摘要
Fe(III)-oxalic acid配合物是天然水体中广泛存在的光活性物质。系统考查了pH值、oxalic acid及投加方式等因素对DMP降解的影响。导致DMP的降解活性物种·OH来自Fe(III)-oxalic acid络合物、Fe(III)的光致激发以及由此引发的Fenton反应过程。当Fe(III)和oxalic acid的浓度比为1∶10时,pH=3.0为最佳酸度;在此酸度下,Fe(III)和oxalic acid的浓度比为1∶9~1∶20时达到最高降解效率。说明了pH和Fe(III)物种存在形式对·OH产生机制的影响。最后对比讨论了体系中oxalic acid对Fe(III)/Fe(II)变化规律的影响。
Fe( III)-oxalic acid complexes are photoreactive and ubiquitous in natural waters. In this study,the effect of pH, oxalic acid concentrations and adding method on the photodegradation of dimethyl phthalate( DMP) was systematically investigated. Hydroxyl radicals,·OH,responsible for the degradation,were formed from Fe( III)-oxalic acid complexes and Fe( III) via photo exciting process and induced Fenton reaction. At the ratio of Fe( III)-to-oxalic acid 1: 10,the optimal pH for ·OH production was 3. 0. At this acidity,the photodegradation of DMP was faster when the ratio of Fe( III) to oxalic acid varied from 1∶ 9 to 1∶ 20. The·OH formation mechanism was elucidated according to the pH-dependent formation of·OH and the speciation distribution analysis of Fe( III) species. Finally,variation of iron species in the UV-irradiated aqueous solution was examined in the presence of Fe( III)-oxalic acid,which was significantly different from that in oxalic acid-free system.
出处
《环境工程》
CAS
CSCD
北大核心
2014年第4期126-130,共5页
Environmental Engineering
基金
国家自然科学基金(41263004)
大学生创新基金
