STUDY ON APPLYING ADVANCED OXYDATION PROCESS FOR REMOVING COLOR OF NAM SON LANDFILL LEACHATE AFTER ELECTRO-COAGULATION PRETREATMENT

Abstract

Landfill leachate is a high-strength wastewater that is most difficult to deal with because the pollutant concentration is often very high and unstable, notably the color. After an electrocoagulation pre-treatment, over 84,6% of the color has been removed from Nam Son landfill leachate, however the output value of color still exceeds the QCVN 40:2011/BTNMT, column B many times because these colours are usually sustainable organic compounds which cannot be treated by electrocoagulation. So, one of the advances oxidation processes, electro-fenton was employed to secondarily treat Nam Son landfill leachate, after an electrocoagulation pre-treatment.  The generation of hydroxyl radical depends on pH, Fe²⁺ ccatalyst concentration and current intensity. At the optimal condition: applied current of 1A, pH 3, Fe²⁺ concentration of  0.1m M,  after 60 minutes  of treatment in an electrofenton system using carbon felt and Pt gauze as electrodes, 98,55 color in Nam Son landfill leachate has been removed and the output value of color is 102 Pt-Co, reaching to QCVN 40:2011/BTNMT, column B. The research results indicated that electro-fenton process can promise as a potential method in practice for secondary treatment of colors in landfill leachate.