Dual benefits on valorization of waste agro-industrial biochar by low-carbon thermal pyrolysis in biochar regeneration for carbon-neutral industrial wastewater treatment and reclaimed water achievement

This study aimed to carbon-neutral industrial wastewater treatment while achieving the reclaimed water standards of effluent for a brewery industry using regenerated biochar. The regenerated biochar was obtained by the valorization of waste malt sprout biochar using the low-carbon solar-powered pyrolysis. Averagely 27.28 % of mitigation on carbon dioxide (CO2) emission from industrial wastewater treatment was achieved by the blending of three regenerated biochar while achieving a reclaimed water of the Class-B quality. The decarbonization potential index (DPI) and wastewater remediation index (WRI) were developed and validated. Also, a risk assessment which was based on water reclamation for irrigation depended on multivariate statistical analysis was performed. This study specifically contributed to the circular economy targets in terms of valorization of an agroindustrial biochar by solar-powered regeneration. Averagely, 73.83 % of mitigation on operational costs was obtained by regenerated biochar while comparing with conventional activated sludge (CAS) process. Also, a saving on operational costs related to freshwater consumption was nearly 30.4 % with reuse process. This study evidenced and addressed that the regenerated biochar use for the industrial wastewater reclamation was lowcost, carbon-neutral and effective treatment technique. The dual benefits of carbon-neutral and effective industrial wastewater treatment were presented by regenerated biochar application in the end of the study.