環(huán)境工程外文翻譯--生物-化學絮凝工藝處理城市的污水和生物作用的研究

1、<p>　　畢業(yè)設計(論文)外文資料翻譯</p><p>　　學院（系）： 資源與環(huán)境工程學院 </p><p>　　專 業(yè)： 環(huán)境工程 </p><p>　　姓 名： </p>&

2、lt;p>　　學 號： </p><p>　　外文出處： Journal of Environmental Sciences</p><p>　　附 件：1.外文資料翻譯譯文；2.外文原文。 </p><p>　　附錄1 外文資料翻譯譯文</p><p

3、>　　生物-化學絮凝工藝處理城市的污水和生物作用的研究</p><p>　　摘要： 本文介紹在處理上海城市的污水時證實生物-化學的絮凝工藝的中試實驗的儀器和程序的可行性。并討論在此過程中生物的功能。最理想運行的結(jié)果顯示，在反應罐中，混合液懸浮固體(MLSS)是2g/L, 液壓的保持時間(HRT)是35min，聚合氯化鋁(PAC)是60mg/L，而濃度聚丙烯酰胺(PAM)是0.5mg/L.并且CODCr，TP

4、，SS和BOD5的平均濃度為分別是50mg/L，0.62mg/L，18mg/L，和17mg/L。這些設計的要求更好。此外，這個系統(tǒng)中的生物降解的存在有幾種方法證明。生物-化學的絮凝工藝的降解效率比在同樣的凝結(jié)劑中化學絮凝工藝提高20%。在不同的條件下進行中試試驗，為將來的設備操作提供最佳的參數(shù)和條件。</p><p>　　關鍵詞： 生物-化學絮凝工藝； 城市污水； 生物作用。</p><p&g

5、t;<b>　　1 試驗</b></p><p>　　1.1 設計對項目進行進水和出水的濃度</p><p>　　根據(jù)顯示評價和標準的水規(guī)格，城市污水的設計進水和出水的濃度見表格1。</p><p>　　表1 　工程設計進水水質(zhì)</p><p>　　1.2 中試試驗的流程圖</p><p>　　

6、生物-化學絮凝工藝中試試驗的示意圖見圖1.</p><p><b>　　圖1 工藝流程圖</b></p><p>　　中試試驗的設備包括一個小的混合罐，寬1.0m、高1.1m、長2.2m的生物-化學絮凝罐, 兩個寬1.0m高2.9m、長3.0m的沉淀池，寬0.6m、高6.5m、長1.2m的硝化罐，空壓泵和水泵。生物-化學的絮凝罐被劃分成為三條廊道，在每一條廊道中加入曝

7、氣管。首先，城市污水被抽吸到混合罐中再進入到生物-化學的絮凝罐中。水在每條廊道中反應之后進入第一沉淀池。然后水在澄清之后進入水罐，它在外排前作為一個水庫或者進一步反應。水的一部分直接排出，而余下的水為了進一步的處理被抽吸到硝化的罐中。伴隨著硝化菌，水進水第二個沉淀池。在澄清之后水被排出。第一沉淀池為系統(tǒng)的生物-化學反應提供回流污泥。曝氣系統(tǒng)向生物-化學絮凝反應提供氧并且控制在不破壞絮凝團的水平上?？諝饬魉僭谌齻€廊道內(nèi)分別是4m3/h，2

8、.5m3/h，和2m3/h。按這種方式，生物-化學反應在同樣的罐內(nèi)迅速地和有效分解有機的污染物和TP(總磷)。從生物-化學的絮凝工藝的液壓的保持時間(HRT)對硝化作用來說太短, 硝化罐懸浮過濾床(SFB)被用來提高氨氮的降解效率。在生物-化學的絮凝結(jié)果和機制在本文中作詳細討論。</p><p>　　中試試驗中的無機的凝結(jié)劑和有機的大分子凝結(jié)劑的選擇在中試試驗中有很大的幫助。首先，助凝劑按要求的濃度被添加到一個反

9、應罐中。接著，助凝劑和絮凝劑的選擇的用量用計量泵(MILTONROY，美國)加到罐中。在其中助凝劑和絮凝劑的增加量是可調(diào)整的。在這個系統(tǒng)中，聚合氯化鋁(PAC)被用作絮凝劑，而助凝劑是聚丙烯酰胺(PAM)。PAC被注入到罐中在第一條廊道的入口，和第二條廊道的入口加入PAM。</p><p><b>　　分析和監(jiān)控</b></p><p>　　項目測量評估見表格2。水質(zhì)

10、量監(jiān)控使用的方法見表格3。</p><p>　　表2 　分析測試項目</p><p>　　1.4 生物作用分析</p><p>　　生物作用研究使用一個特制的密封的反應器、充氧氣泵、電磁攪拌器，Leici JPB~607便攜式的溶解氧計量器，和一個秒表。生物的功能的分析被劃分成為兩個步驟。首先，1000 ml水樣放到特制的密封的反應器中，溶解氧是用充氧氣泵將空氣注入

11、到樣品中。接著，充氣設備被移去，反應器的蓋子蓋緊并且連接到溶解氧計量器。對溶解氧濃度進行連續(xù)記錄。做出溶解氧的消耗的曲線。</p><p>　　表3 　水質(zhì)指標的分析方法</p><p><b>　　結(jié)果和討論</b></p><p>　　2.1　中試試驗結(jié)果</p><p>　　為了對操作結(jié)果進行詳細分析將其劃分成為六

12、個階段見表4。不同的階段的時間間隔表現(xiàn)出了PAC的用量趨勢和PAC的注入位置。</p><p>　　表 4 生物化學絮凝在六個操作期的測定結(jié)果</p><p>　　正如表4所示，PAC的用量從高到適中，然后到低，由計量器控制。隨著PAC劑量的減少從而保持COD的降解效率，而出水的TP濃度在很大程度的增加。通過觀察當PAC用量在60mg/L的時候出水的TP濃度輕微超出正常的標準。結(jié)論，PAC

13、用量為70mg/L是這個工藝的最佳用量。5時期是用來測驗去除COD，TP和SS的最佳加藥量。6時期是用來測驗PAC的最佳注入位置的。當PAC的用量是100mg/L時，結(jié)果證明反應不充分。</p><p>　　2.2　最佳操作條件</p><p>　　表格4表明試驗顯示的最佳操作條件是：在絮凝罐中的藥劑的用量MLSS 2g/L；HRT 35min; 液態(tài)的PAC 70mg/L；PAM (分子

14、量從2百萬到3百萬 )的用量為0.5mg /L在這樣的操作條件下的結(jié)果在下列的段落中分別被論述。</p><p>　　2.2.1 　去除COD</p><p>　　在COD去除的最佳條件下操作的超過25天見圖2。正如圖2所示，進水的COD濃度一天天變化。進水的COD通常在124mg/L到266mg/L之間。出水的COD通常在24mg/L到74mg/L之間，平均的流出物是50mg/L，去除率

15、達到70%。因此得出結(jié)論這個工藝能有效的去除COD并且達到標準。</p><p>　　圖2 對COD的去除效果</p><p>　　2.2.2　去除TP</p><p>　　正如圖3所示，進水的TP濃度變化從1.63mg/L到 3.25mg/L，平均濃度為2.37mg/L。簡言之，出水的濃度在1mg/L以下的TP出水濃度是0.62mg/L，而去除率達到最佳操作條件的

16、74.3%。如果進水的濃度太高，出水的TP濃度將超過1mg/L。</p><p>　　2.2.3　去除懸浮固體(SS)</p><p>　　如圖4所示，超過設計濃度150mg/L的 SS濃度的變化從70mg/L到 380mg/L，平均值濃度為2.7mg/L。所有出水的SS濃度在40mg /L以下，出水的SS的平均濃度為18mg/L，去除率達到88.6 %。在研究工藝中出水的SS濃度都保持在

17、一個較低的水平，而且非常穩(wěn)定。竹園城市污水處理設備(ZMWTP)去除SS的目的很容易實現(xiàn)。</p><p>　　圖3 對TP的去除效果</p><p>　　圖4 對SS的去除效果</p><p>　　2.3生物作用分析測試</p><p>　　2.3.1不同的模擬反應系統(tǒng)的設計</p><p>　　為了證實在生物-化

18、學絮凝罐中的生物活動，試驗中設計使用不同的系統(tǒng)。所有的試驗條件見表格5。</p><p>　　表5 不同反應條件對比</p><p>　　2.3.2　研究結(jié)果</p><p>　　工況1結(jié)果表明ZMWTP 污水本身對溶解氧消耗十分少。在開始時，溶解氧的濃度為8mg/L。在12分鐘之后，濃度保持在7mg/L到8mg/L，其消耗量不超過1mg/L?？梢酝茢喑鲈跒樘幚淼奈?/p>

19、水中有生物存在。對于工況2，增加化學凝結(jié)劑，開始時的濃度為6 mg/L，20分鐘之后極少微生物消費溶解氧不超過1mg/L。工況3，用類比的方法模擬沒有曝氣過程，開始時溶解氧濃度為6mg/L，并且在20分鐘之后濃度的變化超過1mg/L。如果前二個條件沒有回流污泥那么在絮凝期間，即使供氣，這個系統(tǒng)溶解氧的消耗量是輕微的。當回流污泥增加時，如果不曝氣的話這個系統(tǒng)的溶解氧的消耗仍然很低。因此，在在這三個工況下都有微量的微生物存在。工況4用類比的

20、方法模擬有污泥回流和曝氣的絮凝工藝。在20分鐘后溶解氧的濃度約為2.8 mg/L。由于耗氧微生物的存在，如果不曝氣，即使有污泥回流效果仍然不是很好。結(jié)論得出系統(tǒng)有一定的微生物分解作用。</p><p>　　工況5、6、7的溶解氧的消耗曲線見圖6. 如圖5所示，如果活躍的回流污泥(從上海竹園城市污水處理系統(tǒng))存在于生物-化學的絮凝工藝中，因為微生物的活動溶解氧的消耗量增加6.4mg。明顯地，溶解氧的需求量十分高。根

21、據(jù)圖6，試驗結(jié)果顯示出實際運行的中試裝置第一、二廊道在5～7分鐘內(nèi)的耗氧量為5 mg/L左右,溶解氧的消耗量大約為5mg/L。由此可以判斷在竹園污水的中試裝置中存在較好的生物作用</p><p>　　圖5 工況5下的溶解氧消耗曲線</p><p>　　圖6 工況6和7下的溶解氧消耗曲線</p><p>　　2.3.3生物的活動分析的測試數(shù)據(jù)</p>

22、<p>　　一些帶有相似用量的操作條件的結(jié)果列在表6中和測試具有相同BOD5列在表7中。</p><p>　　表6 　 COD和TP在不同條件下的數(shù)據(jù)統(tǒng)計表</p><p>　　表7 　本工況進出水BOD5/COD 測定結(jié)果</p><p>　　在凝結(jié)-絮凝工藝中，污水中的磷的去除機制可能有兩種: 懸浮的磷酸鹽凝聚成固體并在沉降的過程中將磷去除。由金屬離

23、子組成的水解物中的磷酸鹽離子進行直接吸附。形成的在金屬鹽中的磷酸鹽在去除過程中作絮凝劑。磷酸鹽的去處過程受到一些因素的影響 ,例如堿度, 有機的物質(zhì)含量和其他金屬的存在。參加磷的降解過程的基本的反應如下:</p><p>　　這個反應相關對它的一些次要的反應。假設，磷以正磷酸鹽的形式伴隨著金屬離子被磷酸鹽降解，總磷以更復雜的吸附反應吸附絮凝成微粒被去除。</p><p>　　正如表格4中所

24、示，在操作條件2、3和4中的用量分別為70mg/L，70mg/L和60mg/L。但是，在工況3、4中的單位凝結(jié)劑有機物質(zhì)去除率超過工況2的35%,同時，工況3、4中TP的去除率超過工況2的20%。一種解釋是在相同的用量, 由于生物-化學作用的作用生物-化學的絮凝工藝中的污染物的去除率比化學絮凝工藝中的高20%。如果生物-化學的絮凝工藝被使用，要達到相同的去除率，藥劑用量可以減少20 %。</p><p>　　如表

25、格7中所示進水中流出物的BOD5與COD的平均值分別是0.4和0.3。由于生物作用，出水的BOD5與COD濃度小于進水濃度的25%。根據(jù)表格7，BOD5的平均的去除率的72%，這是化學絮凝工藝所不能達到的。去除率表明生物作用對整個系統(tǒng)的穩(wěn)定變得越來越重要。這大大地提高可溶性BOD5的去除率。</p><p>　　作為一個結(jié)論，由于生物-化學的作用，磷和有機的物質(zhì)的化學去除效率被改進。當生物-化學的絮凝工藝成穩(wěn)定的

26、運行時，化學作用對磷去除很重要，而生物的功能對有機物的去除更重要, 諸如BOD5，COD等等。</p><p><b>　　3　結(jié)論</b></p><p>　　生物-化學的絮凝工藝處理上海城市污水是可行的，用空氣攪拌代替機械攪拌是可以完成化學混合反應的。在反應罐中，MLSS的濃度是2g/L，HRT是35min，液態(tài)的PAC的用量70 mg/L，并且濃度PAM是0.5

27、mg/L。并且CODCr，TP，SS的平均的出水的濃度BOD5是50mg/L，0.62mg/L，18mg/L，和17mg/L分別。因此，結(jié)果滿足上海的城市污水處理中的設計的要求。</p><p>　　根據(jù)絮凝劑和凝集沉降劑當前的價格，用量費用是少于0.1RMB元每立方米污水。</p><p>　　在相同的用量，因為生物和化學工藝的共同作用，其去除率超過單獨使用生物-化學的絮凝工藝和化學絮凝

28、工藝的20%。由于生物作用，在生物-化學的絮凝工藝的作用下BOD的平均去除率能達到72%，這不是化學絮凝工藝所能單獨地實現(xiàn)的。</p><p>　　不同的模擬條件下的耗氧量的結(jié)果表明在城市污水處理過程中不僅只有生物作用, 化學絮凝過程的作用，還包括沒有曝氣的回流污泥的化學絮凝過程的作用。然而，生物-化學的絮凝工藝的耗氧量是很明顯的，這表明在反應罐中有很好的生物作用。</p><p>　　當

29、生物-化學的絮凝工藝成穩(wěn)定的運行時，化學作用對磷去除很重要，而生物的功能對有機物的去除更重要。</p><p><b>　　附錄2 外文原文</b></p><p>　　Chemical and biological flocculation process to treat municipal sewage and analysis of biological fu

30、nction</p><p>　　XIA Si-qing, YANG Dian-hai , XU Bin , ZHAO Jian-fu</p><p>　　(State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China. Email: siqin

31、gxia@mail.Tongji.edu.cn)</p><p>　　Abstract: The pilot-scale experimental apparatus and the procedure of the chemical and biological flocculation process to verify the feasibility in treating Shanghai municip

32、al sewage were introduced in this paper. In addition, the biological function of the process was discussed. The results of optimal running showed that in the reaction tank, the concentration of mixed liquor suspended sol

33、id(MLSS) was 2g/L , hydraulic retention time (HRT) was 35min , do sage of liquid polyaluminium chloride (PA</p><p>　　Keywords: chemical and biological flocculation process; municipal water; biological functi

34、on</p><p>　　1 　Experimental</p><p>　　1.1 　Designed influent and effluent concentrations of the project</p><p>　　According to the demonstration evaluation and standard water quality

35、requirements, the designed influent and effluent concentrations of the municipal sewage are shown in Table 1. </p><p>　　Table 1 　Designed influent and effluent concentrations</p><p>　　1.2 　Flow

36、sheet of the pilot-scale experiment</p><p>　　A schematic drawing of the pilot-scale chemical and biological flocculation process employed is shown in Fig. 1. </p><p>　　Fig. 1 Scheme of the pilot

37、-scale experimental apparatus (the flow rate was 50m3/d)</p><p>　　Equipments for the pilot-scale study included a small mixing tank, a 1.1m high chemical and biological flocculation tank with a width of 1.0m

38、 and a length of 2.2m, two 2.9m high sedimentation tanks with a width of 1.0m and a length of 3.0m, a 6.5m high nitrifying tank with a width of 0.6m and a length of 1.2m, and air and water pumps. The chemical and biologi

39、cal flocculation tank was divided into three galleries, with one aeration pipe in each gallery. First, the municipal sewage was pumped into</p><p>　　Inorganic coagulant and organic macromolecule coagulant ai

40、ds, selected by laboratory-scale evaluation, were used in this pilot-scale experiment. First, the coagulant and aid were added to the demand concentration in a solution tank. Second, the selected dosages of coagulant and

41、 flocculant were added into the tank by a metering pump (MILTONROY, made in USA). The point at which the coagulant and flocculant were added was adjustable. In this system, polyaluminium chloride (PAC) was used as the fl

42、oc</p><p>　　1.3 　Analyses and monitoring</p><p>　　The items measured to evaluate performance are shown in Table 2. The methods employed for water quality monitoring are presented in Table 3.<

43、/p><p>　　Table 2 　Parameters of the water quality</p><p>　　1.4 　Analysis of biological function</p><p>　　Biological function was evaluated using a tailored sealed reactor, oxygen pump,

44、 magnetic mixer, Leici JPB~607 portable dissolved oxygen meter, and a stopwatch. The analysis for biological function was divided into two steps. First, 1000 ml water samples were put into the tailored sealed reactor, an

45、d dissolved oxygen was added to the samples by aeration using an air pump. Second, the aeration devices were removed and the lid of reactor was tightened and was connected to a dissolved oxygen meter. </p><p&g

46、t;　　Table 3 　Monitoring methods for water quality analysis</p><p>　　2 　Results and discussion</p><p>　　2.1 　Pilot-scale performance</p><p>　　The operating results are divided into s

47、ix periods for detailed analysis as indicated in Table 4. The time intervals for the periods were chosen based upon performance trends for dosage of PAC and the position PAC injected. </p><p>　　As shown in T

48、able 4, the dosage of PAC was varied from high to moderate, and then to low, as controlled by a meter pump. With the decreased dose of PAC, the removal efficiencies of COD were maintained; however the effluent TP concent

49、ration significantly increased. It was observed that the effluent TP concentration slightly exceeded the regular standard when the PAC dosage was 60mg/L. The conclusion was drawn that 70mg/L was the favorable dosage of P

50、AC for this process. Period 5 was set to verify</p><p>　　Table 4 Chemical and biological flocculation process performance during six operating periods</p><p>　　2.2 　Typical operating conditions&

51、lt;/p><p>　　Table 4 indicates that the typical operating conditions for practical performance were: MLSS 2g/L in the flocculation tank; the HRT 35min; dosage of liquid PAC 70mg/L; and dosage of PAM (molecular w

52、eight is from 2million to 3million) 0. 5mg/L. The results under these operating conditions are discussed individually in the following sections.</p><p>　　2.2.1 　Removal of COD</p><p>　　COD remov

53、al over 25d of operation under typical operating conditions is shown in Fig. 2.</p><p>　　As shown in Fig. 2, the influent COD concentration varied day by day. The influent COD was normally between 124 mg/L a

54、nd 266mg/L. The effluent COD was normally between 24mg/L and 74mg/L, the average effluent was 50mg/L, and removal efficiencies were measured up to 70 %. It is therefore concluded that this process had favorable capacity

55、 to remove COD and reach the standards successfully.</p><p>　　2.2.2 Removal of TP</p><p>　　As seen in Fig. 3, the influent TP concentration ranged from 1.63mg/L to 3.25 mg/L, and the average v

56、alue was 2.37 mg/L. In general, the effluent concentrations were below 1 mg/L. The average effluent TP concentration was 0.62 mg/L, and the removal efficiencies were observed up to 74.3 % under typical operating conditio

57、ns. The effluent TP concentration, however, would exceed the standard of 1 mg/L if the influent concentration were too high.</p><p>　　2.2.3 　Removal of suspended solid(SS)</p><p>　　As shown in F

58、ig. 4, the influent SS concentration ranged from 70mg/L to 380mg/L, and the average was 2.7 mg/L, which is over the designed concentration of 150 mg/L. All effluent SS concentrations were below 40mg/L. The average efflue

59、nt SS concentration was 18mg/L, and the removal efficiencies were up to 88.6 %. The effluent SS concentration was maintained at a low level throughout the study and the effect was stable. SS removal goals for Zhuyuan Mun

60、icipal Wastewater Treatment Plant (ZMWTP) could</p><p>　　2.3 　Analytic test of biological function</p><p>　　2.3.1 Design of different analog reaction system</p><p>　　In order to ve

61、rify biological activity in the chemical and biological flocculation tanks, different system designs were employed in experiments. All conditions are summarized in Table 5.</p><p>　　2.3.2 　Discussion of resu

62、lts</p><p>　　The operating condition 1 shows very little DO consumption by ZMWTP wastewater. At the beginning, the concentration of DO was 8 mg/L. After 12min, the value remained at 7 mg/L to 8 mg/L, and the

63、 reduction was not more than 1 mg/L. It could be concluded that there was little biological activity in the raw wastewater. For operating condition 2, the chemical coagulant was added, the value was 6 mg/L at the beginni

64、ng, and the consumption of DO was also not more than 1 mg/L after 20 min due to few mi</p><p>　　Table 5 　Different analog reaction systems</p><p>　　Operating condition 4 simulated the process wh

65、ich had chemical return sludge mixed with air for coagulation by analogy. The consumption of DO was about 2.8 mg/L after 20min. It is obvious that although the return sludge was not active sludge, with aeration, the DO w

66、as consumed because of the existence of aerobic microorganisms. It could be concluded that the biological metabolism existed in this system. </p><p>　　The DO consumption curves for operating conditions 5, 6,

67、 and 7 are shown in Fig. 5 and Fig. 6. As shown in Fig. 5, if the active return sludge (from Shanghai Quyang Minicipal Wastewater Treatment Plant) was used in the analogizing of the chemical and biological flocculation p

68、rocess , the consumption of DO increased to 6.4mg due to microbe activity. Obviously, the demand for oxygen consumption was very high. According to Fig. 6, after 5 to 7 min, oxygen consumption in the first and second gal

69、lery</p><p>　　2.3.3 Analyses of biological activity by testing data</p><p>　　The results of some operating conditions with similar dosage are listed in Table 6 and some BOD5 tested are included

70、 in Table 7.</p><p>　　Table 6 　Statistical data of COD and TP removal for several operating conditions</p><p>　　In the coagulation-flocculation process, the removal of phosphorus in the wastewat

71、er may be due to two mechanisms: the phosphates being incorporated to solids in suspension and the reduction of these solids during the process including the removal of the phosphorus. The direct adsorption of phosphate

72、ions in the hydrolysis products was formed by the metal ion used as a coagulant. Removal through the formation of phosphate precipitates with the metal salts was used as coagulants. The removal of p</p><p>　

73、　Table 7 　BOD5/COD measured in influent and effluent during pilot-scale experiment</p><p>　　This reaction has a number of secondary reactions associated to it. It is generally assumed that the phosphorus in

74、the form of orthophosphate is removed by precipitation of phosphate with the metal ion while the total phosphorus is removed by a more complicated combination of interaction and adsorption with the flocculated particles.

75、</p><p>　　As shown in Table 6, the dosages in operating conditions 2, 3 and 4 were 70 mg/L , 70 mg/L and 60 mg/L respectively. But the organic substance removal of unit coagulant in operating conditions 3 an

76、d 4 exceeded that of operating condition 2 by 35 %, and the TP removal of unit coagulant in operating conditions 3 and 4 exceeded that of operating condition 2 by 20 %. An explanation is that at the same dosage, the remo

77、val efficiencies of pollutants in the chemical and biological flocculation process </p><p>　　Table 7 shows that the average of BOD5/COD in the influent and effluent was 0.4 and 0.3 respectively. As a result

78、of biological function, the effluent BOD5/COD value is 25 % less than the influent value. According to Table 7, the average removal efficiency of BOD5 was 72 %, which could not be attained by the chemical flocculation pr

79、ocess. The removal efficiencies indicated that the biological function become more and more significant with the stability of system. This enhanced the removal effici</p><p>　　As a conclusion, because of the

80、 cooperation of chemical and biological, both the chemical precipitation efficiency for phosphorus removal and organic substance removal were improved. The chemical function was more important for phosphorus removal and

81、the biological function was more important for solved organic matter, such as BOD5, COD etc., as the chemical and biological flocculation process became a stable run condition.</p><p>　　3 　Conclusions</p&

82、gt;<p>　　It is feasible to treat Shanghai municipal water by a chemical and biological flocculation process. Mechanical mixing can be substituted by air mixing to perform the reaction of chemical mixing. In the re

83、action tank, the concentration of MLSS was 2g/L, HRT was 35min, dosage of liquid PAC was 70 mg/L and the concentration of PAM was 0.5mg/L. The average effluent concentrations of CODCr, TP, SS and BOD5 were 50mg/L, 0.62mg

84、/L, 18 mg/L, and 17mg/L respectively. Therefore, the results were measured u</p><p>　　Given the current price of coagulants and flocculants, the dosage cost is less than 0.1RMB Yuan per cubic meter wastewate

85、r.</p><p>　　At the same dosage, the removal efficiencies due to chemical and biological flocculation process exceeded that of the chemical flocculation process alone by 20% due to the cooperating action of c

86、hemical and biological activity.</p><p>　　As a result of biological activity , the average removal efficiencies of BOD in the chemical and biological flocculation process could as high as 72% , which cannot

87、be achieved by the common chemical flocculation process alone.</p><p>　　The results of oxygen consumption rate under different simulated conditions indicated there is only light biological activity in the mu

88、nicipal wastewater, chemical flocculation process, and chemical flocculation process including return sludge without aeration. However, oxygen consumption in the chemical and biological flocculation process was distinct,

89、 which indicated a good biological activity in the reaction tank.</p><p>　　Chemical function was more important for phosphorus removal and biological function was more important for solved organic matter, as

90、 the chemical and biological flocculation process became a stable run condition.</p><p>　　References:</p><p>　　1. Aguilar M I, Saez J, Lorens M et al., 2002. Nutrient removal sludge production i

91、n the coagulation-flocculation process [J]. Water Research, 36 (11): 2910 —2919.</p><p>　　2. Chritopher B L, 1998. Phosphorus inactivation in wastewater treatment: Biological and chemical strategies [J]. Wat

92、er-Engineering &Management, 2 : 19 —21.</p><p>　　3. Diamadopoulos E, Vlachos C, 1996. Coagulation —filtration of a secondary effluent by means of pre2hydrolized coagulants [J]. Water Sci Technol, 33 (10

93、—11): 193 —201.</p><p>　　4. Kelth E D, Amirtharajah A, Thomas F M et al., 1996. Coagulation: its effect on organic matter [J]. JAWWA,4: 129 —141.</p><p>　　5. Shao L G, 1999. Operation of urban W

94、TP in south China [J]. Water and Wastewater Engineering, 25 (2): 11 —13.</p><p>　　6. You Z L, Jiang Z P, Zhu W P, 1998. The research and development of the chanced primary treatment of municipal wastewater [