石化工业园区有毒废水来源识别研究

针对石化废水对综合污水处理厂的毒性冲击问题,采用耗氧速率抑制试验评价不同石化废水对活性污泥的毒性,评价对象包括石化工业园区内不同生产装置和装置内不同生产节点的废水.试验发现废水的有机质含量与毒性效应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毒性.同时,研究中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的毒性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,作为评价废水毒性排放贡献的指标.对不同装置和节点石化废水的毒性贡献进行排序,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.

Source Identification of Toxic Wastewaters in a Petrochemical Industrial Park

Petrochemical wastewaters have toxic impacts on the microorganisms in biotreatment processes, which are prone to cause deterioration of effluent quality of the wastewater treatment plants. In this study, the inhibition effects of activated sludge's oxygen consumption were tested to evaluate the toxicity of production wastewaters in a petrochemical industrial park. The evaluation covered the wastewaters from not only different production units in the park, but also different production nodes in each unit. No direct correlation was observed between the toxicity effects and the organic contents, suggesting that the toxic properties of the effluents could not be predicted by the organic contents. In view of the variation of activated sludge sensitivity among different tests, the toxicity data were standardized according to the concentration-effect relationships of the standard toxic substance 3, 5-dichlorophenol on each day, in order to improve the comparability among the toxicity data. Furthermore, the Quality Emission Load (QEL) of corresponding standard toxic substance was calculated by multiplying the corresponding 3, 5-dichlorophenol concentration and the wastewater flow quantity, to indicate the toxicity emission contribution of each wastewater to the wastewater treatment plant. According to the rank list of the toxicity contribution of wastewater from different units and nodes, the sources of toxic wastewater in the petrochemical industrial park were clearly identified. This study provides effective guidance for source control of wastewater toxicity in the large industrial park.