Biomanagement of hexavalent chromium: Current trends and promising perspectives

Chromium (Cr) is most widely used heavy metal with vast applications in industrial sectors such as metallurgy, automobile, leather, electroplating, etc. Subsequently, these industries discharge large volumes of toxic Cr containing industrial wastewaters without proper treatment/management into the environment, causing severe damage to human health and ecology. This review gives some novel insights on the existing, successful and promising bio-based approaches for Cr remediation. In lieu of the multiple limitations of the physical and chemical methods for remediation, various biological means have been deciphered, wherein dead and live biomass have shown immense capabilities of removing/reducing and/or remediating Cr from polluted environmental niches. Adsorption of Cr by various agro-based waste and reduction/precipitation by different microbial groups have shown promising results in chromium removal/recovery. Various microbial based agents and aquatic plants like duckweeds are emerging as efficient adsorbents of metals and their role in chromium bioremediation is an effective green technology that needs to be harnessed effectively. The role of iron and sulphur reducing bacteria have shown potential for enhanced Cr remediation. Biosurfactants have revealed immense scope as enhancers of microbial metal bioremediation and have been reported to have potential for use in chromium recovery as well. The authors also explore the combined use of biochar and biosurfactants as a potential strategy for chromium bioremediation for the development of technology worth adopting. Cr is non-renewable and finite resource, therefore its safe removal/recovery from wastes is of major significance for achieving social, economic and environmental sustainability.

Automated summary

Chromium is a widely used heavy metal in industrial sectors, leading to large volumes of toxic industrial wastewaters being discharged into the environment without proper treatment. Biological approaches have shown great potential for chromium removal, including the use of various agro-based waste for adsorption, microbial groups for reduction/precipitation, and emerging agents like biosurfactants for enhanced metal bioremediation. The safe removal and recovery of chromium from wastes is crucial for achieving social, economic, and environmental sustainability as chromium is a non-renewable resource.