城市污染河道沉积物AVS与重金属生物毒性研究

Acid Volatile Sulfide and Heavy Metals Biotoxicity in a Municipal Polluted River

采集珠江三角洲典型城市污染河道佛山水道表层沉积物和上覆水样品,测定了沉积物AVS,Eh,SEMPb,SEMCd,SEMCu,SEMZn,SEMNi,SEMCr,及上覆水Eh,DO.同步进行了底栖动物调查,结合调查结果分析了城市污染河道沉积物AVS与重金属生物毒性的关系.主要研究SEM-AVS判据在判断城市重污染河道重金属生物有效性方面的作用.所测AVS最大值为69.579μmol/g,最小值为0.339μmol/g,均值为20.283μmol/g;各采样站位∑SEM5(SEMPb,SEMCd,SEMCu,SEMZn,SEMNi之和)最大值为23.067μmol/g,最小值为1.062μmol/g;底栖动物种类和数量均较少,且基本为耐污种,优势种为水丝蚓.13个采样站位中,∑SEM5-AVS<0的有9个,MDS分析结果显示:这9个站位中的7个底栖动物群落结构相似程度高.这表明重污染河道沉积物重金属的生物毒性与SEM-AVS的值关系密切,SEM-AVS判据在判断重污染区域重金属的生物毒性方面具有较大作用;同时说明重污染河流重金属生物毒性比较复杂,不能完全由SEM-AVS解释.

The surface layer of sediment and overlying water samples of Foshan Waterway, a typical municipal polluted river in Pearl River Delta, have been sampled and analyzed. The analytical items of sediment and overlying water include AVS,Eh,SEMPb,SEMCd,SEMCu,SEMZn,SEMNi,SEMCr and Eh, DO, respectively. The benthic macroinvertebrate investigation has been done at the same time in the same place. Combing the results above, the relationship between AVS and heavy metals biotoxicity in Foshan waterway has been discussed. The main object is to examine if the SEM-AVS criterion is valid in judging the biotoxicity of heavy metals in the heavily polluted river. The range of AVS is from 0.339 μmol/g to 69.579 μmol/g, with the average of 20.283 μmol/g. The maximum μSEM5 （Sum of SEMPb, SEMCd, SEMCu, SEMZn, SEMNNi ） is 23.067 μmol/g, while the minimum is 1.062 μmol/g. Both the species and quantity of benthic macroinvertebrate are little, and most of them belong to pollution bearable species, with Limnodrilus sp. as dominative species. There are 9 sampling stations where the ∑SEM5-AVS are below zero, and the analytical results of Non-matric multi-dimentional scaling（MDS） indicate the benthic community structure of 7 sampling stations among them are similar. It means that the heavy metals biotoxicity in the heavily polluted river has close relationship with the value of SEM-AVS. It also proves that heavy metals biotoxicity in sediment is complicated, which can＇t be explained by SEM-AVS completely.