Facile Synthesis of Cr-Doped Ferrite Catalyst from Cr-Containing Electroplating Sludge with Activated Persulfate for Efficient Degradation of Tetracycline

Abstract

Electroplating sludge (ES) is a typical industrial hazardous waste, which contains   multitudes of valuable transition metal resources. Hence, there is an urgent need for a method which can not only effectively detoxify but also reasonably reuse ES resources. In this work, we synthesized Cr-doped ferrite catalyst derived from Cr-containing ES via a facile hydrothermal treatment, and applied it for the degradation of tetracycline (TCH).  The Cr-doped ferrites had a large specific surface area (168.3 m2 g-1) and double metal oxide structure, which could provide more active sites to improve catalytic performance. Under the optimum conditions, the removal rate of TCH (50 mg L-1) by Cr-doped ferrite can reach 88% within 2 h. The catalyst also exhibited high resistance to inorganic anions and humic acid and perfect reusability. This work not only achieved the stabilization of Cr-containing ES, but also obtained an excellent catalyst for the removal of TCH, realizing the goal of treating waste with waste.

Keywords: Electroplating sludge, Chromium, Immobilization, Advanced oxidation processes, Tetracycline degradation.