Catalytic degradation of tetracycline hydrochloride by persulfate activated with nano Fe0 immobilized mesoporous carbon

In this study, mesoporous carbon (MC) supported nano Fe 0 was prepared from polyvinyl alcohol (PVA) using MnCO 3 as template, which was used as the catalyst to activate persulfate (PS) for the removal of tetracycline hydrochloride (TC) from aqueous solution. The nano Fe 0 was immobilized on MC by liquid phase reduction to overcome the drawbacks of nano Fe 0 for persulfate (PS) activation, including being easily aggregated and oxidized. The experimental results showed that the nano Fe 0 /MC + PS system achieved 92.1% of TC removal, while the MC + PS system and nano Fe 0  + PS systems showed 78.5% and 33.7% of TC removal, respectively. High removal efficiency in the nano Fe 0 /MC + PS system could be attributed to the superior PS activation capability due to the synergistic effects of nano Fe 0 and MC. In order to better understand the removal mechanism, the effects of nano Fe 0 loading amount ( c ), dosage (m), PS/TC mole ratio ( R m ) and initial pH on TC removal were evaluated in the nano Fe 0 /MC + PS system. The results showed that the removal efficiency of TC was enhanced with the increase of nano Fe 0 loading amount and dosage, while slightly decrease with the increase of PS/TC mole ratio. The maximum removal of TC was 97.7% under the optimal conditions: c  = 20%, m  = 0.8 g/L, R m  = 50/1 and pH = 5. According to the results of radical scavengers’ studies and intermediates analysis, SO 4 − , which was produced from catalytic activation of PS by nano Fe 0 and Fe 2+ on the surface of Fe 0 /MC, plays a significant role for TC degradation in the nano Fe 0 /MC + PS system. The Fe 0 /MC + PS system exhibited a superior oxidation process for the removal of TC from aqueous solution with excellent stability and reusability of Fe 0 /MC.