| 云南阳宗海砷的分布与来源 |
| 摘要点击 2515 全文点击 1688 投稿时间：2012-01-19 修订日期：2012-04-11 |
| 查看HTML全文
查看全文 查看/发表评论 下载PDF阅读器 |
| 中文关键词 砷 形态 分布特征 人为贡献 阳宗海 |
| 英文关键词 arsenic speciation distribution characteristics anthropogenic contribution Yangzonghai Lake |
|
| 中文摘要 |
| 通过采集阳宗海水体、沉积物样品并测定砷的总量及形态组成,分析了水体、沉积物中砷的空间分布,评价了砷的污染现状,计算了人为贡献率与湖中砷的储存量,并调查了砷的来源. 结果表明,2010年4月阳宗海水体中总砷含量介于71.96~101.2 μg·L-1,且随着水深的增加而略有升高. 溶解态砷在68.14~96.72 μg·L-1之间,其中As(Ⅲ)占32%. 水中砷的健康危害风险度在4.77×10-4~6.66×10-4 a-1的范围内,对周围环境产生严重威胁. 沉积物中砷含量介于6.05~396.49 mg·kg-1. 0~2、2~4、4~6、6~8及8~10 cm沉积物中砷的平均含量依次为155.66、52.01、29.78、19.22、17.52 mg·kg-1. 表层0~2 cm沉积物砷的累积程度最高,地累积指数最高达5级. 随着深度增加,砷的累积程度显著降低. 沉积物中砷的各种形态的平均含量由高到低依次为残渣态、腐殖酸结合态、铁锰氧化态、强有机结合态、离子交换态、水溶态、碳酸盐结合态. 随着深度增加,砷的生物可利用态比重逐渐减小,残渣态的比重明显增大. 表层0~2 cm沉积物砷的人为贡献率最大,平均为81.94%. 随深度增加,人为贡献率显著降低. 目前,阳宗海水体与沉积物中的砷储存总量为70.65 t,人为贡献量占砷总储存量的82.68%,这其中主要来自南岸的磷肥厂. 同时,东岸的高尔夫球场及北岸的火电厂、温泉也对阳宗海砷的累积有所贡献. |
| 英文摘要 |
| By collecting water and sediment samples from Yangzonghai Lake and analyzing the total amount and speciation of arsenic, the spatial distribution of arsenic in surface water and sediments was analyzed, the current status of arsenic pollution were estimated, the anthropogenic contribution rate and the arsenic reserve in the lake were calculated respectively. Meanwhile, the sources of arsenic were investigated. The results indicated that the total arsenic content in Yangzonghai Lake was 71.96-101.2 μg·L-1 in April, 2010, and increased slightly with depth. Dissolved arsenic content was 68.14-96.72 μg·L-1, with As(Ⅲ) accounting for 32%. The health risk level of arsenic in the water was 4.77×10-4-6.66×10-4 a-1, posing a considerable threat to the surrounding environment. Arsenic content in sediments lied between 6.05-396.49 mg·kg-1. In sediments at the depths of 0-2, 2-4, 4-6, 6-8 and 8-10 cm, the average arsenic contents were 155.66, 52.01, 29.78, 19.22 and 17.52 mg·kg-1 respectively. Arsenic in sediments at 0-2 cm had the highest accumulation degree, with the maximum geoaccumulation index up to 5. At the deeper depths, the accumulation degree of arsenic significantly lowered. The sequence of arsenic average contents of seven forms in sediments in the descending order is residual fraction, humic acids fraction, oxide fraction, strong organic fraction, ion exchange fraction, water soluble fraction and carbonate fraction. With increase of sediments depths, the percentage of bioavailable arsenic decreased, and the percentage of residual fraction arsenic increased rapidly. The anthropogenic contribution rate of arsenic in sediments was the highest at 0-2 cm depth, with average of 81.94%. This rate was much lower at the deeper depths. Currently, the total arsenic reserve in water and sediments of Yangzonghai Lake was 70.65 t, of which 82.68% was contributed by human activities. The phosphate fertilizer plant on the south bank made the greatest contribution to arsenic accumulation in Yangzonghai Lake, followed by golf course on the east bank, thermal power station and hot spring on the north bank. |
|
|
|
