Humic Substances Removal by Activated Carbon

A commercial humic acid and a fulvic acid extracted from peat were used to evaluate the removal of humic substances by various activated carbons. Different analytical methods were investigated to determine humic substances as possible indicators of chloroform formation potential. Total organic carbon measurement and ultraviolet/visible absorbance correlate well with the chloroform formation potential of humic substances. Evidence was found that pore size distribution was the most important physical characteristics of activated carbon for adsorption of humic substances. Pore volumes of activated carbon in pores between 100 and 500 (ANGSTROM) radius were correlated with adsorption capacity. A decrease of pH in solution, lower molecular weight fractions of humic substances, smaller carbon particles, and presence of soluble alum were found to increase the carbon adsorption. The chemical pretreatment with alum increased the absorption capacity of carbon almost threefold. This increase of adsorption capacity is probably because of the removal of weakly- or non-adsorbable humic substances by alum coagulation. The presence of soluble alum in the solution also enhances the adsorbability of humic substances. The application of a developed mathematical model to predict the performance of the carbon bed for the adsorption of humic substances was successful. Model parameter estimation techniques and model verification were evaluated and the applicability of the model was verified. In general, this model is sensitive to values of adsorption capacity of activated carbon and the surface diffusion coefficient of humic substances inside the adsorbent particle. The surface diffusion coefficient was also correlated with the adsorption capacity. The higher the adsorption capacity, the lower the diffusion coefficient. Based on the model predictions, the empty bed contact time of the carbon bed and the influent concentration were the two most important factors in designing a carbon bed for humic substance removal.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Environmental Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Lee, Michael Chiang-Yuan

• Engineering, Civil

Language dc:language

eng

Identifier

(UMI)AAI8017969

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/66875