近5a北部湾防城港近岸海水重金属的含量分布特征及影响因素  

Distribution Characteristics and Influencing Factors of Heavy Metals' Contents in Nearshore Seawater of Fangchenggang in Beibu Gulf in Recent 5 Years

作　　者：何祥英 

机构地区：[1]防城港市海洋环境监测预报中心,广西防城港538001

出　　处：《安徽农业科学》2014年第23期7956-7959,7978,共5页Journal of Anhui Agricultural Sciences

基　　金：广西科技厅攻关科研项目(桂科攻089504-4);广西近岸海洋环境趋势性监测项目(2009~2013)

摘　　要：根据2009～2013年夏季北部湾防城港近岸海域环境调查资料，分析讨论了该海域海水中7种重金属的含量分布特征、年际变化趋势及影响因素，，结果表明：防城港近岸海水近5a的cu、cr、cd、Ph、As、Hg、zn的平均浓度分别为2．73、1．08、0．137、1．25、1．43、0．042、21．8μg/L，，其中Hg、cu、cr、Cd、As符合一类海水水质标准，Zn、pb属二类海水水质标准范围且接近二类标准下限。近5a各站位重金属综合污染指数绝大部分在0．4～0．7范围区间，重金属综合污染程度较低，总体属清洁水平；在年际变化方面，zn呈现小幅度逐年下降趋势，Hg呈起伏线性上升趋势，cu、cr、ctl、Pll、As除2010年出现高浓度值外，其他年份变化不大；在水平分布方面，cu、cd呈东南高西北低的分布特点，，Zn、Cr呈现从远岸向近岸湾内梯度递减的趋势，Ph、Hg、As呈现近岸湾内高至远岸湾外低的分布特点，，分析控制防城港近岸重金属分布的因素主要有陆源输入影响、海水盐度影响、沉积物释放影响和本底环境影响等4个方面，研究发现防城港近岸海水zn、Pb、hg的本底污染值较高．．Based on the summer of 2009 -2013 environmental data of Fangeheng port in Beibu Gulf coastal water, distribution charaeteris- ties, annual trends and influencing factors of 7 heavy metals were investigated. The results showed that the average concentration of Cu, Cr, Cd, Pb, As, Hg, Zn of Fangehenggang coastal waters was 2.73, 1.08, 0. 137, 1.25, I. 43, 0. 042, 21.8μg/L respectively in nearly 5a. Hg, Cu, cr, Cd and As were up to the first class of marine water quality standards, Zn and Pb met the second class standard of waler quality and they were close to lower limit. The heavy metal pollution index of most stathms was in the 0.4 -0.7 spectrum and integrated polhJtion as- sessment Of heavy metals were in line with clean level. In terms of interannual variability, small amplitude decrease in Zn, and I Ig inereased r＋~lling linear, Cu, Cr, Cd and pb appeared high concentration value in 2010 but little changes in other years. The contents of cu and Cd were higher in Northwest and lower in Southeast, Zn and Cr presented gradient descending trend from offshore to inshore, while distribution trends of Pb, Hg and As were just contrary. Terrestrial input, seawater salinity, sediment re＋lease and background envinmment are main control fac- tors of distribution of heavy metals in the nearshore in Fangehenggang, the study found that background pollution values of Zn, Pb and Hg are high in nearshore water of Fangcheng port.

关 键 词：重金属 分布特征 年际变化 海水 影响因素 防城港 

分 类 号：S181.3[农业科学—农业基础科学]