Modeling equilibrium adsorption of 2-methylisoborneol and geosmin in natural waters

The impact of natural organic matter (NOM) on the adsorption of the taste a nd odor causing compounds 2-methylisoborneol (MIB) and geosmin by powdered activated carbon was investigated. Equilibrium experiments showed that adso rption of MIB and geosmin in natural waters was an order of magnitude lower than single-solute adsorption. It was found that when the equilibrium conc entration was expressed as a percentage of the initial concentration, the r emoval of MIB and geosmin in natural waters was independent of initial conc entration. This relationship was also mathematically derived from the ideal adsorbed solution theorem when the concentration of the target compound wa s assumed to be much lower than the concentration of the competing NOM. A s ingle equivalent background compound (EBC) was used to simulate the competi tive effects of the background NOM and describe the adsorption of MIB and g eosmin. The same EBC was found to be applicable to both MIB and geosmin and , at different initial concentrations, for all four waters. Three of the wa ters had similar ratios of EBC initial concentration to total organic carbo n concentration. (C) 2000 Elsevier Science Ltd. All rights reserved.