The Removal of Heavy Metals by Low Molecular Organic Acids (LMWOAs) from Contaminated Soils and Key Influencing Factors: A Literature Review

Abstract

With the widespread consensus on the sustainable development of economy and society, the environmental issues of heavy metal pollution in soils have received considerable attention. Confronted with these issues, soil washing has been widely studied, due to its advantages of simple operation, wide application, high efficiency and low costs. However, reducing the secondary contamination of the washing agents and selecting the best washing agents have been a barrier to the development of washing technology. Based on this background, this study comprehensively investigated the concentration levels of heavy metals in different types of contaminated sites, analyzed the current research status in this field, and pointed out the urgency and challenge of soil remediation for heavy metal pollution. Meanwhile, the advantages and disadvantages of different remediation techniques and their application case studies for heavy metal contaminated soils were summarized. In addition, the washing effects of different types of low molecular weight organic acids on heavy metal pollutants in soils and their key influencing factors were also fully discussed. Finally, the limitation in this field area and future research directions were pointed out. This review would be expected to provide practical engineering application and development for soil washing.