School of Environmental Science and Engineering, Suzhou University of Science and Technology, No. 1, Kerui Road, Suzhou, 215009, China.
School of Environmental Science and Engineering, Suzhou University of Science and Technology, No. 1, Kerui Road, Suzhou, 215009, China.
Environ Res. 2021 Apr;195:110682. doi: 10.1016/j.envres.2020.110682. Epub 2021 Jan 9.
Bioavailability of phosphorus (P) has close relationship with the microbial community in sediments and plays an important role in the sedimentary P release. However, little is known about the relationship between P bioavailability and microbial community under capping conditions. A 62-day experiment was conducted by capping with modified calcium peroxide ceramsite (MCPC) at different addition dosages (from 1:1 to 1:4, the ratio of mobile P in sediment to MCPC). P disappearance and release were expressed by the dissolved inorganic P (DIP) in overlying water. The results show that the proportion of disappeared P in released P was reduced sharply from 44% (Control) to 2% (1:4) under the capping with MCPC. Under the capping, the concentrations of DIP and Fe(Ⅱ) in pore water decreased markedly compared with the control, the removal up to 71.6% and 59.3% (mean, P < 0.05), respectively. The bioavailable P (BAP) presented the obvious decline under the capping with MCPC, which indicates the inhibition on the algae growth. The algae available P (AAP), water soluble P (WSP) and readily desorbable P (RDP) were reduced obviously at the 1:2 ratio compared with the other ratios. On the contrary, the biggest increase of Olsen-P in sediment was at the 1:2 ratio. This may be the explanation why the disappearance of DIP in the pore water was found. The result of microbial community structures in sediment shows that the relative abundance of Proteobacteria and Nitrospirae increased under the MCPC capping. It is analyzed that the microbial diversity is related negatively with the BAP in the sediments under the capping with MCPC, suggesting that microbial diversity is the key to control the BAP.
磷（P）的生物有效性与沉积物中的微生物群落密切相关，在沉积物 P 释放中起着重要作用。然而，在覆盖条件下，P 生物有效性与微生物群落之间的关系知之甚少。通过用改性过氧化钙陶瓷（MCPC）以不同的添加剂量（从 1:1 到 1:4，即沉积物中可移动 P 与 MCPC 的比例）进行为期 62 天的实验。通过上层水中的溶解无机磷（DIP）来表示 P 的消失和释放。结果表明，在用 MCPC 覆盖的情况下，释放 P 中消失 P 的比例从 44%（对照）急剧降低到 2%（1:4）。在覆盖条件下，与对照相比，孔隙水中的 DIP 和 Fe（Ⅱ）浓度明显降低，分别去除了 71.6%和 59.3%（平均值，P<0.05）。在 MCPC 覆盖下，生物有效磷（BAP）明显下降，这表明藻类生长受到抑制。与其他比例相比，藻类有效磷（AAP）、水溶性磷（WSP）和易解吸磷（RDP）在 1:2 比例下明显减少。相反，在 1:2 比例下，沉积物中 Olsen-P 的增加最大。这可能就是为什么在孔隙水中发现 DIP 消失的原因。沉积物中微生物群落结构的结果表明，在 MCPC 覆盖下，变形菌门和硝化螺旋菌的相对丰度增加。分析表明，在 MCPC 覆盖下，微生物多样性与沉积物中的 BAP 呈负相关，表明微生物多样性是控制 BAP 的关键。
