环境水质学国家重点实验室知识库

      我国的焦化废水具有水量大、污染物浓度高的特点。然而对焦化废水水质特征认识的不足，对污染物转化及生物降解过程产生的抑制缺乏深入理解，导致污染控制工艺的选择带有盲目性。 以某焦化废水处理厂为研究对象， 初步研究其原水水质成分组成、各生化处理单元水质分析，进而对现有生化处理工艺进行升级优化，提高生化出水的水质，降低后续深度处理的压力 ，最终达标排放或回用。
      优化调试后的焦化废水处理 系统， 形成了一套以 缺氧 -好氧 -混凝 -氧化吸附 为核心的处理工艺，采用缩短流程、提高负荷、加大污泥回流比、缩短停留时间等措施，维持一定的污泥负荷和适当污泥龄 特别是调控好氧系统中异养菌与硝化菌的比例 是保证污泥有较高活性的关键，从而实现有机物与氨氮的良好去除。工程运行结果证实该工艺对 CODCr、NH4+-N与 TN都有很好的去除效果 利用混凝 -原位氧化吸附组合技术 ，对生化出水中难降解有机物进行高效吸附， 实现生化出水残留有机物的高效去除，解决了焦化废水出水达标困难的难题。 低温等离子对焦化废水生化出水的深度处理的 探索 结果表明：在最优处理条件下：初始 pH为 7.66 原水 pH COD的去除率为 78.3%。

      Coking wastewater is a kind of wastewater produced during coking production, of which the quantity is large and the pollutant concentrations are quite high. However, the lack understanding of the characteristics of coking wastewater itself and the inhibition of pollutants to biodegradation process leads to blindness in the treatment process selection. On the basis of the analysis of pollutants composition in the different tanks of a coking wastewater treatment plant, the existing treatment process was upgraded and optimized in order to improve the effluent quality of biological process, reduce the pressure of subsequent advanced treatment, and finally discharge or reuse according to the discharge standard.

      The upgraded coking wastewater treatment system was a "anaerobic - aerobic oxidation - coagulation - adsorption" process. By shortening the original process and the HRT, improving COD load, increase the sludge reflux ratio, a certain amount of the aerobic heterotrophic bacteria and the denitrifying bacteria was maintained the upgraded system, which is the key to ensure that the quite high sludge activity and well pollutant removal. Engineering operation results showed that the removal efficiency of CODCr, NH4+-N and TN was very good. The combined process of coagulation and in-situ oxidation adsorption was used to efficiently adsorb refractory organic matter in the effluent of biological treatment units to ensure the final effluent meet the reuse standard. The results of the advanced treatment of coking biological treatment effluent via non-thermal plasma showed that the optimal treatment conditions were: initial pH at 7.66 (raw water pH), applied voltage at 25 kV, repetition frequency of the applied voltage at 1000 pps (pulse per second), and the carrier gas flow rate at 0.5 L-O2/min (standard condition), under which the removal rate of COD was 78.3%.