Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China.
College of Environment, Hohai University, Nanjing 210098, China.
Sci Total Environ. 2022 Mar 1;810:152297. doi: 10.1016/j.scitotenv.2021.152297. Epub 2021 Dec 9.
To balance the high phosphorus concentration in recirculated solution and the stability of biofilm system, this study explored the performance and mechanism of phosphorus uptake/release for recovering phosphorus from sewage when the phosphorus content in biofilm (P) changed. The results showed that the maximum phosphorus concentration in the concentrated solution reached 171.2 ± 2.5 mg·L in harvest 1st-5th stages. Polyphosphate accumulating organisms (PAOs) performed a metabolic shift from glycogen accumulation metabolism (GAM) to polyphosphate accumulation metabolism (PAM) when P increased at each phosphorus enrichment stage, and more phosphorus was absorbed/released by PAOs. Nevertheless, the release of poly-phosphate from PAOs was inhibited after phosphorus concentration stabilized, and PAOs were unable to absorb phosphorus from wastewater as it reached the phosphorus saturation stage. To maintain the stability of the system, phosphorus had to be harvested so that the saturated phosphorus in PAOs was easily released in a new recirculated solution, resulting in adequate storage space for PAOs to absorb phosphorus. Meanwhile, the P NMR analysis demonstrated that phosphorus was stored in EPS and cell of PAOs, whereas EPS played a significant role than cell at the anaerobic phase. Particularly, ortho-phosphate was the major component of phosphorus release by EPS and poly-phosphate was the major part of phosphorus release by cell. Furthermore, the change of P had no impact on biofilm characteristics and microbial communities, whereas some PAOs would be enriched, and others that were not suitable for this process would be inhibited with repeated cycles of alternating aerobic/anaerobic operation.
为了平衡循环溶液中的高磷浓度和生物膜系统的稳定性，本研究探索了在生物膜磷（P）含量变化时，从污水中回收磷的磷吸收/释放性能和机制。结果表明，在收获第 1 至 5 阶段，浓缩液中最大磷浓度达到 171.2±2.5mg·L。当每个磷富化阶段的 P 增加时，聚磷菌（PAO）从糖原积累代谢（GAM）转变为聚磷积累代谢（PAM），PAO 吸收/释放更多的磷。然而，当磷浓度稳定后，从 PAO 中释放的多磷酸盐受到抑制，当达到磷饱和阶段时，PAO 无法从废水中吸收磷。为了维持系统的稳定性，必须进行磷的收获，以便将 PAO 中饱和的磷在新的循环溶液中容易释放，为 PAO 提供充足的储存空间来吸收磷。同时，P NMR 分析表明，磷储存在 PAO 的 EPS 和细胞中，而在厌氧阶段，EPS 比细胞发挥着更重要的作用。特别是，正磷酸盐是 EPS 释放磷的主要成分，多磷酸盐是细胞释放磷的主要成分。此外，P 的变化对生物膜特性和微生物群落没有影响，但是随着好氧/厌氧交替运行的反复循环，一些 PAO 会被富集，而其他不适合该过程的 PAO 会被抑制。
