污染沉积物AVS对水丝蚓体内重金属积累的影响

The influence of AVS in contaminated sediments on heavy metal bioaccumulation in Limnodrilus sp.

对珠江三角洲一条典型城市污染河流中11个采样站位沉积物、上覆水和底栖动物样本进行了分析,测定了寡毛纲颤蚓科底栖动物水丝蚓(Limnodrilus sp.)体内的Pb、Zn、Cu、Ni、Cd含量及沉积物酸挥发性硫化物(Acid Volatile Sulfide,AVS),以及同步提取金属(SimultaneousExtracted Metals,SEM)、有机碳(OC)等环境指标,分析了生物指标与环境指标之间的关系,主要目的是探讨重污染区域沉积物AVS对水丝蚓体内重金属积累的影响.所测28个样品水丝蚓体内重金属含量BIOPb、BIOZn、BIOCu、BIONi、BIOCd的均值分别为0.108、3.087、1.106、0.250、0.016μmol.g-1.Pearson相关分析结果表明,水丝蚓体内重金属积累(∑BIO5)与沉积物重金属含量(∑SEM5)显著相关(r=0.795,p<0.01).当SEM大于AVS时,大部分站位水丝蚓体内重金属较高,但当SEM小于AVS时,水丝蚓体内重金属含量也不低(均值为4.074μmol.g-1).∑BIO5与(∑SEM5-AVS)无相关性,与(∑SEM5-AVS)/fOC的相关系数为0.725(p<0.05),表明OC也是重金属生物积累的重要影响因子,将其作为SEM-AVS判据的一部分,有利于提高预测效果.

The main purpose of this study is to explore the relationship between AVS （Acid Volatile Sulfide） and bioaccumulation of heavy metals in heavily polluted areas. Sediment, overlying water, and benthic invertebrate samples from 11 sampling stations of a typical municipal polluted river in the Pearl River Delta were gathered and analysed. The concentration of Pb, Zn, Cu, Ni and Cd in Limnodrilus sp. and environmental indicators such as AVS, SEM （Sinmltaneous Extracted Metals） , and OC etc. were monitored, and the relationships between the biological indicators and the environmental indicators are discussed. The mean values of BIOpb, BIOZn, BIOCu, BIONi and BIOCd were 0. 108, 3. 087, 1. 106, 0. 250 and 0. 016 umol · g^-1 respectively. Pearson correlation analysis revealed significant correlation between ∑ BIO5 and ∑ SEM5 （ r = 0. 795, p 〈 0.01 ）. ∑ BIO5 of Limnodrilus sp was high in most of the sampling stations where SEN 〉 AVS, however ∑ BIOs is not low （4. 074 umol· g ^-1 ） in the sampling stations where SEM 〈 AVS BIO5 and （∑ SEM5-AVS） have no significant correlation, whereas the coefficient between ∑ BIO5 and （ ∑ SEM5-AVS）/foc is 0. 725 （p 〈 0.05 ） which indicates OC is also an important factor affecting bioaccumulation and can help to improve the accuracy of SEM-AVS predictions.