The potential impact on the bioavailability of organic pollutants from composting for soil remediation

Soil pollution by organic chemicals resulting from industrial and agricultural activities has caused high concerns in recent years. Large numbers of contaminants, such as polycyclic aromatic hydrocarbons (PAHs), pesticides and... [ view full abstract ]

Soil pollution by organic chemicals resulting from industrial and agricultural activities has caused high concerns in recent years. Large numbers of contaminants, such as polycyclic aromatic hydrocarbons (PAHs), pesticides and chlorophenols, are discharged into soil, posing a huge threat to human health and natural ecosystem. Traditional chemical and physical remediation technologies are either incompetent or expensive, and may cause secondary pollution. The technology of soil composting or use of compost as soil amendment can utilize quantities of active microbes to degrade organic pollutants with the help of available nutrients in the compost matrix, in order to remedy organic contaminated soil. It is highly cost-effective for soil remediation. On one hand, compost incorporated into contaminated soil is capable of significantly increasing the organic matter content which improves the soil environment and stimulates the metabolically activity of microbial community. On the other hand, the increased organic matter content will enhance the adsorption of organic pollutants and affect their bioavailability, leading to decreased fraction available for microorganism-mediated degradation. Meanwhile, the aging of bioavailability also brings a great challenge to the soil remediation control. Therefore, the study on bioavailability of organic pollutants in soil is extremely important for the application of composting technology. This work will discuss the changes of physical and chemical properties of contaminated soils and the bioavailability of organic pollutants by the adsorption of composting matrix. Also, the influence of different organic matter contents, types and compositions of compost amendments on removal and bioavailability of organic pollutants will be evaluated.