Polycyclic Aromatic Hydrocarbon (PAH)-Contaminated Soil Decontamination Through Vermiremediation

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants that are usually found in the soil originating from various anthropogenic and natural activities. Soil accumulated PAHs may disrupt the food web and pose adverse impacts on soil and human health. Thus, elimination of PAHs from soil in a feasible and eco-friendly manner is an urgent task. The objective of the study is to review the applicability of earthworms for PAH-contaminated soil remediation and soil health restoration using vermiremediation mechanism. Vermiremediation can degrade, modify, detoxify, or break down these contaminants from contaminated soil. The study explicitly demonstrates the presence of distinct gut microbiome and the enzymatic system in earthworm which help them to break down PAHs and their metabolites in soil. In addition, vermiremediation in conjunction with other bioremediation processes, e.g., phytoremediation and microbe-mediated vermiremediation, greatly increases the efficiency of PAH removal from contaminated soil. These benefits are highly suitable to be applied to contaminated soils. Moreover, the use of surfactants, the sufficient supply of organic material as a food source for earthworms' growth and development, and the integration of all these techniques with other bioremediation procedures may improve the efficiency of vermiremediation in field conditions. It is necessary to understand the interactions between microbial biomass, soil organic matter, earthworms, and PAHs under different soil-climatic-management conditions to develop promising remediation techniques.