Biochar Synthesis for Industrial Wastewater Treatment: A Critical Review
Excess sludge generated from wastewater treatment plants (WWTPs) can cause negative impacts on human health, water bodies, aquatic plants, and soil quality. However, the produced sludge could be appropriately managed to obtain various economic and environmental benefits. One of the feasible and practical options of sludge management is the synthesize of biochar via oxygen-limited pyrolysis. The use of biochar adsorbent for pollutant removal offers various advantages such as high adsorption capability, low operating and chemical costs, no production of toxins. Hence, this study addresses the applications of sewage sludge-derived biochar for industrial wastewater treatment. The methods of sludge collection, drying, pulverization, and pyrolysis are illustrated. Biochar characterization methods (SEM, EDX, XRD, and FTIR analyses) and mechanisms of the adsorption process are described. The sludge-derived biochar could be used as an adsorptive material for industrial effluent treatment. Recommendations for future studies that could enhance the adsorption capacity of biochar and modified-biochar are given.