【Objective】With farmland soil around three typical types of industrial enterprises(electroplating
industry, printing and dyeing textile industry and minmetals rare earth industry)in Guangzhou suburb as the research
object, the heavy metal pollution and potential ecological risk degree were evaluated and the causes were analyzed
with a view to provide a reference basis for heavy metal pollution prevention and remediation of farmland soil around industrial enterprises in Guangzhou.【Method】A total of 39 soil samples were collected from farmland around the industrial
enterprises. The pollution load index method was used to analyze the pollution degrees of heavy metals in the soil, and the
potential ecological risk index method was used to evaluate the potential ecological risk degrees of heavy metals in the
soil.【Result】The heavy metal content in the farmland soil around the electroplating industry and printing and dyeing
textile industry was relatively high, and the comprehensive heavy metal load level was slightly polluted. Cd and Hg in the
surrounding soils of different types had greater potential ecological risks, while other heavy metals(As, Pb, Cr, Cu, Zn,
Ni)had lower ecological risks. Cd had the highest potential ecological risk, with the average risk coefficient ranging from
48.2 to 61.24. Hg had the second highest potential ecological risk, with the average risk coefficient ranging from 25.46 to
59.42. The potential ecological risk coefficient of Zn was the lowest, with the average value ranging from 1.13 to 2.73. The
of potential ecological risks degree of heavy metals(from strong to weak)were showed as: Cd > Hg > As > Cu > Ni
> Pb > Cr > Zn. The soil conditions of the farmlands around the three industrial enterprises were in slight ecological risk
and medium ecological risk, and the comprehensive potential ecological risk degree ranked as: electroplating industry >
rare earth industry > printing and dyeing textile industry.【Conclusion】Heavy metal pollutants from industrial activities
will enter the soil through dry and wet deposition, sewage irrigation, waste leaching and dust, which are important sources
of farmland heavy metal pollution. In order to restrain the transformation of farmland soil to more serious risks, improve the
quality of farmland soil environment, and ensure the safety of farmland soil environment, effective measures should be taken
to strengthen the monitoring of farmland soil environment around industrial enterprises and pollution risk control, especially
to strengthen the soil Cd and Hg pollution control. |