【作者】 李敬美；

【导师】 周集体；

【作者基本信息】 大连理工大学 ， 环境工程， 2010， 硕士

【摘要】 石化废水成分复杂,污染物浓度高、毒性强、难降解,对环境危害较大。目前国内大多石化厂的核心处理工艺为传统或改进的活性污泥工艺,该工艺存在有机物去除效果不稳定及硝化能力差等问题,已经无法满足处理要求。本课题针对目前石化废水处理中普遍存在的问题,对活性污泥与生物膜复合工艺处理石化废水进行研究,以期为石化污水处理厂的技术改造提供依据。本实验以活性污泥工艺为对照,主要考察了活性污泥与生物膜复合工艺对石化废水的处理效果、耐冲击负荷能力、污泥性能及溶解氧利用率等。结果表明,复合工艺对石化废水中CODcr的去除效果略好于活性污泥工艺,而对NH3-N的去除效果明显优于活性污泥工艺。另外,两种工艺对硫化物和油的去除效果类似。提高进水负荷时,复合工艺表现出较强的耐冲击负荷能力。以2 L／h连续运行时,石化废水进水平均CODcr为895mg/L, NH3-N为42.8 mg/L,硫化物为23.8 mg/L,油为47.1 mg/L,经复合工艺处理后出水平均CODCr为116 mg/L,NH3-N为0.82 mg／L,硫化物为0.053 mg/L,油为12.1 mg/L,平均去除率分别为87.0%、98.1%、99.8%、74.3%。利用RIS指纹技术及16S rDNA序列分析技术揭示了两种工艺好氧系统微生物的群落结构存在较大差异,同时也解释了两种工艺在宏观性能上的差异。与活性污泥工艺相比,复合工艺还具有氧的利用率高、污泥产量及回流量少、动力消耗较低、运行管理方便等优点,适用于改造超负荷或不具备硝化能力的石化污水处理厂。石化废水经复合工艺处理后,出水CODcr和油的浓度仍未达到GB8978-1996中的一级排放标准。分别采用微电解法和Fenton氧化法对复合工艺的生化出水进行深度处理,主要是通过实验确定最佳操作条件并在最佳条件下考察对CODCr和油的去除效果。结果表明,微电解法与Fenton氧化法都能对石化废水进行有效深度处理。在各自的最佳条件下,微电解法的出水CODCr为49.4 mg/L,油含量为3.7 mg/L,去除率分别53.9%和65.1%,Fenton氧化法的出水CODCr为30 mg/L,油含量为3.3 mg/L,去除率分别为60%和68%,两种工艺的出水水质均达到GB8978-1996中的一级排放标准。相比于微电解法,Fenton氧化法具有较高的污染物去除效果及较低的运行成本,因此,Fenton氧化法更适用于石化废水的深度处理。更多还原

【Abstract】 Petrochemical wastewater which contains numerous toxic and refractory organic pollutants is greatly harmful to the environment. At present, the core process of many domestic petrochemical wastewater treatment plants (WWTPs) is traditional or improved activated sludge process (ASP). This process has many problems such as unstable organics removal efficiency and poor nitrogen removal capacity. Thus it cannot meet the current standards of petrochemical wastewater treatment. To solve these problems, treatment of petrochemical wastewater using biofilm-activated sludge hybrid process (HP) was studied in this thesis. It was expected that some theoretical and technical information could be obtained from this study to improve the performance of petrochemical WWTPs.The pollutants removal efficiency, resistance capacity to shock loadings, performance of sludge and oxygen utilization ratio of HP were compared with those of ASP in this thesis. The results showed that HP was slightly better than ASP in the removal of CODCr in petrochemical wastewater. Moreover, HP was obviously superior to ASP on the removal of NH3-N. In addition, the two processes had similar removal rate of S2- and oil. When the influent loads were increased, HP showed stronger resistance to shock loadings. When the inflow was 2 L/h and the average concentrations of CODcr, NH3-N, S2- and oil in the petrochemical wastewater were 895 mg/L,42.8 mg/L,23.8 mg/L and 47.1 mg/L, respectively, the average concentrations of CODcr, NH3-N, S2" and oil in the effluent of HP were 116 mg/L, 0.82 mg/L,0.053 mg/L and 12.1 mg/L, respectively, with average removal efficiencies 87.0%, 98.1%,99.8% and 74.3%, respectively. RIS (ribosomal intergenic spacer) fingerprints technique and 16S rDNA gene sequencing were used. The results indicate that there are many differences between microbial communities of aerobic reactors of the two processes, and the differences of the performances between the two processes are explained. Compared with ASP, HP is of higher oxygen utilization ratio, reduced sludge yield, decreased reflux quantity, lower power consumption, and easier operation. Thus HP is proper for upgrading of petrochemical WWTPs which are overloaded or cannot nitrify effectively.The concentrations of CODcr and oil in the effluent of HP didn’t attain class 1 of the National Wastewater Integration Discharge Standard (GB8978-1996). Thus micro-electrolysis process (MEP) and Fenton oxidation process (FOP) were respectively used to treat the effluent of HP. The optimal operating conditions were selected under which the removal efficiencies of CODCr and oil were investigated. The results showed that MEP and FOP both have high treatment efficiency for HP effluent. Under the optimal operating conditions, the concentrations of CODCr and oil in the effluent of MEP are 49.4 mg/L and 3.7 mg/L, respectively, and the removal efficiencies of them are 53.9% and 65.1%, respectively. On the other hand, the concentrations of CODCr and oil in the effluent of FOP are 30 mg/L and 3.3 mg/L, respectively, and the removal efficiencies of them are 60% and 68%, respectively. The concentrations of CODCr and oil in the effluent of MEP and FOP attained class 1 of the National Wastewater Integration Discharge Standard (GB8978-1996). Compared with MEP, FOP has higher pollutant removal efficiency and lower operating cost. Thus FOP is more proper for advanced treatment of petrochemical wastewater.更多还原