ensure compliance with these regulations.Secondly, promoting the use of renewable energy sources is an effective way to reduce air ernments should invest in and promote the utilization of solar, wind, and hydroelectric power, which are cleaner and more sustainable alternatives to fossil fuels.Encouraging the installation of solar panels and wind turbines can significantly reduce the emission of greenhouse gases and improve air quality.Thirdly, transportation plays a significant role in air ernments should focus on developing efficient publictransportation systems, such as buses, trains, and trams, to reduce the number of private vehicles on the road.Additionally, promoting the use of electric vehicles and incentivizing the replacement of older, polluting vehicles can help improve air quality.Fourthly, individuals can contribute to the fight against air pollution by adopting more sustainable habits.For instance, reducing the use of disposable products, recycling waste properly, and conserving energy can help minimize pollution levels.Furthermore, planting trees and participating in community clean-up initiatives can help improve air quality and create a healthier environment for all.In conclusion, air pollution is a significant global concern that requires immediate action.By implementing strict regulations, promoting renewable energy, improving transportation systems, and encouraging individual responsibility, we can work towards achieving cleaner and healthier air for future generations.It is essential for governments, businesses, and individuals to collaborate and take collective action to combat air pollution effectively.。
此文档是毕业设计外文翻译成品（含英文原文+中文翻译），无需调整复杂的格式！下载之后直接可用，方便快捷！本文价格不贵,也就几十块钱！一辈子也就一次的事！外文标题：Air Pollution Prevention and Control - An Integrated Designed Approach外文作者：Dr. Akshey Bhargava, M.tech, Ph.D., LLB文献出处：International Journal of Engineering Science and Computing,April 2018,Volume6,Issue No.4(如觉得年份太老，可改为近2年，毕竟很多毕业生都这样做)英文2873单词， 14698字符(字符就是印刷符)，中文4589汉字。
Air Pollution Prevention and Control - An Integrated DesignedApproachAbstract:The Planning, Management and Control of Air Pollution need to be addressed simultaneously to achieve the maximum output. The present paper signify the importance and high light an integrated approach needs to be infused into the system which inter-alia include Source control, Pathway control, and Receptor control . An effort has been made in the present paper to briefly describe Pathway and Receptor control with main emphasis on design of the Air Pollution Control Systems, particularly Bag Filters to control dust emissions and Wet Scrubbers to control gaseous emissionsby way of Throwaway scrubbing processes, Regenerative Scrubbing Processes, Dry Processes and Spray Towers.Key Words: Air Pollution, Integrated Approach, Design of Control Systems.Introduction:The term “Air Pollution” is used to describe substances that are artificially introduced in to the air in the form of gases and airborne particles which, in excess, are harmful to human health, buildings and ecosystems. Air pollution is mainly caused by combustion of fossil fuel, processing of materials and decomposition of organic matters. The main sources of air pollution is from industrial activities, transport sector, house hold fuel burning, and other commercial activities. The present paper high light an integrated approach which inter-alia include Source Control, Pathway control, and Receptor control . An effort has been made in the present paper to briefly describe Pathway and Receptor control with main emphasis on design of the Air Pollution Control Systems, the details of which are as under:Pathway Control:Pathway control is a control system through which the air pollutants are restricted or arrested between a source and receptor through the mechanism of scavenging and filtration.This can be achieved by having a green belt of suitable species between source and receptor. Such a green belt would be able to absorb the air pollution gases and would also act as filtering media for the particulate matter. Sometimes in certain situations, curtains in the form of high walls or other means are also provided between sources and receptor to restrict air pollutants to reach receptors.Receptor Control:Receptor control is governed by an integrated urban and rural planning which should invariably incorporate environmental policy parameters in the form of following:-Atmospheric stability condition-Aerodynamic effects-Albedo-effect-Heat island effect-Ventilation coefficients-Optimization between concreting and non-concreting surface area-Optimization between vertical to horizontal expansion of urban areaIf the above issues are adequately and scientifically addressed, the level of air pollution at the receptor urban area shall be significantly low.Source Control:Main stress is usually laid on source control techniques with the focus on two fronts, one on “transformatio n of waste gasses / materials into usable products” and second on “end of the pipe treatment “. The first approach is gradually coming to fore front with the advancement of research and developmental activities and which has economic value addition. The second approach is cost intensive in which pollution control equipment or devices are installed to restrict air pollution into atmosphere. Source control is also associated with introduction of cleaner technologies, optimization of processes, controlled combustions, use of cleaner raw materials or fuels etc.Design of Air Pollution control systems:A.Particulate Matter control:There are various air pollution control equipment for the control of dust emissions depending upon particle size, minimum loading, desired efficiency, typical velocity, maximum gas pressure drop, and space requirements. These control equipment’s are dry collectors, as well as, wet collectors depending upon the basic characterises of gas and local conditions.The dry collecting devices are:1.Settling chambers2.Baffle chambers3.Lower chambers4.Cyclone chambers5.Multiple cyclones6.Impingement7.Fabric Filters8.Electrostatic precipitatorsThe wet devices are used where in water or scrubbing media is usually used to control emissions. These control devices are1.Gravity spray tower2.Centrifugal Collectors3.Impingement chambers4.Packed tower5.Jet spray scrubbing tower6.Ventury scrubberBag filters design: Introduction:Filtration is among the most reliable, efficient, and rather economical methods by which particulate matter may be removed from gases.∙Such type of filters are represented by various fabric bag arrangements and capable of high dust loading, more than 1gm / m3∙In-depth or bed filters∙Represented by fibrous array, a paper like mat, and occasionally, as a deep packed bed.Packed beds are applied when particulate concentration is much less. Deep packed beds are prepared from crushed stone or bricks, wire screens, or fibers of many types arranged individually or in combinationFabric bag filters:∙Employed to control emissions involving abrasives, irritating chemical dusts, and exhausts from electric furnaces, oil fired boilers, oxygen fed converters for steel making.Principle of operation:Filtration is principally accomplished by the particle layer that accumulates on the fabric surface. Pressure loss increases with accumulated dust layer, thereby gas velocity decreases. Thus, dust dislodging operation is undertaken to have proper filtration. Many fabric bag filters assembled in one unit is called bag house.Classification of filters:∙Fabric or cloth filtersProperties of fiber materials:Design of Bag Filter:Collection efficiency and pressure drop for a single layer or bag filter∆P = (K1+K2*C ma)*V o = (K1+K2*C ma)*Q/A f Where,C ma = mass area concentration in kg/m2 and represents mass of dust present in the dust cake attached tounit area of filter, also proportional to thickness of dust cakeK1, K2 = constants in N-sec/m3 or kg/m2/s Typical values of K1 and K212000 < K1 < 120000 N-s / m310000 < K2 < 130000 s-1The thickness of dust cake increases with time, its growth can be predicted if flow rate and dust concentration are known. The equation is:C ma = Q*C mv*t / A f = V o*C mv*t Where,C mv = mass volume concentrationt = time since filter was last cleanedBag filters and Bag houses:∙Bag filter most commonly used is in the shape of a long cylinder where filter is clamped around a sleeve at the bottom and around a cap at the top.∙The air enters at the bottom, flows through filter along its sides, leaving the dust to form a cake on the inside of the filter, and flows outside the filter to the exit duct.∙Generally, bags diameter ranges from 12.5 to 30 cm with lengths from 2 to 6 meters. Length to diameter ratio should not usually exceed 20 : 1∙Bags in the bag house are sewed to a strap which is fastened to a hanger at the top end of each bag. The hanger is attached to the shaker mechanism.∙Large bag houses are built with several compartments out of which atleast 2 compartmentsshould be off-line, one for cleaning and one for repair or replacement of bagsBags should be arranged within each compartment in such a way as to utilize the space effectively and yet provide access to each individual bag for replacement. This is done by placing the bags close together, about 5 cm apart, while leaving wide spaces of 1/3 to 2/3 meter between every fourth to eighth row of bags.Cleaning cycles for bag houses∙Cleaning is essential whenever the pressure drop across the filter reaches a certain preset value. The length of cleaning cycle, that is, the time period between the start of onecleaning process and the start of next cleaning process needs to be calculated. Followingassumptions are made:n = number of compartments in bag house Q = total flow raten – 1 = active compartments, as one will always be kept for cleaning∆P= pressure drop∆P m = maximum value of pressure dropC mai= weight of dust cake on each filter, where subscript i represents the ithcompartmentt1= length of cleaning cycleQ i= flow rate through i th compartmentA fi= filter area in each compartment which is same for all compartments∆t c= length of cleaning processø1and ǿ1 are the constants, value of ø1 can be obtained from graph drawn between ø1 andQK1/A fi*∆P mǿ1 can be calculated from equation below: ǿ1= ø1 – 2K2*C mv*∆P m*∆tc / K12t1 can be calculated from equation:t1= (A fi*K1/K2*C mv*Q)*(√1+ǿ1+ ø1* (n – 1)-1))Design of Wet Scrubber: Particulate scrubberIn all scrubbers droplets of the scrubbing media are formed, generally much larger than the particles to be collected.∙In most cases, scrubbing media is water,occasionally a different substance is used∙Different types of scrubbing devices employ different means of forming water droplets and different means of ensuring a relative velocity between water droplets and the gas to becleaned∙In all cases the cleaning mechanism involves attachment of particulates to the droplets. The droplets are then collected and drained to a sump.∙Scrubbers in common use are:∙Spray chamber or spray tower∙Centrifugal or cyclone scrubber∙Orifice or self-induced sprayVentury scrubber: Spray tower:∙The scrubbing liquid, usually water for particulate matter removal, is sprayed into the chamber from a series of nozzles located at the top chamber while the air-particle mixtureenters the bottom of chamber and flows upward, encountering the droplets formed from thesprays which fall to the bottom by gravity. The droplets remove the particles by scrubbingaction, the resulting slurry so formed is collected at the bottom and sent for treatment forremoval of collected particles and treated water is recirculated.Collection efficiency of spray tower, using following:L = length of tower D sc= diameter of towerV a= velocity of upward airV d= velocity of dropping dropletsV∞= relative velocity between drops and air Re d= Reynolds number = 10 <Re d > 700D = diameter of droplet ρd= density of dropletρ= density of airμ= viscosity of airn = no of droplets encountered by a group of particlesN d= rate of drop formation in number per secondA sc= area of towerUpward velocity of air in chamber:V a= Q / A sc, which must not exceed drop velocity V d to prevent air from carrying drops outof the top of chamberF = Force acting on the dropF = π*ρd*D3*g / 6 = 5.135* ρd*D3 If spray liquid is water,F = 5135 D3If Reynolds number for the drop motion is between 10 and 700:V∞= (4.8/ρ*D)*√ ((447*μ2)+(ρ*ρd*D3*g/6)) –20.4*μFor standard air as gas and water as spray liquid. The above equation becomes:V∞= (178.3/D)*√(0.7814*10-10+D3) – 1.520*10-3/DThe Reynolds number becomes:Re d = V∞*D / v = 11.50*106*√ (D3+0.7814*10-10) – 98.06If Reynolds number is greater than 700,V∞= (2.4/D)*√ (π* ρd*D3*g/6*ρ) = 5.44*√ (ρd*D/ρ)For standard air and water V∞ = 158 √ D Re d > 700Reynolds number is given by Re d = 1.020*107*D 3/2Since the drop falls with velocity V d Where,V d = V∞ - V a, (particle travel upward with velocity V a)Time period for impaction, diffusion becomes: L / V a + L / V d , and n becomes:n = (N d* π* D2 / 4* A sc)*(L / V a + L / V d)Total drop formation rate is related to mass flow rate of spray fluid as:N d = 6* m s/ π* d3* ρd n becomes,n= (1.5*m s*L / ρd*D)*(1/Q+1/ (A sc*(V∞-V a)) For water as spray fluid,n = (0.0015*m s*L/ D)* (1/Q+1/ (A sc*(V∞-V a)) If spray chamber is circular, thenA sc= π D sc2/4Collection efficiency for a single droplet = ηd, is defined as ratio of no. of particles collected to no. of particles initially contained in the volume swept through by the droplet.∙To predict the behavior of the particles as they flow around and into the droplet, a particle of given diameter and density will strike the droplet if it lies initially within a certain distance y1of the axis of motion of the droplet. If it lies away from axis than this, it will pass by thedroplet and not collected.∙The collection efficiency of the individual droplet due to interception and inertial impaction combined ηdi can be defined as the ratio of the area of circle having radius y1 to the projectedarea of the droplet. This ratio is modified by an attachment coefficient σ.∙From above, efficiency is defined as :ηdi= (π* y12* σ) /(π* D2/4) = 4* σ* y12 / D2, and β = ( 5 / 72 )*( ρp* d2* V t* C / μ* D ) Now considering boundary layer conditions,ηdi= 8.811* σ*√(v/V∞*D) *((y2/∂2)2– 1/6*( y2/∂2)4))When, y2 < ∂2 And,ηdi=7.342* σ*√v/V∞*D, when y2 = ∂2 And,ηdi=7.342* σ*√v/V∞*D+(2* σ)*(y2/D-∂2/D)*(3+6*y2/D+4*(y2/D)2) , when y2 > ∂22. Control of NOx:In general, the main parameters which effect NOX, formation are temperature, residence time, concentration of various species, and extent of mining. From the experimental view point, the factors which control NOX formation include1)Air-fuel ratio 2)Combustion air temperature3)Extent of combustion zone cooling 4)Furnace-burner configurationConsideration of these basic design factors leads to the combustion techniques known as flue-gas recirculation and two stage combustion. Type of fuel is also a major influence on performance.Among the possible removal techniques for oxides of nitrogen are catalystic decomposition, catalytic reduction, absorption and adsorption.In catalytic decomposition the direct decomposition of NO into N2 and O2 would be highly desirable whereas but in catalytic reduction a reaction with another compound reduces NO to molecular nitrogen. Two types of reduction must be considered-selective and non-selective. In selectivereduction, the excess O2 must be consumed first. Selective reduction is too preferred, since it minimizes the amount of reactant required.Selective reduction can be carried out with H2, CO, NH3, or H2S as reactant gas, and with suitable catalyst.2CO + 2 NO 2CO2 + N2 and4CO + 2 NO24CO2 + N2Rather than the combustion reaction 2CO + O22CO2The use of CO has the disadvantage that any amount which is unreacted adds to the general CO pollution of the atmosphere. Using hydrogen is preferable to using CO. However, some catalysts for H2 are not effective in the presence of CO (present from the main combustion reaction). The catalysts found to be most effective are the platinum-type metals.Infect absorption is quite prominent in the reduction of NOx. The oxides of nitrogen can be absorbed by water, hydroxide and molten alkali carbonates and hydroxides. When aqueous alkaline solutions, such as NaOH and Mg OH are used, complete removal requires that one-half of the NO must first be oxidized to NO2 (or NO2 gas added to the gas stream). Best absorption occurs when the NO/NO2 molar ratio is 1:1, which indicated the absorption of the combined oxide, N2O3, is the most favorable. The absorption of NO2 by alkaline solutions has been confirmed during desulfurization of power plant emissions by such solutions. In the desulfurization process, apparently about 10 % of the NO was oxidized to NO2 before the flue gas reached the scrubber.The scrubber then removed about 20% of the total NO2 in equal parts of NO and NO2.Conclusions:Air Pollution is an area where integrated approach needs to be infused into the system of planning, strategy formulation, and technological advancement in the form of cleaner technology, transformation of waste into usable product, process optimization, andinter-linkage of pollution control devices with production. Significant focus needs to be given on Receptor Control coupled with Pathway Control.References:1. Air Pollution Book, by M.N. Rao and H.V.N. Rao, Tata McGraw-Hill Publishing Company Limited, New Delhi, Page No 160-1672. Handbook of Air pollution Prevention and control by Nicholas P. Cheremisinoff, Ph.D., N & P Limited3. Book on Performance criteria of Air pollution control equipment by Sinclair Knight Merz, Final August 2000 International Journal of Environmental Science and Development, Vol. 2, No. 5, October 20114. Shepherd, C. B., and C. E. Lapple. 1939. Air Pollution Control: A Design Approach. InCyclones. 2nd Edition, ed. C. David Cooper, and F. C. Alley, pp 127-139. Illinois: Woveland Press Inc.5. Parker, R., R. Jain., and S. Calvert. 1981. Particle Collection in Cyclone at High Temperature and High Pressure. Environ. Sci. Technol., 15: 451- 458.大气污染的防控–一条综合性的设计方法摘要：为了实现最大效益的产出，大气污染的规划、管理和控制问题需要进行同步解决。
