Abstract:
Adsorption equilibria and kinetics are important to evaluate the effectiveness of an adsorption system. In this
study, the adsorption behavior of organics in secondary effluent from a sewage treatment plant was investigated, using
granular activated carbon (GAC) as an adsorbent. This paper provides details on the adsorption experiments conducted in a
sewage treatment plant, and emphasizes the suitability of the association theory for describing adsorption characteristics of
secondary sewage. The association theory was found to describe the overall adsorption equilibrium ofthe sewage system
more precisely (with 0.33% error) than the more commonly-used Freundlich isotherm (with 9.9% error). The linear driving
force approximation (LDFA) model and the fixed bed dynamics were used to predict the batch kinetics and the fixed
bed adsorption experimental results respectively. The prediction was only slightly better when the isotherm parameters
estimated from the association theory were used. Average errors in predicting batch and fixed bed experimental results
were 0.25 and 0.55% with the association theory, and 0.34 and 0.75% with the Freundlich isotherm, respectively.
