研究报告
宋媛媛,冯慕华,苏争光,潘继征,李文朝.抚仙湖不同来源沉积物磷形态垂向分布特征[J].环境科学学报,2013,33(9):2579-2589
抚仙湖不同来源沉积物磷形态垂向分布特征
- Vertical distribution of chemical speciation of phosphorus in sediments from different sources of Fuxian Lake
- 基金项目:国家自然科学基金(No.41171366)
- 宋媛媛
- 1. 湖泊与环境国家重点实验室, 中国科学院南京地理与湖泊研究所, 南京 210008;
2. 中国科学院大学, 北京 100049
- 冯慕华
- 湖泊与环境国家重点实验室, 中国科学院南京地理与湖泊研究所, 南京 210008
- 潘继征
- 湖泊与环境国家重点实验室, 中国科学院南京地理与湖泊研究所, 南京 210008
- 李文朝
- 湖泊与环境国家重点实验室, 中国科学院南京地理与湖泊研究所, 南京 210008
- 摘要:采用连续萃取法(SEDEX)对抚仙湖岸带代表不同污染来源的5个样点和湖心沉积物中磷形态的分布特征及垂向变化特征进行分析.结果表明,沉积物中无机磷(IP)是总磷(TP)的主要组成部分,占TP的70.46%±8.06%;磷形态以碎屑磷灰石(CAP)和闭蓄态磷(Org-P)为主,分别占TP的41.65%±17.04%和29.53%±8.06%,而可交换态磷(Ex-P)含量最低,仅占TP的2.42%±1.45%.不同点位TP含量和各形态磷分布特征不同,以磷矿开采污染为主的东大河口沉积物总磷含量及各形态磷含量远高于其它污染来源的沉积物,其中CAP含量达(131.46±84.78)μmol·g-1.沉积物磷形态垂向特征表征了流域人类活动对抚仙湖的污染历程.东大河口沉积物各形态磷含量随深度变化剧烈,尤其是CAP在8~14 cm随深度增加突然增大后又急剧降低,且均在11 cm处达最大值,这与抚仙湖流域磷矿开采兴起到矿点关闭的历史相吻合.湖心沉积物磷形态分布特征显示了湖岸各种污染来源"汇"的特点.
- Abstract:A sequential extraction method (SEDEX) was utilized to analysis the distribution and vertical variations of phosphorus fractions of sediments collected from Lake Center and other five sampling sites with different pollution sources in Fuxian Lake. The results showed that inorganic phosphorus (IP) was the major component of total phosphorus (TP), accounting for 70.46%±8.06% of TP. Among the five pools, detrital apatite (CAP) and refractory organic phosphorus (Org-P) represented the largest and second largest fractions of TP, which accounted for 41.65%±17.04% and 29.53%±8.06% of TP, respectively. Exchangeable phosphorus (Ex-P) was the lowest fractions of TP with 2.42%±1.45%. The concentrations of TP and phosphorus fractions in the sediments varied with sampling sites. The largest contents of TP and phosphorus fractions were found in the sediment of Dongdahe River Mouth, a site contaminated by phosphorus mining activity in the watershed, with the maximum content of CAP of (131.46±84.78)μmol·g-1. The vertical variations of sediments phosphorus indicated the impacts by human activities. The vertical distribution of phosphorus fractions in the sediment of Dongdahe River Mouth varied significantly, especially the contents of CAP increasing suddenly and then decreasing sharply between 8 cm and 14 cm, with the maximum value at the 11 cm depth. This coincided with the period of rise and decline of phosphate mining activity in the watershed. The distribution of phosphorus fractions in the sediment of Lake Center reflected the sink of different pollutants draining by the rivers.
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