Dos Santos Naiara de Oliveira, Busquets Rosa, Campos Luiza C
Department of Civil, Environmental & Geomatic Engineering, Faculty of Engineering, University College London, London WC1E 6BT, United Kingdom.
Department of Civil, Environmental & Geomatic Engineering, Faculty of Engineering, University College London, London WC1E 6BT, United Kingdom; School of Life Sciences, Pharmacy and Chemistry, Faculty of Health, Science, Social Care and Education, Kingston University, Penrhyn Road, Kingston Upon Thames KT1 2EE, United Kingdom.
Sci Total Environ. 2023 Feb 25;861:160665. doi: 10.1016/j.scitotenv.2022.160665. Epub 2022 Dec 5.
Water treatment plants' effluents are hotspots of microplastics (MPs) and microfibres (MFs) released into the aquatic environment because they were not designed to capture these particles. Special attention should be given to MFs, since they mainly come from laundry and are related to one of the main MP shapes detected in water and wastewater treatment plants. In this sense, Advanced Oxidation Processes (AOPs) could be a feasible solution for tackling MP and MF pollution, however, it is still premature to extract conclusions due to the limited number of studies on the degradation of these particles (specifically MFs) using AOPs. This review addresses the impacts of AOPs on MPs/MFs, focusing on their degradation efficiency, toxicity, and sustainability of the processes, among other aspects. The review points out that polyamide MFs can achieve mass loss >90% by photocatalytic system using TiO. Also, the low oxidation of MPs (<30 %) by conventional Fenton process affects mainly the surface of the MPs. However, other Fenton-based processes can provide better removal of some types of MPs, mainly using temperatures >100 °C, reaction time ≥ 5 h, and initial pH ≤ 3, achieving MP weight loss up to 96 %. Despite these results, better operating conditions are still required for AOPs since the ones reported so far are not feasible for full-scale application. Additionally, ozonation in treatment plants has increased the fragmentation of MPs (including MFs), leading to a new generation of MPs. More attention is needed on toxicity effects of intermediates and methods of analysis employed for the analysis of MPs/MFs in wastewater effluent should be standardized so that studies can be compared effectively. Future research should focus on the sustainability of the AOP for MP removal in water treatment (power consumption, chemicals consumed and operational costs) for a better understanding of full-scale applicability of AOP adapted to MP treatment.
污水处理厂的废水是微塑料（MPs）和微纤维（MFs）进入水生环境的热点区域，因为这些污水处理厂并非设计用于捕获这些颗粒。应特别关注微纤维，因为它们主要来自洗衣过程，并且与在水和污水处理厂中检测到的主要微塑料形状之一有关。从这个意义上讲，高级氧化工艺（AOPs）可能是解决微塑料和微纤维污染的可行方案，然而，由于使用高级氧化工艺降解这些颗粒（特别是微纤维）的研究数量有限，目前得出结论还为时过早。本综述探讨了高级氧化工艺对微塑料/微纤维的影响，重点关注其降解效率、毒性以及工艺的可持续性等方面。该综述指出，聚酰胺微纤维通过使用二氧化钛的光催化系统可实现质量损失>90%。此外，传统芬顿工艺对微塑料的低氧化率（<30%）主要影响微塑料的表面。然而，其他基于芬顿的工艺可以更好地去除某些类型的微塑料，主要是使用温度>100°C、反应时间≥5小时以及初始pH≤3的条件，可实现微塑料重量损失高达96%。尽管有这些结果，但高级氧化工艺仍需要更好的操作条件，因为目前报道的条件在实际应用中并不可行。此外，污水处理厂中的臭氧化过程增加了微塑料（包括微纤维）的碎片化，导致产生新一代的微塑料。需要更多关注中间产物的毒性影响，并且用于分析废水排放中微塑料/微纤维的分析方法应标准化，以便有效地比较各项研究。未来的研究应关注高级氧化工艺在水处理中去除微塑料的可持续性（电力消耗、化学药剂消耗和运营成本），以便更好地理解适用于微塑料处理的高级氧化工艺在实际应用中的可行性。
