COMPETITIVE ADSORPTION OF TRICHLOROETHYLENE AND HUMIC SUBSTANCES FROM GROUNDWATER ON ACTIVATED CARBON

The interactions between trichloroethylene (TCE) and humic substances during simultaneous adsorption from groundwater on activated carbon were investigated using a batch equilibrium, rate test and the laboratory scale column system. The column apparatus was used for the comparative experiments of TCE removal from raw water and from water pretreated in a separate activated carbon column. Results obtained show, that the presence of natural organic background in groundwater can considerably decrease the adsorption rate and activated carbon capacity for TCE. The modified SCAM model can be useful for the prediction of the isotherms of TCE and humic substances in the bicomponent systems. The DCBR rate data for TCE removal cannot be successfully predicted using the HSDM model assuming surface diffusion inside of the carbon particles. Complexation effects are supposed to be responsible for the observation of the desorption of relatively low amounts of TCE and the lack of the competitive effect of humic substances on TCE isotherm at the low concentration level. © 1990.