石化废水生物处理毒性评价及其应用研究
发布时间：2019-03-30 09:13
【摘要】：针对石化废水对综合污水处理厂的毒性冲击问题,采用活性污泥耗氧速率抑制试验评价不同石化废水生物处理毒性,评价对象包括石化工业园区内综合污水处理厂工艺流程中各工艺出水以及排入污水处理厂的不同生产装置和装置内不同排放节点的废水。本研究构建了一套相对完善的石化废水生物处理毒性评价方法。明确了操作技术要点,优化操作条件。优化结果为:活性污泥4°C冷藏保存且试验投加浓度为1.6 g/L,样品pH为7左右,曝气时间30min,合成污水投加浓度范围为200-1000 mg/L。针对活性污泥敏感性在不同批次试验之间的差异问题,将各废水对活性污泥耗氧速率的抑制效应数据转化为标准毒性物质3,5-二氯苯酚的浓度,提高了数据之间的可比性。在此基础上,根据废水流量和对应3,5-二氯苯酚浓度,计算废水对应标准毒性物质质量排放负荷,作为评价废水生物处理毒性贡献的指标。通过对石化废水对活性污泥中不同微生物的影响解析,得出石化废水对活性污泥中硝化细菌具有明显抑制效应,但同时对异养菌的耗氧具有促进作用;由于后者对前者的掩盖,直接测定总耗氧速率时容易造成对废水真实生物处理毒性的低估。研究进一步分析了活性污泥中异养菌耗氧速率受易降解基质的影响,证实石化废水中的乙酸盐等易降解成分是导致其促进异养菌耗氧的重要原因。为了避免石化废水中易降解成分对异养菌耗氧的促进,投加浓度为90 mg/L乙酸钠,改进了活性污泥耗氧速率抑制试验方法;并利用改进前后测定结果的比较证明了改进后方法的优越性,同时利用不同排放节点废水和不同污泥证明了方法改进后的可行性和适用性。利用构建的方法评价污水处理厂各工艺流程废水生物处理毒性,发现石化总进水通过各工艺处理对活性污泥中硝化细菌的抑制率从64.3%削减到25.9%,但整个过程中抑制率并非逐渐下降;经曝气沉砂池处理后上升,但在后续初沉池、水解酸化、缺氧段处理后显著下降,其中水解酸化对生物处理毒性削减贡献最大,其次为缺氧段。利用该方法评价排入污水厂的不同生产装置和排放节点废水,研究中发现废水的有机质含量与其生物处理毒性之间没有直接的相关性,并不能单从废水的有机质含量预测其生物处理毒性。利用对应标准毒性物质浓度和对应标准毒性物质质量排放负荷对不同生产装置和排放节点石化废水的生物处理毒性水平及毒性贡献进行排序,有效识别了该石化工业园区内有毒废水的产生来源,为从生产源头控制废水毒性提供有效指导。
[Abstract]:In view of the toxicity impact of petrochemical wastewater on comprehensive wastewater treatment plant, the oxygen consumption rate inhibition test of activated sludge was used to evaluate the toxicity of biological treatment of different petrochemical wastewater. The evaluation objects include the effluent from each process of the integrated wastewater treatment plant in the petrochemical industrial park and the wastewater from different production units and discharge nodes in the wastewater treatment plant. In this study, a set of relatively perfect toxicity assessment methods for bio-treatment of petrochemical wastewater was constructed. The key points of operation technology are defined, and the operation conditions are optimized. The optimized results were as follows: the activated sludge was stored at 4 掳C and the experimental concentration was 1.6g / L, the pH of the sample was about 7, the aeration time was 30min, and the concentration range of the synthetic wastewater was 200,1000 mg/L.. Aiming at the difference of the sensitivity of activated sludge between different batch tests, the data of inhibition effect of wastewater on oxygen consumption rate of activated sludge was transformed into the concentration of standard toxic substance 3,5-dichlorophenol, which improved the comparability of the data. On this basis, according to the flow rate of wastewater and the corresponding concentration of 3,5-dichlorophenol, the discharge load of the corresponding standard toxic substance is calculated, which can be used as an index to evaluate the toxicity contribution of biological treatment of wastewater. Through analyzing the influence of petrochemical wastewater on different microorganisms in activated sludge, it is concluded that petrochemical wastewater has obvious inhibitory effect on nitrifying bacteria in activated sludge, but it can promote oxygen consumption of heterotrophic bacteria at the same time. Because of the concealment of the former, the direct determination of the total oxygen consumption rate is easy to underestimate the toxicity of real biological treatment of wastewater. The oxygen consumption rate of heterotrophic bacteria in activated sludge was further analyzed. It was proved that the easy-to-degrade components such as acetate in petrochemical wastewater were the important reasons for promoting the oxygen consumption of heterotrophic bacteria. In order to avoid promoting the oxygen consumption of heterotrophic bacteria by easily degradable components in petrochemical wastewater, 90 mg/L sodium acetate was added to improve the test method of inhibition of oxygen consumption rate of activated sludge. The advantages of the improved method are proved by the comparison of the measured results before and after the improvement, and the feasibility and applicability of the improved method are proved by using different discharge node wastewater and different sludge. It was found that the inhibition rate of total petrochemical influent on nitrifying bacteria in activated sludge was reduced from 64.3% to 25.9% by using the constructed method to evaluate the toxicity of biological treatment of wastewater from each process of the wastewater treatment plant. However, the inhibition rate did not decrease gradually during the whole process. After treatment with aerated sand sedimentation tank, it increased, but decreased significantly in subsequent primary sedimentation tank, hydrolytic acidification and anoxic stage treatment, in which hydrolytic acidification had the greatest contribution to the reduction of toxicity of biological treatment, followed by anoxic stage. It is found that there is no direct correlation between the organic matter content of the wastewater and the biological treatment toxicity of the wastewater by using this method to evaluate the wastewater of different production units and discharge node wastewater in the wastewater treatment plant. The toxicity of biological treatment can not be predicted from the organic matter content of wastewater alone. Ranking the biological treatment toxicity levels and toxic contributions of petrochemical wastewater from different production units and discharge nodes using the corresponding concentration of the standard toxic substance and the corresponding mass discharge load of the standard toxic substance, Effective identification of the source of toxic wastewater in the petrochemical industrial park provides effective guidance for controlling the toxicity of wastewater from the production source.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X78
本文编号：2449995
[Abstract]:In view of the toxicity impact of petrochemical wastewater on comprehensive wastewater treatment plant, the oxygen consumption rate inhibition test of activated sludge was used to evaluate the toxicity of biological treatment of different petrochemical wastewater. The evaluation objects include the effluent from each process of the integrated wastewater treatment plant in the petrochemical industrial park and the wastewater from different production units and discharge nodes in the wastewater treatment plant. In this study, a set of relatively perfect toxicity assessment methods for bio-treatment of petrochemical wastewater was constructed. The key points of operation technology are defined, and the operation conditions are optimized. The optimized results were as follows: the activated sludge was stored at 4 掳C and the experimental concentration was 1.6g / L, the pH of the sample was about 7, the aeration time was 30min, and the concentration range of the synthetic wastewater was 200,1000 mg/L.. Aiming at the difference of the sensitivity of activated sludge between different batch tests, the data of inhibition effect of wastewater on oxygen consumption rate of activated sludge was transformed into the concentration of standard toxic substance 3,5-dichlorophenol, which improved the comparability of the data. On this basis, according to the flow rate of wastewater and the corresponding concentration of 3,5-dichlorophenol, the discharge load of the corresponding standard toxic substance is calculated, which can be used as an index to evaluate the toxicity contribution of biological treatment of wastewater. Through analyzing the influence of petrochemical wastewater on different microorganisms in activated sludge, it is concluded that petrochemical wastewater has obvious inhibitory effect on nitrifying bacteria in activated sludge, but it can promote oxygen consumption of heterotrophic bacteria at the same time. Because of the concealment of the former, the direct determination of the total oxygen consumption rate is easy to underestimate the toxicity of real biological treatment of wastewater. The oxygen consumption rate of heterotrophic bacteria in activated sludge was further analyzed. It was proved that the easy-to-degrade components such as acetate in petrochemical wastewater were the important reasons for promoting the oxygen consumption of heterotrophic bacteria. In order to avoid promoting the oxygen consumption of heterotrophic bacteria by easily degradable components in petrochemical wastewater, 90 mg/L sodium acetate was added to improve the test method of inhibition of oxygen consumption rate of activated sludge. The advantages of the improved method are proved by the comparison of the measured results before and after the improvement, and the feasibility and applicability of the improved method are proved by using different discharge node wastewater and different sludge. It was found that the inhibition rate of total petrochemical influent on nitrifying bacteria in activated sludge was reduced from 64.3% to 25.9% by using the constructed method to evaluate the toxicity of biological treatment of wastewater from each process of the wastewater treatment plant. However, the inhibition rate did not decrease gradually during the whole process. After treatment with aerated sand sedimentation tank, it increased, but decreased significantly in subsequent primary sedimentation tank, hydrolytic acidification and anoxic stage treatment, in which hydrolytic acidification had the greatest contribution to the reduction of toxicity of biological treatment, followed by anoxic stage. It is found that there is no direct correlation between the organic matter content of the wastewater and the biological treatment toxicity of the wastewater by using this method to evaluate the wastewater of different production units and discharge node wastewater in the wastewater treatment plant. The toxicity of biological treatment can not be predicted from the organic matter content of wastewater alone. Ranking the biological treatment toxicity levels and toxic contributions of petrochemical wastewater from different production units and discharge nodes using the corresponding concentration of the standard toxic substance and the corresponding mass discharge load of the standard toxic substance, Effective identification of the source of toxic wastewater in the petrochemical industrial park provides effective guidance for controlling the toxicity of wastewater from the production source.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X78
【参考文献】
相关期刊论文 前1条
1 颜家保,夏明桂;A/O工艺处理炼油废水的效果分析及对策[J];武汉科技大学学报(自然科学版);2004年03期
，本文编号：2449995
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