Application and mechanism of Fenton-like iron-based functional materials for arsenite removal
(1. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
2. National Engineering Research Centre for Control and Treatment of Heavy Metal Pollution, Central South University, Changsha 410083, China;
3. Water Pollution Control Technology Key Lab of Hunan Province, Changsha 410004, China)
2. National Engineering Research Centre for Control and Treatment of Heavy Metal Pollution, Central South University, Changsha 410083, China;
3. Water Pollution Control Technology Key Lab of Hunan Province, Changsha 410004, China)
Abstract: Between the two major arsenic-containing salts in natural water, arsenite (As(III)) is far more harmful to human and the environment than arsenate (As(V)) due to its high toxicity and transportability. Therefore, preoxidation of As(III) to As(V) is considered to be an effective means to reduce the toxicity of arsenic and to promote the removal efficiency of arsenic. Due to their high catalytic activity and arsenic affinity, iron-based functional materials can quickly oxidize As(III) to As(V) in heterogeneous Fenton-like systems, and then remove As(V) from water through adsorption and surface coprecipitation. In this review, the effects of different iron-based functional materials such as zero-valent iron and iron (hydroxy) oxides on arsenic removal are compared, and the catalytic oxidation mechanism of As(III) in heterogeneous Fenton process is further clarified. Finally, the main challenges and opportunities faced by iron-based As(III) oxidation functional materials are prospected.
Key words: Fenton-like reaction; iron-based functional materials; catalytic oxidation; arsenic removal