Abstract:
A series of experiment on the adsorption of natural organic matter (NOM) originated frompeatwater in Central Kalimantan, Indonesia by local peat clay soils had been carried out.A selected local peat clay soil (LPC) and activated local peat clay soil (ALPC) had been used as adsorbents. The activation ofthelocal peat clay soilwas carried out by immersing itin 1 M HCl solution at 900oC. The effectsof pH on the adsorption capacitieswere investigated. It has been found that at lower pHs (3-5) the adsorption capacities increasedsignificantly. A rotary shakerwasset at 180 rpm asanagitator in performing the kinetically behaviour and adsorption isotherm of NOM ontotheLPC and theALPC. It was found that the equilibration time for theLPC and theALPC were 180 and 150 minutes,respectively. The kinetics equation model that most fittedto the adsorption experimental datafor theboth adsorbentswas pseudo-second orderkinetics model(r2> 0.99). The Dubinin-Radushkevichdepicted the data more accurately to describe the NOM-LPC and NOM-LAPC adsorption isotherms (r2> 0.99). Further analysis on the peat water NOM characteristics and local clay (LPC and ALPC) suggested that physical adsorption, mainly electrostaticinteractionsenhanced adsorption processand hydrophobic or solute drivenadsorption dominated in the early stage of theprocess, followed by a chemical adsorptionprocess.
