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開題報(bào)告
課題名稱
3.0萬(wàn) m3/d自來(lái)水廠的設(shè)計(jì)
系名稱
專業(yè)名稱
）
學(xué)生姓名
指導(dǎo)教師
一、選題的依據(jù)及意義：
（一）水源和水質(zhì)
該自來(lái)水廠以地面水為水源，原水水質(zhì)符合《生活飲用水水源水質(zhì)標(biāo)準(zhǔn)》二級(jí)標(biāo)準(zhǔn),水質(zhì)較好，屬于二級(jí)水源水。
（二）供水水質(zhì)及水壓
出水水壓38 m，水質(zhì)符合《生活飲用水衛(wèi)生標(biāo)準(zhǔn)》
（四）氣象條件
平均氣溫15.3℃
最低氣溫－16.8℃
最高氣溫34℃
全年平均降水量400 mm
最大降雨量76 mm
最大積雪厚度15 mm
夏季主導(dǎo)風(fēng)向西北
最低水溫2.1℃
最高水溫28.0℃
意義：
通過畢業(yè)設(shè)計(jì)，熟悉并掌握給水工程的設(shè)計(jì)內(nèi)容、設(shè)計(jì)原理、方法和步驟，學(xué)會(huì)根據(jù)設(shè)計(jì)原始資料正確地選定設(shè)計(jì)方案，正確計(jì)算, 具備設(shè)計(jì)中、小城鎮(zhèn)水廠的初步能力。對(duì)取水工程、凈水廠進(jìn)行設(shè)計(jì)。要求對(duì)總體布置的設(shè)計(jì)思想，從工藝流程、操作聯(lián)系、生產(chǎn)管理以及物料運(yùn)輸?shù)雀鞣矫婵紤]，而進(jìn)行合理的組合布置設(shè)計(jì)。掌握設(shè)計(jì)說明書、計(jì)算書的編寫內(nèi)容和編制方法，并繪制工程圖紙。
二、國(guó)內(nèi)外研究現(xiàn)狀及發(fā)展趨勢(shì)
長(zhǎng)期以來(lái)，給水工藝仍然是混合、絮凝、沉淀、過濾和消毒幾個(gè)階段，宏觀
上理論上尚無(wú)重大突破，然而在微觀上，凈化工藝確不斷地改進(jìn)，對(duì)給水處理的
認(rèn)識(shí)也不斷地更新。理論的繼續(xù)深化，促進(jìn)了給水工藝水平的提高。傳統(tǒng)工藝、
理論主要是建立在以粘土膠體微粒和致病細(xì)菌為主要工作對(duì)象的基礎(chǔ)上，隨著污
染程度的日益加劇和污染源的逐漸增多，污染物品種的多樣化，為給水處理工作
者帶來(lái)新的課題。現(xiàn)在給水工程較以往的任何時(shí)候都更加注意原水的預(yù)處理工作
和在傳統(tǒng)工藝后面的深度處理，這是當(dāng)前發(fā)展最快的方面，也是我國(guó)和國(guó)外給水
工藝水平主要差距所在。
（一）預(yù)處理
預(yù)處理是設(shè)置在傳統(tǒng)處理工藝之前的各種處理措施，包括格柵篩除原水中的
漂浮雜物，預(yù)氯投加，調(diào)整原水的pH 值，泥砂在預(yù)沉池中預(yù)沉以及投加粉末活
性炭或生物過濾等各種工藝措施。我國(guó)的預(yù)處理工藝主要是格柵隔除漂浮物；預(yù)
氯投加，即在長(zhǎng)距離輸水管的起始點(diǎn)小劑量加氯；或在預(yù)沉池前投氯，以保證充
分的消毒效果。粉末活性炭的投加多為季節(jié)性，當(dāng)水質(zhì)嚴(yán)重污染時(shí)，為了去除臭
味和有機(jī)物而采用的臨時(shí)性措施。由于我國(guó)生活水準(zhǔn)所限，粉末活性炭投加對(duì)制
水成本影響較大，故采用不多。從西方發(fā)達(dá)國(guó)家情況看，原水的調(diào)質(zhì)已是普通采用的水處理手段。
（二）常規(guī)處理
1、混合技術(shù)
理論上早已闡明混合是絮凝的基礎(chǔ)，要求快速劇烈的混合，以促進(jìn)混凝藥劑
擴(kuò)散速度和壓縮水中膠體的雙電層，使膠體脫穩(wěn)。但在實(shí)際工作中對(duì)混合長(zhǎng)期未
給予應(yīng)有的重視。80 年代中后期加強(qiáng)混合才成為給水界最強(qiáng)調(diào)的觀點(diǎn)，因而也
陸續(xù)出現(xiàn)了多種混合設(shè)備。有水力隔板混合、水泵混合、機(jī)械混合、混合池、槽
等以及近幾年應(yīng)用于給水行業(yè)上的靜態(tài)混合器。從混合設(shè)備形式上看，我國(guó)現(xiàn)有
水平不遜于國(guó)外先進(jìn)國(guó)家。由于混合設(shè)備對(duì)水力條件、輸入能量、混合方式要求
比較嚴(yán)格、設(shè)備、構(gòu)造上的差異往往造成混合效果相差較大，單純從理論計(jì)算上
進(jìn)行混合設(shè)計(jì)，往往和預(yù)先設(shè)想結(jié)果有較大偏差，因而影響混合效果。國(guó)外先進(jìn)
國(guó)家對(duì)混合設(shè)備都作嚴(yán)格的測(cè)試，以期取得最佳混合效果。
2、絮凝反應(yīng)
我們的反應(yīng)設(shè)備總體上和國(guó)外水平差距不大，傳統(tǒng)上的絮凝反應(yīng)多采隔板反
應(yīng)，是建立在"近壁紊流"理論基礎(chǔ)上的。隨著給水理論的深入研究和發(fā)展，從能量耗散的角度出發(fā)提出"自由紊流"的微旋渦理論，我國(guó)在此理論之上研制出多種
設(shè)備反應(yīng)亦投入生產(chǎn)運(yùn)行。但我國(guó)機(jī)械反應(yīng)多為垂直軸機(jī)械反應(yīng)，國(guó)外平流沉淀
池多為水平軸機(jī)械反應(yīng)，并采用液力無(wú)級(jí)變速式電機(jī)調(diào)頻無(wú)級(jí)變速。我國(guó)在前一段時(shí)間對(duì)縮短反應(yīng)時(shí)間很感興趣，所設(shè)計(jì)的反應(yīng)池停留時(shí)間有的短達(dá)7 分鐘，認(rèn)
為這樣可以減少占地節(jié)約投資?，F(xiàn)在隨著實(shí)踐和對(duì)高效反應(yīng)的認(rèn)識(shí)加深，又開始傾向延長(zhǎng)反應(yīng)時(shí)間，這與國(guó)外先進(jìn)國(guó)家的認(rèn)識(shí)趨于一致。
3、 沉淀池
平流沉淀池是給水行業(yè)最古老的一種池型，大型水廠應(yīng)用較多，我國(guó)與國(guó)外
技術(shù)水平相差無(wú)幾，所不同的是，國(guó)外停留的時(shí)間較長(zhǎng)，一般為2～4 h，我
國(guó)停留時(shí)間多為1～2 h。選擇較長(zhǎng)的停留時(shí)間可以節(jié)約藥劑，提高沉淀后的
水質(zhì)，并有足夠的調(diào)節(jié)余地，抗沖擊負(fù)荷能力較強(qiáng)。停留時(shí)間短可以節(jié)省基建投
資，減少占地面積。具體設(shè)計(jì)停留時(shí)間多長(zhǎng)為好，這需要根據(jù)國(guó)家發(fā)達(dá)程度、沉
淀后水質(zhì)指標(biāo)要求，并進(jìn)行經(jīng)濟(jì)技術(shù)比較后確定，根據(jù)我國(guó)水質(zhì)標(biāo)準(zhǔn)和國(guó)情，采
用1.5～2.0 h停留時(shí)間為好。
斜管沉淀池是繼平流沉淀池之后于60年代末、70年代初發(fā)展起來(lái)的一種建立在"淺池理論"上的沉淀設(shè)施，具有占地面積少、沉淀效率高的特點(diǎn)，在我國(guó)經(jīng)過近20年的應(yīng)用和發(fā)展，使沉淀技術(shù)日臻完善，也積累了許多設(shè)計(jì)和運(yùn)行經(jīng)驗(yàn)，是一種成熟工藝。
4、澄清池
澄清池在我國(guó)使用普通程度僅次于平流沉淀池和斜管沉淀池。懸浮澄清和水
力循環(huán)澄清池是早期修建?，F(xiàn)在為了提高效率，大多都進(jìn)行了不同程度的改進(jìn)。
我國(guó)現(xiàn)在建造的澄清池多為機(jī)械加速澄清池，用于中小水廠的一級(jí)處理，國(guó)外先進(jìn)國(guó)家仍在研制新型澄清池，以進(jìn)一步擴(kuò)大澄清池的適用范圍和得到高質(zhì)
量的濾前水。法國(guó)德克雷蒙公司(Degrement)最新研制出的“登薩代”(Densadeg)
澄清池，可以認(rèn)為是新型澄清池的代表。。該種澄清池彌補(bǔ)了各種傳統(tǒng)澄清池的不足，具有如下：
特點(diǎn)：①板狀澄清區(qū)有較高的上升流速(5.5～10.1 mm/s)；②能產(chǎn)生特別濃的回流污泥(20～500 g/L)使回流污泥量極大減少，并可以使污泥處理系統(tǒng)省略污泥濃縮池；③可生產(chǎn)高質(zhì)量的水（濁度低于1NTU）；④和通常用的澄清池相比，藥劑費(fèi)用節(jié)約10～30%；⑤運(yùn)行可靠，能耐受流量和水質(zhì)變化的沖擊；
⑥能用于多種水處理工藝，如飲用水凈化、水軟化、城市污水處理。由于Densadeg
澄清池具有以往澄清池所不具備的優(yōu)勢(shì)，目前已在法國(guó)、德國(guó)推廣應(yīng)用。相信不
久的將來(lái)也將引入我國(guó)，縮小我國(guó)在澄清池方面與先進(jìn)國(guó)家的差距。
5、氣浮法
氣浮處理工藝是凈水一級(jí)處理的另一種形式。氣浮法是一個(gè)古老的處理工
藝。從工藝發(fā)展來(lái)看，我國(guó)與先進(jìn)國(guó)家?guī)缀跏峭竭M(jìn)行的。近年我國(guó)的成都市建起了處理規(guī)模達(dá)20 萬(wàn)m3/d的大型氣浮池。從給水工藝上看溶氣氣浮是一種很有發(fā)展前途的處理工藝。它有許多優(yōu)點(diǎn)：①在池中停留時(shí)間短，一般為15～30 min，因而處理效率較高；②能有效地處理低溫低濁水；③能較好地解決除藻問題；④能對(duì)被有機(jī)物污染水體起曝氣作用；⑤氣浮法產(chǎn)生污泥含水率(90～95%)比沉淀池(95～99.8%)的低得多；⑥池子結(jié)構(gòu)簡(jiǎn)單，造價(jià)低。我國(guó)當(dāng)前在氣浮法處理工藝與先進(jìn)國(guó)家相比差距很小，也并非表現(xiàn)在處理工藝水平上，而是污泥的處置。國(guó)外有較完善的污泥處理手段和設(shè)備，對(duì)氣浮法產(chǎn)生的污泥處理不成問題，而我國(guó)由于國(guó)情所致，給水廠的污泥處理還處于未起步階段，沉淀池產(chǎn)生的污泥一般多重新排入水體，而氣浮法產(chǎn)生的污泥則不能排入水體，必須進(jìn)行處理。當(dāng)前氣浮產(chǎn)生的污泥苦于找不到適于我國(guó)國(guó)情的費(fèi)用低廉的污泥處理工藝和設(shè)備，而使其普及帶來(lái)困難。
6、過濾
過濾在水處理上一般稱為二級(jí)處理，通常是設(shè)于沉淀、澄清、氣浮等一級(jí)設(shè)
備之后，用來(lái)進(jìn)一步降低水中濁度。最早的過濾是使用慢濾池。這是利用生物膜
過濾工藝。慢濾池出水水質(zhì)高，但生產(chǎn)效率低。當(dāng)前國(guó)內(nèi)外過濾過程多使用快濾
池以提高生產(chǎn)效率?？鞛V池的過濾機(jī)理是接觸絮凝?？鞛V池發(fā)展歷史已百余年，
創(chuàng)造出多種池型，有四閥濾池、雙閥濾池、虹吸濾池、無(wú)閥濾池、壓濾罐等。
大型水廠多使用四閥濾池及其改型的雙閥濾池。從濾料上看，使用單層砂濾料和砂、煤雙層濾料的較多，三層濾料及三層以上濾料應(yīng)用較少。國(guó)外先進(jìn)國(guó)家的過濾設(shè)備與我國(guó)相比在三個(gè)方面有較大改進(jìn)：①濾料品種、級(jí)配的改進(jìn)；②輔助沖洗的普遍應(yīng)用；③自用水的降低。濾料品種和級(jí)配的改進(jìn)方面，我國(guó)使用的砂濾料，粒徑一般在0.45～1.1 mm，不均勻系數(shù)K80 一般選在1.6～2.0，無(wú)煙煤濾料一般作為雙層濾池的輕質(zhì)濾料，粒徑多為1.0～2.0，不均勻系數(shù)K80 多為2.0左右。歐美許多新建的濾池都有向大粒徑、深厚度方向發(fā)展。我國(guó)近年來(lái)也有這種趨勢(shì)，但象洛杉磯水廠那樣大膽采用單層煤濾料尚未見到。
（三）絮凝劑和絮凝控制技術(shù)
給水處理中，在絮凝藥劑投加控制和絮凝劑的使用方面，我國(guó)還處于一般水
平。主要反應(yīng)在絮凝劑的品種少、質(zhì)量低。在國(guó)外，特別是作為原水調(diào)質(zhì)而采用
的助凝劑較為普遍。我國(guó)這方面差距較大。在藥劑自動(dòng)投加方面，大部分水廠正
處于起步階段。對(duì)于國(guó)外先進(jìn)的自動(dòng)控制工藝，我國(guó)已開始致力于引進(jìn)和研究。
1、絮凝劑和助凝劑的使用情況
目前國(guó)內(nèi)外大部分凈水廠采用的絮凝劑仍鋁鹽和鐵鹽最為普遍。我公司主要使用鐵鹽絮凝劑，如三氯化鐵、硫酸亞鐵、氯化硫酸亞鐵。近幾年來(lái)，國(guó)外正研制和開發(fā)應(yīng)用新型高效絮凝劑方面進(jìn)展很快。引人注意的是兩類絮凝劑。一類是無(wú)機(jī)聚合物絮凝劑；另一類為有機(jī)高分子聚合物絮凝劑。
2、絮凝劑的控制投加
絮凝控制技術(shù)是凈化處理的重要環(huán)節(jié)，因此如果控制不好，既不能達(dá)到預(yù)定
的水質(zhì)要求，又導(dǎo)致藥劑的浪費(fèi)。我們目前大部分凈化水廠仍沿用化驗(yàn)室燒杯攪
拌試驗(yàn)確定投加率與經(jīng)驗(yàn)投加相結(jié)合的方式，人工操作投加。該方法的缺點(diǎn)是不
能滿足連續(xù)運(yùn)行的需要，也就不能隨水質(zhì)水量的變化而及時(shí)調(diào)整投加量。同時(shí)由
于在化驗(yàn)室內(nèi)做燒杯攪拌試驗(yàn)與實(shí)際生產(chǎn)中的水力條件差距較大，因此提供的投
加率僅能作為實(shí)際投加的參考值，不僅不準(zhǔn)確，還帶來(lái)檢驗(yàn)投加效果的滯后性。
目前國(guó)外投藥控制發(fā)展趨勢(shì)已由多參數(shù)控制向單因子控制方向發(fā)展，因?yàn)閱?
因子控制不要求建立較復(fù)雜的數(shù)學(xué)模型，連續(xù)檢測(cè)傳感器單一，管理維護(hù)方便。近幾年來(lái)這一技術(shù)發(fā)展很快，出現(xiàn)了流動(dòng)電流投藥控制系統(tǒng)和絮凝控制在線檢測(cè)
儀（也稱Eloo-nate 連續(xù)探測(cè)器）。最近英國(guó)水研究中心和倫敦大學(xué)研究人員聯(lián)合研制了一種新的絮凝控制在線檢測(cè)儀器(FIOC mate 探測(cè)器)。該儀器根據(jù)水中流動(dòng)懸浮膠體產(chǎn)生的濁度波動(dòng)，極靈敏地顯示絮體形成狀態(tài)，可在實(shí)驗(yàn)室或現(xiàn)場(chǎng)條件下確定最佳投藥量。
上述兩種單因子自動(dòng)控制絮凝檢測(cè)儀是國(guó)外先進(jìn)技術(shù)，我國(guó)正起步研究，尚
未有應(yīng)用實(shí)例。因此今后應(yīng)上述技術(shù)進(jìn)行積極的引進(jìn)和研究，根據(jù)我國(guó)國(guó)情和水
質(zhì)因素，提出可靠的控制方法，以縮小我國(guó)在混凝控制方面與國(guó)外先進(jìn)水平的差
距。
（四）消毒殺菌技術(shù)和水的深度處理
消毒殺菌技術(shù)已成為給水處理中不可缺少的處理手段之一。隨著工農(nóng)業(yè)的發(fā)
展，自80 年代起，由于部分地區(qū)的地面水源水質(zhì)逐漸變差和飲用水水質(zhì)要求的提高，水廠的處理工藝在常規(guī)處理基礎(chǔ)上向深度處理的趨勢(shì)發(fā)展。
1、消毒殺菌技術(shù)
很長(zhǎng)一個(gè)時(shí)期以來(lái)，傳統(tǒng)的消毒殺菌劑主要是采用氯及其化合物。該方法操
作技術(shù)簡(jiǎn)單、價(jià)格低、殺菌效果好。在國(guó)外至今仍為主要?dú)⒕椒ㄖ?，我?guó)應(yīng)
用更為普遍。使用氯氣消毒我國(guó)與國(guó)外的主要差距在于投加的控制手段上，目前
一般采用容量分析比色法測(cè)量投氯后的余氯值，依據(jù)其余氯值采用浮子加氯機(jī)或
真空加氯機(jī)調(diào)節(jié)投加量，靠人工操作。該方法不能提供準(zhǔn)確的投加量，只是靠經(jīng)
驗(yàn)控制，檢驗(yàn)投加效果又具有滯后性。而國(guó)外則采用自動(dòng)余氯檢測(cè)儀檢測(cè)，根據(jù)
余氯量反饋給自動(dòng)加氯機(jī)自動(dòng)調(diào)節(jié)投加量。這套設(shè)施由于國(guó)內(nèi)的余氯檢測(cè)儀以及
氯氨加注自動(dòng)化設(shè)施有待提高，目前尚不普及。
2、水的深度處理
水的深度處理主要在于去除原水中的微量有機(jī)污染物，國(guó)外采用深化處理較
為普遍，我國(guó)在水的深化處理方面還處于起步階段，大部分老水廠均未采用深度
處理，只是部分新水廠采用了活性炭吸附處理。
目前水的深度處理主要包括：活性炭吸附、臭氧氧化、臭氧和活性炭聯(lián)用和
生物活性炭。
除利用臭氧的增氯化能力與活性炭濾池聯(lián)用外，目前國(guó)外還致力于用臭氧與
生物活性炭(O3·BAC)對(duì)水做深度凈化處理的研究。它是當(dāng)前去除水中有機(jī)物質(zhì)
的較為有效的一種深度處理方法，在日本引起極大的重視。試驗(yàn)和生產(chǎn)實(shí)踐表明，
該技術(shù)具有如下特點(diǎn)：①能去除水中溶解性有機(jī)物；②能降低TOC，COD及氨氮；
③能降低進(jìn)水中三鹵甲烷母體；④對(duì)色度、鐵、錳酚都有去除效果；⑤能使Ames
試驗(yàn)為陽(yáng)性的水成陰性。但由于該技術(shù)耗電量較大，使用尚不普及。
三、本課題研究?jī)?nèi)容
1、取水工程
水源選擇、取水方案及位置的確定、取水構(gòu)筑物形式和設(shè)備設(shè)計(jì)計(jì)算并繪圖。
2、給水處理工程
凈水廠場(chǎng)址選擇、水處理方案的比較與選擇、建構(gòu)筑物型式、尺寸及設(shè)備選擇
計(jì)算并繪圖。
四、本課題研究方案
水廠工藝流程圖：
一
級(jí)泵站
機(jī)械混合池
二級(jí)泵站
清水池
普通快濾池
機(jī)械澄清池
五、研究目標(biāo)、主要特色及工作進(jìn)度：
1、通過水廠處理工藝的設(shè)計(jì)使原水經(jīng)處理后達(dá)《生活飲用水衛(wèi)生標(biāo)準(zhǔn)》中的規(guī)定。
2、通過對(duì)水廠的合理設(shè)計(jì)，使工程投質(zhì)和運(yùn)行費(fèi)用較低，使工程具有一定的可
靠度，滿足用戶對(duì)水質(zhì)，水量，水壓的近遠(yuǎn)期要求。
3、運(yùn)用現(xiàn)代化的管理技術(shù)實(shí)現(xiàn)對(duì)水廠的自動(dòng)化控制。
六、參考文獻(xiàn)
[1] GBJ106-87，給水排水制圖標(biāo)準(zhǔn)[S]．北京：中國(guó)計(jì)劃出版社，1988
[2] GB50013-2006，室外給水設(shè)計(jì)規(guī)范[S]．北京：中國(guó)建筑工業(yè)出版，2006
[3] 崔玉川．給水廠處理設(shè)施設(shè)計(jì)計(jì)算[M]．化學(xué)工業(yè)出版社，2002
[4] 鐘淳昌．簡(jiǎn)明給水設(shè)計(jì)手冊(cè)[M]．中國(guó)建筑工業(yè)出版社，2002
[5] 鐘淳昌．凈水廠設(shè)計(jì)[M]．中國(guó)建筑工業(yè)出版社，1986
[6] 張杰，劉喜光．水工業(yè)工程設(shè)計(jì)手冊(cè)水工業(yè)工程設(shè)計(jì)手冊(cè)：水工業(yè)工程設(shè)備[M]．中國(guó)建筑工業(yè)出版社．2000
[7] 任伯幟．城市給水排水工程規(guī)劃[M]．安徽科學(xué)技術(shù)出版社．2001
[8] 嚴(yán)煦世．給水排水工程快速設(shè)計(jì)手冊(cè)[M]．中國(guó)建筑工業(yè)出版社．1999
[9] GBJ13-86，室外給水設(shè)計(jì)規(guī)范[S]．上海：上海市建設(shè)和交通委員會(huì)，1986
選題是否合適： 是□ 否□
課題能否實(shí)現(xiàn)： 能□ 不能□
指導(dǎo)教師（簽字） 年 月 日
選題是否合適： 是□ 否□
課題能否實(shí)現(xiàn)： 能□ 不能□
審題小組組長(zhǎng)（簽字） 年 月 日
任務(wù)書
一、原始依據(jù)（包括設(shè)計(jì)或論文的工作基礎(chǔ)、研究條件、應(yīng)用環(huán)境、工作目的等。）
1. 工作基礎(chǔ)：畢業(yè)設(shè)計(jì)是高等院校培養(yǎng)學(xué)生必不可少的重要環(huán)節(jié)，學(xué)生應(yīng)在所學(xué)專業(yè)課和某些專業(yè)基礎(chǔ)課的基礎(chǔ)上，查閱大量的文獻(xiàn)和資料并認(rèn)真總結(jié)相關(guān)課程設(shè)計(jì)的經(jīng)驗(yàn)，結(jié)合生產(chǎn)實(shí)習(xí)和畢業(yè)實(shí)習(xí)的時(shí)間活動(dòng)，認(rèn)真獨(dú)立地完成本次畢業(yè)設(shè)計(jì)任務(wù)。
2. 研究條件：國(guó)內(nèi)外類似工程實(shí)例，相關(guān)圖紙、論文資料和文獻(xiàn)、設(shè)計(jì)手冊(cè)、相關(guān)設(shè)計(jì)規(guī)范及國(guó)家標(biāo)準(zhǔn)。
3. 應(yīng)用環(huán)境：水資源開發(fā)與利用、市政建設(shè)和工程、給水工程和設(shè)備
4. 工作目的：詳細(xì)了解設(shè)計(jì)程序和規(guī)范，鞏固和加深已有的理論知識(shí)，重點(diǎn)培養(yǎng)學(xué)生的創(chuàng)新精神和獨(dú)立工作能力，加強(qiáng)分析問題和解決問題的能力以及工程實(shí)踐能力的培養(yǎng)和訓(xùn)練，最使師學(xué)生具有嚴(yán)謹(jǐn)?shù)目茖W(xué)精神、科學(xué)作風(fēng)和工作態(tài)度。
二、參考文獻(xiàn)
1.《給水排水制圖標(biāo)準(zhǔn)》 GBJ106-87
2.《室外給水工程規(guī)范》 中國(guó)建筑工業(yè)出版社，2000
3.《給水排水設(shè)計(jì)手冊(cè)》中國(guó)建筑工業(yè)出版社，2002
4.《給水排水標(biāo)準(zhǔn)圖集》中國(guó)建筑標(biāo)準(zhǔn)設(shè)計(jì)研究所，1994
5.《簡(jiǎn)明給排水設(shè)備手冊(cè)》中國(guó)建筑工業(yè)出版社，2002
6.《凈水廠設(shè)計(jì)》中國(guó)建筑工業(yè)出版社，1986
7.《水工業(yè)工程設(shè)備》 中國(guó)建筑工業(yè)出版社，2000
8.《城市給水排水工程規(guī)劃》 安徽科學(xué)技術(shù)出版社，2001
9.《給排水快速設(shè)計(jì)手冊(cè)》 中國(guó)建筑工業(yè)出版社，1999
10.《室外給水設(shè)計(jì)規(guī)范》 GB50013-2006
11.《城市給排水工程概預(yù)算定額與工程量清單計(jì)價(jià)及設(shè)計(jì)施工驗(yàn)收實(shí)務(wù)全書》 中國(guó)科技文化
出版社，2004
三、設(shè)計(jì)（研究）內(nèi)容和要求（包括設(shè)計(jì)或研究?jī)?nèi)容、主要指標(biāo)與技術(shù)參數(shù)，并根據(jù)課題性質(zhì)對(duì)學(xué)生提出具體要求）
1.設(shè)計(jì)內(nèi)容
以地面水為水源，設(shè)計(jì)一座自來(lái)水廠共居民生活和工業(yè)使用，其出廠水質(zhì)按《生活飲用水衛(wèi)生標(biāo)準(zhǔn)》（GB5749-2006）中規(guī)定的數(shù)值執(zhí)行。適當(dāng)考慮預(yù)留增加深度處理工藝的可行性，以適應(yīng)新的《生活飲用水衛(wèi)生標(biāo)準(zhǔn)》對(duì)水質(zhì)的要求。
設(shè)計(jì)成果包括：
（1）開題報(bào)告（不少于2000字）
（2）設(shè)計(jì)說明書（不少于1.2萬(wàn)字）
（3）給水廠總平面圖布置圖（2#圖1張）
（4）給水廠高程布置圖（2#圖1張）
（5）給水泵房工藝圖（2#圖1張）
（6）處理構(gòu)筑物施工平面圖和剖面施工圖（2#圖3張）
（7）外文資料翻譯（不少于5000漢字）
2.主要指標(biāo)和技術(shù)參數(shù)
（1）主要指標(biāo)和技術(shù)參數(shù)：
設(shè)計(jì)水量3萬(wàn)m3/d，出水水壓為38 m，且出廠水質(zhì)按《生活飲用水衛(wèi)生標(biāo)準(zhǔn)》（GB5749-2006）中規(guī)定的數(shù)值執(zhí)行。適當(dāng)考慮預(yù)留增加深度處理工藝的可行性，以適應(yīng)新的《生活飲用水衛(wèi)生標(biāo)準(zhǔn)》對(duì)水質(zhì)的要求。
原水水質(zhì)
最高
最低
平均
懸浮物（mg/L）
125
36
69
濁度（NTU）
46
23
36
色度（度）
21
8
19
耗氧量(mg/L)
6
3
5
含鹽量(mg/L)
240
217
228
總硬度(mg/L)
126
118
122
氯化物(mg/L)
98
87
90
大腸菌群（個(gè)/L）
29
13
18
細(xì)菌總數(shù)(個(gè)/mL）
980
443
544
（2） 氣象條件：
平均氣溫15.3℃
最低氣溫－16.8℃
最高氣溫34℃
全年平均降水量400 mm
最大降雨量76 mm
最大積雪厚度15 mm
夏季主導(dǎo)風(fēng)向西北
最低水溫2.1℃
最高水溫28.0℃
（3） 地質(zhì)條件：
地基承載89 kPa
地下水位1.8 m
最大凍土深度80 cm
河水最高水位13.5 m（大沽標(biāo)高）
河水最低水位10.8 m（大沽標(biāo)高）
設(shè)計(jì)場(chǎng)地平坦標(biāo)高為15.45 m（大沽標(biāo)高）
3.設(shè)計(jì)要求
（1）學(xué)生應(yīng)該獨(dú)立完成畢業(yè)設(shè)計(jì)并提出自己的設(shè)計(jì)文件；
（2）畢業(yè)設(shè)計(jì)目的在于總結(jié)和鞏固所學(xué)知識(shí)必須給予足夠重視并能刻苦鉆研。
四、畢業(yè)設(shè)計(jì)進(jìn)度計(jì)劃及檢查情況記錄表
序號(hào)
起止日期
計(jì)劃完成內(nèi)容
1
11.01.10～11.03.10
熟悉工程制圖標(biāo)準(zhǔn)、收集資料、完成開題報(bào)告
2
11.03.10～11.04.01
基于具體設(shè)計(jì)資料，確定設(shè)計(jì)方案、工藝流程
3
11.04.01～11.04.30
計(jì)算各單體構(gòu)筑物
4
11.05.01～11.05.20
完成工程預(yù)算成本分析、繪制設(shè)計(jì)圖紙
5
11.05.21～11.06.10
整理設(shè)計(jì)計(jì)算、說明書
6
11.06.11～11.06.20
準(zhǔn)備畢業(yè)設(shè)計(jì)答辯
指導(dǎo)教師（簽字）
年 月 日
審題小組組長(zhǎng)（簽字）
年 月 日
外文資料
DRINKING WATER TREATMENT ANDWATER SECURITY
C. P. Gerba, K. A. Reynolds, and I. L. Pepper
Rivers, streams, lakes, and aquifers are all potential sources of potable water. In the United States, all water obtained from surface sources must be filtered and disinfected to protect against the threat of microbiological contaminants. Such treatment of surface waters also improves values such as taste, color, and odor. In addition, groundwater under the direct influence of surface waters such as nearby rivers must be treated as if it were a surface water supply. In many cases however, groundwater needs either no treatment or only disinfection before use as drinking water. This is because soil itself acts as a filter to remove pathogenic micro organisms, decreasing their chances of contaminating drinking water supplies. At first, slow sand filtration was the only means employed for purifying public water supplies. Then, when Louis Pasteur and Robert Koch developed the Germ Theory of Disease in the 1870s, things began to change quickly. In1881, Koch demonstrated in the laboratory that chlorine could kill bacteria. Following an outbreak of typhoid fever in London, continuous chlorination of a public water supply was used for the first time in 1905 (Montgomery,1985). There gular use of disinfection in the United States began in Chicago in 1908. The application of modern water treatment processes had a major impact on water-transmitted diseases such as typhoid in the United States (see also Chapter 11).The following sections describe conventional water treat-ment that is practiced in the public sector (e.g., municipal water supplies).
28.1 WATER TREATMENT PROCESSES
Modern water treatment processes provide barriers, or lines of defense, between the consumer and waterborne disease. These barriers, when implemented as a succession of treatment processes, are known collectively as a treatment process train (Figure 28.1). The simplest treatment process train, known as chlorination, consists of a single treatment process, disinfection by chlorination (Figure 28.1a). The treatment process train known as filtration, entails chlorination followed by filtration through sand or coal, which removes particulate matter from the water and reduces turbidity (Figure 28.1b). At the next level of treatment, in-line filtration, a coagulant is added prior to filtration (Figure28.1c). Coagulation alters the physical and chemical state of dissolved and suspended solids and facilitates their removal by filtration. More conservative water treatment plants add a flocculation (stirring) step before filtration, which enhances the agglomeration of particles and further improves there moval efficiency in a treatment process train called direct filtration (Figure. 28.1d). In direct filtration, disinfection is enhanced by adding chlorine (or an alternative disinfectant, such as chlorine dioxide or ozone) at both the beginning and end of the process train. The most common treatment process train for surface water supplies, known as conventional treatment, consists of disinfection, coagulation, flocculation, sedimentation , filtration, and disinfection (Figure 28.1e).
As already mentioned, coagulation involves the addition of chemicals to facilitate the removal of dissolved and suspended solids by sedimentation and filtration. The most common primary coagulants are hydrolyzing metal salts, most notably alum [Al2(SO4)3 14H2O], ferric sulfate[Fe2(SO4)3], and ferric chloride (FeCl3). Additional chemicals that may be added to enhance coagulation are charged organic molecules called polyelectrolytes; these include high-molecular-weight polyacrylamides, dimethyldially-ammonium chloride, polyamines, and starch. These chemicals ensure the aggregation of the suspended solids during the next treatment step, flocculation. Some times polyelectrolytes (usually polyacrylamides) are added after flocculation and sedimentation as an aid in the filtration step.
Coagulation can also remove dissolved organic an dinorganic compounds. Hydrolyzing metal salts added to the water may react with the organic matter to form a precipitate,or they may form aluminum hydroxide or ferric hydroxidefloc particles on which the organic molecules adsorb. Theorganic substances are then removed by sedimentation and filtration, or filtration alone if direct filtration or in-line filtration is used. Adsorption and precipitation also remove inorganic substances.
Flocculation is a purely physical process in which the treated water is gently stirred to increase interparticle collisions, thus promoting the formation of large particles. After adequate flocculation, most of the aggregates settle out during the 1 to 2 hours of sedimentation. Microorganisms are entrapped or adsorbed to the suspended particles and removed during sedimentation (Figure 28.2).
Sedimentation is another purely physical process, involving the gravitational settling of suspended particles that are denser than water. The resulting effluent is then subjected to rapid filtration to separate out solids that are still suspended in the water. Rapid filters typically consist of 50–75 cm of sand and/or anthracite having a diameter between 0.5 and 1.0 mm (Figure 28.2). Particles are removed as water is filtered through the medium at rates of 4–24 L/min/10 dm2. Filters need to be backwashed on are gular basis to remove the buildup of suspended matter. This backwash water may also contain significant concentrations of pathogens removed by the filtration process. Rapid filtration is commonly used in the United States. Another method, slow sand filtration, is also used. Employed primarily in the United Kingdom and Europe, this method operates at low filtration rates without the use of coagulation. Slow sand filters contain a layer of sand(60–120 cm deep) supported by a gravel layer (30–50cm deep). The hydraulic loading rate is between 0.04 and 0.4 m/h. The buildup of a biologically active layer, called as chmutzdecke, occurs during the operation of a slow sandfilter. This eventually leads to head loss across the filter, requiring removing or scraping the top layer of sand. Factors that influence pathogen removal by filtration are shown in Table 28.1.
Taken together, coagulation, flocculation, sedimentation, and filtration effectively remove many contaminants as shown in Table 28.2. Equally important, they reduce turbidity, yielding water of good clarity and hence enhanced disinfection efficiency. If not removed by such methods, particles may harbor microorganisms and make final disinfection more difficult. Filtration is an especially important barrier in the removal of the protozoan parasites Giardialamblia and Cryptosporidium. The cysts and oocysts of these organisms are very resistant to inactivation by disinfectants, so disinfection alone cannot be relied on to prevent waterborne illness. Because of their larger size, Giardia and Cryptosporidium are removed effectively by filtration. Conversely, because of their smaller size, viruses and bacteria can pass through the filtration process. Removal of viruses by filtration and coagulation depends on their attachment to particles (adsorption), which is dependent on the surface charge of the virus. This is related to the isoelectric point (the pH at which the virus has no charge) and is both strain and type dependent. The variations in surface properties have been used to explain why different types of viruses are removed with different efficiencies by coagulation and filtration. Thus, disinfection remains the ultimate barrier to these microorganisms.
28.2 DISINFECTION
Disinfection plays a critical role in the removal of pathogenic microorganisms from drinking water. The proper application of disinfectants is critical to kill pathogenic organisms
Generally, disinfection is accomplished through the addition of an oxidant. Chlorine is by far the most common disinfectant used to treat drinking water, but other oxidants, such as chloramines, chlorine dioxide, and even ozone, are also used (Figure 28.3).
Inactivation of microorganisms is a gradual process that involves a series of physicochemical and biochemical steps. In an effort to predict the outcome of disinfection, various models have been developed on the basis of experimental data. The principal disinfection theory used today is still the Chick-Watson Model, which expresses the rate of inactivation of microorganisms by a first-order chemical reaction.
Nt/No=e-kt (Eq.28.1)
or
1n Nt/No=-kt (Eq.28.2)
where:
Ne : number of microorganisms at time 0,
Nt : number of microorganisms at time t
k : decay constant (1/time)
t : time
The logarithm of the survival rate (Nt/No) plots as a straight line versus time (Figure 28.4). Unfortunately, laboratory and field data often deviate from first-order kinetics. Shoulder curves may result from clumps of organisms or multiple hits of critical sites before inactivation. Curves of this type are common in disinfection of coli form bacteria by chloramines(Montgomery, 1985). The tailing-off curve, often seen with many disinfectants, may be explained by the survival of a resistant subpopulation as a result of protection by interfering substances (suspended matter in water), clumping, or genetically conferred resistance.
In water applications, disinfectant effectiveness can be expressed as C～t, where:
C disinfectant concentration t time required to inactivate a certain percentage of the population under specific conditions (pH and temperature)Typically, a level of 99% inactivation is used when comparing C~ t values. In general, the lower the C～t value, the more effective the disinfectant. The C～t method allows ageneral comparison of the effectiveness of various disinfectants on different microbial agents (Tables 28.3 through28.6). It is used by the drinking water industry to determine how much disinfectant must be applied during treatment to achieve a given reduction in pathogenic microorganisms. C· t values for chlorine for a variety of pathogenic microorganisms are shown in Table 28.3. The order of resistance to chlorine and most other disinfectants used to treat water is protozoan cysts viruses vegetative bacteria. To obtain the proper C～t, contact chambers (Figure 28.5) are used to retain the water in channels before entering the drinking water distribution system or sewage discharge.
28.3 FACTORS AFFECTING DISINFECTANTS
Numerous factors determine the effectiveness and/or rate of kill of a given microorganism. Temperature has a major effect, because it controls the rate of chemical reactions. Thus , as temperature increases, the rate of kill with a chemical disinfectant increases. The pH can affect the ionization of the disinfectant and the viability of the organism. Most waterborne organisms are adversely affected by pH levels below 3 and above 10. In the case of halogens such as chlorine, pH controls the amount of HOCL (hypochlorous acid) and OCl (hypochlorite) in solution. HOCl is more effective than OCl in the disinfection of micro organisms. With chlorine, the C· t increases with pH. Attachment of organisms to surfaces or particulate matter in water such as clays and organic detritus aids in the resistance of microorganisms to disinfection. Particulate matter may interfere by either acting chemically to react with the disinfectant, thus neutralizing the action of the disinfectant, or physically shielding the organism from the disinfectant (Stewart and Olson, 1996).
Repeated exposure of bacteria and viruses to chlorine appears to result in selection for greater resistance (Bates etal., 1977; Haas and Morrison, 1981). However, the enhanced resistance has not been great enough to overcome concentrations of chlorine applied in practice.
28.4 HALOGENS
28.4.1 Chlorine
Chlorine and its compounds are the most commonly used disinfectants for treating drinking and wastewater (Figure28.6). Chlorine is a strong oxidizing agent that, when added as a gas to water, forms a mixture of hypochlorous acid (HOCl) and hydrochloric acids.
Cl2 + H2O=HOCl + HCl (Eq.28.3)
In dilute solutions, little Cl2 exists in solution. The disinfectant’s action is associated with the HOCl formed.
Hypochlorous acid dissociates as follows:
HOCl?H+ + OCl- (Eq.28.4)
The preparation of hypochlorous acid and OCl (hypochorite ion) depends on the pH of the water (Figure28.7). The amount of HOCl is greater at neutral and lower pH levels, resulting in greater disinfection ability of chlorine at these pH levels. Chlorine as HOCl or OCl is defined as free available chlorine. HOCl combines with ammonia and organic compounds to form what is referred to as combined chlorine. The reactions of chlorine with ammonia and nitrogen-containing organic substances are of great importance in water disinfection. These reactions result in the formation of monochloramine, dichloramine, trichloramine, etc.
Such products retain some of the disinfecting power of hypochlorous acid, but are much less effective at a given concentration than chlorine.
Free chlorine is quite efficient in inactivating pathogenic microorganisms. In drinking water treatment, 1mg/1 or less for about 30 minutes is generally sufficient to significantly reduce bacterial numbers. The presence of interfering substances in wastewater reduces the disinfection efficacy of chlorine, and relatively high concentrations of chlorine (20–40 mg/l) are required (Bitton, 1999). Enteric viruses and protozoan parasites are more resistant to chlorine than bacteria and can be found in secondary wastewater effluents after normal disinfection practices. Cryptosporidium is extremely resistant to chlorine. A chlorine concentration of 80 mg/l is necessary to cause 90% inactivation following a 90-minute contact time (Korich et al.,1990). Chloramines are much less efficient than free chlorine (about 50 times less efficient) in inactivation of viruses.
Bacterial inactivation by chlorine is primarily caused by impairment of physiological functions associated with the bacterial cell membrane. Chlorine may inactivate viruses by interaction with either the viral capsid proteins or the nucleic acid (Thurman and Gerba, 1988).
28.4.2 Chloramines
Inorganic chloramines are produced by combining chlorine and ammonia (NH4) for drinking water disinfection. The species of chloramines formed (see Equations 28.5 through 28.7) depend on a number of factors, including the ratio of chlorine to ammonia-nitrogen, chlorine dose, temperature,and pH. Up to a chlorine-to-ammonia mass ratio of 5, the predominant product formed is monochloramine, which demonstrates greater disinfection capability than other forms, i.e., dichloramine and trichloramine. Chloramines are used to disinfect drinking water by some utilities in the United States, but because they are slow acting, they have mainly been used as secondary disinfectants when a residualin the distribution system is desired. For example, when ozone is used to treat drinking water, no residual disinfectant remains. Because bacterial growth may occur after ozonation of tap water, chloramines are added to prevent re grow thin the distribution system. In addition, chloramines have been found to be more effective in controlling bio film micro organisms on the surfaces of pipes in drinking water distribution systems because they interact poorly with capsular bacterial polysaccharides (Le Chevallier et al., 1990).
Because of the occurrence of ammonia in sewage effluents, most of the chlorine added is converted to chloramines. This demand on the chlorine must be met before free chlorine is available for disinfection. As chlorine is added, the residual reaches a peak (formation of mostly monochloramine) and then decreases to a minimum called the break-point (Figure 28.8). At the breakpoint, the chloramine is oxidized to nitrogen gas in a complex series of reactions summarized in Equation 28.8.
Addition of chlorine beyond the breakpoint ensures the existence of a free available chlorine residual.
28.4.3 Chlorine Dioxide
Chlorine dioxide is an oxidizing agent that is extremelysoluble in water (five times more than chlorine) and, unlikechlorine, does not react with ammonia or organiccompounds to form trihalomethane, which is potentiallycarcinogenic. Therefore it has received attention for use as adrinking water disinfectant. Chlorine dioxide must be generated on site because it cannot be stored. It is generated fromthe reaction of chlorine gas with sodium chlorite:
Chlorine dioxide does not hydrolyze in water but exists as a dissolved gas. Studies have demonstrated that chlorine dioxide is as effective as or more effective in inactivating bacteria and viruses in water than chlorine (Table 28.4). As is the case with chlorine, chlorine dioxide inactivates microorganisms by denaturation of the sulfyhydryl groups contained in proteins, in hibition of protein synthesis, denaturation of nucleic acid, and impairment of permeability control (Stewart and Olson, 1996).
28.4.4 Ozone
Ozone (O3), a powerful oxidizing agent, can be produced bypassing an electric discharge through a stream of air or oxygen. Ozone is more expensive than chlorination to apply to drinking water, but it has increased in popularity as a disinfectant because it does not produce trihalomethanes or other chlorinated by products, which are suspected carcinogens. However, aldehydes and bromates may be produced by ozonation and may have adverse health effects. Because ozone does not leave any residual in water, ozone treatment is usually followed by chlorination or addition of chloramines. This is necessary to prevent regrowth of bacteria because ozone breaks down complex organic compounds present in water into simpler ones thatserve as substrates for growth in the water distribution system. The effectiveness of ozone as a disinfectant is not influenced by pH and ammonia. Ozone is a much more powerful oxidant than chlorine(Tables 28.3 and 28.6). Ozone appears to inactivate bacteria by the same mechanisms as chlorine-based disinfection: bydisruption of membrane permeability (Stewart and Olson,1996), impairment of enzyme function and/or protein integrityby oxidation of sulfyhydryl groups, and nucleic acid denaturation. Cryptosporidium oocysts can be inactivated by ozone, but a C· t of 1–3 is required. Viral inactivation may proceed by breakup of the capsid proteins into subunits, resulting in re-lease of the RNA, which can subsequently be damaged.
28.4.5 Ultraviolet Light
The use of ultraviolet disinfection of water and wastewater has seen increased popularity because it is not known to produce carcinogenic or toxic byproducts, or taste and odor problems. Also, there is no need to handle or store toxic chemicals. A wavelength of 254 nm is most effective against microorganisms because this is the wavelength absorbed by nucleic acids(Figure 28.9). Unfortunately, it has several disadvantages, including higher costs than halogens, no disinfectant residual, difficulty in determining the UV dose, maintenance and cleaning of UV lamps, and potential photo reactivation of some enteric bacteria (Bitton, 1999) (Figure 28.10). However, advances in UV technology are providing lower cost, more efficient lamps, and more reliable equipment. These advances have aided in the commercial application of UV for water treatment in the pharmaceutical, cosmetic, beverage, and electronic industries in addition to municipal water and wastewater application. Microbial inactivation is proportional to the UV dose, which is expressed in microwatt-seconds per square centimeter ( W-s/cm2) orUV dose=I·t (Eq.28.10)
Where:
I: W/cm2
t: exposure time
In most disinfection studies, it has been observed that the logarithm of the surviving fraction of organisms is nearly linear when it is plotted against the dose, where dose is