淀粉废水课题设计

I题目2000m3/d淀粉废水处理厂综合设计专业:环境监测与治理年级:XX学号:姓名:指导教师:XXXXXXX学院2011年06月II摘要我国水体污染主要来自两方面，一是城市化中由于城市污水排放和集中处理设施严重缺乏，二是工业发展超标排放工业废水，大量污水未经处理直接进入水体造成环境污染。如淀粉废水近年来经过治理虽有所减少，但其形势仍然很严峻。淀粉废水属高浓度有机废水，其可生化性较好，废水中主要含有淀粉、糖类、蛋白质、废酸和废碱等污染物，随生产工艺的不同，废水中的COD浓度在2000～20000mg/l之间BOD一般为1000—5000mg/L。这些淀粉废水若不经过处理直接排放，其水中所含有的有机物，进入水体后迅速消耗水中的溶解氧，造成水体缺氧而影响鱼类和其他水生动物的生存，同时废水中悬浮物易在厌氧条件下分解产生臭气，恶化水质。淀粉废水悬浮物较高，可以回收做饲料。本设计要求处理水量为2000m3/d的工业淀粉污水，设计方案针对已运行稳定有效的UASB-水解法-接触氧化法结合的工艺处理污水。工艺由于不同环境条件，不同功能的微生物群落的有机配合，加之厌氧、缺氧条件下，部分不可生物降解的有机物（CODNB）能被开环或断链，使得有机碳被去除，提高对CODNB的去除效果。关键词：工业淀粉废水，UASB,水解法，接触氧化法III目录摘要····················································································II目录······················································································III第一章设计概述······································································-1-1设计任务······································································-1-2设计原则······································································-1-3设计依据······································································-2-第二章工艺流程及说明·····························································-2-1工艺方案分析································································-2-2工艺流程······································································-2-3流程各结构介绍·····························································-3-3.1筛网·················································错误!未定义书签。3.2调节池···································································-4-3.3反应池···································································-4-3.4沉淀池···································································-4-3.5UASB反应器·······································错误!未定义书签。3.6水解池····································································-5-3.7接触氧化池·····························································-5-.3.8二沉池···································································-4-3.9构筑物去除率···························································-5-第三章主要构筑物设计计算·······················································-4-IV1.筛网设计··················································错误!未定义书签。2调节池·········································································-7-3反应池·········································································-8-4沉淀池·······································································-11-5UASB反应器······························································-11-6水解池····················································错误!未定义书签。7接触氧化池·································································-18-8二沉池·········································································-21-9污泥浓缩池···································································-22-10设备选择····································································-22-11工程投资·················································错误!未定义书签。经济分析………………………………………………………………………………….-24-效益分析……………………………………………………………………...-25-参考文献………………………………………………………………….......-26--1-第一章设计概述1设计任务本次课程设计的主要任务是完成的淀粉废水的处理，处理水量为2000m3/d。表1.1设计进出水水质主要污染物原水水质（mg·L-1）排放标准（mg·L-1）去除率(％)CODCr6000≤10098.3以上BOD53000≤2099.3以上SS400≤2095以上PH56-8______SO32-3000100工程设计内容包括：1)细化工艺流程2)选定参数3)计算（构筑物尺寸、管道、阀门、泵、填料、控制及监测设备、土建要求）4)绘制符合规范的工程图5)编制设计说明书2设计原则1)严格执行国家有关环境保护的各项法规。2)采用先进、成熟、合理、可靠、节能的工艺，确保处理量及水质排放达到标准。3)流程布局合理，整体感强，外观装饰美观大方，环境绿化优美。4)在上述前提下，做到投资少，运行费用低的效果-2-3设计依据1《地表水环境质量标准》（GBZB1-1999）2《污水综合排放标准》（GB8979-1996）3《给排水设计手册》4《水处理工程师手册》5《三废处理工程技术手册》废水卷6《水工业工程设计手册废水处理及再用》7《建设项目环境保护设计规定》87国环0028.《建设工程工程量清单计价规范》（GB50500-2008）第二章工艺流程及说明1工艺方案分析本项目污水处理的特点为：1)污水以有机污染为主，BOD/COD=0.2,可生化性一般，重金属及其他难以生物降解的有毒有害污染物一般不超标；2)污水中主要污染物指标BOD、COD、SS值比国内一般城市污水高70﹪左右；针对以上特点，以及出水要求，现有工业污水处理技术的特点，以采用生化处理最为经济。根据国内外已运行的污水处理厂的调查，要达到确定的治理目标，可采用此工艺。2工艺流程污水经过筛网去除较大的悬浮物,然后进入调节池调节水量后进入反应池,主要加药对亚硫酸根进行反应,接着在初沉池中沉淀;再经过UASB,水解池,接触氧化对有机物进行去除,在二沉池进行沉淀.二沉池中的污泥80%回流,其中部分回流到接触氧化池重新利用,其余污泥与初沉池﹑调节池中沉淀一起进入污泥浓缩池进行浓缩,再经过板框压滤进一步脱水,其两部分上清液均回流到调节池,脱水后污泥进行外运.具体流程如下图2.1:-3-回流少量污泥回流上清液回流上清液回流废水管道污泥管道沼气管道图2.1工艺流程图3流程各结构介绍3.1筛网因为排入污水处理厂的污水中含有一定量较小的悬浮物或漂浮物，所以在处理系统之前设置筛网，以截留这些较小的悬浮物或漂浮物，防止堵塞后续处理系统的管理、孔口和损坏辅助设施。本次采用机械清渣方式。筛网淀粉废水调节池沉淀池反应池出水UASB水解池接触氧化池二沉池污泥浓缩池板框压滤机外运加药水封罐沼气利用用-4-3.2调节池由于淀粉废水悬浮物含量较高，且能回收做饲料，因此需设调节池作为预处理，这样即可以去除一部分有机物，减轻后续生化处理单元的负荷，又可以产生经济效益。。采用方形调节池，调节池的功能是对进入系统的水质水量进行调节。3.3反应池采用旋流式反应池砖混结构，主要用于调节废水的水质、和PH值，以及发生事故时暂时储存水量。由于淀粉废水中含有大量的So32-，在调节池投加碱液（Na2CO3或CaCO3），将废水的PH值调整为6.5～7.5之间。3.4平流式沉淀池初沉池是作为二级污水处理厂的预处理构筑物设再生物处理构筑物的前面。处理的对象是悬浮物质（SS约可去除40%～55％以上），同时也可去除部分BOD5（约占总BOD5的25％～40％，主要是非溶解性BOD），以改善生物处理构筑物的运行条件并降低其BOD负荷。初沉池按池内水流方向的不同，可分为平流式沉淀池、竖流式沉淀池和辐流式沉淀池。本设计采用了成本较低，运行较好的平流式沉淀池，该池施工简易，对冲击负荷和温度变化的适应能力较强。3.5UASB反应器通过水解菌及产酸菌的作用，将淀粉中的大分子有机物断链或开环，分解为容易被好氧菌吸收利用的简单的分子有机物，即将淀粉分解为多糖及挥发性脂肪酸，进一步提高好氧处理环节的处理效率。水解酸化属厌氧处理的前一个阶段，因此，水力停留时间较短，从而可以减少厌氧池有效-5-容积。UASB反应器的结构可分为三个区:污泥床区、悬浮区和沉淀区（包括三相分离器）由于能在其污泥区内形成高活性、沉降性能优越的颗粒污泥使反应器中厌氧细菌达到30gvss/L以上,,对有机物去除率高造价低,占地少,运行管理方便.3.6水解池混合液经UASB反应器进入接触氧化池污水中溶解氧不足,需要经过缺氧池提高水中溶解氧含量和可生化性有利于后续接触氧化池的去除效率的提高,并能去除一部分BOD、COD、ss.3.7生物接触氧化生物接触氧化法是细菌和原生动物、后生动物一类微型动物在滤料或某些载体上生长繁殖，形成膜状生物污泥——生物