工业区污水处理厂短链氯化石蜡迁移转化及排放特征解析

The Yellow River Delta has the second largest oil production base in China—— Shengli Oilfield. Short-chain chlorinated paraffins (SCCPs) have an important application as an important flame retardant and plasticizer in the petrochemical industry. SCCPs ultimately accumulated into wastewater treatment plants during production, storage, industrial usage of manufactured products. Previous studies indicate that the conventional technologies for treating emerging POPs are very limited during sewage treatment processes, leading to effluents from sewage treatment plants being an important contamination source for SCCPs in the environment. This project selected the municipal wastewater treatment in the industrial region of Yellow River Delta as research area. We aim to systematically study the distribution characteristics and removal efficiency of SCCPs in various processes of wastewater treatment. The results of this project would be expected to clarify the degradation and transformation mechanisms of SCCPs in the primary, secondary and advanced treatment of wastewater. This project could provide scientific assessment of the secondary environment risks of SCCPs caused by reclaimed water and sludge disposal.

黄河三角洲有我国第二大石油生产基地——胜利油田，具有非常广泛的石油化工生产企业，短链氯化石蜡（SCCPs）作为一种重要的增塑剂和阻燃剂在化工企业中具有重要的应用，SCCPs可以随着工业污水的排放而进入到污水处理厂。研究表明，传统的污水处理工艺对于新型持久性有机污染物(POPs)的处理能力十分有限，导致污水处理厂出水和污泥处置成为SCCPs向环境释放一个重要途径。本项目拟选择黄河三角洲工业区污水处理厂为研究对象，建立和优化复杂环境介质中SCCPs的分离检测方法，系统性研究SCCPs在污水处理各流程的分布特征和去除效率，揭示它们在污水初级、二级和深度处理过程中的环境化学行为和归趋，阐明其迁移转化规律和去除机制，对再生水和污泥处置造成环境中SCCPs的二次污染风险做出科学评估。

水资源在工业、农业和公共活动中发挥着重要作用。这些活动产生的废水中的氯化石蜡（CPs）是环境中CP污染的重要来源。在本研究中，我们选取了中国第二大石油生产基地（胜利油田）附近的一个典型污水处理厂（STP）为研究目标，研究了该污水厂春夏秋冬四个季节里短链氯化石蜡（SCCPs）和中链氯化石蜡（MCCPs）的赋存状态。进水中SCCPs和MCCPs的浓度分别为3809±670 ng/L和4803±478 ng/L，出水中SCCPs和MCCPs的浓度分别为524.3±49.5 ng/L和955.3±75.5 ng/L。C14-CP是主要的同系物，占总CPs浓度的37%。CPs在水相中的去除率为83.5%。质量平衡计算结果表明，出水中CPs的含量占CPs总量的3.2%，脱水污泥中CPs含量占CPs总量的66.3%，由于生物降解和挥发损失的CPs占CPs总量的30.4%。该研究结果表明污泥吸附是CPs在污水处理中的主要归趋。在不同的季节研究中我们发现，冬季污水厂出水和污泥中发现了较高含量的CPs，主要是由于冬季较低的环境温度导致了较低的生物降解转化效率和挥发扩散作用。