School of Environmental and Chemical Engineering, Shanghai University, Shanghai, People's Republic of China.
Environ Technol. 2021 Sep;42(23):3698-3706. doi: 10.1080/09593330.2020.1739145. Epub 2020 Mar 15.
The enhancement of phosphorus (P) released from waste activated sludge (WAS) by electrochemical treatment was investigated in this study. Results showed that the concentration of orthophosphate (ortho-P) and organic phosphorus (OP) in liquid both increased after electrochemical treatment. The ortho-P and OP concentration reached a maximum of 5.020 and 1.888 mg/L under the optimal condition respectively (voltage of 4.5 V and time of 60 min), which were 2.86 and 4.93 times higher than that in raw sludge. Meanwhile, the role of extracellular polymeric substances (EPS) in this process was also studied. The variation trends of P-release in tightly bound EPS (TB-EPS) and loosely bound EPS (LB-EPS) were different. In TB-EPS, the concentration of total phosphorus (TP) and ortho-P decreased when the voltage increased. In contrast, the concentration of TP and ortho-P in LB-EPS increased and reached the maximum under the optimal condition. Released metal ions (Ca, Mg, Fe, and Al) had some effects on P-release both in liquid and EPS, which indicated that EPS played an important role. SCOD and TSS revealed that the disintegration of sludge was also enhanced by electrochemical treatment. Additionally, the P fractions in sludge phase suggested that OP was more likely to be released in liquid phase.
本研究考察了电化学处理对废活性污泥（WAS）中磷（P）释放的增强作用。结果表明，电化学处理后液体中正磷酸盐（ortho-P）和有机磷（OP）的浓度均增加。在最佳条件下（电压为 4.5 V，时间为 60 min），液体中 ortho-P 和 OP 的浓度分别达到 5.020 和 1.888 mg/L，分别是原污泥中的 2.86 倍和 4.93 倍。同时，还研究了胞外聚合物物质（EPS）在此过程中的作用。紧密结合的 EPS（TB-EPS）和松散结合的 EPS（LB-EPS）中 P 释放的变化趋势不同。在 TB-EPS 中，当电压增加时，TP 和 ortho-P 的浓度降低。相比之下，LB-EPS 中 TP 和 ortho-P 的浓度在最佳条件下增加并达到最大值。释放的金属离子（Ca、Mg、Fe 和 Al）对液体和 EPS 中的 P 释放都有一定的影响，这表明 EPS 发挥了重要作用。SCOD 和 TSS 表明，电化学处理还增强了污泥的解体。此外，污泥相中 P 组分表明 OP 更有可能释放到液相中。
