School of Environmental Science and Engineering, Shanghai Jiao Tong University, No. 800, Dongchuan Rd., Shanghai, 200240, China.
School of Agriculture and Biology, Shanghai Jiao Tong University, No. 800, Dongchuan Road, Shanghai, 200240, China.
Environ Pollut. 2019 Apr;247:9-17. doi: 10.1016/j.envpol.2019.01.008. Epub 2019 Jan 8.
Release of phosphorus (P) from sediment to overlying water has to be dealt with to address algal blooms in eutrophic lakes. In this study, the sediment from the Lake Taihu was amended with lanthanum modified zeolite (LMZ) to reduce P release under different pH, temperature and anaerobic conditions. LMZ performed well, to decreasing P concentration in Lake Taihu water in the presence of sediment. The EPC value, the critical P concentration at which there was neither P adsorption nor P release, was lowered by adding LMZ, suggesting that amendment with LMZ could diminish the risk of P release from the sediment. From the Langmuir isotherm model, the adsorption capacity of phosphate by LMZ was estimated to be 64.1 mgP/g. The LMZ-amended sediment had a higher content of stable P forms (HCl-P and Res-P) and a lower content of P forms with a high (NHCl-P and BD-P) or medium-high (NaOH-P and Org-P) risk of release, when compared with the original sediment. The fractionation simulates conditions which release potentially mobile P which can then be simply re-bound to LMZ. At high pH (>9.0), anaerobic condition or high temperature promoted the liberation of P from sediment. However, P release could be greatly inhibited by LMZ. In addition, although Mn and NH ions were released from sediment under the anaerobic condition, the release could also be hindered by adding LMZ. LMZ is a promising P inactivation agent to manage eutrophication in the sediment of Lake Taihu.
为了解决富营养化湖泊中的藻类水华问题，必须控制沉积物向水体中释放磷（P）。本研究采用镧改性沸石（LMZ）对太湖沉积物进行改良，以减少不同 pH 值、温度和厌氧条件下 P 的释放。LMZ 可有效降低太湖沉积物存在条件下水体中 P 的浓度。添加 LMZ 降低了 EPC 值（即无吸附和释放 P 的临界 P 浓度），表明 LMZ 改良可降低沉积物中 P 释放的风险。从 Langmuir 等温模型可以看出，LMZ 对磷酸盐的吸附容量估计为 64.1mgP/g。与原始沉积物相比，LMZ 改良后的沉积物中稳定态磷（HCl-P 和 Res-P）的含量较高，而高（NHCl-P 和 BD-P）或中高（NaOH-P 和 Org-P）释放风险的磷形态含量较低。这种分级提取模拟了潜在可移动磷的释放条件，然后这些磷可以被简单地重新结合到 LMZ 上。在高 pH 值（>9.0）、厌氧条件或高温下，P 从沉积物中释放出来，但 LMZ 可极大地抑制 P 的释放。此外，尽管 Mn 和 NH4+离子在厌氧条件下从沉积物中释放出来，但添加 LMZ 也可以阻碍其释放。LMZ 是一种有前途的 P 固定剂，可用于管理太湖沉积物的富营养化。
