Remediation of heavy metal contaminated soils by dissolved organic matter

Dissolved organic matter (DOM) isolated from soils enriched in fulvic acid (FA) or from processed organic wastes rich in low-molecular-weight-organic-acids (LMWOAs) was tested as extractant of heavy metals (HMs) from contaminated soils. The test showed that DOM can be as effective as the environmentally problematic, synthetic aminopolycarboxylic acids such as EDTA and NTA. Therefore, DOM is suggested as a possible chelant in remediation of contaminated soils by chelant-enhanced phytoextraction and soil washing. However, the efficiency of DOM as chelant depends on numerous factors, e.g., pH, the soil and DOM compositions and extraction time, which need further studies before DOM can be recommended for practical use in the field.