Acidification, heavy metal mobility and nutrient accumulation in the soil-plant system of a revegetated acid mine wasteland

Chemosphere. 2010 Aug;80(8):852-9. doi: 10.1016/j.chemosphere.2010.05.055. Epub 2010 Jun 30.

Abstract

A revegetation program was established at an extreme acidic and metal-toxic pyrite/copper mine wasteland in Guangdong Province, PR China using a combination of four native grass species and one non-native woody species. It was continued and monitored for 2 y. The emphasis was on acidification, metal mobility and nutrient accumulation in the soil-plant system. Our results showed the following: (i) the acid-forming potential of the mine soils decreased steadily with time, which might be due to plant root-induced changes inhibiting the oxidization of sulphide minerals; (ii) heavy metal extractability (diethylene-triamine-pentaacetic acid-extractable Pb and Zn) in the soils increased with time despite an increase in soil pH, which might be attributed to soil disturbance and plant rhizospheric processes, as well as a consequence of the enhanced metal accumulation in plants over time; and (iii) the vegetation cover increased rapidly with time, and plant development accelerated the accumulation of major nutrients (organic matter, total and ammonium-N, and available P and K). The 2-y field experiment demonstrates that direct seeding/planting of native plant species in combination with lime and manure amelioration is a practical approach to the initial establishment of a self-sustaining vegetation cover on this metalliferous and sulphide-bearing mine wasteland. However, heavy metal accumulation in the soil-plant system should be of great concern, and long-term monitoring of ecological risk must be an integral part of such a restoration scheme.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acids / chemistry*
  • Biodegradation, Environmental
  • Carbon / analysis
  • Carbon / chemistry
  • Environmental Restoration and Remediation / methods*
  • Kinetics
  • Metals, Heavy / analysis*
  • Metals, Heavy / chemistry
  • Mining
  • Phosphorus / analysis
  • Phosphorus / chemistry
  • Plant Development
  • Plants / chemistry*
  • Potassium / analysis
  • Potassium / chemistry
  • Quaternary Ammonium Compounds / analysis
  • Quaternary Ammonium Compounds / chemistry
  • Soil Pollutants / analysis*
  • Soil Pollutants / chemistry

Substances

  • Acids
  • Metals, Heavy
  • Quaternary Ammonium Compounds
  • Soil Pollutants
  • Phosphorus
  • Carbon
  • Potassium