壓縮包內含有CAD圖紙和說明書,均可直接下載獲得文件，所見所得，電腦查看更方便。Q 197216396 或 11970985
任務書
一、原始依據（包括設計或論文的工作基礎、研究條件、應用環(huán)境、工作目的等。）
根據相關設計資料，確定合理的工藝方案，使給水廠出水水質達到《生活飲用水衛(wèi)生標準》（GB5749-2006），并安全輸配到用戶，滿足用戶的需求。
（1）設計水量：近期滿足最高日供水量 6×104m3/d；遠期滿足最高日供水量12 ×104m3/d。
（2）原水水質：各項指標達到地表水環(huán)境質量標準（GB 3838-2002)中的Ⅱ類水質標準；
（3）氣象水文資料：
溧陽市屬太湖湖西地區(qū)，地形復雜，三面環(huán)山，地勢起伏，既有山丘、平原，又有低洼圩地。自然情況如下：
1）氣溫：年平均15.2；歷年極端最高40；歷年極端最低-17.9
2）降雨量：年平均1100mm；雨量集中在4—9月份。
3）主要風向：夏季為東南風，冬季為西北風。
4）地震烈度為7度。
5）地下水位：常年穩(wěn)定水位地面下0.7～0.9m，最高為地面下0.5m。
（4）水處理所用材料
混凝劑：硫酸鋁、三氯化鐵 、堿式氯化鋁等有供應。投加量參考資料如下：
渾濁度
混凝劑
5
10
20
30
50
80
100
硫酸鋁
21
18
16
17
18
23
28
三氯化鐵
20
16
15
16
15
22
25
堿式氯化鋁
18
15
13
15
14
20
23
濾料：石英砂、無煙煤、鐵礦石等有供應。
消毒藥劑：液氯、二氧化氯等有供應。
（5）工程地質資料：據地質鉆探資料知，該地區(qū)地基承載力滿足基建設計要求。
（6）二泵站輸水管起端節(jié)點水壓 46 m。
附：日用水量變化規(guī)律
小時
0-1
1-2
2-3
3-4
4-5
5-6
6-7
7-8
%
2.53
2.45
2.50
2.53
2.57
3.09
5.31
4.92
小時
8-9
9-10
10-11
11-12
12-13
13-14
14-15
15-16
%
5.17
5.10
5.21
5.21
5.09
4.81
4.99
4.70
小時
16-17
17-18
18-19
19-20
20-21
21-22
22-23
23-24
%
4.62
4.97
5.18
4.89
4.39
4.17
3.12
2.48
學生在畢業(yè)設計過程中熟悉相關的工作方法、工作過程，掌握主體工藝的設計計算和繪圖，加強對所學基礎知識的應用技能，為日后工作打下堅實基礎。
二、參考文獻
[1] 陳培康.給水凈化新工藝[M]．北京:學術書刊出版社，1990.
[2] 許保玖.給水處理理論與設計[M]．北京:中國建筑工業(yè)出版社，1992.
[3] 金兆豐.21世紀的水處理[M]．北京:化學工業(yè)出版社，2003.
[4] 丁亞蘭．國內外給水工程設計實例[M]．北京：化學工業(yè)出版社，1999.
[5] 崔玉川．凈水廠設計知識[M]．北京：中國建筑工業(yè)出版社，1987.
[6] 鐘淳昌.凈水廠設計[M]．北京:中國建筑工業(yè)出版社，1986.
[7] 陸柱．水處理技術[M]．上海：華東理工大學出版社，2000.
[8] 高湘．給水工程技術及工程實例[M]．北京：化學工業(yè)出版社，2002.
[9] 王業(yè)俊.水處理手冊[M]．北京:中國建筑工業(yè)出版社，1983.
[10] 鐘淳昌.簡明給水設計手冊[M]．北京:中國建筑工業(yè)出版社，1989.
[11] 張啟海.城市給水工程[M]．北京:中國水利水電出版社，2003.
[12] 楊松林.水處理工程CAD技術應用及實例[M]．北京:化學工業(yè)出版社,2001.
[13] 姜乃昌.水泵及水泵站[M]．北京:中國建筑工業(yè)出版社,1989.
[14] 崔玉川.給水廠處理設施設計計算[M]．北京:化學工業(yè)出版社,2002.
[15] 中國給水排水[J].專業(yè)期刊.
[16] 給水排水[J].專業(yè)期刊
三、設計（研究）內容和要求（包括設計或研究內容、主要指標與技術參數(shù)，并根據課題性質對學生提出具體要求。）
1．設計內容要求
（1）根據水質、水量、地區(qū)條件、施工條件和水廠運行情況、確定凈水廠的處理工藝流程；
（2）擬定各處理構筑物的設計流量，并根據確定的凈水廠位置，選擇適宜采用的處理構筑物，確定設計采用的處理構筑物的形式及數(shù)量；
（3）進行各構筑物的設計計算，確定各構筑物和各主要構件的尺寸并繪制部分計算簡圖，設計時要考慮到構筑物及其構件施工上的可能性，并符合要求。
1）投藥及混合
根據原水水質、處理要求、貨源及其他經濟技術條件選定混凝劑品種及投加量，設計溶解池、溶液池，布置加藥間及藥庫，畫出草圖；確定混合方式，進行混合工藝設計計算和設備選擇。
2）絮凝、沉淀（或澄清池）
絮凝池和沉淀池應同時進行計算和設計，并應注意兩者的關系與配合，要使兩池之間在高程、水流銜接、深度和池數(shù)等方面相互配合。根據設計流量，絮凝池、沉淀池應至少分為獨立相同的兩組，每組可根據需要分為若干格。也可根據水質情況選用澄清池，并進行設計計算。
3）濾池
在北方，濾池一般應設在室內，沖洗水泵房應盡可能與濾池合建。
4）消毒
選定消毒劑并根據水質有關參考資料確定其投加量，投加點應根據水質情況確定。進一步選擇投加設備，布置加藥間及藥庫，繪出草圖。
5）清水池
清水池之間要既能互相連通，又能單池運行。清水池應根據水量大小、地形及設計高程而定，由單池容積和設計水深決定水池平面尺寸。
（4）根據各構筑物的確定尺寸，確定各構筑物在平面位置上的確切位置，完成平面布置；確定各構筑物間聯(lián)接管道的位置，管徑、長度、材料及附屬設施，完成水廠的高程布置。
（5）繪制凈水廠平面及高程布置圖，凈水構筑物工藝平、剖面圖。
（6）二泵站設計計算
選泵臺數(shù)不宜過多，也不宜過少，應能滿足各種不同流量及揚程之需要為宜，一般4-7臺，盡可能同型號。確定泵站形式，進行泵站設計計算；繪制二泵站工藝圖。
2．設計成果要求
（1）設計說明書一份（≮1.2萬字）；參考文獻≮10篇；相關外文文獻資料翻譯1份（≮5000漢字）。
（2）繪制的圖紙折合零號圖紙≮3張。
指導教師（簽字）
年 月 日
審題小組組長（簽字）
分析重力過濾水廠的污泥沉降試驗
摘要：在恒壓條件下，對市政水廠進行了重力沉降實驗和重力過濾實驗。理論分析中明確指出，污泥的沉淀對過濾率有明顯影響。當?shù)夭煌牧鲃幼枇Q定了不同污泥濃度的沉降速率。固體的沉淀特征和當?shù)氐目紫堵逝c該地區(qū)固體抗壓壓力有關。從沉降速率和沉降平衡的基礎數(shù)據上評估了重力過濾與過濾率的關系。
關鍵詞：壓縮特性;重力過濾;滲透特征，沉積;水廠污泥
一 引言
重力過濾是固液分離的一個潛在的操作方法，只涉及簡單設計和運行。這種方法對懸浮物的過濾尤其有效，在驅動力不大的情況下很容易達到分離效果。例如，在自來水廠污泥分離的過程中，增加重力增稠劑，可大大改善分離效果。以往的研究都集中在一般的加壓過濾。因此，沒有多少人注重重力過濾的行為。
沉積過程中懸浮的粒子，經常導致濾餅的過濾速率發(fā)生變化。特別是，在大多數(shù)情況下，重力過濾的沉淀顆粒懸浮效果顯著。因此，重力過濾行為的分析，必須考慮到顆粒沉淀效果。通過調查了向上和向下加壓過濾的沉淀效果和其發(fā)展的理論模型來描述通量下降的行為。
此外，過濾密切相關的問題是沉積作用中有相似粒子的溶劑和滲透溶劑通過填料床的顆粒越大。在此假設的基礎上，根據壓縮的壓縮餅滲透率，當?shù)氐目紫堵师藕彤數(shù)毓腆w壓縮壓力Ps的具體流動阻力，來做重力沉降實驗。結果表明，從傳統(tǒng)的壓縮滲透率數(shù)據中得到，在固體壓力相對低的地方壓縮滲透性能很好。還應該指出，這是相當困難的情況下在壓縮細胞通透性較低的條件下取得的結果。通過應用超濾方法，使用壓縮滲透與超速離心機分析評估了蛋白質溶液超濾通量衰減行為。最近，用離心機對O/ W乳液油滴的壓縮變形滲透特性進行了評價分析，據預計，在相對低壓條件下評估重力過濾，得到重力沉降壓滲透特性使用方便。
在這篇文章中，對市政自來水廠污泥進行批次重力過濾和重力沉降實驗，以及關于重力沉降粒子對過濾行為的影響進行了調查，以評估的濾餅平均過濾比阻。其次在壓縮滲透的基礎上，針對重力沉降用沉降速度發(fā)和沉淀平衡法代替?zhèn)鹘y(tǒng)的重力沉降粒子測量。利用壓縮滲透的特點對重力過濾的過濾率下降行為進行評價。
二 材料與方法
材料
在Kasugai水廠，增加污泥增稠劑對懸浮顆粒進行研究。硫酸鋁中加入無機混凝劑作為增稠劑，測量用比重瓶，質量分數(shù)S的懸浮固體和固體的真密度ρs，分別是4.68?×?10-3 kg/m3和3.35?×103 kg/m3。
用激光散射粒度分布儀對污泥的固體顆粒粒度分布進行了分析，測量結果如圖一所示，直徑dp與頻率f 為正態(tài)分布關系。由于混凝劑的使用，分布明顯變廣，顆粒的平均比表面積大小是65.8微米。用超純水稀釋過的污泥進行試驗。
圖一：
重力沉降
在直徑為4.5厘米的垂直有機玻璃圓筒內進行重力沉降批次實驗。在實驗開始之前開始,將污泥確?；旌暇鶆?然后緩慢倒入一個沉降氣缸。測量沉積物與上清液之間的高度，所用時間沉淀時間和懸浮顆粒濃度，一個星期后測量最終平衡高度。測量沉淀速率的方法是，通過對沉淀物的高度變化與時間數(shù)據來分析，確定沉淀速率。與此同時，在沉淀平衡方法中，用平衡狀態(tài)下統(tǒng)一泥沙高度進行分析。
重力過濾
研究中采用的重力過濾器如圖二所示，垂直氣缸內徑和沉淀試驗采用的相同。采用的過濾介質為非織造，平均孔徑大小為9μm，污泥瞬間被充分攪拌，并倒入汽缸中，開始重力過濾。同樣數(shù)量的純水作為排放濾液添加，不斷從污泥表面進入氣缸。因此，試驗過程中重力過濾驅動器始終保持頂部高度不變，如圖所示。
圖 2 重力過濾裝置
結論
市政自來水廠污泥重力沉降過濾實驗采用批次實驗，以研究有關對重力過濾通量衰減行為的粒子沉淀效果。結果清楚地表明,形成濾餅的平均過濾比阻在中立的條件下可精確的顯示離子的沉降水平。壓縮滲透的特點，代表了當?shù)氐木唧w流動阻力和當?shù)毓腆w壓縮壓力函數(shù)的孔隙率，這一切都基于從最終的泥沙淤積試驗取得的沉積速度數(shù)據和綜合平衡高度。據重力過濾顯示，通量下降的現(xiàn)象是通過對滲透特性所得的沉降數(shù)據進行良好的計算所獲得的。
Analysis of Gravity Filtration Behaviors of Waterworks Sludge Based upon Sedimentation Tests
Abstract
Both gravity filtration experiments under constant pressure conditions and gravity sedimentation experiments were conducted using the municipal waterworks sludge. It was clarified from the theoretical analysis that the effect of sedimentation on the filtration rate was noticeable for the sludge used in this study. The local specific flow resistance at various sludge concentrations was determined by the sedimentation velocity method. The local porosity was related to the local solid compressive pressure by the sedimentation equilibrium method. The decline behaviors in the filtration rate in gravity filtration accompanied by sedimentation were well evaluated only from the sedimentation data based upon the sedimentation velocity method and the sedimentation equilibrium method.
Keywords:Compression characteristics; Gravity filtration; Permeability characteristics; Sedimentation; Waterworks sludge
INTRODUCTION
Gravity filtration is one of the potential solid-liquid separation methods because of the energy-savings involving the simple design and operation. The method is especially efficient for suspension, which is relatively likely to be filtered since the available driving force of separation is not so high. For instance, in the concentration process of waterworks sludge, the separation efficiency may be significantly improved in the case that the space in the gravity thickener is used for gravity filtration. Previous studies have concentrated on the usual pressurized filtration. Hence, not much is known about the behaviors of gravity filtration.[1]
The process of sedimentation of particles in suspension above the filter cake frequently results in a variation of the filtration rate in filtration. [2-7] Especially, in gravity filtration, the effect of sedimentation of particles in suspension is remarkable in most cases.[1] Therefore, the effect of particle sedimentation must be taken into consideration in the analysis of the gravity filtration behaviors. Iritani et al.[8] investigated the effect of sedimentation on properties of upward and downward pressurized filtration and developed the theoretical model to describe the flux decline behaviors.
In addition, there is an analogy between sedimentation of particles in a solvent and permeation of a solvent through the packed bed of particles, which is closely related to filtration. On the basis of this hypothesis, the compression-permeability characteristics of the compressed cake, which represent the local porosity ε and the local specific flow resistance as functions of the local solid compressive pressure ps, are obtained from batch gravity sedimentation test.[9, 10] It was shown that the compression-permeability characteristics in the relatively low solid compressive pressure region obtained from the sedimentation test were well correlated to those obtained from the conventional compression-permeability cell data.[11] It should also be noted that it is quite difficult to obtain the compression-permeability characteristics under relatively low pressure conditions by the compression-permeability cell test. By applying the method to ultracentrifugation, Iritani et al. evaluated the flux decline behaviors of dead-end ultrafiltration of protein solutions using the compression-permeability characteristics obtained with the use of an analytical ultracentrifuge.[12, 13] More recently, the compression-permeability characteristics of deformable oil droplets in O/W emulsions were evaluated using an analytical centrifuge.[14, 15] It is expected that the use of the compression-permeability characteristics obtained from the gravity sedimentation is convenient in order to evaluate the behaviors of gravity filtration, which is conducted under relatively low pressure conditions.
In this article, gravity filtration and batch gravity sedimentation experiments are conducted using the municipal waterworks sludge, and the effect of the sedimentation of particles on the behaviors of gravity filtration is investigated in order to evaluate the true values of the average specific filtration resistance of the filter cake. Subsequently, the compression-permeability characteristics are obtained from the batch gravity sedimentation data based upon the sedimentation velocity method and sedimentation equilibrium method in place of the conventional compression-permeability cell measurements. The decline behaviors of the filtration rate in gravity filtration are evaluated from the compression-permeability characteristics thus obtained
MATERIALS AND METHODS
Materials
The sludge drawn out of the thickener in Kasugai Waterworks (Kasugai City, Japan) was employed as a test suspension in this research. Aluminum sulphate was added to the suspension in the thickener as the inorganic coagulant. The mass fraction s of solids in suspension and the true density ρs of solids, measured using a pycnometer, are 4.68 10-3 and 3.35 103 kg/m3, respectively.
The volume-based size distribution of the solid particles in the sludge was measured by a laser scattering particle size distribution analyzer (LA-920, Horiba, Ltd., Kyoto, Japan). The measured result is depicted in Fig. 1. In this graph, the frequency f is plotted semi-logarithmically against the particle diameter dp. The size distribution tends to be appreciably broad due to the use of the coagulant. The mean specific surface area size of particles is 65.8 μm. The sludge was diluted by the specified concentrations with the ultrapure, deionized water prepared by an ultrapure water system for laboratory use (Milli-Q SP, Millipore Corp., Tokyo, Japan) prior to being used as the
text suspension.
FIG. 1.Volume-based size distribution of solid particles in multiple waterworks sludge.
Gravity Sedimentation
Batch gravity sedimentation experiments were conducted by using vertical Plexiglas cylinders with 4.5-cm internal diameter. Before the experiments started, the sludge was agitated sufficiently to ensure that the contents were well mixed, and then it was gradually poured into a graduated settling cylinder. The sediment height H of the interface plane between the clear supernatant and top of the settling bed sludge was measured with the lapse of the sedimentation time θ for both various initial solid concentrations s and various initial heights H0. Final equilibrium heights H∞ were measured after a week. In the sedimentation velocity method, the initial sedimentation velocity determined from the measurements of the variation with time of H in the incipience of sedimentation was used in the data analysis. Meanwhile, in the sedimentation equilibrium method, the height H∞ of the consolidated sediment at the equilibrium state was used in the analysis.
Gravity Filtration
A schematic drawing of the gravity filter used in this research is shown in Fig. 2. The inner diameter of the vertical cylinder is the same as that employed in the sedimentation tests. The nonwoven filter cloth (FT7501SS, Shikishima Canvas Co., Ltd., Osaka, Japan) with an average pore size of 9 μm was employed as the filter medium. The instant the sludge agitated sufficiently was gradually poured into the cylinder, gravity filtration was started. The same amount of pure water as the discharged filtrate was added gently and constantly on the surface of the sludge into the cylinder. As a result, the head H0 acting as the driving force of gravity filtration was kept constant throughout the experiment, as shown in Fig. 2.
FIG. 2.Schematic diagram of experimental gravity filtration apparatus.
CONCLUSIONS
Gravity filtration experiments and batch sedimentation experiments were performed using the municipal waterworks sludge in order to examine the effect of the particle sedimentation on the flux decline behaviors of gravity filtration. The results clearly demonstrate that the accurate values of the average specific filtration resistance of the filter cake formed in gravity filtration can be obtained in view of the particle sedimentation. The compression-permeability characteristics, which represent the local specific flow resistance and the local porosity as functions of the local solid compressive pressure, were determined from the data of the initial sedimentation velocity and the final equilibrium height of the consolidated sediment obtained from batch sedimentation tests. It was revealed that the behaviors of flux decline of gravity filtration were well evaluated on the basis of the compression-permeability characteristics obtained only from the sedimentation data.
ACKNOWLEDGMENT
This work has been supported in part by a Grant-in-Aid for Scientific Research from Ministry of Education, Culture, Sports, Science and Technology, Japan. The authors acknowledge with sincere gratitude the financial support leading to the publication of this article.
REFERENCES
1. Lu, W. M. , Tung, K. L. , Pan, C. H. and Hwang, K. J. (1998) The effect of particle sedimentation on gravity filtration. Separation Science and Technology 33:12 , pp. 1723-1746.
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