Physical-Chemical Treatment of Stabilized Leachate : USING LIMESTONE, ACTIVATED CARBON AND ZEOLITE

Leachate from a landfill in Taiping was characterized. The potential use of activated carbon, limestone and zeolite and their possible mixtures as an adsorbent was investigated. The batch experiments demonstrated that both combine mixtures of activated carbon with zeolite at 15:25 and activated carbon with limestone and zeolite at 15:10:15 gave the best results. Both Langmuir and Freundlich isotherms fitted well to the experimental data. The kinetic results showed that the data fitted well with the pseudo second order equation. The regeneration experiments showed that 0.2 M HNO3 can be used to regenerate activate carbon and 0.2 M HCl and NaCl mixture and regenerate zeolite. Results of the continuous flow experiments for both mixtures indicated that removal can reach up to 50-90% of colour, 70-90% of COD, 85-90% of iron and 50-90% of ammoniacal nitrogen. The results indicated that the arrangement of layers of adsorption media inside the column is not significant. It can be concluded that the activated carbon-limestone-zeolite and activated carbon-zeolite mixtures media exhibited better results for all parameters as compared with the use of individual media.