Zhu Guang-Wei, Li Jing, Zhu Meng-Yuan, Gong Zhi-Jun, Xu Hai, Yang Gui-Jun, Zhang Yun-Lin, Qin Bo-Qiang
State Key Laboratory of Lake Environment and Science, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
College of Environmental and Civil Engineering, Jiangnan University, Wuxi 214122, China.
Huan Jing Ke Xue. 2017 Apr 8;38(4):1451-1459. doi: 10.13227/j.hjkx.201609123.
Famous as the world cultural heritage, West Lake in Hangzhou city has plenty of soft sediments with high organic matter content. To search the countermeasures for internal phosphorus release reduction from the sediment, the sediment core incubation was conducted to understand the efficacy of Phoslock on internal phosphorus release in spring, summer and winter, respectively. The results showed that the internal phosphorus release fluxes in winter and spring were relatively low, with averaged values in the entire lake of 0.13 mg·(m·d) and 0.29 mg·(m·d), respectively, while the release flux was 3.29 mg·(m·d) in summer, more than ten times higher than those in spring and winter. It was estimated that 23.7 kg of phosphorus could be released from sediment in the entire lake every day in summer. Spatially, the phosphorus release flux was related to organic matter contents in sediments, but not the phosphorus or bioavailable phosphorus contents in sediments in West Lake. With Phoslock added at the rate of 630 g·m, sediment phosphorus release was successfully controlled, which reduced the phosphorus concentration in the lake water to less than 0.010 mg·L. Especially during summer time, the sediment phosphorus release was reduced by 98% after Phoslock application. The research suggested that Phoslock is powerful for phosphorus control even for sediments with high organic matter content, which could be considered in ecological restoration of WEst Lake.
作为世界文化遗产而闻名的杭州西湖，拥有大量有机质含量高的软沉积物。为了探寻减少沉积物内部磷释放的对策，分别在春季、夏季和冬季进行了沉积物柱样培养实验，以了解磷素固定剂对沉积物内部磷释放的效果。结果表明，冬季和春季的沉积物内部磷释放通量相对较低，整个湖泊的平均值分别为0.13mg·(m²·d)和0.29mg·(m²·d)，而夏季的释放通量为3.29mg·(m²·d)，比春季和冬季高出十余倍。据估计，夏季整个湖泊的沉积物每天可释放23.7kg磷。在空间上，磷释放通量与沉积物中的有机质含量有关，而与西湖沉积物中的总磷或生物可利用磷含量无关。以630g·m²的用量添加磷素固定剂后，沉积物磷释放得到成功控制，湖水磷浓度降至0.010mg·L以下。特别是在夏季，施用磷素固定剂后沉积物磷释放减少了98%。该研究表明，即使对于有机质含量高的沉积物，磷素固定剂在控制磷方面也很有效，这在西湖生态修复中值得考虑。
