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Oxidation of pharmaceuticals and personal products by permanganateGibson, Sara Nichols 08 April 2010 (has links)
Pharmaceuticals and personal care products (PPCPs) are widely used, resulting in trace amounts being detected in the aquatic environment. This presence is of human health and ecological concern and it is necessary to determine the best methods to eliminate them from our waters. The oxidation of PPCPs by permanganate was evaluated using a spectrophotometer to monitor permanganate reduction. Thirty-nine compounds were chosen to represent numerous classifications, including beta blockers, cephalosporins, fluoroquinolones, macrolides, non-steroidal anti-inflammatory drugs, phenol structures, polypeptides, sulfonamides, tetracyclines, and triazines. The reactivity of each compound was determined by measuring the absorbance of permanganate over time as it reacted with an excess of the compound. The absorbance data was fit to a pseudo-first-order reaction model that accounted for the growth of manganese dioxide colloids. The most reactive groups that reduced permanganate within minutes at pH 7.0 were the cephalosporins, phenol structures, and tetracyclines. The majority of the remaining pharmaceuticals and personal care products were moderately or weakly reactive (reducing permanganate within hours). Caffeine, carbadox, monensin, simetone, and tri(2-carboxyethyl)phosphine were poorly reactive (reducing permanganate over days). Metoprolol was the only selected compound that was determined to be potentially non-reactive (no reaction after 1 day). Polarizability and refractive index of the organic compounds showed significant positive correlations (R-squared > 0.50) with the first-order reaction rates for non-steroidal anti-inflammatory drugs and the phenol structures group. The half-life of each PPCP was determined based on a typical dosage of permanganate used for pre-oxidation. Eleven of the thirty-nine PPCPs had a half-life of less than thirty minutes (a typical contact time), indicating that oxidation by permanganate may be a viable option. There are many opportunities for further research in this area, including investigating more PPCPs, physicochemical property correlations, and the impact of water quality conditions
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