Nanomaterial-mediated strategies for enhancing bioremediation of polycyclic aromatic hydrocarbons: A systematic review

Polycyclic aromatic hydrocarbons (PAHs) are pervasive organic pollutants in the environment that are formed as an outcome of partial combustion of organic matter. PAHs pose a significant threat to ecological systems and human health due to their cytotoxic and genotoxic effects. Therefore, an immediate need for effective PAH remediation methods is crucial. Although nanomaterials are effective for remediation of PAHs, concerns regarding environmental compatibility and sustainability remains. Therefore, this study emphasizes integration of nanomaterials with bioremediation methods, which might offer a more sustainable and ecofriendly approach to PAHs remediation. A systematic search was conducted through scholarly databases from 2013 to 2023. A total of 360 articles were scrutinized, among which 26 articles were selected that resonated with the application of nano-bioremediation. These literatures comprise both comparative analysis of bioremediation only as well as nano-bioremediation. There is an elevation of 18.9 % in PAHs removal of liquid-phase samples, when comparing bioremediation (52.2 %) with nano-bioremediation (71.1 %). A consistent trend was observed in soil samples, with bioremediation and nano-bioremediation that successfully remove PAHs, with 60.8 % and 75.1 % respectively, indicating a 14.3 % improvement. Furthermore, the review elaborated on the various features of nanomaterials that led to their efficiency in the bioremediation of PAH. The review also discussed the strategies of nano-bioremediation namely nanomaterial-assisted microbial degradation, nanomaterial-assisted enzyme-enhanced microbial activity, nanomaterial-immobilized microbial cells, nanomaterial-facilitated electron transfer, and even some eco-green approaches to remediate PAHs, like biogenic nanomaterial for PAHs.