[Comparisons of three advanced oxidation processes in organic matter removal from Esfahan composting factory leachate]

ABSTRACT

Wet air oxidation [WAO] is one of the advanced oxidation process which is mostly used to reduce organic matter concentration from industrial wastewater, toxic and non biodegradable substance and solid waste leachate. The objective of this paper is comparisons of three advance oxidation in organic matter removal in different conditions from Esfahan composing factory leachate. The experiment was carried out by adding 1.5 Lit pretreated leachate sample to 3Lit autoclave reactor and adding 10 bar pressure at temperature of 100, 200 and 300 °C and pressure [10 bars] with retention time of 30, 60 and 90 min. leachate sample in 18 stages from composting factory in Isfahan in the volume of 20 lit was taken and the three methods WAO, WPO, and a combination of WAO/GAC were used for pre-treatments. Pure oxygen and 30% hydrogen peroxide was used as oxidation agent. The result shows significant improvement on the removal rate of COD [7.8-33.3%], BOD5 [14.7-50.6%] by WAO process. The removal efficiency of 4.6-34% COD, 24-50% BOD, was observed in the reactor. Adding the GAC to the reactor improved removal efficiency of all parameters. Combination Process [WAO/GAC] removed 48% of COD, 31-43.6% of BOD. Combination process demonstrated higher efficiency than two other previous methods as BOD5/COD ratio of 90% achieved. The WAO process presented in this paper is efficient for pretreatment of leachate, And the modified WPO process remove organic materials and ammonia moreover WAO/GAC can be considered as an excellent alternative treatment for removing reluctant organic matter [COD, BOD5] and organic nitrogen compounds, which found in leachate