Sheng Bo, Huang Ying, Wang Zhaohui, Yang Fei, Ai Luoyan, Liu Jianshe
State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, College of Environmental Science and Engineering, Donghua University Shanghai 201620 China
International Centre for Balanced Land Use (ICBLU), The University of Newcastle Callaghan NSW 2308 Australia.
RSC Adv. 2018 Apr 13;8(25):13865-13870. doi: 10.1039/c8ra00600h. eCollection 2018 Apr 11.
Both chloride and phosphate are common inorganic anions in industrial wastewater, however, their effects on peroxymonosulfate (PMS)-based oxidation systems are largely unknown. The present results show that addition of chloride (>1 mM) apparently enhanced the degradation of Acid Orange 7 (AO7) independent of the presence of phosphate (PBS) buffer. Both PBS and chloride favored the degradation of AO7, while PBS played a more important role when they co-existed. The degradation efficiency of AO7 was enhanced by increasing the concentration of PBS and chloride. A maximum of absorbable organic halides (AOX) accumulation was observed; indicating some chlorinated byproducts could be initially generated and further oxidized by increasing the reaction time. It is demonstrated that the PBS/PMS system, with a lower AOX formation at the same chloride concentration, is superior to the Co/PMS system, a typical sulfate radical-based system. The active chlorine species (HClO/Cl) were found to be the dominant oxidants in the presence of higher chloride concentration (>50 mM) under neutral conditions. The findings of this work may promote the further application of PMS-based oxidation processes in saline effluents treatment.
氯离子和磷酸根都是工业废水中常见的无机阴离子，然而，它们对基于过氧单硫酸盐（PMS）的氧化系统的影响在很大程度上尚不清楚。目前的结果表明，添加氯离子（>1 mM）明显增强了酸性橙7（AO7）的降解，且与磷酸盐（PBS）缓冲液的存在无关。PBS和氯离子都有利于AO7的降解，而当它们共存时，PBS发挥了更重要的作用。通过增加PBS和氯离子的浓度，AO7的降解效率得到提高。观察到可吸收有机卤化物（AOX）积累达到最大值；这表明一些氯化副产物可能最初生成，并通过延长反应时间进一步氧化。结果表明，在相同氯离子浓度下，PBS/PMS系统产生的AOX较少，优于典型的基于硫酸根自由基的Co/PMS系统。发现在中性条件下，当氯离子浓度较高（>50 mM）时，活性氯物种（HClO/Cl）是主要的氧化剂。这项工作的发现可能会促进基于PMS的氧化工艺在含盐废水处理中的进一步应用。
