Abstract:
The adsorption characteristics of metsulfuron-methyl (MM) onto powdered
activated carbon (PAC) and granular activated carbon (GAC) were studied at varying
solution pHs (4–9) and temperatures (20–408C). The dependence of pH was observed
in aqueous solution with MM. The film mass transfer and intraparticle diffusion coefficients
were estimated from concentration decay curves obtained in the batch adsorber.
The maximum adsorption capacity decreased with increasing pH and temperature.
Among the PAC used, the coconut based PAC had the best adsorption capacity. The
adsorption isotherms could be plotted using the Freundlich and Toth models with a
reasonable degree of accuracy. The overall adsorption isotherm such as the
modified-Toth model should be applied. The performances of the fixed-bed GAC
system was also simulated by a model developed. The objective of the present study
was to investigate the adsorption and pH dependence behavior of MM onto PAC
and GAC in order to diminish the environmental risk of MM pollution.
