佛山陶瓷工业区土壤重金属含量及生态风险评价

以佛山市禅城区、南海区、高明区及三水区的陶瓷工业厂区土壤为研究对象,分析厂区周边500 m内表层土壤(0～20 cm)的Cd、Cr、Pb、Cu、Ni、Zn等6种重金属含量,并采用单因子污染指数(Pi)法、内梅罗指数(PN)法、潜在生态危害指数(R I)法对土壤重金属进行污染和潜在生态危害评价.结果显示,高明区的6种重金属含量均未超过珠江三角洲土壤背景值,禅城区、南海区与三水区的Cd超过背景值的倍数最大,均超过背景值的4倍以上,但4个区的重金属含量均未超过工业用地标准.4个区的综合污染等级均属于安全等级,其中高明区的PN最小,南海区的PN最大,分别为0.07和0.34.多种重金属的潜在生态危害评价结果显示,禅城区与高明区为低风险,南海区与三水区为中等风险,C d的潜在风险系数Ei最高.研究表明,佛山市陶瓷工业区土壤重金属含量在工业用地标准中是合格的,但已存在潜在生态危害风险,在今后的生产和土地再利用时要做好重金属污染防治工作,需要重点关注对土壤Cd污染的防治.

Contents and Ecology Risk Assessments of Heavy Metals in Foshan Ceramics Industry Area

The heavy metal (Cd, Cr, Pb, Cu, Ni and Zn) contents in the surface soil(0-20 cm) within 500m of the ceramic industrial plants in Chancheng District, Nanhai District, Gaoming District and Sanshui District of Foshan City was?measured. Single pollution index Pi, Nemerow index PN and Hakanson potential ecological risk index RI were used to comprehensively evaluate the heavy metal pollution. The six heavy metals in Gaoming District were all below background value?of the Pearl River Delta. The Cd content in Chancheng District, Nanhai District and Sanshui Districtexceeded the background value by 4 times. But the heavy metals in the four districts did not exceed the standard of industrial land. The pollution levels of the four districts were safe, the PN value of?Gaoming District were lowest while the PN value of?Nanhai District were highest, which is 0.07 and 0.34. The potential ecological risk assessment results of multiple heavy metals were moderate risk and the potential ecological risk coefficient of?single heavy metal of Cd was the highest. The heavy metals in Foshan ceramics?industry area within the standard range of industrial land,?but there is potential ecological risk. It is still necessary to do a good job in the prevention of heavy metal pollution of industrial production and the reuse of contaminated land in the future, and should be paid more attention to the Cd pollution.