【摘要】 利用过氧化氢(H2O2)产生活性氧自由基(ROS)去除水中有机污染物是重要的高级氧化技术之一,干扰ROS产生将直接影响处理结果。利用紫外光诱导,考察了甲醇、乙腈、丙酮、乙醇等重要小分子有机溶剂及碳酸根(CO2-3)、碳酸氢根(HCO-3)、铁离子(Fe3+)、亚铁离子(Fe2+)、氯离子(Cl-)、硫酸根(SO2-4)和硝酸根(NO-3)等无机离子对水中H2O2产生ROS的影响。结果表明,缓冲体系富氧环境中ROS产生稳定,该体系同时有利于ROS被捕捉;非缓冲体系ROS的产生可能在瞬间发生。4种小分子有机质对H2O2光解影响的程度和性质不同,具有体积分数和反应时间的依赖性。钠离子(Na+)共存时,CO2-3和HCO-3对ROS产生的影响同样具有浓度和时间的依赖性;Na+共存时Cl-、SO2-4对H2O2光解没有明显影响;NO-3的影响在铅离子(Pb2+)替代Na+后受到抑制。在中性非缓冲水溶液中,低浓度Fe2+对H2O2光解具有强促进作用,且很快趋于平衡。研究表明,小分子有机溶剂和离子对光诱导H2O2产生ROS具有不易确定的复杂的影响,可能导致高级氧化技术在应用中的不稳定性。更多还原

【Abstract】 This paper is aimed to investigate the effects of small molecular organic species(methanol,ethanol,acetone and acetonitrile,the key organic reagents in environmental engineering science) and inorganic ions(CO2-3,HCO-3,Cl-,SO2-4,NO-3,Fe3 +,Fe2 +) in ROS’s production photo-induced from H2O2 in water.As is known,it is a kind of vital technological advances to apply the ROS(the Reactive Oxygen Species) from H2O2 to Advanced Oxidation Processes(AOPs) and the disturbance will directly influence the processing results.The results of our experiments show that the buffer system helps to realize a stable release of ROS in the oxygen-enriched environment,which can facilitate the reaction with the ROS by capturing the agent.ROS can be produced as an instantaneous result to the difficult capture in the water with an instable pH value,in which the four small molecule organic species tend to have different effects on the production of ROS.The production of ROS in the test proves to be dependent on their volume fraction in the water as well as on the reaction time.Both CO2-3and HCO-3tend to influence the production of ROS at the presence of Na+.Both promotion and inhabitation can be found possible.The production of ROS can also be found dependent on their concentrations and reaction time,though Cland SO2-4have no obvious effects whereas NO-3has been found to affect indeed the production of ROS in the presence of Na+and inhabit its production when Na+has been replaced by Pb2 +.Besides,in the case of neutral water without the help of the buffer assistance,the reaction of photolysis of H2O2 can be promoted at the presence of Fe2 +,which is likely to lead to the stability of the reaction.Thus,it can be concluded that the small molecular organic species and ions aforementioned in our experiments are prone to produce complex and uncertain impacts on the production of photo-induced ROS from H2O2 in the water,which proves to result in the instability of the process in AOP application.更多还原