污泥有机污染物降解研究进展

Research progress on degradation of sludge organic pollutants

城市污水处理过程迁移并富集在污泥中的有机污染物稳定性高、难降解,存在较高的生态风险,已成为制约污泥土地利用的主要因素。考虑到物化法处理污泥有机污染物的工程局限性,本文介绍了城市污泥中多环芳烃、苯并(a)芘与矿物油3种代表性有机污染物的来源、性质及危害。围绕污泥厌氧消化、好氧堆肥以及两者联合的作用机理,论述了有机污染物在污泥处理过程中的降解转化规律。分析了有机污染物降解的成因,指出有机污染物的生物利用度是影响降解效果的关键因素,污泥微生物细胞壁和有机污染物结构的稳定性阻碍了有机污染物与微生物的充分接触,从而影响了生物降解速率。为此,分析了热解法、超声法、臭氧法和添加外源物4种辅助手段的作用及其强化降解的效果。通过归纳总结,明确了污泥有机污染物降解的工艺组合及其过程优化的方向。

Organic pollutants, which migrated in the urban sewage treatment process and enriched in the sludge, have high stability. They are difficult to degrade, and have high ecological risks, which have become the main factors restricting the utilization of sludge land. Considering the engineering limitations of physicochemical treatment of sludge organic pollutants, the sources, properties and hazards of three representative organic pollutants, polycyclic aromatic hydrocarbons, benzo(a)pyrene and mineral oil, in municipal sludge were introduced in this paper. Based on the anaerobic digestion of sludge, aerobic composting and the combined action mechanism of the two, the degradation and transformation of organic pollutants in the sludge treatment process were discussed. The causes of degradation of organic pollutants were analyzed. It was pointed out that the bioavailability of organic pollutants was the key factor affecting the degradation effect. The stability of sludge microbial cell wall and organic pollutant structure hindered the full contact of organic pollutants with microorganisms as well as affected the biodegradation rate. To this end, the effects of pyrolysis, ultrasonic method, ozone method, four auxiliary means of adding exogenous substances and the effect of enhanced degradation were analyzed. Through summarizing and summarizing, the process combination of sludge organic pollutant degradation and the direction of process optimization were clarified.