Separation of humic matter from groundwater via anion exchange resin: Comparison of bead and powder form
This work describes a comparison of a bead and powder form of anion exchange resin for removing humic matter from groundwater. The materials and procedures described herein involve a manufactured dry humic matter and two forms of the same anion exchange resin. Spectroscopy was the chosen procedure for analysis of organics. Preliminary experiments were required to gain a better understanding of the materials and to prepare the best conditions for actual experimental research. Five concentrations of humic acid were used for experimental purposes at 0.5, 1, 5, 10 and 20 mg/L. Three concentrations of resin were used: 500, 750 and 1000 mg/L for both bead and powder form of resin. These humic acid concentrations were chosen because ranges found in nature are between 1-10 mg/L. Resin concentrations were selected after a set of preliminary experiments was conducted. This research tested the hypothesis that more surface area on the powder form of resin will result in more and faster organic removal compared to the same resin in bead form. After applying kinetic model equations the hypothesis was proven correct. The resin in powder form achieved approximately 90% removal of humic matter in 10 min minutes; the resin in bead form achieved only approximately 30% removal in 15 minutes. Kinetic experiments were conducted for different combinations of resin and humic acid. Kinetic experiments show the change in concentration over a period of time; this is useful to better understand the removal reaction that is occurring. Data was collected in the laboratory to obtain first and second order kinetic plots and results were compared to determine best fitting. Second order showed higher correlation for both forms of resin with r-squared values no less than 0.95. Batch equilibrium experiments were conducted to study the effect of pH and feed concentration on humic acid removal efficiency. Langmuir and Freundlich adsorption isotherm models were applied to correlate the experimental data. The results proved conclusive with a favor of Langmuir isotherm.
Everett, Sandra June, "Separation of humic matter from groundwater via anion exchange resin: Comparison of bead and powder form" (2011). ETD Collection for University of Texas, El Paso. AAI1494345.