SOIL HEAVY METAL CONTAMINATION AND PRACTICAL APPROACHES TO REMEDIATION IN SOME PARTS OF CHINA

摘要

This paper mainly deals with the current status of soil contamination with heavy metals, sources of pollutants, and some practical approaches to reduce metal contents in the food chain and soil remediation accepted by Chinese farmers. For the whole country, soil contamination is not an important issue but in some individual sites, e.g., mining, industrial sites, or areas with wastewater irrigation, heavily contaminated soils have been found. The metals are usually from untreated wastewater irrigation, sewage sludge, industrial or domestic waste disposal, or metal-containing agrochemical application in agriculture, e.g. Cd-abundant phosphates, besides atmospheric deposition of metal dusts in the vicinity of industrial areas. In regards to soil remediation for such a country with a large population as in China, keeping high output or production of enough food from agriculture is still a bottleneck-like problem. To prevent food contamination from polluted soil, a series of practical approaches has been developed. Among them, non-edible crop growth, exploiting as breeding sites, choosing tolerant crops, etc. have showed a wide acceptability and benefit to farmers before a more hopeful approach, e.g., phytoremediation is put into practice.