硫酸根自由基:强化污泥脱水新利器

Sulfate Radicals:A New Tool for Enhancing Sludge Dewatering

污泥是污水处理过程中不可避免的副产物。由于其含水率高、体积大且含有大量有毒有害物质,因此需要进行减量化和无害化处理。然而,污泥拥有带负电官能团电离形成的胞外聚合物(EPS),能够维持稳定的水合胶体结构阻止水的释放,是造成污泥脱水困难的关键因素。近十年,基于硫酸根自由基的高级氧化技术(SR-AOPs)因其对EPS破解效率高、反应迅速且环境友好等优点受到大量关注,硫酸根自由基也因此成为强化污泥脱水的新利器。本文详细梳理了硫酸根自由基的发展时间线和活化机制,系统评价了国内外SR-AOPs改善污泥脱水性能、去除污泥中微量污染物和重金属的研究现状。基于现阶段SR-AOPs在污泥调理方面存在的科学问题,从机理研究、成本效益、试验规模等角度展望了未来的发展研究方向,以期为我国污水处理厂的污泥调理提供参考。

Sludge is an inevitable by-product of the wastewater treatment process and due to its high water content,large volume,and inclusion of a large amount of toxic and hazardous substances,needs to be minimized and harmlessly treated.However,sludge possesses extracellular polymeric substances(EPS)formed by ionization of negatively charged functional groups,which maintain a stable hydrated colloidal structure and prevent the release of water.This is a key factor in the difficulty of sludge dewatering.In the last decade,sulfate radical-based advanced oxidation processes(SR-AOPs)have received considerable attention due to their high efficiency for EPS disintegration,rapid reaction time and environmental friendliness,and thus sulfate radicals have become a new powerful tool for enhancing sludge dewaterability.In this paper,the development timeline and activation mechanisms of sulfate radicals are reviewed in detail,and the research advances of SR-AOPs for improving sludge dewaterability and removing micropollutants and heavy metals from sludge are systematically evaluated.Based on the current scientific problems of SR-AOPs in sludge conditioning,the future research directions of SR-AOPs are proposed from the perspectives of mechanism research,cost-effectiveness,and experimental scale,in order to provide a solid theoretical reference for sludge conditioning in wastewater treatment plants in China.