Use of Dubinin-Astakhov Equation to Describe Preloading Effect of Natural Organic Matter

• Published in: Journal of environmental engineering (New York, N.Y.) N.Y.), 2004-04, Vol.130 (4), p.472-477
• Main Author: Qi, Shaoying
• Format: Article
• Language: English
• Subjects: Applied sciences; Biological and physicochemical phenomena; Exact sciences and technology; Natural water pollution; Pollution; TECHNICAL NOTES; Water treatment and pollution
• ISSN: 0733-9372; 1943-7870
• DOI: 10.1061/(ASCE)0733-9372(2004)130:4(472)

This note presents a simple model to quantify the preloading effect of naturally occurring organic matter (NOM) in water on the adsorption capacity of activated carbon for a trace synthetic organic chemical (SOC). The model was developed from the Dubinin-Astakhov (DA) equation based on the assumption that the NOM preloading irreversibly reduced the limiting adsorption pore volume for the target SOC. Given that the DA-n value equal to one, the model reduces to a form similar to the one obtained by modifying the Freundlich equation directly. By assuming that the reduction of the limiting adsorption pore volume was proportional to the volume of NOM adsorbed, the NOM preloading effect was correlated directly to the amount of total organic carbon preloaded on the carbon. The resulting model was then compared with the experimental data in the literature. This simple model may be useful for certain practical applications that require only the estimation of the NOM preloading effect on the adsorption capacity of a target SOC from natural water.