【作者】 丁瑾；

【导师】 朱南文；

【作者基本信息】 上海交通大学 ， 环境工程， 2010， 硕士

【摘要】 城市污水处理厂污泥成分复杂、含有大量的有毒有害物质,极易给环境带来二次污染。为降低环境污染风险,我国制定了《城镇污水处理厂污染物排放标准》（GB18918-2002）,该标准明确规定:污泥需经稳定化处理后再进行进一步处置。然而,由于经济、技术等方面的原因,我国具有污泥稳定处理设施的污水处理厂很少,污泥大多未经稳定化处理便排放,然而,随着环保法规执行力度的加大,各污水处理厂污泥的稳定化处理势在必行。因此寻求一种处理成本低、运行效果好、操作简单、易于管理的污泥稳定化技术具有深远的意义。生物稳定法具有运行成本低、可靠性强等特点,是目前最常用的污泥稳定化方法,但传统的生物稳定法具有污泥处理时间长、设施占地大、处理效率低等缺点,从而给一些用地紧张的大中城市带来了建设成本过高、征地困难等问题。为解决这一难题,本课题在污泥好氧消化相关研究基础上,采用电化学方法作为剩余污泥好氧消化之前的预处理措施,以提高污泥处理效率、节约单位污泥稳定化处理设施的占地面积。本文通过研究电化学反应中不同工艺参数对于剩余污泥稳定化的影响,得出最佳的工艺参数,并通过药剂添加的方式进一步提高其处理效率。根据上述研究所得结果,将药剂添加、电化学反应等作为预处理,与污泥的好氧消化相结合,考察不同的预处理方式对剩余污泥好氧消化的影响,以达到污泥稳定化的标准。主要得出以下研究结果:（1）以网状RuO₂/Ti电极板为电极,进行剩余污泥的稳定化处理,最佳的工艺参数为:在污泥pH为11,极板间距为2.0cm,工作电压为15V,通过气流曝气搅拌（曝气量为0.78⁰.80 m³/h·m³）的条件下处理30min后,剩余污泥（污泥浓度约18.35²0.50g/L）的MLVSS去除率可达10.5%左右,剩余污泥的SCOD值由原来的202 mg/L上升至2191 mg/L,TN、TP和NH₃-N等指标均有所上升;剩余污泥固体的热稳定性及污泥沉降性能和脱水性能有所降低。（2）尿素、NaCl及Fenton试剂的添加均能有效提高电化学处理对于剩余污泥的稳定化效果。当尿素投加量为1.5g/L时,污泥MLVSS去除率为13.4%;当NaCl投加量为0.025mol/L时,污泥MLVSS去除率为13.9%;在Fenton反应最佳参数污泥初始pH为3,n（H2O2/Fe2+）为10,H2O2投加量为1.00mL/L,反应60min条件下,MLVSS去除率为6.9%,电化学处理后为13.3%。（3）电化学预处理能够显著提高剩余污泥的好氧消化效率,实验表明,在电化学最佳工艺参数件下进行电化学预处理后进行好氧消化处理,消化14d后MLVSS的去除率达40.0%,达到稳定化指标,比空白对照组提前了6d。（4）分别将尿素、Fenton试剂与电化学反应结合作为预处理,与好氧消化相结合,对剩余物污泥的稳定化效果均具有非常显著的促进作用。在最佳工艺参数下进行预处理后进行好氧消化,其达到污泥稳定化标准的所用时间分别比空白对照组分别提前了8d和10d。故Fenton试剂与电化学相结合的预处理方式,对于污泥好氧消化的效果最佳。在好氧消化结束时,剩余污泥的SCOD值稳定在300mg/L左右,同时剩余污泥的沉降性能有所降低,其MLVSS去除率、OUR及TTC-脱氢酶活性等相关指标表明:经过上述预处理及污泥的好氧消化后,剩余污泥已到达稳定化标准。更多还原

【Abstract】 The sludge produced by municipal sewage plants contains many different kinds of hazardous substances, which is responsible to the secondary environment pollution. In order to reduce the pollution risk, Pollutant Emission Standards of Municipal Sewage Treatment Plant (GB18918-2002) was developed. It rules that the sludge must be stabilized before further treatment. However, only few sewage plants apply sludge stabilization treatment because of the economical and technological difficulties. As a result, large mounts of sludge is discharged without treatment. It has become a growing trend that sewage plants apply sludge stabilization treatment, since the execution of the Environmental Protection Law is becoming stronger. So it is of great significance to develop a new sludge stabilization technique, which has a low cost, great effects, easy performance and management.Biological stabilization is the most common treatment method because of its low cost and reliability. However, its shortages, such as time-consuming, space-consuming and low efficiency, cause high construction expense and great difficulty of land acquisition in some land-lacking cities. In order to raise the efficiency and to save the construction land, this research applied electrochemical treatment method based on the relevant study on sludge aerobic digestion. By the way of value operation, optimal values of factors were obtained, and the treatment efficiency was improved by chemicals insertion. On the basis of the test results above, electrochemical pretreatment and sludge aerobic digestion were combined, and the effects the different pretreatment brought to the sludge aerobic digestion were analyzed. The results mainly show that: (1) The mixed liquor volatile suspended solid (MLVSS) removal rate of waste activated sludge (18.35~20.50g/L) reached to about 10.5% after 30min electrochemical treatment with RuO2/Ti polar plates when optimum operating conditions were as follows: pH was 11, polar plate spacing was 2.0cm, and voltage was 15V. SCOD of waste activated sludge was increased to 2191 mg/L from 202 mg/L. Simultaneously, the index of TN、TP and NH3-N increased. Thermal stabilization and dewatering performance were reduced.(2) The effect of electrochemical treatment could be greatly improved by adding urea, NaCl and Fenton agent. MLVSS removal efficiency was increased to 13.4% when the dosage of urea was 1.5g/L; MLVSS removal efficiency was increased to 13.9% when the dosage of NaCl was 0.025mol/L.(3) After electrochemical pretreatment under optimum operating conditions, the performance of aerobic digestion was greatly enhanced. The MLVSS removal rate reached to 40.0% after 14 days’aerobic digestion, while the MLVSS removal rate of WAS without any pretreatment just reached to 33.2%, and it reached to 40.2% after 20 days’aerobic digestion.(4) Electrochemical pretreatment by adding urea, Fenton agent will greatly improve the performance of aerobic digestion and sludge stabilization. When adding urea and Fenton before electrochemical pretreatment under optimum operating conditions, the aerobic digestion time could be shortened by 8 and 10 days respectively comparing with the one without pretreatment. It was found the performance of aerobic digestion was the best with Fenton reaction and electrochemical pretreatment. At the end of aerobic digestion, MLVSS removal rate, sludge OUR and TTC-DHA activity values showed that sludge stabilization had reached to the standard.更多还原