焦化工业产生大量废水，所含污染物种类多、性质复杂、毒性强，危害大。经预处理和生化处理后仍难以达标，焦化废水深度处理是亟待解决的问题。本研究利用电离辐照技术，以酚类（苯酚）和杂环芳烃类（吲哚、3-甲基吲哚、噻吩）为代表性污染物，探讨了污染物浓度、辐照剂量、阴离子、pH值等的影响，提出了污染物可能的降解途径，预测了降解中间产物的生物毒性，研究了污染物在辐照降解体系中的去除效率，在此基础上研究了臭氧氧化联合电离辐照技术降解实际焦化废水二次处理出水中污染物降的性能。研究了电离辐照降解苯酚、吲哚、3-甲基吲哚、噻吩的影响因素。当吸收剂量从1 kGy增加到5 kGy时，污染物的降解率和矿化率（TOC去除率）相应增加；随着污染物浓度增加，电离辐照降解污染物的效率降低；污染物辐照降解受溶液pH及阴离子的影响。分析了吲哚、3-甲基吲哚、噻吩的辐照降解中间产物，并提出了其可能的降解途径。预测了吲哚、3-甲基吲哚、噻吩及其降解中间产物的生物毒性。分析了电离辐照降解上述四种污染物混合时的TOC去除率。研究了臭氧氧化对苯酚、吲哚、3-甲基吲哚、噻吩的降解情况。在300 mg/h的臭氧通气量下，臭氧氧化30分钟内，上述污染物的降解率可达到100%；经过2 h臭氧氧化处理后，苯酚的TOC去除率可达到60%，但吲哚、3-甲基吲哚、噻吩的TOC去除率较低，并且变化不明显。臭氧氧化上述四种污染物的混合物时，污染物的去除率和矿化率比污染物单独臭氧氧化时下降。研究了臭氧-辐照技术联合使用对苯酚的降解及矿化情况。在臭氧-辐照体系中，臭氧预处理时间越长，苯酚的TOC去除率越高。当臭氧预处理时间为120 min，再结合2 kGy的辐照处理，苯酚的TOC去除效率可达81%；而在辐照-臭氧体系中，当辐照剂量为2 kGy，臭氧通气时间为120 min时，苯酚的TOC去除效率仅为40%。研究了臭氧-辐照技术对实际焦化废水二级出水的深度处理情况。当臭氧预处理时间为120 min，再结合2 kGy的辐照处理，实际焦化废水的TOC去除率为36%，处理实际焦化废水+ 20 mg/L苯酚的去除率为31%，均高于电离辐照和臭氧单独进行处理时的TOC去除率。
The large amount of wastewater has been produced by the coking industry, which contains a wide variety of complex, toxic and harmful pollutants. After pretreatment and biological treatment, it cannot meet the discharge standard. Advanced treatment of coking wastewater is an urgent problem to be solved. In this paper, we investigated the degradation of typical pollutants in coking wastewater, such as phenolic (phenol) and heterocyclic aromatic hydrocarbons (indole、3-methyindole、thiophene) by ionizing radiation technology. The effect of initial concentration of pollutants, absorbed dose, inorganic anions, initial pH was investigated. The degradation pathway of pollutants was proposed, and the biotoxicity of intermediates was predicted. The removal efficiency of pollutants in the radiation-induced degradation system was studied, and the degradation of pollutants in the effluent of the secondary treatment of actual coking wastewater was studied based on the above results. The influencing factors, such as initial concentration of pollutants, absorbed dose and initial pH on the degradation of phenol, indole, 3-methylindole and thiophene by ionizing radiation were investigated. The experimental results showed that when the absorbed dose increased from 1 kGy to 5 kGy, the removal efficiency and mineralization efficiency (TOC removal efficiency) of pollutants increased accordingly; the removal efficiency of pollutants decreased with the increase of the initial concentration; the initial pH and anions had also influence on the degradation of pollutants. The degradation products of indole, 3-methylindole and thiophene were analyzed, and their possible degradation pathways were proposed. The biotoxicity of indole, 3-methylindole, thiophene and their degradation intermediates was predicted. The TOC removal efficiency of the mixed solution of above four pollutants were studied.The degradation of phenol, indole, 3-methylindole and thiophene by ozone oxidation was investigated. The degradation efficiency of the above four pollutants could reach 100% within 30 min of ozone oxidation at an ozone aeration volume of 300 mg/h. After 2 h ozone oxidation treatment, the TOC removal efficiency of phenol could reach 60%, while the TOC removal efficiency of indole, 3-methylindole and thiophene was low and their variation was not obvious. When the mixture of the above four pollutants was oxidized by ozone, the removal efficiency and mineralization efficiency of pollutants were lower than single pollutant. The degradation and mineralization of phenol were studied by combined ozone-radiation technology. The TOC removal efficiency of phenol increased with the increase of ozone pretreatment time in the ozone-radiation system. When the ozone pretreatment time was 120 min, combined with 2 kGy radiation treatment, the TOC removal efficiency of phenol was as high as 81%. In the radiation-ozone system, when the absorbed dose was 2 kGy and the ozonation time was 120 min, the TOC removal efficiency of phenol was only 40%. The advanced treatment of the secondary effluent of actual coking wastewater by ozone-radiation technology was studied. When the ozone pretreatment time was 120 min, combined with 2 kGy radiation treatment, the TOC removal efficiency of actual coking wastewater was 36%, and the removal efficiency of the actual coking wastewater + 20 mg/L phenol was 31%, both were higher than the TOC removal efficiency by ionizing radiation alone and by ozonation alone.
