Enhanced purification efficiency for pharmaceutical wastewater through a pollutant-mediated H2O2 activation pathway over CuZnS nano-aggregated particles

Abstract

Active pharmaceutical ingredients (APIs) are refractory organic pollutants that often require massive amounts of energy and resources to attain discharge standards in traditional water treatment processes. Herein, a solution strategy is proposed to reduce energy consumption by utilizing a pollutant-mediated H₂O₂ activation pathway over a novel Fenton-like catalyst CuZnS nano-aggregated particles (CuZnS-Naps) prepared via an in situ co-precipitation process. Typical APIs are removed over 80% in CuZnS-Naps suspensions within only 20 min accompanied by very low H₂O₂ consumption under natural conditions. CuZnS-Naps also show high efficiency in the purification of actual pharmaceutical wastewater. Characterization techniques reveal that the key to reducing H₂O₂ consumption is the construction of electron-poor/-rich microregions on the CuZnS-Nap surface. This particular structure results in APIs acting as electron donors instead of H₂O₂ during the reaction process. The mechanism of the pollutant-mediated H₂O₂ activation pathway to reduce decomposition is proposed. This work solves the limitation of high energy consumption in the conventional advanced wastewater treatment process and has a positive significance for the development of new nano-Fenton catalysts with low energy consumption and high efficiency.