Heterogeneous Fenton process coupled with microfiltration for the treatment of water with higher arsenic content

Abstract

Arsenic is well known by its effect as human carcinogen along with its acute toxicity; recently long term health effects of arsenic traces have been studied. The objective of the present study is to evaluate the efficiency of iron-loaded activated carbon (Fe-AC) as a heterogeneous catalyst in the Fenton process for the removal of arsenic from water. The effects of catalyst dosage, initial pH, H₂O₂ dosage, arsenic concentration, and aeration on arsenic removal rate were studied to find out the optimum conditions. Heterogeneous Fenton process carried out with iron loaded activated carbon (Fe-AC) catalyst resulted in 90.7% arsenic removal for a catalyst dosage of 2500 mg/L, pH 5, arsenic concentration of 1.5 mg/L, 0.014 M H₂O₂ with aeration. The study conducted with H₂O₂ alone and catalyst alone (adsorption) yielded less removal of arsenic than the combined process (adsorption + oxidation). After a subsequent microfiltration step, the residual arsenic content reduced to 0.105 mg/L. This indicates that heterogeneous Fenton coupled with microfiltration is efficient for elimination of arsenic from water medium.

Keywords:

• Arsenic
• Fenton process
• iron loaded activated carbon
• microfiltration