【文章內(nèi)容簡(jiǎn)介】 4mm are set in the nullah. The water pumping station needs to design with 800000 m3/d.建議采用自流明渠引水的取水方式，為避免海水中雜物及生物的影響，在明渠內(nèi)設(shè)置的50mm間隙粗格柵，44mm旋轉(zhuǎn)篩網(wǎng)濾網(wǎng)。取水泵站采用按照80萬m3/d設(shè)計(jì)。The inlet of priming nullah is more than lower than the guaranteed low tide level of the project needed, and setup the washing cycle according to the actual water quality.，并根據(jù)取水水質(zhì)實(shí)際情況設(shè)定清洗周期。Fig Coarse Screen Fig Intake water pump station Screen Pretreatment System 預(yù)處理系統(tǒng)Pretreatment is of the utmost importance for the seawater desalination, especially for the RO membrane. The RO membrane is more sensitive to the colloid, organism, microorganism, siliceous pound and other pollution in seawater。 blockage, scaling and degradation may be caused by the pollutants, ultimately lead to the decline of seawater desalination rate and water production. Therefore, the seawater reverse osmosis desalination system has a special strict requirement on the pretreatment。 the pretreatment is an important guarantee for the successful operation of the system.預(yù)處理對(duì)于海水淡化工程至關(guān)重要，尤其是反滲透膜對(duì)進(jìn)水更加敏感，容易被水中的膠體、有機(jī)物、微生物、硅等物質(zhì)污染，造成反滲透膜的污堵、結(jié)垢和膜降解，最終導(dǎo)致系統(tǒng)除鹽率和產(chǎn)水量的下降。因此，反滲透海水淡化系統(tǒng)對(duì)海水預(yù)處理有著特殊嚴(yán)格的要求，預(yù)處理是反滲透系統(tǒng)成功運(yùn)行的重要保證。For the specific circumstances of this project, coagulative precipitation and multimedium filter are remend as the pretreatment. The main function is to remove the suspended solids, colloid, organism, germ, algae, halobios in the raw water.針對(duì)該項(xiàng)目的具體情況，推薦采用混凝沉淀及多介質(zhì)濾池作為預(yù)處理手段。主要作用是去除原水中含有的懸浮物、膠體有機(jī)污染物質(zhì)、細(xì)菌、藻類、海生物等。 Unit of Coagulative Precipitation混凝沉淀單元Coagulation and flocculation sedimentation tank is a pretreatment facilities which take charge of reaction, oxidation, inclined plate clarification and automatic sludge discharge. The filtration rate up to 20m/ h ~ 30m/ h, which enable to reduce the floor space greatly, also makes setting roof on the top of the structure possible, in order to avoid the breeding of algae. The medicine generally adopt inorganic iron salts, aluminum salts, oxidizer, disinfectants and coagulant aid. When water quality break, oxidizer and powder activated carbon can be dosed as an emergency measure.混凝沉淀池是集絮凝反應(yīng)、氧化、斜板澄清、自動(dòng)排泥于一體的預(yù)處理設(shè)備，濾速可達(dá)20m/h~30m/h，占地面積大大減小，這也使得池體頂部設(shè)置頂棚成為可能，從而避免藻類滋生。藥劑一般可投加無機(jī)鐵鹽、鋁鹽、氧化劑、消毒劑、助凝劑等。水質(zhì)突變時(shí)可以投加氧化劑和粉末活性炭作為應(yīng)急措施。 coagulative precipitation tank 混凝沉淀池示意圖 Multimedia filtration unit多介質(zhì)過濾單元Multimedia filter can make use of one or several media to remove suspended impurities, microorganisms and colloids from water. The filter monly used are quartz sand, anthracite coal and manganese grain, which can be used in turbidity removal, water softening, and pretreatment of purified water, etc. 多介質(zhì)過濾器是利用一種或幾種過濾介質(zhì)，有效去除水中的懸浮雜質(zhì)、微生物和膠體物質(zhì)，使水澄清的過程。常用的濾料有石英沙，無煙煤，錳砂等，主要用于水處理除濁，軟化水，純水的前級(jí)預(yù)處理等。過濾速度一般小于8m/h，一般每天自動(dòng)反沖洗一次。The quality of effluent treated by pretreatment system is as follows: turbidity ≤ 1NTU, CODMn≤ 3 ppm, and SDI≤5, which protects the following equipment run firmly.預(yù)處理系統(tǒng)出水水質(zhì)可以達(dá)到：濁度≤1 NTU；CODMn≤ 3 ppm， SDI≤5，從而更有效地保護(hù)后續(xù)設(shè)備的穩(wěn)定運(yùn)行。 Multimedia filter in a seawater desalination plant 某海水淡化廠多介質(zhì)過濾裝置 Nano filter System納濾系統(tǒng)According to our engineering experiment, organic pollutants(TOC) in seawater is posed mainly of small molecules. More than 80% of molecular weight of TOC is less than 1000, while NF can get rid of molecular weight between 200 and 1000. Therefore, NF is the most suitable process for organicremoving.根據(jù)我方工程經(jīng)驗(yàn)，一般海水有機(jī)污染物質(zhì)（TOC）中以小分子為主，一般海水中80%以上的TOC物質(zhì)分子量小于1000，而納濾截留分子量一般恰好在200~1000之間，因此，對(duì)于有機(jī)物質(zhì)的去除最適合的處理工藝就是納濾。NF is also effective in the removal of inorganic substances. The retention rate of sodium chloride is 40%~90%, and that of ions especially anions is up to 99%. As a result, the osmosis pressure of effluent is reduced and the recovery rate of the following RO system and MED system is improved.同時(shí)，納濾對(duì)氯化鈉截留率一般40~90%，對(duì)二價(jià)離子特別是陰離子截留率可達(dá)99%，可以有效降低出水滲透壓，提高后續(xù)反滲透及MED系統(tǒng)的回收率。The NF system consists of the highpressure pump, NF membrane module, cleaning system, dosing system, etc.納濾系統(tǒng)包括高壓泵、納濾膜組件、清洗系統(tǒng)、加藥系統(tǒng)等。In this design report, we adopt NF272400 NF membrane, which is used one stagetwo phase design, totally used 10556 pieces of NF membrane modules. Additionally, the device also includes dosing system, to remove remaining residual chlorine。 adding antisludging agent to protect NF membrane elements and RO membrane elements. Meanwhile, the Stiff amp。 Davis index of raw water will improved from 0 to , to prevent scale formation and dangerous for membrane.本次設(shè)計(jì)納濾采用NF27400納濾膜，采用一級(jí)兩段設(shè)計(jì)，共使用NF膜10556支，此外還設(shè)加藥系統(tǒng)去除余氯、添加阻垢劑，以防止破壞納濾膜元件及后續(xù)的反滲透膜元件，同時(shí)將原水的Stiff amp。 ，防止鈣鎂硬度在膜內(nèi)結(jié)垢以及硫酸鈣等物質(zhì)對(duì)膜的危害。The product water quality of NF system as follows:NF系統(tǒng)產(chǎn)水水質(zhì)如下： Items項(xiàng)目Unit單位Value值pHTDSmg/LClmg/LSO4mg/LNa+mg/LK+mg/LCa2+mg/LMg2+mg/LThe reject water quality of NF system as follows：NF系統(tǒng)排放濃水水質(zhì)如下： Items項(xiàng)目Unit單位Value值pHTDSmg/LClmg/LSO4mg/LNa+mg/LK+mg/LCa2+mg/LMg2+mg/L RO System 反滲透系統(tǒng)SWRO system is included of lift pressure pump, RO membrane module, energy recovery equipment, flushing system and cleaning system etc.反滲透海水淡化系統(tǒng)（SWRO）由：高壓泵、反滲透膜組件、能量回收裝置、沖洗系統(tǒng)、清洗系統(tǒng)等組成。RO system is one of the key devices in seawater desalination system, which can remove soluble salts, colloids, organics and microorganism. According to the water quality, one stage RO membrane applies pound RO membrane, which is especially suitable for the seawater, each piece of membrane can rea