State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, P.R. China.
State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China.
Water Res. 2020 Dec 15;187:116440. doi: 10.1016/j.watres.2020.116440. Epub 2020 Sep 21.
The treatment and disposal of waste activated sludge (WAS) has become one of the major challenges for the wastewater treatment plants (WWTPs) due to large output, high treatment costs and enriched substantial emerging contaminants (ECs). Therefore, reducing sludge volume, recovering energy and resource from WAS, and removing ECs and decreasing environmental risk have gained increasing attentions. Calcium peroxide (CaO), a versatile and safe peroxide, has been widely applied in terms of WAS treatment including sludge dewatering, anaerobic sludge digestion and anaerobic sludge fermentation due to its specific properties such as generating free radicals and alkali, etc., providing supports for sludge reduction, recycling, and risk mitigation. This review outlines comprehensively the recent progresses and breakthroughs of CaO in the fields of sludge treatment. In particular, the relevant mechanisms of CaO enhancing WAS dewaterability, methane production from anaerobic digestion, short-chain fatty acids (SCFA) and hydrogen production from anaerobic fermentation, and the removal of ECs in WAS and role of experiment parameters are systematically elucidated and discussed, respectively. Finally, the knowledge gaps and opportunities in CaO-based sludge treatment technologies that need to be focused in the future are prospected. The review presented can supply a theoretical basis and technical reference for the application of CaO for improving the treatment of WAS.
由于产量大、处理成本高以及富含大量新兴污染物（ECs），废活性污泥（WAS）的处理和处置已成为污水处理厂（WWTPs）面临的主要挑战之一。因此，减少污泥体积、从 WAS 中回收能源和资源，以及去除 ECs 和降低环境风险已引起越来越多的关注。过碳酸钠（CaO）作为一种多功能且安全的过氧化物，由于其产生自由基和碱等特性，已广泛应用于包括污泥脱水、厌氧消化和厌氧发酵在内的 WAS 处理中，为污泥的减少、回收和风险缓解提供了支持。本综述全面概述了 CaO 在污泥处理领域的最新进展和突破。特别是，系统地阐明和讨论了 CaO 提高 WAS 脱水性能、厌氧消化产甲烷、厌氧发酵产短链脂肪酸（SCFA）和氢气、以及去除 WAS 中 ECs 的相关机制，以及实验参数的作用。最后，展望了基于 CaO 的污泥处理技术中需要关注的知识空白和机遇。本综述为 CaO 改善 WAS 处理的应用提供了理论基础和技术参考。
