School of Civil Engineering and Architecture, Zhejiang University of Science and Technology, Hangzhou 310023, China.
Department of Earth and Environmental Studies, Montclair State University, Montclair, NJ 07043, USA.
Int J Environ Res Public Health. 2023 Feb 6;20(4):2849. doi: 10.3390/ijerph20042849.
Dissolved organic phosphorus (DOP), which is recalcitrant in municipal wastewater treatment, accounts for 26-81% of dissolved total phosphorus in the effluent. More importantly, the majority of DOP could be bioavailable, potentially threatening the aquatic environment through eutrophication. This study aimed to develop a ferrate (VI)-based advanced treatment to effectively destruct and remove DOP from secondary effluent and use deoxyribonucleic acid (DNA) and adenosine-5'-triphosphate (ATP) as DOP model compounds to explore the relevant mechanisms. The results showed that ferrate (VI) treatment could efficiently destruct and remove 75% of the DOP in secondary effluent from an activated sludge-adopted municipal wastewater treatment plant, under normal operating conditions. Moreover, the coexistence of nitrate, ammonia, and alkalinity barely affected the effectiveness, while the presence of phosphate significantly inhibited DOP removal. The mechanistic study revealed that ferrate (VI)-induced particle adsorption was the dominant way to achieve DOP reduction, rather than oxidating DOP to phosphate and forming precipitation afterward. Meanwhile, DOP molecules could be effectively decomposed into smaller ones by ferrate (VI) oxidation. This study clearly demonstrated that ferrate (VI) treatment could achieve a promising DOP removal from secondary effluent for mitigating the risk of eutrophication in receiving water bodies.
溶解性有机磷（DOP）在城市污水处理中难以去除，占污水中溶解性总磷的 26-81%。更重要的是，大部分 DOP 可能具有生物可利用性，通过富营养化对水生态环境构成潜在威胁。本研究旨在开发一种高铁酸盐（VI）基高级处理方法，以有效破坏和去除二级出水中的 DOP，并使用脱氧核糖核酸（DNA）和腺苷-5'-三磷酸（ATP）作为 DOP 模型化合物来探讨相关机制。结果表明，在正常运行条件下，高铁酸盐（VI）处理可有效破坏和去除采用活性污泥的城市污水处理厂二级出水中 75%的 DOP。此外，硝酸盐、氨和碱度的共存几乎不影响处理效果，而磷酸盐的存在则显著抑制 DOP 的去除。机理研究表明，高铁酸盐（VI）诱导的颗粒吸附是实现 DOP 减少的主要方式，而不是将 DOP 氧化为磷酸盐并随后形成沉淀。同时，DOP 分子可被高铁酸盐（VI）氧化有效地分解为更小的分子。本研究清楚地表明，高铁酸盐（VI）处理可有效去除二级出水中的 DOP，从而降低受纳水体富营养化的风险。
