Sludge based micro-electrolysis filler for removing tetracycline from solution.

In this study, a novel catalytic micro-electrolysis filler (CMEF) was prepared using waste sludge as the main raw materials. The preparation process was optimized in terms of the mass ratio of raw materials and sintering temperature based on the tetracyclines (TCs) removal efficiency. The physicochemical characteristics (e.g., surface area, morphology features, function groups, and valence state of Fe) of the prepared CMEF were determined. Finally, the removing performance and mechanism of CMEF were discussed by removing TCs from solution. The results showed that the optimum conditions for CMEF preparation were a sintering temperature of 1050 °C, and the mass ration for sludge:clay:Fe powder of 3:2:2. The CMEF exhibited a high degradation capacity for TCs with a removal rate up to 99.9% in 2.5 h, and the removal kinetics fit well with a pseudo-second-order model. Introducing Fe into the CMEF significantly promoted TCs removal, comparing to the removal of TCs by sludge based ceramic (without addition of iron). This study provides a novel cost-effective CMEF based on sludge, and is also of significance for co-friend recycling of waste sludge.