RESUMO
The advanced treatment of landfill leachate by electrochemical oxidation was carried out in a box-style electrochemical reactor, using oxide-coated titanium anode. The effects of the concentration of FeSO4, reaction time, the initial pH value, and voltage (current) on the removal of contaminants were investigated. The removal efficiency of contaminant was compared when Fe2+ and Fe3+ used. The results show, compared with the traditional oxidation of electrolysis, the electrolysis of iron promoting can enhance the organism removal efficiency prominently. The increase of the concentration of FeSO4 can result in the increasing organism removal, but when it exceeds 1 250 mg x L(-1), the increasing range decreases. The removal progress of contaminants is very fast in the first 30 minutes, and then slows down. The reasonable initial pH value is 3 - 4. To eliminate COD and NH4(+) -N from leachate effectively, voltage and current must be larger than 3.3 V and 4.8 A respectively. Compared with Fe2+, the organism removal efficiency is slightly lower when Fe3+ used. Two tentative ideas, making recycle use of iron and the application of acid waste water in the process, were proposed.
