Removal of Oxytetracycline in Simulated Wastewater by Coagulation

DOI: 10.5176/2301-3761_CCECP.46

Authors: Aileen D. Nieva, Kathleen Mae A. Cedula

Abstract:

Oxytetracycline (OTC) is a tetracycline derivative obtained from a soil bacterium named Streptomyces Rimosus. OTC is excreted unchanged primarily via glomerular filtration. Most wastewater treatment plants rely on conventional processes such as coagulation and Poly-aluminum chloride (PACl) was used as the coagulant. The presence of dissolved organics such as humic acid could cause a decrease in the percent removal of OTC. The main objective of this study is to quantify the efficiency of removal of OTC in the simulated wastewater after coagulation process using PACl in the presence of humic acid. The effects of the presence of humic acid, the pH of the effluent and the optimum concentration of PACl at 35, 45 and 55 ppm humic acid that will yield the highest percent removal of OTC were also determined. Fixed concentration of OTC which is 0.1 ppm was used in the simulated wastewater. The initial pH of the solutions was set to 4, 6 and 8. Fixed concentration of PACl which were 40, 50 and 60 ppm were used throughout the experiment. For all of the solutions, the dosage of humic acid was from 5 ppm to 60 ppm with 5 ppm intervals. The treated water was analyzed using UV-Vis Spectroscopy. Results showed that the percent removal of OTC decreased when humic acid was present. The optimum percent removal of OTC obtained for both blank and with humic acid samples were 89.4{6e6090cdd558c53a8bc18225ef4499fead9160abd3419ad4f137e902b483c465} and 66.6{6e6090cdd558c53a8bc18225ef4499fead9160abd3419ad4f137e902b483c465} at pH 6, respectively. The pH of the effluent after coagulation at the set conditions of pH 4 and 6 increases slightly. But at pH 8, the pH of the effluent decreases slightly. Knowing the optimum raw water conditions will provide information on more efficient coagulation treatment to ensure that antibiotic resistance, bioaccumulation and biomagnification can be mitigated.

Keywords: oxytetracycline (OTC); polyaluminum chloride; humic acid; UV-Vis Spectroscopy