广州车陂涌底泥重金属污染及生态风险评价

合理处置重金属污染超标的底泥,是河道清淤工程的重点。以车陂涌清淤工程为例,通过原位测试、化学检验等,掌握河道清淤段不同位置底泥的污染特征。采用潜在生态危害指数法进行底泥污染潜在生态风险评价,得出河涌底泥低风险占31.71%、中等风险占29.27%、较高风险占2.44%、极高风险占36.59%,说明大多底泥需要处理。采用内梅罗综合污染指数法来评价底泥作为农用地土壤的适宜性,73.2%样点属于清洁,尚清洁、轻微污染各占9.8%,中度及严重污染共占7.2%,说明大部分底泥可用于农田。最后提出了该清淤工程应注意的问题,为车陂涌水环境治理提供科学依据。

Pollution characteristics and ecological risk assessment of heavy metals in sediments of Chebeichong River in Guangzhou City

Properly disposing the sediment with exceeded heavy metal pollution is the focus of channel dredging. Taking Chebeichong channel dredging project as an example, the pollution characteristics of sediment at different positions in the dredging section were analyzed by in-situ and chemical testing. The potential ecological risk assessment of sediment pollution was analyzed by potential ecological risk index method. The results showed that the low risks accounted for 31.71%, the medium risks accounted for 29.27%, the high risks accounted for 2.44%, and the extremely high risks accounted for 36.59%, indicating that most of the sediment had to be treated. Nemerow comprehensive pollution index method was used to evaluate the suitability of sediment as soil for agricultural land. 73.2% of sample points were clean, 9.8% were clean, 9.8% were slightly polluted, and 7.2% were moderately and severely polluted, indicating that most sediment could be used as farmland soil. Finally, issues that should be noted were raised to provide scientific basis for the water environment management of Chebeichong River.