摘要
由四氧化三铁(Fe3O4)-过氧化氢(H2O2)构成的非均相Fenton体系主要利用H2O2分解产生的羟基自由基氧化去除难降解有机污染物.研究了邻苯二酚在纳米Fe3O4-H2O2构成的非均相Fenton体系中的催化氧化特征,同时对实验室制备的纳米级Fe3O4和商品微米级Fe3O4两种催化剂的催化活性进行比较,并考察了H2O2初始浓度对邻苯二酚的催化氧化的影响.结果表明,自制纳米Fe3O4-H2O2体系较商品Fe3O4-H2O2体系,能更快速地去除溶液中的邻苯二酚和总有机碳(TOC),邻苯二酚的去除率接近100%,同时能迅速催化H2O2分解.邻苯二酚的催化氧化反应遵循准一级反应动力学方程,H2O2的分解反应能用三级反应动力学方程较好拟合.此外,反应过程中铁释放低于0.3 mg.L-1,不足以启动均相Fenton反应,反应机制为由界面反应控制的非均相反应机制.
A Fenton-like system,consisting of magnetite（Fe3 O4） and hydrogen peroxide（H2 O2）,was utilized to remove refractory organic pollutants using the hydroxyl radicals generated from the decomposition of H2 O2.The characteristic of the catalyzed oxidation of catechol in a nano-Fe3 O4-H2 O2 Fenton-like system was studied.The catalytic activity of the synthesized nano-Fe3 O4 was compared to that of the purchased micro-Fe3 O4.The effect of initial H2 O2 concentration on the oxidation of catechol was also studied.Results showed that the removal of catechol and total organic carbon and the decomposition of H2 O2 were faster in the nano-Fe3 O4-H2 O2 system than in the purchased-Fe3 O4-H2 O2 system.The removal of catechol achieved nearly 100% in the former system.The catalyzed oxidation of catechol in nano-Fe3 O4-H2 O2 system followed pseudo-first-order kinetics.The decomposition of H2 O2 could be fitted by third-order kinetics.The release of total iron was below 0.3 mg·L^-1,implying that the homogeneous Fenton reaction was not dominant.Therefore,surface reaction controlled heterogeneous Fenton-like reaction mechanism was deduced.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2013年第5期1773-1781,共9页
Environmental Science
基金
国家自然科学基金项目(21107125)
国家重点基础研究发展规划(973)项目(2011CB933704)
国家自然科学基金创新群体课题项目(50921064)
