State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Nanjing, Nanjing, 211135, China.
State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; Institute of Blue and Green Development, Shandong University, Weihai, 264209, China.
J Environ Manage. 2023 Sep 15;342:118321. doi: 10.1016/j.jenvman.2023.118321. Epub 2023 Jun 9.
Controlling the release of sediment phosphorus (P) using chemical agents is a promising method for controlling internal P in eutrophic lakes. However, mineral P formation and changes in the organic P composition after sediment amendment with P-inactivation agents remain poorly understood. Furthermore, little is known about the changes in the sediment microbial community composition after remediation. Here, various ratios of poly aluminum chloride (PAC) and lanthanum-modified bentonite (LMB) were added to nutrient-rich sediments and incubated. Sequential P extraction, solution/solid-state P nuclear magnetic resonance (NMR), and microbial analyses were periodically performed on the inactivated sediments. The results indicate that PAC and LMB effectively reduced sediment iron-bound P and organic P, respectively, markedly increasing the content of aluminum- and calcium-bound P in the sediment, respectively. Solid-state P NMR results confirmed the formation of rhabdophane (LaPO. nHO) in the LMB-amended sediment. Solution P NMR results showed that PAC preferentially reduced the organic P fractions of pyrophosphate, whereas LMB efficiently reduced the organic P fractions of orthophosphate, monoesters, and diesters in the sediment. Compared with the control sediment, PAC addition can cause short-term negative effects on sediment microbes at high doses, whereas LMB addition can increase bacterial diversity or richness in the sediment. These results provide a deeper understanding of the differences between PAC and LMB in internal sediment P control.
使用化学药剂控制沉积物磷（P）的释放是控制富营养化湖泊内部 P 的一种很有前途的方法。然而，对于添加 P 失活剂后矿物 P 的形成和有机 P 组成的变化仍知之甚少。此外，对于修复后沉积物微生物群落组成的变化也知之甚少。在此，将不同比例的聚合氯化铝（PAC）和镧改性膨润土（LMB）添加到富营养化沉积物中进行孵育。定期对失活的沉积物进行连续 P 提取、溶液/固态 P 核磁共振（NMR）和微生物分析。结果表明，PAC 和 LMB 分别有效地降低了沉积物中铁结合态 P 和有机 P，分别显著增加了沉积物中铝结合态 P 和钙结合态 P 的含量。固态 P NMR 结果证实了 LMB 改性沉积物中形成了磷铈矿（LaPO. nHO）。溶液 P NMR 结果表明，PAC 优先降低了焦磷酸盐的有机 P 分数，而 LMB 则有效地降低了沉积物中 orthophosphate、monoesters 和 diesters 的有机 P 分数。与对照沉积物相比，高剂量 PAC 加聚会对沉积物微生物产生短期的负面影响，而 LMB 加聚会增加沉积物中的细菌多样性或丰富度。这些结果提供了对 PAC 和 LMB 在内部沉积物 P 控制方面差异的更深入理解。
