【作者】 赵杰；

【导师】 高俊发；

【作者基本信息】 长安大学 ， 市政工程， 2016， 硕士

【摘要】 陕西省从2015年5月1日起实施《汉丹江流域(陕西段)重点行业水污染物排放限值》(DB61/942-2014),标准中规定,处理规模Q≥2000m3/d的城镇污水处理厂出水执行《城镇污水处理厂污染物排放标准》(GB 18918-2002)(以下简称《标准》)中的一级A标准。柞水县污水处理厂原设计出水执行一级B标准,柞水县位于南水北调中线工程水源涵养区汉江流域,原设计出水水质标准已经不能满足国家与地区新标准的要求,其出水排入汉江支流乾佑河后会影响汉江流域水质,故必须对其进行提标改造,使出水水质满足一级A标准。本文首先对国内外污水处理厂提标改造工程所用的工艺方案进行了分析,并介绍了柞水县污水处理厂现状使用的工艺,指出了柞水县污水处理厂目前存在的问题;其次,本文详细分析了柞水县污水处理厂现状运行的进水、出水的水质、水量数据资料,并对柞水县污水处理厂现状处理能力进行了校核,得出本次提标改造工程的设计水质及提标改造工程的最佳工艺方案,并详细介绍了最佳方案的工艺流程、工艺特点和设计参数。论文得出的主要结论如下:(1)柞水县污水处理厂的现状实际出水水质稳定达到一级B标准,现状出水水质的平均值为:COD=27.7mg/L,BOD5=11.9 mg/L,SS=13 mg/L,NH3-N=4.4 mg/L,TN=9.3mg/L,TP=0.7 mg/L,其中COD、NH3-N和TN接近或已达到了一级A标准(保证率分别为98%、78.3%和100%),而BOD5、SS和TP达到一级A标准的保证率不高(保证率分别为18.9%、10%和5.5%)。(2)柞水县污水处理厂提标改造工程各项指标的去除率分别为:COD≥83.4%,BOD5≥94.5%,SS≥90%,NH3-N≥80%,TN≥62.5%,TP≥92.8%;重点涉及BOD5、NH3-N、SS和TP四项指标。SS和TP可以通过深度处理系统(化学除磷、沉淀、过滤等)来提高去除率,而NH3-N和BOD5则主要是通过改造生化系统来提高去除率。(3)对柞水县污水处理厂生化处理系统的改造如下:(1)在鼓风机房内增加1台同性能的鼓风机,提高供气量到86.6 m3/min,并更换CAST池好氧区的曝气头680个;(2)更换CAST池厌氧区内的高速搅拌器,并在安装方式上进行改善;(3)在CAST池好氧区内增设1台内回流泵,使混合液内回流比增大至150%~200%,强化反硝化脱氮能力;(4)在CAST池好氧区内投加直径为100mm的悬浮填料,投加量为池容的25%,共投加填料1925m3。(4)在二级生化处理系统后增加深度处理系统,通过技术经济比选,推荐采用混凝沉淀+过滤+紫外消毒(原有)处理工艺,进一步去除SS和TP,并且随着SS的浓度降低,其它污染物的浓度也会降低。更多还原

【Abstract】 The "Discharge standards of water pollutants for key industries of Hanjiang and Danjiang River Basin in Shaanxi Province"(DB61/942-2014) has been implemented in Shaanxi Province, Since May 1,2015. The standard clearly stipulates that the effluent of municipal wastewater treatment plant whose effluent quantity is larger than 2000m3/d executes the level A in first grade standard of " Discharge standard of pollutants for municipal wastewater treatmentplant "(GB18918-2002). Located in Zhashui Danjiangkou Hanjiang River Basin Conservation Area, the Zhashui wastewater treatment plant’s effluent quality can be up to standard of the level B in first grade before reconstruction. But due to the implementation of the new standard, its effluent quantity can not be up to the standards of the country and local region. When the effluent is discharged into the QianYou River, the water quality of Han River basin will be polluted deeply. Therefore, the treatment facility must be redesigned and reconstructed to make sure that the effluent quantity is up to the standard of level A in first grade.First of all, this article analyzes a series of process used in the wastewater treatment at home and abroad, introduces the process used in the wastewater treatment plant of Zhashui at present, and points out some problems existing in the wastewater treatment plant. Secondly, based on the detailed analysis of the data of quality and quantity influent and effluent in the wastewater treatment plant of Zhashui, the optimum design about water quality and Technology Programme is put forward, introducing The process, process characteristics and design parameters of the optimum solution are also introduced detailed in this article. The main conclusions of this article are as follows:(1)The actual water quality of effluent in Zhashui wastewater treatment plant is up to the standard of level B in first grade. The quantity of effluent in quo: COD=27.7mg/L, BOD5=11.9 mg/L, SS=13 mg/L, NH3-N=4.4 mg/L, TN=9.3 mg/L, TP=0.7 mg/L. The COD, NH3-N and TN are close to standard of level A in first grade.(guaranteed rates are 98%, 78.3% and 100%, respectively), the guaranteed rate of BOD5, SS and TP reaching the standard of level A in first grade is not high(the guaranteed rates are 18.9%, 10% and 5.5%, respectively).(2)The removal efficiency of all indicators in Zhashui wastewater treatment plant renovation project are: COD≥83.4%, BOD5≥94.5%, SS≥90%, NH3-N≥80%, TN≥62.5%, TP ≥92.8%, and emphasis lies in four indicators: BOD5, NH3-N, SS and TP. The aim to improve the removal efficiency of SS and TP can be achieved by adding advanced treatment system(chemical phosphorus removal, sedimentation, filtration, etc.). By transforming the biochemical treatment system, NH3-N and BOD5 removal efficiency can be improved.(3)The transformation of Zhashui wastewater treatment plant for biological treatment systems are as follows:(1)increasing a blower with the same performance in the blower room, which can improve aeration amount to 86.6m3/min, and replacing the aerobic zone head of the CAST tank;(2)replacing the high-speed stirrer in the CAST anaerobic pool area with perfect installation;(3)adding a return pump station in the aerobic zone of the CAST tank, making the mixture reflux ratio increases to 150% to 200 %, strengthening denitrification capacity;(4)puting 100 mm diameter filler suspension in the aerobic zone of the CAST tank, and the total dosage is 1925m3, accounting for 25% of the tank volume.(4)The advanced treatment system after secondary biochemical treatment system will be added. The process of coagulating sedimentation + filtration + UV disinfection(original) will be recommended after technical and economic comparison to remove SS and TP further. With the SS concentration reducing, other contaminants will be removed too.更多还原