Na Chen,Ying Zhao,Meiqi Li,Xiaobing Wang,Xing Peng,Hongwei Sun,Lizhi Zhang
Safe treatment of antibiotics requires efficient removal of both antibiotics and their degraded intermediates. In this study, we demonstrate that FeC 2 O 4 •2H 2 O enables the more sustainable conversion of H 2 O 2 to • OH than commonly used FeSO 4 •7H 2 O, promoting the detoxification of a typical antibiotic sulfadimidine. It was found that the FeC 2 O 4 /H 2 O 2 system could completely degrade 250 mg L −1 of sulfadimidine within 40 min at pH 3.0, along with decreasing the contents of chemical oxygen demand and total organic carbon by 295.0 and 33.5 mg L −1 , respectively, more efficient than those in a classical Fenton system (FeSO 4 /H 2 O 2 ). Analysis of sulfadimidine degraded intermediates and toxicity evaluation suggested that the FeC 2 O 4 /H 2 O 2 treatment could more effectively decrease the overall toxicity of the sulfadimidine solution than the FeSO 4 /H 2 O 2 counterpart. The sustainability of FeC 2 O 4 •2H 2 O in H 2 O 2 conversion to • OH was attributed to its controlled release of Fe 2+ into the solution to prevent the quenching of • OH by excessive Fe 2+ , as well as the simultaneous release of C 2 O 4 2− to complex with Fe 2+ and Fe 3+ , which could inhibit iron sludge formation and accelerate Fe 3+ /Fe 2+ redox cycle. This study provides a promising Fenton system for the safe treatment of antibiotics and sheds light on the potential of FeC 2 O 4 •2H 2 O in environmental remediation.
In this study, we coated a high proton conductive shell on the zero-valent iron (ZVI) surface by mechanically ball-milling ZVI with oxalic acid dihydrate (OX-ZVI), and demonstrated that the generated FeC 2 O 4 ·2H 2 O shell dramatically improved the Cr(VI) removal rate of ZVI by about 15–80 times. Owing to a higher proton conductivity of FeC 2 O 4 ·2H 2 O shell than that of Fe 2 O 3 shell, proton could easily transfer through FeC 2 O 4 ·2H 2 O shell into iron core and be reduced to H, accompanying with fast surface-bound Fe 2+ generation, resulting in high efficiency of Cr(VI) removal in a wide pH range. Meanwhile, the removed Cr(VI) was deposited on OX-ZVI surface in the formation of Fe x Cr 1-x (OH) 3 composites, accompanied by the appearance of typical hollow structure derived from iron core dissolution. This study clarifies the significance of proton transfer on the reactivity of zero-valent iron, and also provides a new strategy to prepare highly active zero-valent iron for Cr(VI) removal.
危险品化学品经营许可证（带存储）