National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, China.
National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, China.
J Hazard Mater. 2023 Jun 5;451:131157. doi: 10.1016/j.jhazmat.2023.131157. Epub 2023 Mar 5.
Sulfate in wastewater can be reduced to sulfide and its impact on the stability of enhanced biological phosphorus removal (EBPR) is still unclear. In this study, the metabolic changes and subsequent recovery of polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) were investigated at different sulfide concentrations. The results showed that the metabolic activity of PAOs and GAOs was mainly related to HS concentration. Under anaerobic conditions, the catabolism of PAOs and GAOs was promoted at HS concentrations below 79 mg/L S and 271 mg/L S, respectively, and inhibited above these concentrations; whereas anabolism was consistently inhibited in the presence of HS. The phosphorus (P) release was also pH-dependent due to the intracellular free Mg efflux from PAOs. HS was more destructive to the esterase activity and membrane permeability of PAOs than those of GAOs and prompted intracellular free Mg efflux of PAOs, resulting in worse aerobic metabolism and subsequent recovery of PAOs than GAOs. Additionally, sulfides facilitated the production of extracellular polymeric substances (EPS), especially tightly bound EPS. The amount of EPS in GAOs was significantly higher than that in PAOs. The above results indicated that sulfide had a stronger inhibition to PAOs than GAOs, and when sulfide was present, GAOs had a competitive advantage over PAOs in EBPR.
废水中的硫酸盐可以还原为硫化物，但其对增强生物除磷 (EBPR) 稳定性的影响尚不清楚。本研究在不同硫化物浓度下研究了聚磷积累菌 (PAOs) 和糖原积累菌 (GAOs) 的代谢变化及其随后的恢复情况。结果表明，PAOs 和 GAOs 的代谢活性主要与 HS 浓度有关。在厌氧条件下，当 HS 浓度分别低于 79mg/L S 和 271mg/L S 时，PAOs 和 GAOs 的分解代谢会被促进，而高于这些浓度时则会被抑制；而在存在 HS 的情况下，合成代谢则一直受到抑制。由于 PAOs 细胞内游离 Mg 的外流，磷 (P) 的释放也与 pH 有关。HS 对 PAOs 的酯酶活性和膜通透性的破坏作用大于对 GAOs 的破坏作用，并促使 PAOs 细胞内游离 Mg 的外流，导致 PAOs 的好氧代谢和随后的恢复比 GAOs 更差。此外，硫化物促进了细胞外聚合物物质 (EPS) 的产生，特别是紧密结合的 EPS。GAOs 中的 EPS 量明显高于 PAOs。上述结果表明，硫化物对 PAOs 的抑制作用强于 GAOs，当存在硫化物时，GAOs 在 EBPR 中比 PAOs 具有竞争优势。
