Biodegradation of POPs in Contaminated Land/Water

Persistent organic pollutants (POPs) are a group of hazardous chemical compounds that originates intentionally and unintentionally from anthropogenic activities related to manufacturing, recycling, thermal processes, and waste disposal activities. Over the past few decades, the load of organic pollutants in land or water has been tremendously increased. POPs consist of pesticides such as dichlorodiphenyltrichloroethane (DDT), hexachlorocyclohexanes (HCH), and hexachlorobenzenes (HCB), industrial chemicals such as polychlorinated biphenyls (PCBs), and unintentional by-products of industrial processes such as polychlorinated dibenzo-p- dioxins and dibenzofurans (PCDD/PCDF) and polycyclic aromatic hydrocarbons (PAH). Stockholm convention was adopted as a legal international agreement in 2001 to tackle the problems associated with POPs. The first priority list of POPs consisted of 12 compounds commonly referred to as the dirty dozen under the Stockholm Convention. Over the past decade, the POP priority list has been updated to include brominated flame retardants (BFRs), such as polybrominated diphenyl ethers (PBDEs), listed in the Stockholm Convention in 2017, and hexabromocyclododecanes (HBCDDs), currently under consideration for inclusion. POPs pose a risk of adverse effects to human and wildlife health and to the environment in general. PCDDs/PCDFs and PCBs pose large-scale environmental hazards due to their slow decomposition in the environment and the risks they pose for living things. There are different types of technique used for biodegradation of POPs. Aerobic and anaerobic microorganisms are considered as cost-effective remediation strategies to biodegrade POPs. Microbial glycoconjugates are used for the biodegradation of POPs in soil and water. Arbuscular mycorrhizal fungi (AMF) association in the roots of transgenic plants is commonly used in the biodegradation of POPs. There is no well-developed single technology, but various types of technologies have been suggested which are used for remediation of contaminated soil and water.