大学专业英语阅读教程 给水排水 李田 全文翻译
给水排水专业英语课件(李田)11
hypochlorite n. 次氯酸盐 hypo- “在...之下,亚,次,次于,不足,从属于” hypochlorous adj. 次氯酸的 hypochlorous acid n. 次氯酸 hydrochloric adj. 氯化氢的 盐酸的 dissociate v. 分离, 电离 ionize vt. 使离子化 vi. 电离 equilibria n. 均衡, 平衡 equilibrium 的复数形式 ammonium n. 铵 ammonia n. 氨, 氨水 chloramine n. 氯胺 monochloramine n.一氯胺 di- tri3
因此，可以得到结论，不管氯或次氯酸根添加与否，在水 中都建立了相同的平衡。
11
The significant difference would be in pH effects and the influence of chlorine or hypochlorites on the relative amounts of OCland HOCl at equilibrium. Chlorine tends to decrease the pH, whereas hypochlorites tend to increase the pH.
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Chemistry of Chlorination
Chlorine is used in the form of free chlorine or as hypochlorites. In either form it acts as a potent oxidizing agent and often dissipates itself in side reactions so rapidly that little disinfection is accomplished until amounts in excess of the chlorine demand have been added.
翻译原文
The influence of temperature on nutrient treatmentefficiency in stormwater biofilter systemsG.-T.Blecken*,Y.Zinger***,T.M.Muthanna**,A.Deletic***,T.D.Fletcher***and M.Viklander* *Urban Water,Department of Civil,Mining and Environmental Engineering,Lulea˚University of Technology, 97187Lulea˚,Sweden(E-mail:godecke.blecken@ltu.se;maria.viklander@ltu.se)**Norwegian Institute for Water Research,Havnegata9,7010Trondheim,Norway(E-mail:tone.muthanna@niva.no)***Department of Civil Engineering,Facility for Advancing Water Biofiltration,Monash University,Victoria 3800,Australia(E-mail:yaron.zinger@.au;Tim.Fletcher@.au;ana.deletic@.au)Abstract Nutrients can cause eutrophication of natural water bodies.Thus,urban stormwater which is an important nutrient source in urbanised areas has to be treated in order to reduce its nutrient loads.Biofilters which use soilfilter media,biofilms and plants,are a good treatment option for nutrients.This paper presents the results of a biofilter column study in cold temperatures(þ28C,þ88C,control atþ208C) which may cause special problems regarding biofilter performance.It was shown that particle-bound pollutants as TSS and a high fraction of phosphorus were reduced well without being negatively influenced by cold temperatures.Nitrogen,however,was not reduced;especially NO x was produced in the columns. This behaviour can be explained with both insufficient denitrification and high leaching from the columns. Keywords Biofilter;cold climate;nutrients;stormwater treatmentIntroductionNutrients can cause eutrophication in receiving natural water bodies(Browman et al., 1979;Pitt et al.,1999;Kim et al.,2003).Stormwater runoff is an important source of nutrients in urbanised areas(Larm,2000;Graves et al.,2004;Taylor et al.,2005),and it should therefore be treated.Stormwater biofiltration,also known as bioretention,is a novel option that might be able to treat nutrients in stormwater in order to prevent eutrophication of recipients.A biofilter consists offilter media placed in a trench or basin that is planted on the top.It has a detention storage on the top(by placement in a depression)and a drainage pipe at the bottom to collect the treated water.Stormwater is treated by mechanical,biological and chemical processes in thefilter media,but also by the plants and biofilms,that develops in the media and on the plant roots(Prince George’s County,2002;Hsieh and Davis,2005).Several studies conducted so far have shown a significant removal of phosphorus, phosphate and ammonium,but with low(and sometimes negative)removal of nitrate (Davis et al.,2001;Lloyd et al.,2001;Henderson et al.,2007).However,biofilters are still a relatively new technology and hence,only limited data of the performance of these systems are available.Particular problems could arise when implementing biofilters in regions with constant or temporary cold temperatures,due to reduced biological activity, shorter growing seasons and a smaller number of adapted plant species.However,these systems may still perform well in these instances,since adequate nutrient removal has been achieved in constructed wetlands in cold subalpine climates(Heyvaert et al.,2006). Biofilter performance in cold temperatures is the deciding factor to their successful implementation in regions with rainfall on non-frozen ground during cold periods Water Science & Technology Vol 56 No 10 pp 83–91 Q IWA Publishing 2007 83doi:10.2166/wst.2007.749(autumn,winter and spring in temperate climate;autumn,later spring and summer in cold climate).This paper presents preliminary results of a study of the performance of biofilters in relation to temperature.The aim was to determine the nutrient treatment performance of stormwater biofilters in low temperatures in order to enable an analysis of whether there is a correlation between temperature and treatment rate.Material and methods Experimental set-up Laboratory tests were conducted on 15biofilter mesocosms (‘biofilter columns’)made of PVC stormwater pipe (inner diameter:377mm,area:0.11m 2,height:900mm).A trans-parent top (height:400mm)allowed water to pond without affecting light availability for plant growth.The inside wall was sandblasted to prevent preferential flow along the wall.A drainage pipe (diameter:58mm)at the bottom discharged to a sampling outlet (Figures 1and 2).The filter media in the columns included four layers (listed from top,Figure 2):(1)sandy loam layer,400mm,medium to coarse sand with 20%topsoil in the upper 100mm,(2)sand layer,400mm,fine to medium sand,(3)transition layer,30mm,coarse sand and (4)underdrain,70mm,fine gravel with embedded drainage pipe.The columns were planted with Carex rostrata Stokes (Bottle sedge)which is wide-spread in the northern hemisphere (Anderberg and Anderberg,2006).The plant density in the columns was 8plants per column,which corresponds to a density of approximately 73plants/m 2.Before they were planted in the columns,the plants were grown for 5weeks outside to develop a substantial root system.Afterwards they were grown in the columns for two month and irrigated with tapwater.Figure 1Biofilter columns in climate roomG.-T.Bleckenetal.84In order to investigate the temperature effect on the biofilter performance,the tests were carried out in three thermostat controlled climate rooms at constant target tempera-tures of þ28C,þ88C,and þ208C (þ35.68F,þ46.48F,and þ688F,resp.).Five columns each were placed in every climate room (Figure 1).The air temperature in the climate rooms was logged at a 15minute interval using one EBI 20-T (88C)and two EBI 2T-112(28C and 208C)temperature loggers (ebro Electronic,Ingolstadt,Germany).All columns were illuminated with high pressure sodium greenhouse lamps (G-Power Agro,400W,55,000Lm)12hours daily.Experimental procedureStormwater .Since natural stormwater was not available in the required quantity and with constant water quality over the time of the experiment,nor could be stored without significant changes to its quality,semi-synthetic stormwater was used.It was made by mixing tap water with gully pot sediment to achieve the required TSS concentration,topped with certain pollutants to achieve the targeted pollutant concentrations,as outlined in Table 1(only for nutrients;heavy metals were added as well,but are not reported in this paper).A new mixture was made for every stormwater application.The water was stored at the respective temperature (28C,88C,208C,resp.)for at least 24hours before dosing the columns in order to have similar water and air temperatures.In Lulea ˚(Sweden)it rains approximately two times per week in September and October (the month with the most rain events in cold temperatures)with a total precipi-tation amount of around 110mm (SMHI,2005).This corresponds to an average of 5.4L/m 2stormwater runoff per rain event from a catchment with 85%impervious surface.It Figure 2Biofilter column configurationG.-T.Blecken et al.85was assumed that the biofilter area represents appr.4%of the catchment area (one col-umn with 0.11m 2for 2.75m 2catchment)(Wong et al.,2006).Therefore every column was dosed with 15L (5.4L/m 2·2.75m 2¼14.85L <15L)of stormwater twice weekly.Sampling .From the stormwater a sample was taken in three replicates before every stormwater application.All outflow water was collected in PE-tanks until the next dosing event,it was stored at þ28C,and a composite sample was taken from each PE-tank,i.e.15samples per each dosing.This paper reports on results of the first four weeks of stormwater dosing (i.e.eight events).Analyses .All samples were analysed for total and dissolved N,ammonium (NH þ4),nitrate/nitrite (NO x ),TSS,and pH.The dissolved samples were filtered,using Whatman ME25membrane 0.45m m pore size filters.Before analysing P and N,the samples were digested with peroxo-disulphate (according to the Swedish standard method SS 028127)and oxidised with peroxisulphate (SS 028131),resp.The analyses were conducted with a continuous micro flow analyser (QuAAtro,Bran þLuebbe,Hamburg,Germany)according to the device-specific methods no.Q-031-04for P,no.Q-003-04for N and NO x and no.Q-001-04for NH þ4.TSS was determined by filtration through Whatman GF/A 1.6m m pore size glass microfibre filters (SS-EN 872)in one replicate.pH was measured with a field pH-meter (pH330,WTW GmbH,Weilheim,Germany).Data analyses Pollutant reduction was calculated as reduction ¼(1-(out/in))·100%.Thus,production of pollutants results in a negative reduction rate.Analysis of variance (ANOVA)was used to test the influence of temperature on outflow concentrations.Furthermore,box plots were created for nitrogen species and phosphorus to compare in-and outflow concen-trations and their evolution over time.All statistical calculations and plots were computed with the software MINITAB w 15.1.Results and discussion The mean temperature in the three different rooms were 1.88C (SD:1.018C),7.48C (SD:0.358C)and 20.38C (SD:1.028C)respectively.Thus,the real temperatures were very near the target temperatures.The mean inflow and outflow pollutant concen-trations (mg/L)as well as reduction rates (%)at the three different temperatures are shown in Table 2.pH .The average pH-value of the stormwater was 6.9.The pH increased in the columns and the outflow pH at all temperatures was around 7.4.Table 1Semi-synthetic stormwater pollutants and their sourcesPollutant Targeted SourcepH6.9H 2SO 4TSS140mg/L Stormwater gully pot sediment (#400m m Phosphorus (total)0.3mg/L KH 2PO 4(potassium dihydrogen phosphate)0.32mg/L nitrate:KNO 3(potassium nitrate)Nitrogen (total) 1.4mg/L 0.24mg/L ammonium:NH 4Cl (ammonium chloride)organic nitrate:C 6H 4NO 2(nicotinic acid)G.-T.Bleckenetal.86TSS .Reduction of TSS was around 97%,and whilst the effect of temperature on this removal was statistically significant (p ¼0.001),it accounted for very little of the observed variation,and was of no practical significance (Table 3,Figure 3).Other factors are clearly influencing TSS removal,although it was high in all cases.The low difference between the columns at different temperatures is not surprising since the TSS removal is mainly a matter of mechanical filtration which itself is not influenced by temperature (unless the soil media soil freezes forming channels).Because of the high TSS removal,a high (and largely temperature independent)removal of particle bound pollutants could be expected.Phosphorus .In the stormwater inflow 85%of the total phosphorus was particle bound.The fraction was slightly different in the outflow at the different temperatures (28C:87%particle bound,88C:84%particle bound and 208C:82%particle bound).A temperature independent removal of about 80%was detected for total phosphorus (p ¼0.933,Table 3).There is a very clear decrease in the outflow concentrations and their variances over time (Figure 4).Dissolved phosphorus was also well removed by the biofilter,with no significant temperature dependence (p ¼0.285,Table 3).However,its reduction rate was slightly higher at cold temperatures.The results make sense,if we assume that physical filtration is the main mechanism for P removal,while biological activity within the soil may cause some leaching of P from media (the higher biological activity occurs at higher temperatures).This leaching is getting smaller with time as the Table 2Pollutant concentrations and removalStormwater (2)all temp.Outflow (3)28C 88C 208CpH 6.90(0.20)7.32(0.13)7.40(0.10)7.46(0.18)TSS concentration 142.7(13.9) 3.6(1.4) 5.1(1.7) 4.6(2.1)mean reduction 97.5%96.4%96.8%N total concentration 1.38(0.16) 1.38(0.29) 1.54(0.25) 4.23(0.68)mean reduction 20.5%211.6%2207.8%N dissolved concentration 1.16(0.08) 1.33(0.26) 1.31(0.15) 3.94(1.02)mean reduction 214.9%213.2%2240%NO x (1)concentration 0.24(0.01)0.72(0.26)0.89(0.13) 3.79(0.57)mean reduction 2198%2265%21461%NH 4(1)concentration 0.32(0.05)0.11(0.05)0.14(0.06)0.15(0.05)mean reduction 64.5%56.2%51.7%P total concentration 0.292(0.018)0.055(0.036)0.058(0.032)0.056(0.030)mean reduction 81.2%80.3%80.7%P dissolved concentration 0.031(0.017)0.007(0.002)0.009(0.004)0.010(0.005)mean reduction 77.5%71.5%69.3%(1)only the first 4events have been analysed (2)three replicates per event analysed (3)mean value of five replicate columns and all events.Table 3One-way ANOVA:p-value of temperature influence on outflow concentrations and R 2(adjusted)of the modelp -value R 2(adj.)TSS 0.0019.0%N total 0.00089.4%N dissolved 0.00080.4%NO x (2)0.00093.7%NH ð2Þ40.065 6.0%P total0.9330.0%P ð2Þdiss :0.285 2.1%G.-T.Blecken et al.87source is depleted,which explains the decreasing outflow concentrations with time in Figure 4.Overall however,mechanical removal of phosphorus is the most important factor and therefore overall P removal is high.Nitrogen .While the biofilters at 28C and 88C showed little or no leaching of total nitrogen,a high production (on average 2208%removal)was observed at 208C (Figure 5,Table 2).No trend over time wasobserved.Figure 3Box plot of in-and outflow TSS concentrations at the 3different temperatures and 8samplings Figure 4Box plots of in-and outflow total phosphorus concentrations at the 3different temperatures and 8samplingsG.-T.Bleckenetal.88The total nitrogen in the synthetic stormwater influent was 84%dissolved,whilst in the treated outflow water 96%,85%and 93%was at 28C,88C and 208C,respectively.The proportion of the nitrogen compounds changed during the treatment in the biofilter.NH þ4was reduced at all temperatures,whilst NO x was produced (Table 2,Figure 6).This means that nitrification in the unsaturated zone of the biofilter was occurring and there-fore NH þ4levels were decreased and NO x levels were increased.Since no denitrification was taking place due to the lack of an anoxic zone and/or a carbon source,levels of NO xFigure 5Box plots of in-and outflow total nitrogen concentrations at the 3different temperatures and 8samplingsFigure 6Box plots of in-and outflow:(a)dissolved NO x ,(b)and dissolved NH þ4concentrations at the 3different temperatures and 8samplings G.-T.Blecken et al.89However,a significant temperature effect was demonstrated for dissolved nitrogen behaviour (p ¼0.000dissolved N and NO x ,Table 3):the higher the temperature the higher the NO 3production due to increasing nitrification with increasing temperatures.More importantly,more nitrogen from the soil leached to the outflow water at higher temperatures.Unfortunately,it is not clear yet whether the leaching will stop over time as plants mature,as has been observed in similar biofilter studies (Zinger et al.,2007).The plants had only 2–3months of establishment,while in Zinger at al ’s experiments they had 5months to establish.It is known that plants (and in particular their roots)play a major role in N removal,since unvegetated biofilters are always demonstrated to leach nitrogen (Hatt et al.,2006;Lee and Schloz,2007),whilst vegetated biofilters do not (Henderson et al.,2007).Conclusion Even in cold climates,it is clear that effective removal of particle-bound pollutants (TSS and particulate phosphorus)can be achieved.This verifies the findings of other cold climate studies (Ba ¨ckstro ¨m,2002;Muthanna et al.,2007).However,the results showed poor overall removal of nitrogen from the stormwater.In particular,there was a very high production of NO x ,which was probably caused by nitrification,and limited denitrifi-cation.Such large net production of nitrogen was not expected as other studies have shown a reduction or at least only minor production of nitrogen even in biofilters without an anoxic zone (Kim et al.,2003;Scholz,2004;Zinger et al.,2007).However,it is possible that the short establishment time of the plants in the presented experiments is the main cause of this.Further research should be conducted to investigate if the removal of N will begin to improve over time.The biofilters showed the best performance for nitrogen (i.e.the lowest production)at the coldest temperatures.A key area of subsequent research is therefore to determine if the addition of an anoxic zone with added carbon source,which has been shown to improve denitrification in biofilters (Kim et al.,2003;Zinger et al.,2007),would remain effective,even in cold temperatures.References Anderberg,A.-L.and Anderberg,A.(2006).Den virtuella floran:Naturhistoriska Riksmuseet.http://linnaeus.nrm.se/flora/(accessed 08October 2007).Browman,M.G.,Harris,R.F.,Ryden,J.C.and Syers,J.K.(1979).Phosphorus loading from urban stormwater runoff as a factor in lake eutrophication -Theoretical considerations and qualitative aspects.J.Environ.Qual.,8(4),561–566.Ba ¨ckstro ¨m,M.(2002).Grassed Swales for Urban Drainage .Doctoral Thesis 2002:06,Division of Sanitary Engineering,Lulea ˚University of Technology,Lulea ˚,Sweden.Davis,A.P.,Shokouhian,M.,Sharma,H.and Minami,C.(2001).Laboratory study of biological retention for urban stormwater management .Water Environ.Res.,73(1),5–14.Graves,G.A.,Wan,Y.and Fike,D.L.(2004).Water quality characteristics of storm water from major land uses in south Florida .J.Am.Water Resour.Assoc.,40(6),1405–1418.Hatt,B.E.,Siriwardene,N.,Deletic,A.and Fletcher,T.D.(2006).Filter media for stormwater treatment and recycling:the influence of hydraulic properties of flow on pollutant removal .Water Sci.Technol.,54(6–7),263–271.Henderson,C.,Greenway,M.and Phillips,I.(2007).Removal of dissolved nitrogen,phosphorus and carbon from stormwater by biofiltration mesocosms .Water Sci.Technol.,55(4),183–191.Heyvaert,A.C.,Reuter,J.E.and Goldman,C.R.(2006).Subalpine,cold climate,stormwater treatment with a constructed surface flow wetland .J.Am.Water Resour.Assoc.,42(1),45–54.Hsieh,C.-H.and Davis,A.P.(2005).Multiple-event study of bioretention for treatment of urban storm water runoff.Water Sci.Technol.,51(3–4),177–181.G.-T.Blecken et al.90Kim,H.,Seagren,E.A.and Davis,A.P.(2003).Engineered bioretention for removal of nitrate from stormwater runoff.Water Environ.Res.,75(4),355–367.Larm,T.(2000).Stormwater quantity and quality in a multiple pond-wetland system:Flemingsbergsviken case study.Ecol.Eng.,15(1–2),57.Lee,B.-H.and Scholz,M.(2007).What is the role of Phragmites australis in experimental constructed wetlandfilters treating urban runoff?Ecol.Eng.,29(1),87–95.Lloyd,S.,Fletcher,T.D.,Wong,T.H.F.and Wootton,R.M.(2001).Assessment of pollutant removalperformance in a bio-filtration system-preliminary results.Paper presented at the Second South Pacific Stormwater Conference,New Zealand.Muthanna,T.M.,Viklander,M.,Blecken,G.-T.and Thorolfsson,S.T.(2007).Snowmelt pollutant removal in bioretention areas.Water Res.,41(18),4061–4072.Pitt,R.,Clark,S.and Field,R.(1999).Groundwater contamination potential from stormwater infiltration practices.Urban Water,1(3),217.Prince George’s County(2002).Bioretention Manual.Lead Author:D.A.Winogradoff.Department of Environmental Resources,Programs&Planning Division,Prince George’s County,Maryland,USA. Scholz,M.(2004).Treatment of gully pot effluent containing nickel and copper with constructed wetlands ina cold climate.J.Chem.Technol.Biotechnol.,79,153–162.SMHI.Swedish Meteorological and Hydrological Institute(2005).Klimatkarta Uppma¨tt nederbo¨rd 1961–1990,ma˚nadsvis.(In Swedish).Taylor,G.D.,Fletcher,T.D.,Wong,T.H.F.,Breen,P.F.and Duncan,H.P.(2005).Nitrogen composition in urban runoff–implications for stormwater management.Water Res.,39(10),1982.Wong,T.H.F.,Fletcher,T.D.,Duncan,H.P.and Jenkins,G.A.(2006).Modelling urban stormwater treatment–A unified approach.Ecol.Eng.,27(1),58.Zinger,Y.,Fletcher,T.D.,Deletic,A.,Bleckenr,G.-T.and Viklande,M.(2007).Optimisation of the Nitrogen Retention Capacity of Stormwater Biofiltration Systems.Paper presented at the NOVATECH 2007,Lyon,France.G.-T. Blecken et al.91。
给水排水专业英语课件(李田)6
4-1
The following factors have been found to influence water consumption in a major way:
1. 2. 3. 4. 5. Industrial activity; Meterage; System management; Standard of living; Climate.
5-1
Small
rural and suburban communities will use less water per person than industrialized communities. Industry is probably the largest single factor influencing per capita water use.
3-4
Many factors influence water use for a given system. For example, the mere fact that water under pressure is available stimulates its use, often excessively, for watering lawns and gardens , for washing automobiles, for operating air-conditioning equipment, and for performing many other activities at home and in industry.
The storage reservoir may be elevated (the ubiquitous water tower), or it may be at ground level. The stored water is used to meet high demand during the day. Storage compensates for changes in demand and allows a smaller treatment plant to be built. Storage is also used to provide emergency backup in case of a fire.
给水排水专业英语课件(李田)13
给水处理污泥工艺的选择
1
Historically, settled coagulation wastes and backwash waters had been disposed of without treatment. 过去，沉淀的混凝废弃物与反冲水是不经处理而直接排放的。 The practice was justified on the basis that the returned material had originally been present in the river or lake. 基于这些返回的物质是河流与湖泊中原本就有的，这种做法 曾经被认为正确的。
Emphasis is placed on preventing magnesium hydroxide precipitation, since it inhibits dewaterability and processing for recovery of lime. 应当强调的是，由于氢氧化镁抑制脱水性能和 回收石灰的处理，要防止形成氢氧化镁沉淀。
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Table 2-2 Treatment and Disposing of Water Treatment Sludges Storage prior to processing Sedimentation basins Separate holding tanks F1occulator-c1arifier basins Thickening prior to dewatering Gravity settling Chemical conditioning prior to dewatering Polymer application Lime addition to alum sludges
大学专业英语给排水专业课文翻译
第7章 水处理工艺选择 流域管理应该被视为给水系统运行的一部分，这对于保护原水水质非常重要。 在取水构筑物之后，是水的处理工艺。目前在市政水处理的预处理工艺有：筛选，预沉淀或 清淤，化学药剂添加和曝气。 筛选应用在地表水的预处理之中。预沉淀常常用于从河水去 除悬浮物质. 化学处理，在水厂内混凝之前，频繁用于提高预沉淀效果，处理难去除的物质， 如味道和气味的化合物、色度，降低高的细菌浓度。用于预沉淀的传统化学药剂是聚合电解 质和明矾。曝气习惯上是从地下水中除铁除锰的第一步，也是分离溶解性气体如硫化氢和二 氧化碳的标准的方法。用于水厂的处理工艺依赖原水水源和所需的出厂水水质。 选择用于 处理的具体化学药剂基于运行所需反应的有效性和成本。例如，活性炭、氯、二氧化氯和高 锰酸钾都可用于味道和气味的控制。虽然价格最低廉，但过量的氯化，会产生不期望出现的 三卤甲烷。在地表水处理厂中经常提供用于投加两到三种除味的化学药剂的设备，所以操作 者可以选择最有效和最经济的化学应用。没有用于各种水体的色度去除的固定方法。经过足 够预处理明矾混凝，采用化学氧化药剂或者活性炭，可能提供满意的去除。另一方面，更昂 贵的混凝剂有可能证明更加有效并降低整体化学药剂成本。也许在水处理工艺设计要考虑最 重要的是提供灵活性。操作者应该有一些手段来改变某些化学药剂的应用点（投加点）。例 如，加氯的投药管线常常提供满足前投加、中间投加、后投加氯的要求。应该提供多种药剂 进料器和存储容器，使处理工艺能采用不同的化学药剂。原水水质的降解，或者药剂成本的 改变，可能决定了在混凝中混凝剂和助凝剂使用药剂类型的改变。在地表水处理厂情况下， 预留场地以背建额外的预处理设施建设空间是值得考虑的。河水流量可能由于水坝的建设、 渠道的改进或者上游用水而改变。水质会因人为改变和流域的侵占而改变源于市政和工业废 物和农业地表径流的污染物浓度可能增加。湖泊会变得更加富营养化。通过增加曝气装置容 量、增加加氯量，使用沉淀池作为调节池，安装完毕后，水厂生产能力得到扩大，处理工艺 转变成只去除铁锰。目前该水厂只能够运行曝气氧化去除铁锰与氯化消毒。由于水井供水稳 定，全年的出厂水水质优良。图 2-3 的给水处理厂是一个始建于 1950 年代的传统的地表水 处理厂。从那时起，湖水水源日益富营养化，已经提供额外的设备进行味道与气味的控制。 在较差原水水质的关键时期，活性炭、二氧化氯和各种用于提高药品处理的辅助药剂目前是 适宜的。在一年之中的大部分时间，最终出水是非常可口的，但是在春秋季节的湖泊倒层期 间，味道和气味不能够被完全去除。对于水质剧烈变化的浑浊污染的河水而言，应该采用一 个复杂而灵活的处理系统。一般的处理方案包括：用于沉砂的普通沉淀，混合与沉淀，必要 的情况下采用混凝剂；分离处根据原水水质的变化，这个水厂的运行每天都会改变，每个季 节都会改变。即使这样，一些难处理的无机或有机物质仍然能够通过复杂的处理系统。 理以实现部分软化；在澄清池中的絮凝，双媒过滤，加氯获得余氯，pH 调节和结垢控制。 一个河水处理厂应该具有足够的工艺高度，以防止任何污染紧急事件短流的可能性。 第8章 混凝 显然，如果在水的混凝与软化过程中的化学反应将要发生的话，那么化学药剂必须与水进行 混合。在这一章节我们将要开始关注必要的物理方法以完成混凝与软化的过程。 下面将要提出的基本原理对于混合、絮凝以及过滤的操作都是适用的。或者，或者称为快速 混合，是由此化学药剂快速均匀的分布到水中的过程。理想状态下，化学药剂会迅速分散到 水中。在混凝和软化的过程中， 在快速混合中发生的化学反应形成了沉淀。在混凝过程中 形成氢氧化铝或氢氧化铁，而在软化过程中形成碳酸钙和氢氧化镁。在形成沉淀后，有必要 使它们互相碰触，以使得它们能够聚集，然后形成更大的颗粒，叫做絮体。这个接触的过程 叫做絮凝，它是通过缓慢、柔和的混合完成的。在给水处理与污水处理的过程中，混合的程
给水排水专业英语课件(李田)20
In some circumstances, these pollutants may be of major concern.
2
In these cases, processes capable of removing pollutants not adequately removed by secondary treatment are used in what is called tertiary wastewater treatment (these processes have often been called advanced wastewater treatment, or AWT for short). The following processes. sections describe available AWT
Unit 20
Advanced Wastewater Treatment
污水深度处理
1
Although secondary treatment processes, when coupled with disinfection, may remove over 85 percent of the BOD and suspended solids and nearly all pathogens, only minor removal of some pollutants, such as nitrogen, phosphorus, soluble COD, and heavy metals, is achieved .
The biological process is called nitrification/ denitrification. The chemical process is called ammonia stripping.
给水排水专业英语原文
Unit1水文循环也称为水循环或水循环，描述水在地球表面之上，之下的连续运动。
水可以在水循环中的各个地方在液体，蒸气和固体之间改变状态。
虽然地球上的水平衡保持不变，但是水分子可以进出大气。
通过蒸发，冷凝，降水，渗透，径流和地下流动等物理过程，水从一个水库移动到另一个水库，例如从河流到海洋，或从海洋到大气。
[1]这样做，水经历了不同的阶段：液体，固体和气体。
水循环涉及热能的交换，这导致温度变化。
例如，在蒸发过程中，水分从周围吸收能量，冷却环境。
相反，在凝结过程中，水会向周围环境释放能量，使环境变暖。
水循环在维持地球生命和生态系统方面具有重大意义。
即使每个水库的水都起着重要的作用，水循环给我们这个星球上的水的存在带来了更多的意义。
？通过将水从一个水库转移到另一个水库，水循环净化水，补充淡水，并将矿物运送到全球不同地区。
[2]它还涉及通过侵蚀和沉积等过程来重塑地球的地质特征。
另外，由于水循环也涉及热交换，所以也对气候产生影响。
驱动水循环的太阳加热海洋中的水分。
水分蒸发成水蒸气。
冰雪可以直接升华成水汽。
蒸散是从植物中蒸发出来并从土壤中蒸发出来的。
上升的气流将蒸汽带入大气中，在较冷的温度下，气体凝结成云。
气流使全球各地的水汽移动，云粒子相互碰撞，成长，并由于降水而从天而降。
？一些降水如雪或冰雹，雨雪，可以积蓄成冰盖和冰川，可以储存数千年的冷冻水。
大部分的水回落到海洋中，或者像雨水一样落到地面上，在地表径流时，水流过地面。
一部分径流进入山谷中的河流，河流将水流向海洋。
径流和地下水在湖泊中作为淡水储存。
？并非所有径流都流入河流，大部分径流都渗透到地下渗透。
有些水深入地下，补充含水层，长期储存淡水。
有些渗入物靠近地表，可以渗入地表水体（和海洋）作为地下水排放。
一些地下水在地表上找到开口，并以淡水泉的形式出现。
随着时间的推移，水回到了我们的水循环开始的海洋。
一个水库在水文循环中的停留时间是水分子在该水文循环中花费的平均时间。
给排水专业英语课文翻译
There are several species of bacteria that are widely found in the aquatic environment but so not normally cause illness in the immuno-competent. They are not therefore particularly associated with health problems from drinking-water. It is important to be aware of them nevertheless, as they have occasionally been associated with disease where people may already be ill with other conditions or their immune system is reduced and unable to cope (Dufour 1990).They are usually known as environmental bacteria, but I have also come across the terms adventitious or heterotrophic in this context (although heterotrophic strictly means they get their source of energy and cellular carbon from the oxidation of organic material, that is, by feeding on plants or animals-rather than photosvnchesis). Where laboratories carry out plare counts, it is often these bacteria that are cultured. There will be many different types of environmental bacturia but the imporiant ones for drinking-water safety are listed here.AeromonasAeromonas are commonly found in both fresh and salt waters. There are several species, each one favouring a particular environmental niche. Aeromonas bydropbila is found mainly in clean river water, Aeromonas sobria in stagnant water and Aeromonas caviae in marine water. They are so common that people have tried to use them in rivers as indicators of pollution. They are known to cause diarrhoea and infection in soft tissue where damaged skin comes into contact with contaminated river or lake water.Aeromonas caviae is the one most commonly associated with diarrhoea. Diarrhoeal infection is usually mild, although more severe symptoms have occasionally been known, including bloody diarrhoea and chronic colitis (inflammation of the colon).Aeromonas have been found in treated chlorinated water and sometimes, there is re-growth in the distribution pipes. Chlorine only appears to have a temporary effect on them and this may mean that it stops them from reproducing but does not kill them. If left (presumably so they can get their breath back and have a bit of a rest after the chlorine attack) they can continue as normal.有一些种类的细菌在水生环境中被发现,但通常不引起疾病immuno-competent。