摘要
研究了东寨港红树林湿地潮间带沉积物中汞(Hg)、砷(As)的化学形态组成、垂直分布及理化性质对其形态转化的影响。结果表明:分别有80%和25%的沉积物样品中Hg和As超过背景值;YF采样点沉积物中Hg和As相对较高,XB采样点沉积物样品中Hg和As相对较低。Hg和As随深度的增加总体呈降低趋势。沉积物中Hg形态累积质量分数大致为:残渣态>可氧化态>可还原态>酸溶态,As主要以残渣态存在。沉积物中Hg污染指数和迁移系数远大于As,受人类活动影响较大。YF采样点沉积物中Hg和As污染指数和迁移系数较其他采样点高,环境风险相对较大。不同采样点Hg和As形态与理化性质相关程度不同,无污染或轻度污染采样点沉积物中两种元素在一定程度上受沉积物pH、有机质及盐度影响,污染相对较重的YF采样点沉积物中Hg、As形态与沉积物pH、有机质及盐度的相关性较弱。
Chemical fraction and vertical distribution of Hg and As in sediments of mangrove wetlands in Dong- zhai Harbor and the influence of physical-chemical properties on chemical forms changing were investigated. The Hg in 80% samples and As in 25% samples were exceed natural background values. The Hg and As in sediments at YF were higher and at XB were lower relatively. The content of Hg and As in sediments was decreased with the depth generally. Hg fractionation in sediments presented a sequence of residual 〉 oxidizable 〉reducible 〉 acid soluble fraction. As was mainly present as residual form. The pollution index and migration coefficient of Hg was much larger than As showed greatly affected by the human activities. The pollution index and migration coefficient of Hg and As in sediments at YF were significantly higher than other point showed a potential environmental risks. The species of two metals from different sampling points were affected at different levels by sediments properties, the two metals in sediments from unpolluted and light polluted sampling points partly affected by pH,organic matter and salinity, but two metals in sediments with relatively serious pollution from YF was weakly related with pH,organic matter and sa- linity.
出处
《环境污染与防治》
CAS
CSCD
北大核心
2016年第7期15-24,共10页
Environmental Pollution & Control
基金
国家自然科学基金资助项目(No.81560347)
海南医学院科研培育基金资助项目(No.HY2015-07)
国家大学生创新性项目(No.201411810050)
关键词
东寨港
沉积物
汞
砷
化学形态
垂直分布
Dongzhai Harbor
sediments
Hg
As
chemical fraction
vertical distribution
