Meng Chun-Hong, Zhao Bing
College of Resources and Environmental Sciences, Wuhan University, Wuhan 430072, China.
Huan Jing Ke Xue. 2008 Jul;29(7):1831-7.
Donghu Lake is a typical urban shallow lake. Miaohu Lake was analyzed in Southwest of Donghu Lake. Characteristics of nitrogen and phosphorus in sediment cores were analyzed and assessed with investigation and chemical analysis in laboratory in 2004. Vertical distributions and seasonal changes of nitrogen and phosphorus chemical species in the sediments of two sampling sites were examined and analyzed. The results showed that concentration of TN decreased with the increase of sediment depth and the concentration of the mean TN was 1.62-3.17 g/kg. The concentration of TN reached its minimum in spring, and began to increase in summer. The concentration of TN reached its maximum till autumn and winter. Dissolved ammoniac nitrogen (DAN) was controlled by both the content of TN and the sediment environment, so the vertical profiles and seasonal changes of DAN presented the same trend as those of TN. The lowest concentration of DAN was 117.66 mg/kg in spring, and the highest concentration of DAN was 216.20 mg/kg in summer and autumn. It was decreasing in winter. Vertical profiles of phosphorus species showed that total phosphorus (TN), labile phosphorus (LP), Al- and Fe- bound phosphorus (Al-P, Fe-P) were characterized by a similar distribution pattern and enrichment in the upper 0-10cm sediment layers. The concentration decreased steeply within 10cm sediment layers, then it became steady. The concentration of TP, LP, Fe-P and Al-P was 0.255-3.36 g/kg, 0.192-11.00 mg/kg, 13.47-1 379.94 mg/kg and 7.77-317.64 mg/kg, respectively. The results indicate that sources of pollution which cause water body in the lake eutrophication have the extraneous source and the internal one. After the extraneous sources are truncated, nutrient salt in sediments still possibly causes the lake to be at the eutrophication condition. Phosphorus is the most restricting nutritious element in Donghu Lake. The proportion of Fe-P is the biggest in spring and its proportion is 44.30%. These show that pollution is serious in Miaohu Lake.
东湖是典型的城市浅水湖泊。对东湖西南部的庙湖进行了分析。2004年通过实地调查和实验室化学分析，对沉积物岩芯中的氮磷特征进行了分析和评估。研究了两个采样点沉积物中氮磷化学形态的垂直分布和季节变化。结果表明，总氮（TN）浓度随沉积物深度增加而降低，平均TN浓度为1.62 - 3.17 g/kg。TN浓度在春季达到最低，夏季开始升高，直至秋冬达到最高。溶解态氨氮（DAN）受TN含量和沉积物环境共同控制，其垂直分布和季节变化趋势与TN相同。春季DAN最低浓度为117.66 mg/kg，夏秋最高浓度为216.20 mg/kg，冬季呈下降趋势。磷形态的垂直分布表明，总磷（TP）、活性磷（LP）、铝铁结合态磷（Al-P、Fe-P）在沉积物0 - 10cm上层具有相似的分布模式和富集特征。在10cm沉积物层内浓度急剧下降，之后趋于稳定。TP、LP、Fe-P和Al-P的浓度分别为0.255 - 3.36 g/kg、0.192 - 11.00 mg/kg、13.47 - 1379.94 mg/kg和7.77 - 317.64 mg/kg。结果表明，导致湖泊水体富营养化的污染源有外源和内源。截断外源后，沉积物中的营养盐仍可能使湖泊处于富营养化状态。磷是东湖最具限制性的营养元素。春季Fe-P的比例最大，为44.30%。这些表明庙湖污染严重。
