给排水工程专业饮用水水质问题及对策大学毕业论文外文文献翻译及原文

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给水排水中英文对照外文翻译文献

给水排水中英文对照外文翻译文献

中英文对照外文翻译文献(文档含英文原文和中文翻译)原文:Optimum combination of water drainage,water supply and eco-environment protection in coal-accumulated basin of North ChinaAbstract The conflict among water drainage,water supply and eco-environment protection is getting more and more serious due to the irrational drainage and exploitation of ground water resources in coal-accumulated basins of North China.Efficient solutions to the conflict are tomaintain long-term dynamic balance between input and output of theground water basins,and to try to improve resourcification of the mine water.All solutions must guarantee the eco-environment quality.This paper presents a new idea of optimum combination of water drainage,water supply and eco-environment protection so as to solve theproblem of unstable mine water supply,which is caused by the changeable water drainage for the whole combination system.Both the management of hydraulic techniques and constraints in economy,society,ecology,environment,insustuial structural adjustments and sustainable developments have been taken into account.Since the traditional and separate management of different departments of water drainage,water supply and eco-environment protection is broken up these departments work together to avoid repeated geological survey and specific evaluation calculations so that large amount of national investment can be saved and precise calculation for the whole system can be obtained.In the light of the conflict of water drainage,water supply and eco-environment protection in a typical sector in Jiaozuo coal mine,a case study puts forward an optimum combination scheme,in which a maximum economic benefit objective is constrained by multiple factors.The scheme provides a very important scientific base for finding a sustainable development strategy.Keywords combination system of water drainage,water supply and eco-environment protection,optimal combination,resourcification of mine water.1Analyses of necessity for the combinationThere are three related problems in the basin.It is well known that the major mine-hydrogeological characteristics of the coal accumulated basin in North China display a stereo water-filling structure,which is formed by multi-layer aquifers connected hydraulically together with various kinds of inner or outer boundaries.Mine water hazards have seriously restricted the healthy development of coal industry in China because of more water-filling sources and stronger water-filling capacity in coal mines of the basin.Coal reserves in the basin are threatened by the water hazards.In Fengfeng,Xingtai,Jiaozuo,Zibao,Huaibei and Huainan coal mine districts,for example,it is estimatedthat coal reserves are threatened by the water hazards up to 52%,71.%40,%,60%,48%and 90%of total prospecting reserves respectively.It is obvious that un-mining phenomenon caused by the water hazards is serious.Water-bursting accidents under coal layers have seriously influenced safe production.Some statistical data show that there were 17 water-bursting accidents with over 1 m3/s inflow from 1985.Water drainage is an increasing burden on coal mines threatened by water hazards:high cost of water drainage raises coal prices and reduces profits of the enterprise.On the other hand,it is more and more difficult to meet the demand of water supply in coal mine districts in the basin.The reasons are not only arid and semi-arid weather conditions,but also a large amount of water drainage with deep drawdown in coal mines and irrational water exploitation.The deterioration of eco-environment is another problem.Phenomena of land surface karst collapse can be found.Many famous karst springs,which are discharge points for the whole karst groundwater syatem,stop flowing or their discharge rates decrease on a large scale.Desert cremophytes in large areas in west China die because of falling groundwater level.These three problems are related and contradictory.In order to solve the problems while ensuring safe mining,meeting water resource demands and slowing down the pace of eco-environment deterioration,it is necessary to study the optimum combination of water drainage,water supply and eco-environment protection in the basin.2The state of the art of research and the problemsAlthough research into the combination of water drainage and water supply started much earlier in some countries,their conception is simple and some shortcomings remain in their study on the theory and pattern of combination.China’s research history on the combination can be divided into three stages.The first stage is the utilization of mine water.A century ago mine water started to be used as water supply for mines.But the utilization scale and efficiency were quite limited at that time.The second stage is a comprehensive one:mine water was used while water hazards were harnessed.Great progress was made both in theory and practice of the combination.For example,the combination of water drainage and water supply not only means the utilization of mine water,but also means that it is a technique of preventing water hazards.It is unfortunate,however,that the combination research in this stage offered less sense ofeco-environment protection.Optimum combination management of water drainage,water supply and eco-environment protection is the third stage.Main features in this stage are to widen traditional research,and to establish an economic-hydraulic management model,in which safe mining,eco-environment protection and sustainable development demands,etc.are simultaneously considered as constraint conditions.3Trinity systemThe trinity system combines water drainage,water supply and eco-environment quality protection.The water-collecting structures of the system consist of land surface pumping wells in the mines,shallow land surface well in groundwater recharge areas and artificial relief wells under the mines.Both integration and coordination for the trinity system are distinguished according to the combination.The integration for the system means to utilize drainage water under the mines and pump water onto the land surface as water supply for different purposes without harming the eco-environmental quality.The coal mines are not only drainage sites,but also water supply sources.The purpose of drilling pumping wells on the land surface is to eliminate special influences on different consumers,which are caused by terminating drainage processes under the mines due to unexpected accidents in mining.The coordination for the system means to bulid some water supply sources for different consumers while ensuring eco-environmental quality in groundwater recharge positions,where pumping groundwater is quite effective on lowering groundwater heads in the mine areas.Itintercepts in advance the recharging groundwater flow towards the mines,which may not only provide consumers with good quality groundwater,achieve the goal of dropping down groundwater heads in the mines,but also effectively reduce the high costs of drainage and water treatment,which are needed by traditional dewatering measures with large drainage flow rates under the mines.The coordination changes the traditional passive pattern of preventing and controlling groundwater hazards under the mines into that of active surface interception.Both very developed karst flow belts and accumulated groundwater recharge ones under the ground are relatively ideal interceptive coordination positions in the system.For the integration of the trinity system,artificial relief wells under the mines and the land surface pumping wells mainly penetrate into direct thin bedded karst aquifers interbedded with the mining coal layers,while for the coordination of the system,the shallow land surface wells mainly penetrate into very thick karst aquifer.Therefore,hydrogeological conceptual model for the system involves the multi-layer aquifers connected hydraulically by different inner boundaries.Setting up stereo hydrogeological conceptual models and corresponding mathematical models is a prerequisite for solving the managemental problems for the system.Management of the trinity system not only considers the effects of lowering groundwater heads and safe operation for water drainage subsystem,but also pays attention to the water demands for water supply subsystem and quality changes for eco-environment protection subsystem.They play the same important role in the whole combination system.It controls the groundwater heads in each aquifer to satisfy the conditions of safe mining with certain water head pressures in the mines,and to guarantee a certain amount of water supply for the mines and near areas,but the maximum drawdown of groundwater must not be ex ceded,which may result in lowering eco-environmental quality.4Economic-hydraulic management modelIn the trinity system management,groundwater resources in the mines and nearby areas,which are assessed on the premise of eco-environment qualities and safe operation in the mines,may be provided as water supply prices,drainage costs,transportation costs(including pipeline and purchasing the land costs)and groundwater quality treatment costs for the three different waterconsumers,the optimum management models may automatically allocate to each consumer a certain amount of groundwater resources and a concrete water supply scenario based on comparisons of each consumer’s economic contribution to the whole system in objective function.Therefore the management studies on the optimal combination among water drainage,water supply and eco-environment protection involve both the management of groundwater hydraulic techniques and the economic evaluations,eco-environment quality protection and industrial structure programs.In addition to realizing an economic operation,they also guarantee a safe operation which is a key point for the combination of the whole system.5The management model for the trinity system can reach water supply goals with drainage water under the mines and the land surface pumping water on the premise of ensuring eco-environmental quality.And it can make use of one model to lay down comprehensively optimum management scenarios for each subsystem by means of selecting proper constraints and maximum economic benefit objective produced by multiple water consumers.The model can raise the security and reliability of operation for the whole trinity system,and the drainage water can be forecast for the mines and the management of water supply resource and the evaluation of eco-environment quality can be performed at the same time so as to respectively stop the separate or closed management,of departments of drainage water,water supply and eco-environment protection from geological survey stage to management evaluation.This,in economic aspect,can not only avoid much geological survery and special assessment work which are often repeated by the three departments,and save a lot of funds,but also ,in technical aspect,make use of one model to simultaneously consider interference and influence on each other for different groundwater seepage fields so as to guarantee calculating precision of the forecast,the management and the evaluation work.The economic-hydraulic management model can be expressed as follows.6 A case studyA typical sector is chosen.It is located in the east of Jiaozuo coal mine,Henan Province,China.Itconsists of three mines:Hanwang Mine,Yanmazhuang Mine and Jiulishan Mine.The land surface is flat,and the whole area is about 30 km2.An intermittent river Shanmen flows through the sector from the north to the south.Average annual precipitation in the sector is about 662.3mm.Theprecipitation mainly concentrates inJune,July,August and September each year.Strata in the sector consist of very thick limestone in Middle Ordovician,coal-bearing rock series in Permo Carboniferous and loose deposits in Quaternary.There are four groups of faulted structures.The first is in northeast-southwest direction such as F3 and F1..The second is in the northwest-southeast direction such as Fangzhuang fault.The third is in the east-west direction such as Fenghuangling fault.The last is almost in north-south.These faults are all found to be normal faults with a high degree of dip angle.Four major aquifers have been found in the sector.The top one is a semi-confined porous aquifer.The next one is a very thin bedded limeston aquifer.The third is a thin bedded limestone aquifer.The last one at the bottom is a very thick limestone aquifer.Objective function of the management model is designed to be maximum economic benefit produced by domestic,industrial and agricultural water supply.Policy making variables of the model are considered as the domestic,industrial and agricultural groundwater supply rates in every management time step,and they are supplied by artificial relief flow wells under the mines,the land surface pumping wells in the mines and the shallow land surface wells in the groundwater recharge areas.All the 135 policy making variables are chosen in the model,27 for drainage wells under the mines in aquifer,27 for the land surface pumping wells in the mine districts in aquifer 27 in aquifer 27 in aquifer O2 27 for the shallow land surface wells in aquifer O2Based on the problems,the following constraint conditions should be considered:(1)Safe mining constraint with groundwater pressure in aquifer L8.There are altogether three coalmines in the typical sector,i.e.Hanwang Mine,Yanmazhuang Mine and Jiulishan Mine.Elevations of mining level for these mines are different because it is about 88-150 m in the second mining level for Hanwang Mine,and -200m in the second mining level for Yanmazhuang Mine,and-225 m in the first mining level for Jiulishan Mine.According to mining experiences,pressure-loaded heights for groundwater heads in safe mining state are considered as about 100-130m.Therefore,the groundwater level drawdowns in the three management time steps for aquifer L8 at three mines have to be equivalent to safe drawdown values at least in order to pervert groundwater hazards under the mines and to guarantee their safe operation.(2)Geological eco-environment quality constraint.In order to prevernt groundwater leakage fromupper contaminater porous aquifer into bottom one and then to seepage further down to contaminate the thin bedded limestone aquifer in the position of buried outcrop,the groundwater heads in the bottom porous aquifer must keep a certain height,i.e.the groundwater drawdowns in it are not allowed to exceed maximum values.(3)Groundwater head constraint at the shallow land surface wells in aquifer O2,The shallow landsurface wells should penetrate in aquifer O2 in order to avoid geological environment hazards,such as karst collapse and deep karst groundwater contamination.Groundwater head drawdowns in aquifer O2 for the shallow land surface wells are not allowed to exceed criticalvalues.(4)Industrial water supply constraint for the groundwater source in aquifer O2 .The rate ofindustrial water supply needed by the planned thermal power plant in the north of the sectoris designed to be 1.5 m3/s according to the comprehensive design of the system in thesector.In order to meet the demands of water,the rate industrial water supply for thegroundwater source in aquifer O2 in every management time step must be equivalent at leastto 1.5 m3/s.(5)Maximum amount constraint of groundwater resource available for abstraction.In order tomaintain the balance of the groundwater system in the sector for a long time and to avoid anyharmful results caused by continuous falling of groundwater head,the sum of groundwaterabstraction in each management time step is not allowed to exceed the maximum amount ofgroundwater resource available for abstraction.Since there is not only water drainage in the mines,but also water supply in the whole combination system,management period for the model is selected from June 1,1978 to May 31,1979,in which annual average rate of precipitation is about 50%.Management time steps for the period are divided into three.The first one is from June to September,the second from October to next January,and the last one from next February to May.According to comprehensive information about actual economic ability,economic development program and industrial structure adjustment in the sector at present and in the near future,and different association forms of water collecting structures among the land surface pumping wells,the shallow land surface wells and artificial relief flow wells under the mines,this paper designs 12 management scenarious,all of which take the safe operation in the trinity system as the most important condition.After making comparisons of optimum calculation results for the 12 scenarious,this paper comes to a conclusion that scenarios is the most ideal and applicable one for the typical sector.This scenario not only considers the effective dewatering advantage of the artificial relief flow wells under the mines and safe stable water supply advantage of the land surface pumping wells,but also pays attention to the disadvantage of low safe guaranty rate for the relief flow wells under the mines for water supply and of large drilling investment in the land surface pumping wells.Meanwhile,eh shallow land surface wells inaquifer O2in this scenario would not only provide water supply for the thermal power plant as planned,but also play an important role in dewatering the bottom aquifer,which is major recharge source of groundwater for the mines.If the drainage subsystem under the mines runs normally,this scenario could fully offer the effective dewatering functions of the artificial relief flow wells under the mines,and makes the trinity system operate normally.But if the drainage subsystem has to stop suddenly because of unexpected accidents,the scenario could still fully utilize the land surface pumping wells and the shallow land surface wells,and increae their pumping rates in order to make up for temporary shortage of water supply for the trinity system and to make its economic losses reduced to a minimum extent.Increasing groundwater abstraction rate for the land surface pumping wells and the shallow land surface wells,in fact,is very favorable for harnessing the water-accidents under the mines and for recovery production of the mines.To sum up,this scenario sets up a new pattern for the combination of water drainage,water supply and eco-environment protection.It solves quite well the conflicts between the low safe guaranty rate and the effective dewatering result for the artificial relief flow wells under the mines.It makes full use of beneficial aspect of the conflicts,and meanwhile compensates for the unbeneficial one by arranging the land surface pumping wells in the coal mine districts.Therefore,this scenario should be comprehensive and feasible.In this scenario,Hanwan Mine,Yanmazhuang Mine and Jiulishan Mine are distributed optimally for certain amount of domestic and industrial water supply,but not for much agricultural water supply.The land surface pumping wells are also distributed for different purposes of water supply.The water supply for the thermal power plant (1.5 m3/s) is provided by the shallow land surface prehensive effects,produced by the above three kinds of water collecting structures,completely satisfy all of the constraint conditions in the management model,and achieve an extremely good economic objective of 16.520551million RMB yuan per year.In order to examine the uncertainty of the management model,12management scenarios are all tested with sensitive analysis.7Conclusion(1)The optimum combination research among water drainage,water supply and eco-environmentprotection is of great theoretical significance and application value in the basin of North China for solving unbalanced relation between water supply and demands,developing new potential water supply sources and protecting weak eco-environment.(2)The combination research is concerned not only with hydraulic technique management but alsowith constraints of economic benefits,society,ecology,environment quality,safe mining and sustainable development in the coal mines.(3)The combination model,for the first time,breaks up the closed situation existing for a longtime,under which the government departments of drainage water,water supply and eco-environment protection from geological survey stage to management evaluation work respectively.Economically,it can spare the repeated geological survey and special assessment work done by the three departments and save a lot of funds;technically,one model is made use of to cover the interference and influence each other for different groundwater seepage fields soas to guarantee a high calculating precision of the forecast,the management and the evaluation work.(4)The management scenario presented in the case study is the most ideal and applicable for thetypical sector.This scenario not only makes full use of the effective dewatering advantages of the artificial relief flow wells under the mines and safe stable water supply advantages of the land surface pumping wells,but also pays attention to the disadvantages of low safe guaranty rate for the relief flow wells under the mines for water supply and of large drilling investment for the land surface pumping wells.References1.Investigation team on mine-hydrogeology and engineering geology in the Ministry ofGeology and Mineral Resources.Investigation Report on Karst-water-filling Mines(inChinese).Beijing:Geological Publishing House,19962.Liu Qiren,Lin Pengqi,Y u Pei,Investigation comments on mine-hydrogeological conditionsfor national karst-water-filling mines,Journal of Hydrogeology and Engineering Geology(in Chinese),19793.Wang Mengyu,Technology development on preventing and curing mine water in coalmines in foreign countries,Science and Technology in Coal(in Chinese),19834.Coldewey,W.G.Semrau.L.Mine water in the Ruhr Area(Federal Republic of Germany),inProceedings of 5th International Mine Water Congress,Leicestershire:Quorn SelectiveRepro Limited,19945.Sivakumar,M.Morten,S,Singh,RN,Case history analysis of mine water pollution,inProceedings of 5th International Mine Water Congress,Leicestershire;Quorn SelectiveRepro Limited,19946.Ye Guijun.Zhang Dao,Features of Karst-water-filling mines and combination betweenwater drainage and water supply in China,Journal of Hydrogeology and EngineeringGeology(in China),19887.Tan Jiwen,Shao Aijun,Prospect analyses on Combination between water drainage andwater supply in karst water basin in northern China,Jounnal of Hebei College ofGeology(in Chinese),19858.Xin Kuide,Yu Pei,Combination between water drainage and water for seriouskarst-water-filling mines in northern China,Journal of Hydrogeology and Engineering Geology(in Chinese),19869.Wu Qiang,Luo Yuanhua,Sun Weijiang et al.Resourcification of mine water andenvironment protection,Geological Comments(in Chinese),199710.Gao Honglian,Lin Zhengping,Regional characteristics of mine-hydrogeological conditionsof coal deposits in China,Journal of Hydrogeology and Engineering Geology(in Chinese),198511.Jiang Ben,A tentative plan for preventing and curing measures on mine water in coal minesin northern China,Geology and Prospecting for Coaofield(in Chinese),1993中国北方煤炭积聚区的最佳组合排水,供水和生态环境保护摘要为了开采中国北方煤炭资源丰富的区域,不合理的排水使排水、供水和保护生态环境之间的冲突日趋严重。

水污染与治理英文论文

水污染与治理英文论文

Author:李煜哲Abstract:This paper make a description and analysis about the present situation of water resources and pollution in our country, using the method of state governance, and puts forward personal views and opinions.Key words:Current situation,lawsIntroductionThe national polluted water emissions increased by 31.5 billion tons in 1980 to 63.1 billion tons in 2002. Most urban groundwater polluted to some extent, and has a tendency to increase year by year. The use of the increasingly serious water pollution not only reduces the water functions, further aggravated the contradiction of water resource shortage, but also a serious threat to urban residents drinking water safety and health. For our life source being polluted, how should we respond?1.The water resources and pollution situation in our country1.1Water resources situation in our countryFrom The first national water resources census bulletin,By the end of 2011,there are 45000 reasons basin area of 50 square kilometers above, total length of 1.5085 million km. There are 22900 reasons basin area of 100 square kilometers above. There are 2865 natural lakes water is greater than 1 square kilometers with a total area of 7.8 square kilometers. The country has about 98000 reservoirs, with a total capacity of 98000 cubic meters. The national total of 638900 lakes water inlet, the earth's surface and underground water source is respectively 1.17 and 1847.China's per capita water resources is only 2100 cubic meters, only 28% of the world's per capita. In the northern region, water resource is very shortage, the Yellow River, huaihe river, haihe river three per capita water resources quantity respectively for the national average of only 30.1%, 21.6% and 12.9%.China's per capita fresh water resources is only a quarter of the world's average, ranked 110 in the world, is one of the poorest countries in the world per capita water resources. Available water resources per capita is only 900 cubic meters, and unevenly distributed.The end of the 20th century, the presence of more than 400 cities in more than 600 cities has water supply shortage problem, the serious water shortage city more than 110, the national total water shortage of 6 billion cubic meters. [2]1.2Situation of water pollution in ChinaChina's top ten river basin water quality success rate is 2/3, Local water quality is worrying,overall,Through years of efforts, we have improved water quality in China, the top ten overall for watershed water quality mild pollution, but at local area, the water quality of local water environment pollution is still serious.Recently published in domestic academic journal "science bulletin", according to an article. Surface water contains 68 kinds of antibiotics in China, and the concentration is higher. There are 90 kinds of the antibiotic pharmaceutical ingredients being checked out..The antibiotic concentration is much higher than abroad. 90% of our country urban groundwater by different level of organic and inorganic pollution of poisonous and harmful pollutants, 70% of the pollution of river water system, more than 90% of the river pollution flows through the city.2.reasonable solutionsOn enhancing urban water supply water saving and water pollution prevention and control work Promulgated by the state council in 2000 point out that we should gradually change the past a drainage system, a single reservoir and a river water to the city water supply way, Take "library series more, drainage network, surface water and groundwater alignment, the optimized configuration of water resources".2.1Methods in our country at presentBy the end of 2013, the total 3895 key projects, medium and small rivers Management River is 35000 kilometers long. By 2015, the project management of small and medium-sized rivers around 5000, governance river is 60000 kilometers long, can make the 340 million population and 330 million mu of farmland protected by flood control.In order to ensure the river health life, implementing strict water management system in our country, defined the development and utilization of water resources, water use efficiency, water function area restriction, they use "three line":1. Set the limits of the total water 2. The red line to promote water-saving efficiency of water use 3. The red lines limit, protect water quality,Expert introduction, the current "three line" index system of water resources to cover 95% of the local administrative region and more than 50% of the county administrative region, which means that the water resources management in the future will be more strictly: Strict management and protection of groundwater, the groundwater water withdrawal amount control and water level control.Strict control into the lakes pollution gross, the position is beyond the water function area limits of the total area, limit for examination and approval of new water and sewage outlet into the rivers. [3]2.2Personal viewsI think the best way to curb water pollution is in legislation and law enforcement supervision.The water pollution problem has to be reckoned with, because it has two characteristics:The first: concealment, imperceptible. Second: once the pollution, it is difficult to treatment and recovery. In the driven of the interests, pale the role of the propaganda work, to really stop water pollution phenomenon only can depends on the guarantee of law and law enforcement supervision. Therefore, a specific law to protect drinking water sources is fundamental. Strengthen the regulation of drinking water sources protection law enforcement is the important guarantee. To continue increasoing the intensity of law enforcement inspection, investigate seriously illegal threat to drinking water quality environment act.For urban water conservation, I put forward the following Suggestions:First, optimize the urban layout and industrial structure, Second, increase the level and efficiency of utilization of the urban internal water cycle.Third, to strengthen the construction of urban water supply. Fourth, strengthen the protection of urban water supply.I believe that as long as there is a reasonable means and strict supervision legislation and a determined, theproblem of water pollution can be effectively improve!Reference:[1]"The first national water resources census bulletin, March 26, 2013 [2], the People's Daily, on May 26, 2014, 09 edition [3] the Chinese environmental protection online。

柯常彬给排水专业英文文献翻译

柯常彬给排水专业英文文献翻译

Sewage treatmentAbstractSewage treatment, or domestic wastewater treatment, is the process of removing contaminants from wastewater and household sewage, both runoff (effluents) and domestic. It includes physical, chemical, and biological processes to remove physical, chemical and biological contaminants. Its objective is to produce a waste stream (or treated effluent) and a solid waste or sludge suitable for discharge or reuse back into the environment. This material is often inadvertently contaminated with many toxic organic and inorganic compounds.Key words: Sewage treatment, fixed-film and suspended-growth, Activated sludgeOrigins of sewageSewage is created by residences, institutions, and commercial and industrial establishments. Raw influent (sewage) includes household waste liquid from toilets, baths, showers, kitchens, sinks, and so forth that is disposed of via sewers. In many areas, sewage also includes liquid waste from industry and commerce. The separation and draining of household waste into greywater and blackwater is becoming more common in the developed world, with greywater being permitted to be used for watering plants or recycled for flushing toilets. A lot of sewage also includes some surface water from roofs or hard-standing areas. Municipal wastewater therefore includes residential, commercial, and industrial liquid waste discharges, and may include stormwater runoff. Sewage systems capable of handling stormwater are known as combined systems orcombined sewers. Such systems are usually avoided since they complicate and thereby reduce the efficiency of sewage treatment plants owing to their seasonality. The variability in flow also leads to often larger than necessary, and subsequently more expensive, treatment facilities.In addition, heavy storms that contribute more flows than the treatment plant can handle may overwhelm the sewage treatment system, causing a spill or overflow. It is preferable to have a separate storm drain system for stormwater in areas that are developed with sewer systems.As rainfall runs over the surface of roofs and the ground, it may pick up various contaminants including soil particles and other sediment, heavy metals, organic compounds, animal waste, and oil and grease. Some jurisdictions require stormwater to receive some level of treatment before being discharged directly into waterways. Examples of treatment processes used for stormwater include sedimentation basins, wetlands, buried concrete vaults with various kinds of filters, and vortex separators (to remove coarse solids).Process overviewSewage can be treated close to where it is created (in septic tanks, biofilters or aerobic treatment systems), or collected and transported via a network of pipes and pump stations to a municipal treatment plant (see sewerage and pipes and infrastructure). Sewage collection and treatment is typically subject to local, state and federal regulations and standards. Industrial sources of wastewater often requirespecialized treatment processes (see Industrial wastewater treatment).Conventional sewage treatment may involve three stages, called primary, secondary and tertiary treatment. Primary treatment consists oftemporarily holding the sewage in a quiescent basin where heavy solids can settle to the bottom while oil, grease and lighter solids float to the surface. The settled and floating materials are removed and the remaining liquid may be discharged or subjected to secondary treatment. Secondary treatment removes dissolved and suspended biological matter. Secondary treatment is typically performed by indigenous, water-borne micro-organisms in a managed habitat. Secondary treatment may require a separation process to remove the micro-organisms from the treated water prior to discharge or tertiary treatment. Tertiary treatment is sometimes defined as anything more than primary and secondary treatment. Treated water is sometimes disinfected chemically or physically (for example by lagoons and microfiltration) prior to discharge into a stream, river, bay, lagoon or wetland, or it can be used for the irrigation of a golf course, green way or park. If it is sufficiently clean, it can also be used for groundwater recharge or agricultural purposes.Pre-treatmentPre-treatment removes materials that can be easily collected from the raw wastewater before they damage or clog the pumps and skimmers of primary treatment clarifiers (trash, tree limbs, leaves, etc).ScreeningThe influent sewage water is strained to remove all large objects carried in the sewage stream. This is most commonly done with an automated mechanically raked bar screen in modern plants serving large populations, whilst in smaller or less modern plants a manually cleaned screen may be used. The raking action of a mechanical bar screen is typically paced according to the accumulation on the bar screens and/orflow rate. The solids are collected and later disposed in a landfill or incinerated.Grit removalPre-treatment may include a sand or grit channel or chamber where the velocity of the incoming wastewater is carefully controlled to allow sand, grit and stones to settle.Primary treatmentIn the primary sedimentation stage, sewage flows through large tanks, commonly called "primary clarifiers" or "primary sedimentation tanks". The tanks are large enough that sludge can settle and floating material such as grease and oils can rise to the surface and be skimmed off. The main purpose of the primary sedimentation stage is to produce both a generally homogeneous liquid capable of being treatedbiologically and a sludge that can be separately treated or processed. Primary settling tanks are usually equipped with mechanically driven scrapers that continually drive the collected sludge towards a hopper in the base of the tank from where it can be pumped to further sludge treatment stages. Grease and oil from the floating material can sometimes be recovered for saponification.Secondary treatmentSecondary treatment is designed to substantially degrade the biological content of the sewage which are derived from human waste, food waste, soaps and detergent. The majority of municipal plants treat the settled sewage liquor using aerobic biological processes. For thisto be effective, the biota require both oxygen and a substrate on which to live. There are a number of ways in which this is done. In all these methods, the bacteria and protozoa consume biodegradable soluble organic contaminants (e.g. sugars, fats, organic short-chain carbon molecules, etc.) and bind much of the less soluble fractions into floc. Secondary treatment systems are classified asfixed-film and suspended-growthFixed-film OR attached growth system treatment process including trickling filter and rotating biological contactors where the biomass grows on media and the sewage passes over its surface.In suspended-growth systems, such as activated sludge, the biomass is well mixed with the sewage and can be operated in a smaller space than fixed-film systems that treat the same amount of water. However, fixed-film systems are more able to cope with drastic changes in the amount of biological material and can provide higher removal rates for organic material and suspended solids than suspended growth systems.Roughing filters are intended to treat particularly strong or variable organic loads, typically industrial, to allow them to then be treated by conventional secondary treatment processes. Characteristics include typically tall, circular filters filled with open syntheticfilter media to which wastewater is applied at a relatively high rate. They are designed to allow high hydraulic loading and a high flow-through of air. On larger installations, air is forced through the media using blowers. The resultant wastewater is usually within the normal range for conventional treatment processes.Activated sludgeMain article: Activated sludgeIn general, activated sludge plants encompass a variety of mechanisms and processes that use dissolved oxygen to promote the growth of biological floc that substantially removes organic material.The process traps particulate material and can, under ideal conditions, convert ammonia to nitrite and nitrate and ultimately to nitrogen gas, (see also denitrification).Surface-aerated basinsMost biological oxidation processes for treating industrial wastewaters have in common the use of oxygen (or air) and microbial action. Surface-aerated basins achieve 80 to 90% removal of Biochemical Oxygen Demand with retention times of 1 to 10 days. The basins may range in depth from 1.5 to 5.0 metres and use motor-driven aerators floating on the surface of the wastewater.In an aerated basin system, the aerators provide two functions: they transfer air into the basins required by the biological oxidation reactions, and they provide the mixing required for dispersing the air and for contacting the reactants (that is, oxygen, wastewater and microbes). Typically, the floating surface aerators are rated to deliver the amount of air equivalent to 1.8 to 2.7 kg O2/kW·h. However, they do not provide as good mixing as is normally achieved in activatedsludge systems and therefore aerated basins do not achieve the same performance level as activated sludge units.Biological oxidation processes are sensitive to temperature and, between 0 °C and 40 °C, the rate of biological rea ctions increase with temperature. Most surface aerated vessels operate at between 4 °C and 32 °C.Filter beds (oxidizing beds)Main article: Trickling filterIn older plants and plants receiving more variable loads, trickling filter beds are used where the settled sewage liquor is spread onto the surface of a deep bed made up of coke (carbonized coal), limestone chips or specially fabricated plastic media. Such media must have high surface areas to support the biofils that form. The liquor is distributed through perforated rotating arms radiating from a central pivot. The distributed liquor trickles through this bed and is collected in drains at the base. These drains also provide a source of air which percolates up through the bed, keeping it aerobic. Biological films of bacteria, protozoa and fungi form on the media’s surfaces and eat or otherwise reduce the organic content. This biofilm is grazed by insect larvae and worms which help maintain an optimal thickness. Overloading of beds increases the thickness of the film leading to clogging of the filter media and ponding on the surface.Biological aerated filtersBiological Aerated (or Anoxic) Filter (BAF) or Biofilters combine filtration with biological carbon reduction, nitrification or denitrification. BAF usually includes a reactor filled with a filter media. The media is either in suspension or supported by a gravel layer at the foot of the filter. The dual purpose of this media is to support highly active biomass that is attached to it and to filter suspended solids. Carbon reduction and ammonia conversion occurs in aerobic mode and sometime achieved in a single reactor while nitrate conversion occurs in anoxic mode. BAF is operated either in upflow or downflow configuration depending on design specified by manufacturer.Membrane bioreactorsMembrane bioreactors (MBR) combine activated sludge treatment with a membrane liquid-solid separation process. The membrane component uses low pressure microfiltration or ultra filtration membranes and eliminates the need for clarification and tertiary filtration. The membranes are typically immersed in the aeration tank; however, some applications utilize a separate membrane tank. One of the key benefits of an MBR system is that it effectively overcomes the limitations associated with poor settling of sludge in conventional activated sludge (CAS) processes. The technology permits bioreactor operation with considerably higher mixed liquor suspended solids (MLSS) concentration than CAS systems, which are limited by sludge settling. The process is typically operated at MLSS in the range of 8,000–12,000 mg/L, while CAS are operated in the range of 2,000–3,000 mg/L. The elevated biomass concentration in the MBR process allows for very effective removal of both soluble and particulate biodegradable materials at higher loading rates. Thus increased Sludge Retention Times (SRTs) —usually exceeding 15 days — ensure complete nitrification even in extremely cold weather.The cost of building and operating an MBR is usually higher than conventional wastewater treatment. Membrane filters can be blinded with grease or abraded by suspended grit and lack a clarifier's flexibility to pass peak flows. The technology has become increasingly popular for reliably pretreated waste streams and has gained wider acceptance where infiltration and inflow have been controlled, however, and the life-cycle costs have been steadily decreasing. The small footprint of MBR systems, and the high quality effluent produced, make them particularly useful for water reuse applications.There are MBR plants being built throughout the world, including North Librty, Iowa, Georgia, and Canada.Secondary sedimentationThe final step in the secondary treatment stage is to settle out the biological floc or filter material and produce sewage water containing very low levels of organic material and suspended matter.Rotating biological contactorsMain article: Rotating biological contactorRotating biological contactors (RBCs) are mechanical secondary treatment systems, which are robust and capable of withstanding surges in organic load. RBCs were first installed in Germany in 1960 and have since been developed and refined into a reliable operating unit. Therotating disks support the growth of bacteria and micro-organisms present in the sewage, which breakdown and stabilise organic pollutants. To be successful, micro-organisms need both oxygen to live and food to grow. Oxygen is obtained from the atmosphere as the disks rotate. As the micro-organisms grow, they build up on the media until they are sloughed off due to shear forces provided by the rotating discs in the sewage. Effluent from the RBC is then passed through final clarifiers where the micro-organisms in suspension settle as a sludge. The sludge is withdrawn from the clarifier for further treatment.A functionally similar biological filtering system has become popular as part of home aquarium filtration and purification. The aquarium water is drawn up out of the tank and then cascaded over a freely spinning corrugated fiber-mesh wheel before passing through a media filter and back into the aquarium. The spinning mesh wheel develops a biofilm coating of microorganisms that feed on the suspended wastes in the aquarium water and are also exposed to the atmosphere as the wheel rotates. This is especially good at removing waste urea and ammonia urinated into the aquarium water by the fish and other animals.污水处理摘要自然或生活污水处理,是指清除包括家庭排放的和地面径流在内的污水废水和地面污染物的过程。

给排水工程外文翻译

给排水工程外文翻译

给排水工程外文翻译 Final approval draft on November 22, 2020Short and Long Term Advantage roof drainage design performanceDecade has witnessed great changes in the design of the roof drainage system recently, particularly, siphon rainwater drainage system has been gradually improved, and there is likely to be the key application. At the same time these changes, urban drainage system design has undergone tremendous changes, because the scope of a wider urban drainage system design for sustainable development, as well as people for climate change flooding more attention. The main contents of this article is how to design roof drainage systems and make a good performance. Special attention is how to get rid of bad habits already formed the design, but also need to consider innovative roof drainage system, such as green roofs and rainwater harvesting systems.Practical application: In the past few years, the design of the roof rainwater drainage system has undergone tremendous changes. On large buildings, siphon rainwater drainage technology has been very common, as well as green roofs because it is conducive to green development, being more and more applications. Taking into account the ongoing research, this article focuses on how to effectively design a variety of roof rainwater drainage system, and make it achieve the desired design effect.1. IntroductionIn the past decade, the city and the water drainage system design has been widely accepted thinking about sustainable urban drainage system, or the optimal management direction. The main principles of the design of these systems is both a local level in line with the quality of development, but also to create some economic benefits for the investors. This principle has led to the development of new changes in the sump. Although the application of such a device is gradually reduced, but the urban environment relatively high demand areas still require 100% waterproof and rapid drainage, such as the roof. Typically roof drainage system in the design, construction and maintenance has not been given due attention. Although the drainage system investment costs account for only a small portion of the total construction investment, but not able to judge the loss caused by poor design.There are two different forms of roof drainage system design methods, namely the traditional and siphon method. Traditional systems rely on atmospheric pressure work, the drive ram affectedsink flow depth. Therefore, the conventional roof drainage systems require a relatively large diameter vertical drop tube, prior to discharge, all devices must be connected to the groundwatercollection pipe network. In contrast, siphonic roof drainage pipe systems are generally designed to full flow (turbulent flow meansthat require less exhaust pipe), which will form a negative pressure, the larger the higher flow rate and pressure head. Typically siphon system requires less down pipe work under negative pressure to the water distribution network can mean higher altitude work, thereby reducing the amount of underground pipe network.Both systems consists of three parts: the roof, rainwater collection pipes, pipe network.All of these elements are able to change the water pressure distribution system. This section focuses on the role and performance of each part. Due to the principle of siphon system has not been well understood, resulting argument is relatively small, this article will highlight siphon system.2. RoofThe roof is usually designed by the architect, designer and not by the drainage design. There are three main roof.2.1 Flat roofFlat roofs are used in industrial buildings less rainfall regions and countries. This roof is not completely flat, but lower than the minimum roof slope may require. For example, the United Kingdom require maximum slope of 10 °. Setting minimum slope in order to avoid any unnecessary water.Despite the flat roof if it is not properly maintained will have more problems, but it will reduce the dead zone within the building, and the ratio of sloping roofs in favor of indoor air.2.2 sloping roofsMost residential and commercial buildings are pitched roof, inclined roof is the biggest advantage can quickly drain, thereby reducing leakage. In temperate regions, we need to consider carrying roof snow load. Once it rains, rainfall through the sloping roofs can be determined by calculation. When rainfall data can be used, you can use the kinematic theory to solve such problems.2.3 green roof (flat or inclined)It can prove roof is the oldest green roofs, including rainfall can reduce or disperse roof planted with plants. It can be planted with trees and shrubs roof garden, it can also be a vegetated roof light carpet. Wherein the latter technique has been widely used. Some of these applications tend to focus on aesthetic requirements and are often used in green development. Since the aesthetic requirements and pressure requirements, as well as green roofs thermal insulation function, reduce the heat island effect, silencer effect, extend the life of the roof.Green roofs in Germany, the most widely used, followed in North America, but to consider the impact on the aesthetics. Germany is by far the most experienced countries in the 19th century have practical application, then as an alternative to reduce the risk of fire tarroof an option in urban areas. Germany is currently the main research question on the cultivation of other issues to consider smaller cities. A study from 1987 to 1989, was found packed with 70 mm thick green roof can be reduced by 60% -80% of heat loss. In a Canadianwork computer model based on the roof indicates that as long as the sump, the area can reach 70% of the roof area can be reduced by 60 percent in one year, the same model was also used for artificial rainfall, which the results indicate that rainfall in the catchment season helps to drain away rainwater.However, none of these studies show that green roofs can play a useful role in the rainfall season, or how high collection efficiency of water supply. The United States did some tests, as long as the green roofs regular watering, can reduce 65 percent of the runoff ina rainfall. America's most authoritative green roof guidelines by the New Jersey state environmental agencies promulgated. The mainprinciple is to solve the structural problems of light, and how can the normal drainage after two years.Rainfall period is based on the probability of failure is determined. The system is typically based on rainfall during rainstorms two minutes, two minutes, have a choice. Although this model will get more traffic, but there is no other better alternative. Studies have shown that the traditional model is applied to study green roofs are premature.Loss factor than traditional roof records should be small, about 98.7%.Peak flow will be reduced, although not penetrate, the surface roughness but also have a significant impact.Concentrated rainfall than two minutes for a long time,especially for large roof areas, such as public buildings, commercial buildings, industrial buildings.Urban drainage design should also consider other factors, for a complex system, a green roof in a rain is not enough. Water flow duration curve shows a longer than traditional systems. And two independent and will affect between is possible, which requires a more precise time period.3. Rainwater CollectorBasic requirements rainwater collector is designed to be able to accommodate rainfall rainstorms. Although it is possible to make a slightly inclined roof drainage purposes, but the nature of the construction industry and building settlement will become flat roofTypically, the tank is placed in a horizontal, sectional view of the water is outwardly inclined, which the role of hydrostatic.3.1 drain outletAnalyzing rainwater collector has sufficient volume is the key to the sump outlet external setting conditions. Also affect the flow rate into the storm water drainage system piping, but also affect the depth of the water catchment. Although the depth of the sump will not bring any particular problems, but too deep can cause excessive sump.Numerous studies in the 1980s showed that the flow of conventional roof drainage system outlet can be divided into two cases. It depends on the size of the depth and size of the outlet. When the water depth is less than half the diameter of the outlet, the flow of the first type, and the outlet of the flow can be calculated by an appropriate equation; water depth increases, exports are slowly clogging the flow will become another form forms, at the same time, the flow of exports can be obtained through other equations. While conventional roof drainage systems are designed to be free-draining, but may cause limitations encountered in the design of the flow is not free. In this case, it will require additional depth.Siphon roof drainage systems, the outlet is designed to be submerged stream. In this case, the depth of the outlet of the decision is more complicated, because the design of the sump depends on the flow. Recent studies have shown that conventional roof drainage systems use a variety of non-standard catchment, their depth and height, bigger than the diameter of the outlet. This will eventually result in a siphon effect. For a given catchment, the flow depends on the starting end of the drop tube diameter. A similar phenomenon has also been used to study the standard catchment, in these circumstances, only limited siphon action occurs within relatively close distance from the exit.3.2 tank flow classificationIn the complex flow sump outlet flow classification, can be seen from Table 2a, the flow will be uniform layering, regardless of whether the same inlet flow. Table 2b and 2c show, exportdistribution will greatly influence the flow.When the outlet is not a free jet, sump outlet complex flow classification is difficult to describe. Because each catchment tank pressures are likely to be merged. For example, the siphon tube system design point is at near full jet outlet flow classification depends on the energy loss of each branch.3.3 hydrostatic sectionalSump shape of the water surface in the canal can be classified according to the flow equation. In most cases, a low flow rate meansthat there is less friction loss, if exports are free jet, thefriction loss is negligible cross-section through the hydrostatic equation 1 to determine the horizontal distance.Where Q-- flow (m3 / s)T- surface width (m)g- acceleration of gravity (m / s2)F- flow area (m2)Equation 1 can not be ignored when the friction required to correct (or very long pipe velocity is large), or not a free jet.3.4 The current design methodsThe previous discussion has highlighted the main factors that should be considered with sink design. However, without the help of a certain number of models, computing hydrostatic sectional roof drainage system, the volume of the sump is possible. This large commercial and manufacturing industry, is a development opportunity, you can merge several kilometers of water routes. Thus, the conventional drainage system sump design methods are mainly based on experience, and assume that exports are free jet.Sump location in the building, it may cause the example to fail. Different interface sumpExcept in the case cited above, but also allows designers to use empirical data.3.5 Digital ModelLarge number of digital models can be used to accurately describe the flow of any form of catchment tank, regardless of whether the roof flows stable. An example of this model is a combination of roof space model. This model enables users to classify different aspects of the data indicated, includes: details of the rains, the roof surface drainage and other details. Kinematics have also been used to study rainwater tank to flow from the research collection. A typical method is based on open system to solve a basic problem of spatial mobility. This model automatically resolve the sump outlet flow situation, but also to deal with the case of free jet can also be simulated space limited mobility and submerged discharge. Output values include depth and flow rate.Currently, the model is essentially just a variety of research tools, but also through practical engineering test. However, we should face up to the various role models.4 pipe systems groupComposition in the form and scope of the tube group determinesthe roof drainage system relies mainly on the traditional system or siphon action.4.1 Traditional stormwater systemsConventional roof drainage systems, the ground plane is generally vertical pipe-line network, connected to the sump outlet and underground drainage systems, critical systems as well as compensating tube. It should be emphasized that the angle between the ground and the compensating tube is less than 10 °. Capacity of the entire system relies mainly on the outlet tube instead of down.Flow vertical tube is usually free-flowing, full of only 33%, the efficiency depends on the excess length of the tube. If the drop tube long enough (typically greater than 5m), there may be an annular flow. Similarly, under normal circumstances flow compensation pipe is free-flowing, full of up to 70%. Such designed process both for the design, various equations can also be used.4.2 Siphon roof drainage systemIn contrast with the traditional drainage systems, Siphon roof drainage system relies on air flow outside the system, and the tubeis full pipe flow stream.The designs are usually made on the assumption that the design of heavy rain, the system can quickly siphon discharge rainwater. This assumption allows the application of hydrostatic siphon system theory. Often used steady flow energy equation. While this approach ignores the small amount of energy loss at the entrance, but after the experiment showed that there are still conducive to practical use.However, steady-state design methods in the siphon system is exposed to rain when the system does not meet the standard requirements or changes in rainfall intensity is large is not applied. In the first case, there will be some mixing of air quality, annular flow occurs. These problems are not integrated in the system when more serious. Because usually designed rains are common, it is clear now design methodology over time may not apply to siphon system. This is a major disadvantage, because the design of the main problem isthe noise and vibration problems.Despite the disadvantages of the prior design approach, but a lot of the world's very few engineering failure reports. When a failure occurs, most likely for the following reasons:An incorrect understanding of the operation pointsSubstandard materials listInstallation defectsMaintenance mismanagementTo overcome these disadvantages, we have recently launched aseries of research projects, to discuss the siphon system, and the development of digital models. From this work we learn a lot.In contrast with conventional design methods of some assumptions, siphon system mainly has the following aspects:1) non-flow system of full flow2) levels of certain pipe-flowing full pipe flow3) full pipe flow downstream propagation through a vertical pipe, riser, etc.4) the inner tube flow occurs over the vertical section, the system to reduce the pressure5) downward tube is full pipe flow, there will be air lock6) appears completely siphon action until well into the air system is lower than a certain levelTable 4a column data indicate that below the design point, the system will siphon unstable flow, depth of the water collecting tank is insufficient to maintain the siphon action. Table 4b show that the unsteady flow in siphon system when it will appear.Table 5 lists the data output of a digital model. It can be seen that the model can accurately describe the siphon action, siphon and steady state, the data also show that the model can accurately describe the complex siphon action.5 ConclusionThis article has illustrated the critical roof drainage systems, but these are often overlooked in the urban drainage system design. This article also shows that the design process is a complex process, rely mainly on the performance of exports. The following conclusions are based on the design summed up:1) Run depend on three interacting parts: the roof, sump, water pipes2) Green roofs can reduce traffic and beautify the city3) the export performance of the system is essential4) siphon drainage system have a greater advantage in large-scale projects, but must be considered high maintenance costs5) Design siphon drainage system should consider additional capacity and operational issuesAlthough the green roof is a more attractive option, but the traditional roof of a building in the country will continue to dominate. Green roofs will be gradually developed, and gradually been widely accepted. Similarly, the roof drainage system shown effective that it will continue to play a huge role in the commercial building drainage systems.Roof drainage system of the greatest threats from climate change, existing systems tend to be not simply aging; rainfall patterns of change will result in inefficient operation, self-cleaning rate will be reduced. Changes in wind speed and the roof will also accelerate the aging of the roof, it is necessary to carry out maintenance. Taking into account the climate change, the increase in materials, roof collected rainwater will be more extensive. Currently, the amount of rain around the globe per person per day 7-300 liters in the UK, with an average consumption of 145L / h / d, of which onlyabout one liter is used by people, about 30 per cent of the toilet, study shows If water shortage, rainwater collected on the roof of developed and developing countries are recommended approach.屋顶排水设计性能的近期与远期优势最近十年见证了屋顶排水系统设计方面的巨大变化,特别的是,虹吸雨水排水系统已经得到逐步改善,并且有可能得到重点应用。

毕业设计 - 给水排水工程专业本科毕业设计文献翻译

毕业设计 - 给水排水工程专业本科毕业设计文献翻译

中国化学工程学报155(2009)1就有氧厌氧处理工业和城市废水化学与环境工程学院,工程学院,诺丁汉大学马来西亚校区,惹布罗加,雪兰莪州,马来西亚文章信息文章历史:1四月2009关键词:工业废水厌氧处理城市污水有氧综合厌氧有氧生物反应器工业和城市废水厌氧- 好氧系统已良好运行多年。

虽然以前大部分的废水处理已开展传统的厌氧- 好氧处理厂,近年来,高速率厌氧- 好氧生物反应器已被越来越多的高化学需氧量(COD)的废水。

本文提供了一个高速率厌氧- 好氧污水处理技术的各类审查目前提供包括高速率生物反应器和综合厌氧- 好氧生物反应器。

综合分为四种类型,其中包括(i)与物理整合的生物反应器,生物反应器厌氧- 好氧区的分离,(二)无物理隔离的一体化生物反应器厌氧- 好氧区,(三)结合厌氧- 好氧序列间歇式反应器(SBR)及(iv)厌氧- 好氧文化系统。

在好氧和厌氧降解途径整合一个单一的生物反应器是能够提高整体的降解效率。

不同的集成的优点厌氧- 好氧生物反应器是突出和比较,以确定未来可能研究领域,充分利用这些污水处理方法。

比较表明治疗高强度工业废水的一体化生物反应器,使用堆叠配置是有利的,由于最小的空间要求,较低的资本成本和优良的COD去除率(超过83%)。

1.介绍过去一个世纪中,人口的不断增长和工业化,导致各种生态系统退化,影响人类生活的依靠。

在远洋和内河,这种污染主要是由于自净能力不足处理的工业和市政污水。

在初始阶段,这些废水含有高浓度的可以很容易生物降解的污染物,但其影响对生态系统的加载,无论是在总悬浮固体(TSS),生化需氧量(BOD5),化学需氧量(COD),可能在数万数千mg / L的[1]。

为了解决这个问题,我们的水环境增加负担,日益严格的正在实施的各种污染排放的监管,以减少废物的主要焦点。

“经常被视为产业发展的治疗系统,作为一个监管的义务,增加资本和运行成本,产生负面的经济回报。

环保立法应该没有必要带头创建额外费用,但是可以提供一个次要来源收入。

蓝梅主编 给排水科学与工程专业英语部分课文翻译中文版

蓝梅主编 给排水科学与工程专业英语部分课文翻译中文版

第四单元给水系统一般来说,供水系统可划分为四个主要组成部分:(1)水源和取水工程(2)水处理和存储(3)输水干管和配水管网。

常见的未处理的水或者说是原水的来源是像河流、湖泊、泉水、人造水库之类的地表水源以及像岩洞和水井之类的地下水源。

修建取水构筑物和泵站是为了从这些水源中取水。

原水通过输水干管输送到自来水厂进行处理并且处理后的出水储存到清水池。

处理的程度取决于原水的水质和出水水质要求。

有时候,地下水的水质是如此的好以至于在供给给用户之前只需消毒即可。

由于自来水厂一般是根据平均日需求流量设计的,所以,清水池为水需求日变化量提供了一个缓冲区。

水通过输水干管长距离输送。

如果输水干管中的水流是通过泵所产生的压力水头维持的,那么我们称这个干管为增压管。

另外,如果输水干管中的水流是靠由于高差产生的可获得的重力势能维持的,那么我们称这个干管为重力管。

在输水干管中没有中间取水。

与输水干管类似,在配水管网中水流的维持要么靠泵增压,要么靠重力势能。

一般来说,在平坦地区,大的配水管网中的水压是靠泵提供的,然而,在不平坦的地区,配水管网中的压力水头是靠重力势能维持的。

一个配水管网通过引入管连接配水给用户。

这样的配水管网可能有不同的形状,并且这些形状取决于这个地区的布局。

一般地,配水管网有环状或枝状的管道结构,但是,根据当地城市道路和街区总体布局计划,有时候环状和枝状结构合用。

城市配水管网大多上是环状形式,然而,乡村地区的管网是枝状形式。

由于供水服务可靠性要求高,环状管网优于枝状管网。

配水管网的成本取决于对管网的几何形状合适的选择。

城市计划采用的街道布局的选择对提供一个最小成本的供水系统来说是重要的。

环状管网最常见的两个供水结构是方格状、环状和辐射状;然而,我们不可能找到一个最佳的几何形状而使得成本最低。

一般地,城镇供水系统是单入口环状管系统。

如上所说,环状系统有一些通过系统相互连接的管道使得通过这些连接接的管道,可以供水到同一个需水点。

给水排水工程专业英语文献翻译译文第五篇

给水排水工程专业英语文献翻译译文第五篇

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。

给水排水工程专业英语文献翻译译文第一篇

给水排水工程专业英语文献翻译译文第一篇

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。

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毕业设计(论文)外文文献翻译文献、资料中文题目:饮用水水质问题及对策文献、资料英文题目:文献、资料来源:文献、资料发表(出版)日期:院(部):专业:给水排水工程班级:姓名:学号:指导教师:翻译日期: 2017.02.14毕业设计外文文献翻译学生姓名:学号:所在学院:专业:给水排水工程论文题目:Drinking Water Problems andSolutions Abstract指导教师:2007 年6月15日Drinking Water Problems and Solutions Abstract1 Introduction:Chlorination oxidation Introduction nearly half a ce ntury, the world economy has been developing rapidly, modernizationof industries, in particular synthetic chemical is used. Thesechemicals through most of human activities into a body of water, such as sewage and industrial wastewater discharges Agricultural use of fertilizers, pesticides wastage so that the water body accepted the physical and chemical traits a significant change [1]. Early 1980s found that more than 2,000 water organisms, water is more than 700, Among them, 20 kinds of carcinogens, suspected carcinogens 23 species, 18 species of croton oil, and 56 kinds of mutagens [2]. Now the world has attached great importance to trace organics pollution and human health.Currently many of the world's developing countries for drinking water purification methods, basically conventional coagulation sedimentation → → → sand filter chlorine disinfection process. This process for clarifying water to eliminate pathogens in water is very effective. After generally considered the conventional process, filter water after E. coli bacteria and infectious diseases such as HIV have access to basic removal. But with the water pollution, the intensification of a wide variety of organic matter into a body of water formed real solution, the conventional process is almost powerless. China's GB5749-85 "standard of drinking water" [3] Water detected a total of 35 projects. EC Directive provides drinking water were 66, the World Health drinking water regulations is 47. Compared with China, mainly to the increase in the trace organics project. Organic pollution of the drinking water situation, we must find new approaches.2 Commonly used method of disinfection of water treatmentIt is low cost, simple equipment, operation and management easy. But with the water chlorination of organic reaction occurred replace skull organic compounds, the so-called "three to" material, right, poses a potential human health hazards.1970s, the Netherlands and the United States found that treatment workers, chlorination, drinking water produced trihalomethanes (TCM) compounds, mainly chloroform,dichloroacetic acid, chlorine and bromine between the intermediate product. After the chlorination of drinking water has not only generated three skull methane, but also generate other skull Organics (TCO), concentration of TCM general concentration of 5 ~ 10%, which on human health have the same adverse effects [4]. TCM TCO and the main precursorof the three major categories : ①wreckage from the plant as a result of humic acid and fulvic acid degradation products, such as resorcinol, homovanillic acid and fulvic acid degradation products; ②algae from the pyrimidine amino acid, tryptophan, proline, uracil, protein; ③ industrial wastewater of certain compounds, such as phenols. Use chlorine to disinfect TCM TCO and the emergence of awareness of the existence of the hidden danger. Thus, non-chlorine disinfection technology research to develop rapidly.3 measures and the development trend [5] to solve the drinking water problem of pollutionthere are two ways : ①protection of drinking water sources;②strengthen water treatment processes. Generally speaking, the quality of our water environment is also hard to improve short period of time. To the increasing demands for drinking water, water pollution from access to quality drinking water, alternative method is to strengthen the water treatment process that uses advanced deep water treatment technology. Is briefly described below4 ConclusionClosing above the new water treatment technology now have their own shortcomings, to be further explored and examined. If UV-ozone and UV-CO2 is the most promising of the two photochemical oxidation, desire of the family or group users of drinking water depth and special treatment of organic wastewater treatment play an important role. UV-O3 combinedtechnique has been USEPA (EPA) to address the identification of multiple chlorobenzene the most effective technology. But the process in the current obstacles to the use of CO2 is separated from the water, choose a suitable carrier and fixed method, preparation or other forms of photo-catalyst, and research and development of photochemical oxidation and water needs to deal with the combination of UV light or metal skull of lights, so power, wavelength suitable and convenient. Membrane operate with convenience, good effect, but easy to silting and pollution, with its investment and operating costs are too high. KMnO4 and ozone oxidation, often generate many intermediate products, and even some organic fundamental ineffective. Therefore, in recent years more and more emphasis on the treatment of workers in physical, chemical, biological purification organically combine bold attempt, Research such as O3 - H2O2 - BAC, O3 - coagulation-activated sludge, KMnO4 - BAC O3-UV-H2O2, O3-film processing, O3-stripping and other possible joint technology, give full play to their respective means of the technical features and advantages of comprehensive management, in order to achieve the best removal.饮用水水质问题及对策1 引言近半个世纪以来,世界各国经济迅速发展,现代化工业,尤其是合成化工业更是突飞猛进,这些化学物质的大部分通过人类活动进入水体,如生活污水和工业废水的排放,农业使用化肥、杀虫剂的流失等,使接纳水体的物理化学性状发生了显著的变化〔1〕。

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