焦化废水生化尾水特征及其深度处理技术进展

Characteristics of biochemical tail water from coking wastewater and current progress in advanced treatment technologies

焦化废水污染负荷高、有机污染物组成复杂、生物毒性强,是一类非常难处理的煤化工废水。经传统的“物化+生化”工艺处理后,其生化尾水中仍残留部分难降解有机物与一定的生物毒性,COD难以达到《炼焦化学工业污染物排放标准》(GB 16171—2012)的限值要求,需进一步处理。分析了焦化废水生化尾水中的残余有机物和生物毒性特征,归纳总结了混凝、吸附、膜过滤等分离技术,Fenton、催化臭氧氧化、电磁强化氧化、过硫酸盐氧化与电化学氧化等转化技术及分离转化协同工艺对生化尾水中难降解有机物的去除效能和不同有机组分及生物毒性的变化规律,指出在认识水质特征与生物毒性转化规律的基础上,兼顾有机物高效去除和处理出水的生物安全性,开发协同组合工艺与短流程技术是焦化废水生化尾水深度处理技术的发展方向。

Coking wastewater is one of refractory coal chemical wastewater with a high pollution load,complex organic pollutant composition and strong biological toxicity.The biochemical tail water still retains refractory organic compounds and exhibits a certain level of biological toxicity after conventional physical-chemical and biological treatment.COD fails to meet the discharge standards for pollutants from Emission Standard of Pollutants for Coking Chemical Industry(GB 16171-2012),and further processing is required.The characteristics of residual organic matter and biological toxicity in the biochemical tail water of coking wastewater were analyzed firstly.Subsequently,this review summarized the COD removal efficiency,the change rules of different organic components and biological toxicity in biochemical tail water after application of separation technologies(coagulation,adsorption,membrane filtration),transformation technologies(Fenton,catalytic ozone oxidation,electromagnetic enhanced oxidation technology,persulfate oxidation and electrochemical oxidation)and collaborative processes.It was pointed out that on the basis of understanding the characteristics of the biochemical tail water and biological toxicity transformation rules with various advanced technologies,the collaborative combination process and short process technology would be desired for the efficient treatment and the biological safety.