Enhanced bioremediation of pulp effluents through improved enzymatic treatment strategies: A greener approach

The massive load of effluents released from the pulp and paper industry has an adverse environmental impact due to the discharge of hazardous materials. These effluents contain mostly recalcitrant compounds like lignin, which are rigid and resilient to degradation. Bioremediation technologies such as biostimulation using nutrients and biological techniques are being used for the biodegradation of hazardous effluents. But they are not up to that level of remediation efficiency. Many enzymes have been used for bioremediation in recent years, which are easy to use, eco-friendly, and adequate to ensure the public safety. Such enzymes, along with their mechanisms, have been well studied for the bioremediation of effluents. This review describes enzyme technologies, including laccase mediated treatment, lignin peroxidase, and manganese peroxidase treatment to reduce effluent load into the environment. The other methods including aerobic and anaerobic treatments utilizing bio-sludge for producing beneficial products such as biofuels, and bio-sorbents for oil peeling are also described in the present review. This review also gives a summarized but unique description of the aspects of the immobilized biocatalysts and biosorbents used to mitigate the production of toxic pollutants from the pulp and paper industry. The strategies based on the advanced enzyme engineering technologies for bioremediation of such contaminants are also briefly described. This review also discusses the techno-economic assessment of enzymatic remediation and future challenges for the bioremediation of these effluents. In conclusion, enzyme-based advanced technologies are crucial ‘green technologies’ for providing a sustainable solution for bioremediation and reduced environmental pollution.