九龙江口沉积物砷含量的分布特征及与环境因子的相关性

采集九龙江河口表层和柱状沉积物样品,对表层沉积物中总砷、不同形态砷和其他重金属元素、有机质含量以及粒径等参数进行测定.分析了柱状沉积物中总砷和各形态砷的含量,结合沉积速率和响应因子,探讨总砷的污染累计特征.结果表明：（1）沉积物中检出的形态砷是As3＋和As5＋,未检出有机砷.（2）表层沉积物中总砷含量范围为10.03～11.29μg/g,河端总砷含量为11.28μg/g,高于海端总砷含量10.42μg/g.As3＋的含量范围为0.84～1.08μg/g,As5＋的含量范围为6.87～8.99μg/g；As5＋含量表现为河端（8.63μg/g）高于海端（7.31μg/g）,As3＋则不明显.（3）有机质含量是影响本区域表层沉积物中砷及其他重金属含量分布的重要因素,粒径与砷及其他重金属显著相关性不强,影响较小.（4）柱状沉积物中总砷含量范围为9.15～13.61μg/g,随深度的变化不明显,人为污染程度较轻.（5）柱状沉积物中As3＋含量介于2.45～5.35μg/g之间,As5＋含量范围为5.58～11.77μg/g,二者含量随深度的增加而降低.

Arsenic distribution and correlation with environmental factors in sediments of Jiulongjiang Estuary

A study was carried out to investigate the levels and distributions of total arsenic and arsenic species in surface sediments and core sediments collected from 6 sampling stations located in Jiulongjiang Estuary. Heavy metals,organic matter,particle size and other parameters were determined. Combining the deposition rate with the response factor,the cumulative characteristics of total arsenic were studied. Results show that（1）the detected arsenic species of sediment were As3 ＋and As5 ＋. And organic arsenic were not detected.（2）Concentration of total arsenic were in range of 10. 03 ～11. 29 μg / g,As3 ＋ concentration 0. 84 ～1. 08 μg / g and As5 ＋concentration 6. 87 ～8. 99 μg / g. Total arsenic and As5 ＋concentration in river side（11.28,8.63 μg/g） was higher than that of seaward（10.42,7.31 μg/g）.（3）Correlation analysis found that organic matter content was the main impact factor on arsenic and other heavy metal concentrations in this area,and particle size had little effect.（4）Total arsenic concentrations were in range of 9. 15 ～13. 61 μg / g in the core sediment suggested slight anthropogenic pollution. The trend between total arsenic concentration and increasing depth were not obvious.（5）Concentrations range 2. 45 ～5. 35 μg / g for As3 ＋and 5. 58 ～11. 77 μg / g for As5 ＋. As3 ＋and As5 ＋concentration decreased with depth.