The advanced treatment of landfill leachate by electrochemical oxidation with iron promoting

摘要

Landfilling of municipal waste is still a very important issue of the waste management system in china and the rest of the world. However, in many countries, the problem of leachate treatment has been existed for many years. In this paper, the advanced treatment of the landfill leachate pre-treated by sequencing batch reactor via an electrochemical process was carried out in an electrochemical reactor with oxide-coated titanium anodes. The electrochemical process assisted by iron (electro-chemical oxidation of iron promoting) was employed and found to be highly efficient in removing a large amount of refractory organic and inorganic compounds in the leachate. The influence of ferrous sulfate (FeSO4), voltage, reaction time, and initial pH value on removal of contaminants was investigated systematically. The results show that with the increasing dosage of FeSO4, pollutants removal was enhanced, especially for organic pollutants and turbidity. The increase of voltage to 5.2V led to a rapid increase in the removal of COD and NH3-N. COD and NH3-N was removed quickly in the first 15min, and then with the increasing reaction time, degradation rates slow down. The lower pH was advantageous to electrochemical oxidation of organic pollutants. And a lower energy consumption of 22.24 kwh/(kgCOD) indicated it was a promising alternative for leachate treatment.