Municipal Landfill Leachate Treatment by Advanced Oxidation Process (Ultrasound/H2O2)

Municipal landfill leachate has pollutant and refractory matters. Advanced oxygen procrsses (AOPs) are one of the wastewater treatment methods which have refractory matters. The aim of this research was to evaluate the effect of ultrasound as AOP and ultrasound and H2O2 simultaneously on reduction of leachate organic load and VSS:FSS ratio. This was an experimental study. In the first stage, organic matters are determined in raw leachate collected randomly. Then samples are sonicated in an ultrasonic bath to determine sonication effect on leachate. Each 400 ml sample was sonicated in four sonication times: 10,20,30, and 40 minutes. In other sonication step, H2O2 is added in 0.05 and 0.1 mol per liter, and samples are analyzed. Each sample was analyzed before and after sonication to determine: COD, VSS and FSS. The most COD reduction rate was 8.22% in 40 min sonication. When H2O2 was added (0.05 mol/lit), COD reduction was 19.60%. When H2O2 was added (0.1 mol/lit), COD reduction was 19.72%. The ratio of VSS:FSS was 2.06 in raw leachate. After 10 min sonication, VSS:FSS ratio was decreased to 1.67. When H2O2 was added (0.05 mol/lit) in raw leachate, VSS:FSS ratio is increased to 2.94. The ratio of VSS:FSS was decreased to 2.67 and 2.16 when sonication (10 and 40 min) and H2O2 (0.05 mol/lit) was used, respectively. The ratio of VSS:FSS was increased to 3.61 and 2.16 when sonication (10 and 40 min) and H2O2 (0.1 mol/lit) was used, respectively. The results show that ultrasound can reduce VSS in leachate as pretreatment. H2O2 as an oxidant agent can also reduce organic matters in leachate and can be affect efficiency in next step of leachate treatment.