Residues from secondary aluminum dross to fabricate Fe-based catalysts for efficiently removing tetracycline from wastewater

Secondary aluminum dross (SAD) as a hazardous waste has been widely studied on recycling by acid leaching process, but residues accounting for approximately 50 wt% of SAD are still produced and rarely reused. In this study, residues from secondary aluminum dross are retrieved to fabricate Fe-based acidized aluminum ash sludge (FAS) heterojunction catalyst for photocatalytic degrading tetracycline hydrochloride under visible light, which does not only reduce resource utilization cost of SAD, but also realize efficient wastewater treatment by clean photocatalytic technique. Firstly, acidized sludge was obtained from SAD via an acid leaching and then utilized to fabricate FAS by calcination method. From the results of characterizations, BaFeO 3-x and Fe 2 O 3 were demonstrated to be deposited on the surface of acidized sludge, resulting in the successful formation of FAS heterojunction catalyst. As a result, the FAS exhibits an excellent performance in the removal of tetracycline hydrochloride (TCH), reaching to 92.2 % within 150 min under dark adsorption and visible light excitation. To further broaden the application of FAS in actual circumstance, the degradation of mixed dye in wastewater and actual medical wastewater were conducted over the optimal sample of FAS. After four cycles, the removal ability remained at 86.0 %, which shows the exceptional stability.