海水淡化在加利福尼亞州

1、海水淡化在加利福尼亞州 CHAPTER ONE: BACKGROUND第一章： 背景 · Desalination Plants Worldwide海水淡化廠世界范圍 · Desalination Technologies海水淡化技術(shù) o Reverse Osmosis (RO)反滲透（反滲透） o Distillation蒸餾 · Input Water (Feedwater)投入水（給水） · Product Water生產(chǎn)用水 · Product Water Recovery產(chǎn)品水回收 · Pretreatment Proces

2、ses預(yù)處理過(guò)程 · Filter Backwashing, Membrane Cleaning and Storage, Scaling Prevention and Removal, and Pipeline Cleaning過(guò)濾器反沖洗，膜的清洗和存放，防結(jié)垢和移除，以及管道清洗 · Waste Discharges廢污水排放 · Energy Use能源使用 · Comparison of Distillation and Reverse Osmosis Technologies比較蒸餾和反滲透技術(shù) · Costs of Desalin

3、ated Water成本的淡化水 · Costs of Other Water Sources成本的其他水源 Desalination Plants Worldwide海水淡化廠世界范圍 Of the more than 7,500 desalination plants in operation worldwide, 60% are located in the Middle East.對(duì)超過(guò)7500名的海水淡化廠在世界各地運(yùn)行， 60 是位于中東地區(qū)。 The world's largest plant in Saudi Arabia produces 128 MGD o

4、f desalted water.世界上最大的核電廠在沙特阿拉伯生產(chǎn)128 mgd的脫鹽水。 In contrast, 12% of the world's capacity is produced in the Americas, with most of the plants located in the Caribbean and Florida.相比之下， 12 的世界的能力，是產(chǎn)于美洲，而且大部份的工廠位于加勒比海和佛羅里達(dá)州。 To date, only a limited number of desalination plants have been built alon

5、g the California coast, primarily because the cost of desalination is generally higher than the costs of other water supply alternatives available in California (eg, water transfers and groundwater pumping).迄今為止，只有有限數(shù)量的海水淡化廠已建成沿加州海岸，這主要是因?yàn)楹Ｋ某杀酒毡楦哂诔杀镜钠渌┧k法可在加利福尼亞州（例如，水資源轉(zhuǎn)移和地下水抽水） 。 However, as dr

6、ought conditions occur and concern over water availability increases, desalination projects are being proposed at numerous locations in the state.然而，由于干旱條件下發(fā)生和關(guān)注水的供應(yīng)增加，海水淡化項(xiàng)目正在擬議在許多地點(diǎn)設(shè)在國(guó)家。 Desalination Technologies海水淡化技術(shù) Desalination is a process that removes dissolved minerals (including but not li

7、mited to salt) from seawater, brackish water, or treated wastewater.海水淡化是一個(gè)過(guò)程，可去除溶解礦物質(zhì)（包括但不限于鹽） ，從海水，半咸水或處理過(guò)的廢水。 A number of technologies have been developed for desalination, including reverse osmosis (RO), distillation, electrodialysis, and vacuum freezing.一些技術(shù)已經(jīng)開(kāi)發(fā)出來(lái)，用于海水淡化，包括反滲透（反滲透） ，蒸餾法，電滲析法，真空

8、冷凍。 Two of these technologies, RO and distillation, are being considered by municipalities, water districts, and private companies for development of seawater desalination in California.兩個(gè)這些技術(shù)，反滲透法和蒸餾，警方現(xiàn)正考慮由直轄市，水區(qū)，而私人公司，為發(fā)展海水淡化技術(shù)在加利福尼亞州。 These methods are described below.這些方法介紹如下。 · Reverse Os

9、mosis (RO) 反滲透（反滲透） In RO, feedwater is pumped at high pressure through permeable membranes, separating salts from the water (Figure 1).在反滲透，給水泵在高壓下，通過(guò)滲透膜，分離鹽從水（圖1 ） 。 The feedwater is pretreated to remove particles that would clog the membranes.給水預(yù)處理，以消除粒子，將阻塞膜。 The quality of the water produced de

10、pends on the pressure, the concentration of salts in the feedwater, and the salt permeation constant of the membranes.水的質(zhì)量產(chǎn)生了依賴(lài)于壓力，濃度鹽在給水和鹽滲透常數(shù)膜。 Product water quality can be improved by adding a second pass of membranes, whereby product water from the first pass is fed to the second pass.產(chǎn)品水質(zhì)得以改善，增

11、加了第二個(gè)通過(guò)的膜，即產(chǎn)品的防水，從第一通是美聯(lián)儲(chǔ)第二次通過(guò)。 Figure 1. Flow Diagram of a reverse osmosis system (courtesy of USAID). 圖1 。流程圖一個(gè)反滲透系統(tǒng)（禮貌美國(guó)國(guó)際開(kāi)發(fā)署） 。 (Kahn, 1986.) （卡恩， 1986 ） 。 · Distillation 蒸餾 In the distillation process, feedwater is heated and then evaporated to separate out dissolved minerals.在蒸餾過(guò)程中，給水加熱，然

12、后蒸發(fā)分離出來(lái)，溶解礦物質(zhì)。 The most common methods of distillation include multistage flash (MSF), multiple effect distillation (MED), and vapor compression (VC) (Figure 2).最常見(jiàn)的方法包括蒸餾多級(jí)閃光（無(wú)國(guó)界醫(yī)生組織） ，多效蒸餾（ MED ） ，以及蒸汽壓縮（ VC ）的（圖2 ） 。 Figure 2. Common methods of distillation. 圖2 。常用方法蒸餾。 In MSF, the feedwater is h

13、eated and the pressure is lowered, so the water "flashes" into steam.在無(wú)國(guó)界醫(yī)生組織，給水加熱和壓力降低，所以水"閃亮"變成蒸汽。 This process constitutes one stage of a number of stages in series, each of which is at a lower pressure.這個(gè)過(guò)程構(gòu)成了一個(gè)階段一個(gè)階段的數(shù)目在系列，其中每正處在一個(gè)較低的壓力。 In MED, the feedwater passes through

14、a number of evaporators in series.在地中海，給水通過(guò)多項(xiàng)蒸發(fā)器系列。 Vapor from one series is subsequently used to evaporate water in the next series.蒸氣從一個(gè)系列是后來(lái)用于蒸發(fā)水，在未來(lái)系列。 The VC process involves evaporating the feedwater, compressing the vapor, then using the heated compressed vapor as a heat source to evaporate a

15、dditional feedwater.風(fēng)險(xiǎn)投資過(guò)程中涉及到蒸發(fā)了給水，壓縮蒸氣，然后用加熱壓縮蒸氣作為熱源蒸發(fā)增加給水。 Some distillation plants are a hybrid of more than one desalination technologies.有些蒸餾廠，是一種混合的一個(gè)以上的海水淡化技術(shù)。 The waste product from these processes is a solution with high salt concentration.垃圾產(chǎn)品，從這些過(guò)程是最佳的解決方案與高鹽的濃度。 Input Water (Feedwater)投

16、入水（給水） Desalination plants may use seawater (directly from the ocean through offshore intakes and pipelines, or from wells located on the beach or seafloor), brackish groundwater, or reclaimed water as feedwater.海水淡化廠可利用海水（直接從印度洋經(jīng)離岸金融攝入量和管道，或從水井坐落于海灘或海底） ，含鹽地下水，或再生水作為給水。 Since brackish water has a l

17、ower salt concentration, the cost of desalting brackish water is generally less than the cost of desalting seawater.由于微咸水具有較低的鹽分濃度，所花費(fèi)用的脫鹽苦咸水處理普遍低于生產(chǎn)成本的淡化海水。 Intake pipes for desalination plants should be located away from sewage treatment plant outfalls to prevent intake of discharged effluent.進(jìn)水口管

18、道海水淡化廠應(yīng)設(shè)在遠(yuǎn)離污水處理廠排污渠，以防止攝入出院污水。 If sewage treatment discharges or other types of pollutants are included in the intake, however, the pre- and post-treatment processes should remove the pollutants.如果污水處理廠的排放物或其他種類(lèi)的污染物，都包括在入伙事宜，不過(guò)，會(huì)前和會(huì)后的處理過(guò)程，應(yīng)該消除污染物的影響。 Product Water生產(chǎn)用水 Distillation plants produce a h

19、igh-quality product water that ranges from 1.0 to 50 ppm tds, while RO plants produce a product water that ranges from 10 to 500 ppm tds.蒸餾廠生產(chǎn)高品質(zhì)的產(chǎn)品水范圍從1.0至50 ppm的全港發(fā)展策略，而反滲透廠生產(chǎn)的產(chǎn)品水范圍從10到500 ppm的全港發(fā)展策略。 (The recommended California drinking water standard for maximum tds is 500 mg/L, which is equival

20、ent to 500 ppm.) In desalination plants that produce water for domestic use, post-treatment processes are often employed to ensure that product water meets the health standards for drinking water as well as recommended aesthetic and anti-corrosive standards. （推薦加州飲用水標(biāo)準(zhǔn)為最高，全港發(fā)展策略是500毫克/升，相當(dāng)于500百萬(wàn)分之一）

21、 。海水淡化廠所生產(chǎn)的水供家庭使用，后處理過(guò)程中，往往聘用，以確保產(chǎn)品的水質(zhì)符合衛(wèi)生標(biāo)準(zhǔn)飲用水以及推薦的審美與反腐蝕的標(biāo)準(zhǔn)。 Desalination product water may be used in its pure form (eg, for make-up water in power plant boilers) or it may be mixed with less pure water and used for drinking water, irrigation, or other uses.海水淡化的產(chǎn)品水可用于在其純粹的形式（例如，在化妝水在電廠鍋爐） ，也可能混有

22、少純凈水和用于飲水，灌溉，或其他用途。 The desalinated product water is usually more pure than drinking water standards, so when product water is intended for municipal use, it may be mixed with water that contains higher levels of total dissolved solids.該產(chǎn)品的淡化水是通常較單純，比飲用水標(biāo)準(zhǔn)，因此，當(dāng)產(chǎn)品水是為市政用途，它可能與水混合含有更高水平的總?cè)芙夤腆w。 Pure des

23、alination water is highly acidic and is thus corrosive to pipes, so it has to be mixed with other sources of water that are piped onsite or else adjusted for pH, hardness, and alkalinity before being piped offsite.海水淡化純凈水是高度酸性，因此，這是腐蝕管道，因此它已經(jīng)被混在其他水源，這是管道輸送的現(xiàn)場(chǎng)，否則調(diào)整pH值，硬度，堿度，然后以管道輸送外。 Product Water Re

24、covery產(chǎn)品水回收 The product water recovery relative to input water flow is 15 to 50% for most seawater desalination plants.該產(chǎn)品水回收相對(duì)投入水流量為15至50 ，大部分海水淡化廠。 For every 100 gallons of seawater, 15 to 50 gallons of pure water would be produced along with brine water containing dissolved solids.每100加侖的海水中， 15至

25、50加侖的純凈水會(huì)產(chǎn)生隨著鹽水含有溶解固體。 A desalination plant's recovery varies, in part because the particulars of plant operations depend on site-specific conditions.海水淡化廠的復(fù)蘇有所不同，其中部分原因是因?yàn)楫?dāng)事人的工廠作業(yè)依賴(lài)于特定地點(diǎn)的條件。 In several locations in California, pilot projects are being proposed to test plant operations before fu

26、ll-scale projects are built.在若干地點(diǎn)，在加利福尼亞州，試點(diǎn)項(xiàng)目正在擬議中的測(cè)試工廠作業(yè)，然后才全面大規(guī)模項(xiàng)目的建成。 Pretreatment Processes預(yù)處理過(guò)程 Pretreatment processes are needed to remove substances that would interfere with the desalting process.預(yù)處理過(guò)程中，需要拆除的物質(zhì)會(huì)干擾與脫鹽過(guò)程。 Algae and bacteria can grow in both RO and distillation plants, so a bi

27、ocide (usually less than 1 mg/L chlorine) is required to clean the system.藻類(lèi)和細(xì)菌能夠在成長(zhǎng)中都反滲透法和蒸餾廠，所以殺生劑（通常小于1毫克/升氯氣） ，是需要清理的制度。 Some RO membranes cannot tolerate chlorine, so dechlorination techniques are required.一些反滲透膜所不能容許的氯，使脫氯技術(shù)要求。 Ozone or ultraviolet light may also be used to remove marine organ

28、isms.臭氧或紫外線光也可能被用來(lái)去除海洋生物。 If ozone is used, it must be removed with chemicals before reaching the membranes.如果臭氧是用，它必須拆除與化學(xué)品才到達(dá)膜。 An RO technology has been developed recently that does not require chemical pretreatment.一個(gè)反滲透技術(shù)已經(jīng)研制成功，最近不需要化學(xué)預(yù)處理。 In RO plants, suspended solids and other particles in t

29、he feedwater must be removed to reduce fouling of the membranes.在滾裝植物，懸浮固體及其它粒子在給水必須拆除，以減少污染的膜。 Suspended solids are removed with coagulation and filtration.懸浮固體去除混凝和過(guò)濾。 Metals in the feedwater are rejected along with the salts by the membranes and are discharged in the brine.金屬在給水不允隨鹽由膜，并已出院，在鹵水。 W

30、ith normal concentrations for metals in seawater, the metals present in the brine discharge, though concentrated by the RO process, would not exceed discharge limits.與正常濃度的重金屬在海水中，金屬，目前在鹵水排放，但集中由反滲透過(guò)程中，將不會(huì)超出排放限制。 Some distillation plants may also need to remove metals due to potential corrosion prob

31、lems.有些蒸餾廠可能還需要清除金屬由于潛在的腐蝕問(wèn)題。 Filter Backwashing, Membrane Cleaning and Storage, Scaling Prevention and Removal, and Pipeline Cleaning過(guò)濾器反沖洗，膜的清洗和存放，防結(jié)垢和移除，以及管道清洗 The filters for pretreatment of feedwater at RO plants must be cleaned every few days (backwashed) to clear accumulated sand and solids.該

32、過(guò)濾器的預(yù)處理給水在滾裝植物必須清洗，每隔數(shù)天（ backwashed ） ，以明確積累了沙子和固體。 The RO membranes must be cleaned approximately four times a year and must be replaced every three to five years.該反滲透膜必須清理了大約4倍，一年必須更換，每3至5年。 Alkaline cleaners are used to remove organic fouling, and acid cleaners are used to remove scale and other

33、inorganic precipitates.堿性清潔劑是用來(lái)去除有機(jī)污垢和酸性清潔工人用來(lái)去除規(guī)模及其它無(wú)機(jī)沉淀物。 All or a portion of RO plants must be shut down when the membranes are replaced.全部或部分滾裝廠必須關(guān)閉時(shí)，膜的更換。 When RO plants are not used continuously, the RO membranes must be stored in a chemical disinfection/preservation solution that must be disp

34、osed of after use.當(dāng)滾裝植物是不會(huì)持續(xù)使用，反滲透膜，必須存放在化學(xué)消毒/保存液必須加以處置后使用。 Distillation plants can also be shut down for tube bundle replacement, which is analogous to membrane replacement.蒸餾廠也可以關(guān)閉，進(jìn)行管束更換，這是類(lèi)似于膜替換。 Desalination plant components must be cleaned to reduce scaling-a condition where salts deposit on p

35、lant surfaces, such as pipes, tubing or membranes.海水淡化廠的部件必須清洗，以減少結(jié)垢的條件，如鹽礦床于植物表面，如水管，油管或膜。 Scaling is caused by the high salt concentration of seawater and can result in reduced plant efficiency and corrosion of the pipes.結(jié)垢是由高鹽濃度海水，可以導(dǎo)致降低機(jī)器的效率和腐蝕的水管。 In general, scaling increases as temperature in

36、creases; thus scaling is of greater concern for distillation plants, since RO plants require lower temperatures to operate.一般來(lái)說(shuō)，結(jié)垢的增加，因?yàn)闇囟仍黾?，因此結(jié)垢是更令人關(guān)注的蒸餾廠，自滾裝植物需要更低的溫度下運(yùn)作。 Scaling can be reduced by introducing additives to inhibit crystal growth, reducing temperature and/or salt concentrations, rem

37、oving scale-forming constituents, or seeding to form particles.結(jié)垢可減少引入添加劑，以抑制晶體生長(zhǎng)，降低溫度和/或鹽的濃度，除垢形成的選民，或播種，形成粒子。 Once scales have formed, they can be removed with chemical or mechanical means.一旦規(guī)模形成，他們可以去除化學(xué)或機(jī)械手段。 In addition to scaling, both RO and distillation plant intake and outfall structures an

38、d pipelines can become fouled with naturally occurring organisms or corroded.除了縮放，既反滲透法和蒸餾廠進(jìn)水口和排污渠結(jié)構(gòu)和管道能成為犯規(guī)，與自然發(fā)生的有機(jī)體或銹蝕。 Structures and pipelines may be cleaned by mechanical means or by applying chemicals or heat.結(jié)構(gòu)和管道，可清洗機(jī)械手段或采用化學(xué)品或熱量。 Feedwater may also be deaerated to reduce corrosion.給水也可能除氧，

39、以減少腐蝕。 Waste Discharges廢污水排放 Desalination plants produce liquid wastes that may contain all or some of the following constituents: high salt concentrations, chemicals used during defouling of plant equipment and pretreatment, and toxic metals (which are most likely to be present if the discharge wat

40、er was in contact with metallic materials used in construction of the plant facilities).海水淡化廠所生產(chǎn)的液體廢料可能包含全部或部分以下三方：高鹽的濃度，化學(xué)品使用期間defouling的工廠設(shè)備和預(yù)處理和有毒金屬（其中最有可能被目前如果排放水接觸金屬所用的材料建造的核電廠設(shè)施）的保護(hù)。 Liquid wastes may be discharged directly into the ocean, combined with other discharges (eg, power plant coolin

41、g water or sewage treatment plant effluent) before ocean discharge, discharged into a sewer for treatment in a sewage treatment plant, or dried out and disposed of in a landfill.液體廢物，可直接排放到海洋，再加上其他排放物（如電廠冷卻水或污水處理廠的污水） ，然后海洋排放，排放到污水處理的污水處理廠，或干涸，并棄置在堆填區(qū)。 Desalination plants also produce a small amount

42、 of solid waste (eg, spent pretreatment filters and solid particles that are filtered out in the pretreatment process).海水淡化廠也生產(chǎn)少量的固體廢棄物（如用預(yù)處理過(guò)濾器和固體微粒過(guò)濾列于預(yù)處理程序） 。 For example, the capacity of the City of Santa Barbara's desalination plant is 7,500 AF/yr (about 7.16 MGD).舉例來(lái)說(shuō)，容量的城市圣巴巴拉的海水淡化廠，是7500

43、個(gè)自動(dòng)對(duì)焦/里亞爾（約7.16 mgd ） 。 In May 1992, the plant produced 6.7 MGD of product water and generated 8.2 MGD of waste brine with a salinity approximately 1.8 times that of seawater. 1992年5月，該廠生產(chǎn)的6.7 mgd產(chǎn)品的水和產(chǎn)生8.2 mgd廢鹵水鹽度約1.8倍的海水。 An additional 1.7 MGD of brine was generated from filter backwash.另外1.7 mgd

44、鹵水產(chǎn)生后，從濾池反沖洗。 Assuming that concentrations of suspended solids in the seawater feed range from 10 to 50 ppm, approximately 1.7 to 5.1 cubic yards per day of solids were generated, which is equivalent to one to two truck-loads per week.假設(shè)濃度的懸浮固體量，在海水飼料范圍從10到50 ppm ，使用約170 to 5.1立方碼每天的固體產(chǎn)生，即相等于1時(shí)59分貨車(chē)

45、荷載每星期。 (Source: Woodward-Clyde Consultants, EIR for the City of Santa Barbara and Ionics, Inc.'s Temporary Emergency Desalination Project, March 1991.) （資料來(lái)源：伍德沃德-克萊德顧問(wèn)，審查機(jī)構(gòu)，為城市圣塔芭芭拉和對(duì)Ionics公司奇摩臨時(shí)性緊急海水淡化項(xiàng)目， 1991年3月） 。 Energy Use能源使用 The energy used in the desalination process is primarily electr

46、icity and heat.能源用在海水淡化過(guò)程中，主要是電力和熱力。 Energy requirements for desalination plants depend on the salinity and temperature of the feedwater, the quality of the water produced, and the desalting technology used.所需能源為海水淡化廠在很大程度上依賴(lài)于鹽度和溫度的給水，水的質(zhì)量產(chǎn)生了，和除鹽技術(shù)的使用。 Estimates for electricity use requirements for

47、various technologies for seawater desalination are:估計(jì)用電量的要求，各種技術(shù)，海水淡化是： In addition to electricity requirements, MSF, MED, and some VC plants also use thermal energy to heat feedwater.除了電力需要，無(wú)國(guó)界醫(yī)生，醫(yī)學(xué)，和一些VC的植物，也利用熱能加熱給水。 (Because of the inefficiency of converting thermal energy to electricity, there

48、is a high energy "penalty" if electricity is used to heat feedwater.) For example, in addition to the 3,500 to 7,000 kWh/AF of energy required for electricity, the thermal energy needs for a MSF distillation plant is estimated at 270 million Btu/AF (about 26,000 kWh/AF); for MED plants, th

49、e estimated additional thermal energy requirements are 230 million Btu/AF (about 22,000 kWh/AF). 1 Consequently, the total energy needs for distillation technologies are higher than for RO technologies. （由于政府工作效率低下的轉(zhuǎn)換熱能電力，因此是一個(gè)高能量的"罰款" ，如果電力是用來(lái)供熱給水） 。舉例來(lái)說(shuō)，除了以3500年至7000年千瓦時(shí)/自動(dòng)對(duì)焦的能源所需的電力，熱力能

50、源需求為無(wú)國(guó)界醫(yī)生蒸餾廠，估計(jì)在2.7億美元價(jià)/自動(dòng)對(duì)焦（約有26000千瓦時(shí)/自動(dòng)對(duì)焦） ，而地中海植物中，估計(jì)有額外的熱能所需經(jīng)費(fèi)2.3億元價(jià)/自動(dòng)對(duì)焦（約22000千瓦時(shí)/自動(dòng)對(duì)焦） 。 1 因此，其總的能源需求，為蒸餾技術(shù)是高于反滲透技術(shù)。 Energy use requirements for desalination plants are high.能源的使用要求，為海水淡化廠高。 For example, an estimated 50 million kWh/yr would be required for full-time operation of the City of

51、Santa Barbara's desalination plant to produce 7,500 AF/yr of water.舉例來(lái)說(shuō)，據(jù)估計(jì)， 50000000千瓦時(shí)/年，將需要全時(shí)間的運(yùn)作，該市的圣巴巴拉的海水化淡廠，生產(chǎn)7500個(gè)自動(dòng)對(duì)焦/年的水。 In contrast, the energy needed to pump 7,500 AF/yr of water from the Colorado River Aqueduct or the State Water Project to the Metropolitan Water District (MWD) of

52、Southern California is 15 to 26 million kWh/yr.相比之下，能源需要泵7500個(gè)自動(dòng)對(duì)焦/年的水來(lái)自科羅拉多河，興建輸水管道或國(guó)家的水利水電工程，以大都市水區(qū)（分布）的南加州是15至26000000千瓦時(shí)/年。 These energy requirements may be compared to the energy use of a small- to medium-sized industrial facility (such as a large refinery, small steel mill, or large computer c

53、enter) which uses 75,000 to 100,000 kWh/yr.這些能源條件的，方可相比，能源使用的一個(gè)小型到中型的工業(yè)設(shè)施（如大型煉油廠，小軋鋼廠，還是大型計(jì)算機(jī)中心） ，其中利用75000至10萬(wàn)千瓦時(shí)/年。 Both RO and distillation plants can benefit from cogeneration plants to reduce energy use.雙方反滲透法和蒸餾廠可受惠熱電廠，以減少能源的使用。 Since increased energy use may cause adverse environmental impact

54、s, the individual and cumulative impacts of energy use and production at a proposed desalination plant will require case-by-case analysis.由于提高了能源使用可能造成對(duì)環(huán)境的不良影響，對(duì)個(gè)人和累積影響，能源的使用和生產(chǎn)，在擬議的海水淡化廠將要求逐案分析。 Comparison of Distillation and Reverse Osmosis Technologies比較蒸餾和反滲透技術(shù) One advantage of distillation plan

55、ts is that there is a greater potential for economies of scale.的一個(gè)好處是蒸餾廠是有一個(gè)更大的潛力，形成規(guī)模經(jīng)濟(jì)。 Distillation plants also do not shut down a portion of their operations for cleaning or replacement of equipment as often as RO plants, although distillation plants can and have shut down for tube bundle replac

56、ement and cleaning.蒸餾廠也沒(méi)有關(guān)閉自己的部分業(yè)務(wù)，為清洗或更換設(shè)備經(jīng)常滾裝植物，雖然蒸餾廠可以且已經(jīng)關(guān)閉，進(jìn)行管束更換及清潔工作。 Pretreatment requirements are greater for RO plants, because coagulants are needed to settle out particles before water passes through the membranes.預(yù)處理要求更大滾裝植物，因?yàn)榛炷齽?，是需要解決的微粒，然后水穿過(guò)膜。 Unlike RO plants, distillation plants do

57、 not generate waste from backwash of pretreatment filters.不像滾裝廠，蒸餾廠不產(chǎn)生廢棄物，從沖洗的預(yù)處理過(guò)濾器。 Advantages of RO plants over distillation include: RO plant feedwater generally does not require heating, so the thermal impacts of discharges are lower; RO plants have fewer problems with corrosion; RO plants usua

58、lly have lower energy requirements; RO plants tend to have higher recovery rates-about 45% for seawater; the RO process can remove unwanted contaminants, such as trihalomethane-precursors, pesticides, and bacteria; and RO plants take up less surface area than distillation plants for the same amount

59、of water production.優(yōu)勢(shì)滾裝植物超過(guò)蒸餾包括：反滲透廠給水一般并不需要加熱，所以熱的影響，排放低;滾裝植物少出現(xiàn)腐蝕;滾裝植物通常有較低的能源需求;滾裝植物往往有較高的回收率- 45 左右，為海水;滾裝過(guò)程中，才能消除有害污染物，如三鹵甲烷母質(zhì)，殺蟲(chóng)劑和細(xì)菌;滾裝和植物采取了以下表面積比蒸餾廠，為同等數(shù)量的水生產(chǎn)。 Costs of Desalinated Water成本的淡化水 The cost to produce water from desalination depends on the technology used and the plant capacity, among other factors.成本生產(chǎn)用水由海水淡化取決于所使用的技術(shù)和核電廠的能力，除其他因素外。 For example, the cost of desalted water in Santa Barbara ($1,900/AF) results from the following: a write-off of the capital cost over a short five-year period, high financing costs, and high energy costs.舉例來(lái)說(shuō)，成本的脫鹽水在圣巴巴拉（元1900/af ）結(jié)果如下：注銷(xiāo)資本成本