在这项工作中,探索了黄铜矿(CuFeS2)用于过碳酸钠(SPC)活化对磺胺二甲嘧啶(SMT)降解的新应用。几个关键影响因素,如SPC浓度,CuFeS2用量,反应温度,pH值,阴离子,和腐殖酸(HA)进行了研究。实验结果表明,CuFeS2/SPC工艺可以有效降解中性反应介质中的SMT(86.4%,在pH=7.1时0.054min-1)。阐明了CuFeS2激活SPC的机理,这被发现是与羟基自由基(•OH)共存的多活性氧(multi-ROS)过程,碳酸根(CO3·-),超氧自由基(O2·-),和单线态氧(1O2),正如淬火实验和电子自旋共振(ESR)测试所证明的那样。通过传统的非均相类Fenton工艺产生的·OH不仅会与碳酸根离子反应以产生其他ROS,而且还涉及SMT降解。大量的表面结合的Fe(II)被认为是SPC活化的主要催化活性位点。同时,已证实还原性硫物种,Cu(I)和Fe(III)之间的相互作用以及由分子氧的活化和·OH的转化产生的有效O2·-有利于Fe(II)在CuFeS2表面上的再生。此外,对SMT的降解中间体及其毒性进行了评价。这项研究提出了一种新的策略,通过将过渡金属硫化物与过碳酸盐相结合来处理抗生素污染的水。
In this work, the novel application of chalcopyrite (CuFeS2) for sodium percarbonate (SPC) activation towards sulfamethazine (SMT) degradation was explored. Several key influencing factors like SPC concentration, CuFeS2 dosage, reaction temperature, pH value, anions, and humic acid (HA) were investigated. Experimental results indicated that SMT could be effectively degraded in the neutral reaction media by CuFeS2/SPC process (86.4%, 0.054 min-1 at pH = 7.1). The mechanism of SPC activation by CuFeS2 was elucidated, which was discovered to be a multiple reactive oxygen species (multi-ROS) process with the coexistence of hydroxyl radical (•OH), carbonate radical (CO3•-), superoxide radical (O2•-), and singlet oxygen (1O2), as evidenced by quenching experiments and electron spin resonance (ESR) tests. The generated •OH via the traditional heterogeneous Fenton-like process would not only react with carbonate ions to yield other ROS but also involve in SMT degradation. The abundant surface-bound Fe(II) was deemed to be the dominant catalytic active sites for SPC activation. Meanwhile, it was verified that the reductive sulfur species, the interaction between Cu(I) and Fe(III) as well as the available O2•- derived from the activation of molecular oxygen and the conversion of •OH favored the regeneration of Fe(II) on CuFeS2 surface. Furthermore, the degradation intermediates of SMT and their toxicities were evaluated. This study presents a novel strategy by integrating transition metal sulfides with percarbonate for antibiotic-contaminated water treatment.