Abstract：
The homogeneous sodium percarbonate (SPC) systems are limited by narrow pH range, ineffective consumption of oxidant, and weak reusability of catalyst. Herein, molybdenum (Mo) powder and sodium tripolyphosphate (STPP) were selected to overcome these challenges. Sulfamethoxazole (SMX), as a model contaminant, was almost completely degraded in 60 min with higher removal rate (0.1367 min-1) than the Mo or STPP-absent system. In addition, Mo/STPP-Fe(Ⅲ)/SPC system was cost-effective in terms of oxidant consumption, requiring only 0.2 mM SPC. About activation mechanism, the main active species for SMX degradation was pH-dependent, with hydroxyl radical (·OH) as the dominant active species at pHi = 7 and ·OH, carbonate radical (CO3·-), and superoxide radical (O2·-) derived from a series of chain reaction at pHi = 10, respectively. Due to the generation of various electrophilic free radical, the system exhibited excellent performance towards electron-rich pollutants under a wide pH range. Furthermore, Mo exhibited excellent stability and reusability. SMX was degraded through hydroxylation, N-S cleavage, amino and sulfanilamide oxidation into intermediates whose toxicities were evaluated by Toxicity Estimation Software Tool (T.E.S.T.) software. This work provided new insights to Fe/SPC system towards high-efficiency and low consumption treatment of practical application.
摘要：
均匀的过碳酸钠（SPC）系统受到窄pH范围的限制，氧化剂的无效消耗，和弱的可重用性的催化剂。在这里，选择钼（Mo）粉末和三磷酸钠（STPP）来克服这些挑战。磺胺甲恶唑(SMX),作为模型污染物，在60分钟内几乎完全降解，去除率（0.1367min-1）高于不含Mo或STPP的系统。此外,Mo/STPP-Fe(Ⅲ)/SPC体系在氧化剂消耗方面具有良好的性价比,只需要0.2mMSPC。关于激活机制，SMX降解的主要活性物种是pH依赖性的，以羟基自由基（·OH）为主要活性物种，pHi=7和·OH，碳酸根(CO3·-)，和超氧自由基（O2·-）分别来自pHi=10时的一系列链反应。由于各种亲电自由基的产生,该系统在宽pH范围内对富含电子的污染物表现出优异的性能。此外，Mo表现出优异的稳定性和可重用性。SMX通过羟基化降解，N-S裂解,氨基和磺胺氧化成中间体，其毒性通过毒性估计软件工具(T.E.S.T.)软件。这项工作为Fe/SPC系统在实际应用中的高效低耗处理提供了新的见解。
