Hydroxylamine facilitated catalytic degradation of methylene blue in a Fenton-like system for heat-treatment modified drinking water treatment residues

Abstract

Rational treatment of drinking water treatment residues (WTR) has become an environmental and social issue due to the risk of secondary contamination. WTR was commonly used to prepare adsorbents due to its clay-like pore structure, but further treatment is subsequently required. In this study, a Fenton-like system of H-WTR/HA/H2O2 was constructed for degrading organic pollutants in water. Specifically, in this study, WTR was modified by heat treatment to increase its adsorption active site, and accelerated Fe(III)/Fe(II) cycling on the catalyst surface by the addition of hydroxylamine (HA). Moreover, the effects of pH, HA and H2O2 dosage on the degradation were discussed using methylene blue (MB) as the target pollutant. The mechanism of the action of HA was analyzed and the reactive oxygen species in the reaction system was determined. Combined with the reusability and stability experiments, the removal efficiency of MB remained 65.36% after 5 cycles, and this study may provide new insights into the resource utilization of WTR.