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The presence of pharmaceuticals in the environment presents a challenge to researchers to develop new technologies to remove or destroy these contaminants. A major fraction of pharmaceuticals in the waste stream comes from urine, where ~70% of consumed pharmaceuticals are excreted. Only about 1% of the total waste stream is made up of urine therefore urine source separation has been proposed as a more efficient treatment method to isolate pharmaceuticals at a much more concentrated level and smaller volume. The purpose of this research was to investigate the removal of 5 common pharmaceuticals (diclofenac, ibuprofen, naproxen, ketoprofen, and paracetamol) in synthetic human urine under ureolyzed conditions. Ion-exchange equilibrium experiments were conducted using four resins (Purolite A520E, Dowex 22, Dowex Marathon 11, and Amberlite IRA958) to remove diclofenac (C0 = 0.2 mmol/L) from urine. The experimental equilibrium data was fit non-linearly using Matlab to the Freundlich, Langmuir, Dubinin-Radushkevitch (D-R), and Dubinin-Astakhov (D-A) isotherm models. It was determined from these isotherms that Dowex 22 had the highest affinity for diclofenac. The isotherm model was used to estimate resin requirements to remove diclofenac, and other pharmaceuticals at realistic concentrations in urine (C0 = 2000 µg/L). Equilibrium experiments of each pharmaceutical, as well as a mixture of acidic pharmaceuticals will be conducted in ureolyzed urine. It is expected that removal of the mixture of acidic pharmaceuticals will be additive. If the hypothesis is correct, the individual pharmaceutical isotherms can be used to predict how the removal of various mixtures of pharmaceuticals will behave. The resultant isotherms will be used to design a column experiment to understand the practical application of ion-exchange resins for pharmaceutical removal. |