Acetylene black doped zinc oxide (AB-ZnO) nanorods activated peroxydisulfate for degradation of dyeing wastewater

Abstract

Zinc oxide (ZnO) nanorods and acetylene black (AB) doped ZnO (AB-ZnO) nanorods were fabricated by the hydrothermal method, and characterized by various methods (XRD, EDS, SEM, BET, FT-IR, Zeta potential). The photo-catalytic degradation ability of AB-ZnO/PDS/vis system on simulated dyeing wastewater was studied with methyl orange (MO) as the target pollutant. The effects of AB doping ratio, AB-ZnO dosage, PDS concentration, initial pH, and temperature on MO degradation were comprehensively investigated. The AB-ZnO/PDS/vis system has a wide range of pH applications from 3 to 11. The prepared material of AB-ZnO had excellent stability that the degradation efficiency on MO remained above 90 % after 4 cycles. The theoretical optimal removal rate of MO was 98.59 % when AB-ZnO dosage was 1.0 g/L, PDS concentration was 2.0 mmol/L, initial pH was 5, and temperature was 50 °C. Furthermore, degradation kinetic model, the orthogonal experiment and the degradation mechanisms were elaborated. By using methanol and tert-butanol as free radical inhibitors, it was confirmed that SO4·- and ·OH were the main active free radicals in AB-ZnO/PDS/vis system.