Liu Yong-Jiu, Huang Su-Zhen, Zhang Lu, Peng Xue, Zhang Xin-Yi, Ge Fang-Jie, Liu Bi-Yun, Wu Zhen-Bin
School of Resource & Environmental Engineering, Wuhan University of Technology, Wuhan 430070, China.
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
Huan Jing Ke Xue. 2021 Jul 8;42(7):3198-3205. doi: 10.13227/j.hjkx.202009090.
According to a spatial distribution analysis of phosphorus in sediments from Honghu Wetland, it was found that TP content in sediments at the mouth of Honghu Lake was 781.31-1955.84 mg·kg and the average value was(1287.21±437.28)mg·kg. TP content in sediments in the open water area was 438.33-1554.04 mg·kg, with an average value of(718.10±238.15)mg·kg. The TP content of sediments in lake inlet was significantly higher than that of sediments in the open water area(<0.05), and that in the enclosed aquaculture was higher than in the open water area, although no significant difference was observed (>0.05). The TP content of sediments to the northwest and northeast of Honghu Lake was higher than that to the southwest of Honghu Lake, and the TP content of sediments in The Four-lake main canal was significantly higher than that of Luoshan main canal(<0.05). The phosphorus input in the Four-lake main canal may be the main source of phosphorus in Honghu Lake sediments. The phosphorus fraction composition in sediments from different sampling sites were significantly different. Fe/Al-P and Ca-P were the main forms of phosphorus in sediments from the lake inlet, while OP and Ca-P were the main forms of phosphorus in sediments from the open water area. The variation in spatial phosphorus form composition was related to the influence of human activity and the distribution of aquatic plants. Fe/Al-P and OP contents were used to estimate the content of biological available phosphorus (BAP) in evaluated sediments, and the proportion of BAP in TP was used to estimate the risk of phosphorus release in Honghu sediments. BAP/TP was 39.8%-69%, with an average of(56.5±7.23)%, indicating a high risk of phosphorus release. OP and BAP were significantly correlated with TP in overlying water(<0.01), and the correlation between BAP and phosphate in the overlying water was the highest. The results showed that phosphorus concentration in the overlying water may be related to the release of Fe/Al-P and OP into water bodies.
根据对洪湖湿地沉积物中磷的空间分布分析，发现洪湖湖口沉积物中总磷（TP）含量为781.31 - 1955.84mg·kg，平均值为（1287.21±437.28）mg·kg。开阔水域沉积物中TP含量为438.33 - 1554.04mg·kg，平均值为（718.10±238.15）mg·kg。湖泊进水口沉积物的TP含量显著高于开阔水域沉积物（<0.05），围隔养殖区沉积物的TP含量高于开阔水域，但差异不显著（>0.05）。洪湖西北和东北方向沉积物的TP含量高于西南方向，四湖总干渠沉积物的TP含量显著高于螺山干渠（<0.05）。四湖总干渠的磷输入可能是洪湖沉积物中磷的主要来源。不同采样点沉积物中磷的形态组成差异显著。湖泊进水口沉积物中磷的主要形态为铁/铝结合态磷（Fe/Al-P）和钙结合态磷（Ca-P），而开阔水域沉积物中磷的主要形态为有机磷（OP）和Ca-P。磷形态组成的空间变化与人类活动影响及水生植物分布有关。采用Fe/Al-P和OP含量估算评价沉积物中生物有效磷（BAP）含量，用BAP占TP的比例估算洪湖沉积物中磷释放风险。BAP/TP为39.8% - 69%，平均为（56.5±7.23）%，表明磷释放风险较高。OP和BAP与上覆水中TP显著相关（<0.01），且BAP与上覆水中磷酸盐的相关性最高。结果表明，上覆水中磷浓度可能与Fe/Al-P和OP向水体中的释放有关。
