Keywords: adsorption kinetics, limestone, activated carbon, anaerobic landfill, leachate treatment, colour removal, iron removal, COD removal, chemical oxygen demand, nitrogen removal, ammoniacal nitrogen, old landfills, landfill leachate, Malaysia, chemisorption, ion exchange
Primary treatment of anaerobic landfill leachate using activated carbon and limestone: batch and column studies
Leachate generated from an old landfill in Taiping, Perak, Malaysia contains high colour, COD, iron and ammoniacal nitrogen. Activated carbon?limestone mixture was used as a primary treatment process. More than 86% of colour and COD, 95% of iron, and 48% of ammoniacal nitrogen were removed by a mixture of activated carbon and limestone (15:25 by volume) in the batch study compared with 70, 80 and 90% respectively, by column study on the first five days. Both Langmuir and Freundlich isotherms had fitted well with the experimental data. The adsorption kinetics followed the pseudo-second-order model indicating that chemisorption or ion exchange was the rate-controlling step in the adsorption.