Color and Chemical Oxygen Demand Removal from Mature Semi-Aerobic Landfill Leachate Using Anion-Exchange Resin: An Equilibrium and Kinetic Study

摘要

Stabilized leachate generated from an aged sanitary landfill is typically classified as nonbiodegradable. The ionnexchange technique has been rarely used for the treatment of stabilized landfill leachate, particularly for thenremoval of color and nonbiodegradable substances (measured as chemical oxygen demand [COD]). Thus, thisnstudy was undertaken to examine the effectiveness of anion-exchange resin (i.e., INDION FFIP MB) in removingncolor and COD from stabilized semi-aerobic landfill leachate in Malaysia. To predict the performance of thenprocess, the effects of anion exchanger dosage, shaking speed, contact time, and pH on pollutant removalnefficiency were investigated. Adsorption of color and COD was realistically explained through Langmuir andnFreundlich isotherms. Adsorption kinetics mechanism was studied using reaction-based models. The anionicnresin efficiently removed 91.2% color and 69.4% COD at pH 3 and removed only 69.4% color and 60.3% COD atnpH 9. The color and COD adsorption data were fitted to the Langmuir and Freundlich isotherms. The monolayernadsorption capacity was found to be 15.2 Pt-Co/g for color and 3.7mg/g for COD. Pseudo second-order modeln(R2 > 0.99) sufficiently described the adsorption kinetics, which indicates that the adsorption process was controllednby chemisorptions.