Bioremediation represents one of the most cost-effective, adaptable, and ecologically beneficial way to get rid of contaminants. It is a technology which can be simultaneously used with other physical and chemical treatment methods for complete management of diverse group of environmental pollutants. Combined application (biochar + microbes) can be applied successfully for reuse of wastewater and contaminated soil for environment protection and sustainable development.
Biochar is a solid carbonaceous material produced through the conversion of organic biomass using hydrothermal and thermochemical processes such as pyrolysis. Biochar surface properties, aromaticity and interactions between active functional groups on the biochar are main factors influencing removal of micropollutants. Microbial immobilization using biochar is a bioaugmentation approach that reduces the loss of functioning microorganisms while increasing bacterial resistance to actual water bodies. Biochar can be a good biofilm carrier because of its ability to support microbial life. It contains nitrogen, phosphate, and potassium as also rich in organic carbon. Microbial cells are immobilized to biochar through many methods, including adhesion or adsorption on a solid surface, encapsulation, and aggregation via flocculation and crosslinking. Because of its unique physicochemical qualities such as high porosity and wide specific surface, biochar can expedite nitrogen cycling, improve soil composting quality and promote the growth of microorganisms.
In this research, the removal of hydrocarbons in wastewater was investigated using hydrocarbon sludge-produced biochar generated using various activation agents followed by Anaerobic Digestion. The results showed a removal efficiency of hydrocarbons, 57.3% removal efficiency, with chemical oxygen demand decreasing from 89,233 mg/L to 38,000 mg/L. On the success of these initial results, the team has now developed composites of bacteria/biochar for the effective treatment of various industrial wastewaters. The bacteria used in this study were previously isolated and tested for remediation of various pollutants in wastewaters. Hence, this research confirmed that the biochar derived from oily sludge combined with microorganisms, an innovative bioaugmentation approach, is effective for wastewater treatment and reuse of highly contaminated industrial wastewater. Therefore, implementing large scale facilities that allows reuse of hydrocarbon sludge and wastewater provides a potentially meaningful circular economy pathway in oil and gas industries.