Effect of Fe(Ⅲ) on the bromate reduction by humic substances in aqueous solution

作     者：XIE Li SHANG Chii ZHOU Qi 

作者机构：State Key Laboratory of Pollution Control and Resources Reuse Tongji University Shanghai 200092 China Department of Civil Engineering Hong Kong University of Science and Technology Hong Kong 852 China 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2008年第20卷第3期

页      面：257-261页

核心收录：

学科分类：083001[工学-环境科学] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 08[工学] 

基　　金：supported by the National Natural Science Foundation of China(No.50608056) the Hong Kong Research Grants(No.HKUST6106/03E) the Program for Young Excellent Talents in Tongji University in part(No.2006KJ033) 

主　　题：humic acid Fe(Ⅲ) ion bromate reduction electron mediator 

摘      要：Humic substances are ubiquitous redox-active organic compounds of environment. In this study, experiments were conducted to determine the reduction capacity of humic acid in the man-ix of bromate and Fe（Ⅲ） solutions and the role of Fe（Ⅲ） in this redox process. The results showed that the humic acid regenerated Fe（Ⅱ） and reduced bromate abiotically. The addition of Fe（Ⅲ） could accelerate the bromate reduction rate by forming humic acid-Fe（Ⅲ） complexes. Iron species acts as electron mediator and catalyst for the bromate reduction by humic acid, in which humic acid transfers electrons to the complexed Fe（Ⅲ） to form Fe（Ⅱ）, and the regenerated Fe（Ⅱ） donate the electrons to bromate. The kinetics study on bromate reduction further indicated that bromate reduction by humic acid-Fe（Ⅲ） complexes is pH dependent. The rate decreased by 2-fold with the increase in solution pH by one unit. The reduction capacity of Aldrich humic acid was observed to be lower than that of humic acid or natural organic matter of Suwanne River, indicating that such redox process is expected to occur in the environment.