Combining granular UASB and biochar adsorption as two-step sustainable domestic wastewater treatment for resource recovery and micropollutant removal

The anaerobic process is a promising solution, given its potentiality to recover energy and nutrients, which is advantageous for water reuse. Nevertheless, resource recovery from domestic wastewater in biological processes is challenging due to its low substrate concentrations resulting in reduced process kinetics. This drawback can be faced by high-rate anaerobic bioreactors, able to achieve high biomass concentration and increase process performance. We investigated the feasibility of a granular biomass Upflow Anaerobic Sludge Blanket (UASB) to treat domestic wastewater at low temperatures and different HRTs to enhance energy and resource recovery. Relevant to water reuse, the fate of a target contaminant of emerging concern, sulphamethoxazole (SMX), and its potential impact on process performance have been evaluated. In addition, to further improve treated water quality, a post-treatment has been proposed for the anaerobically treated effluent. This method is based on a cost-effective approach that utilizes biochar derived from a green material i.e. forest wastes.