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.