Occurrence and Removal Efficiencies of Four Antibiotics in Kisii and Kabarnet Waste Water Treatment Plants, Kenya
Joseph K. Wendott
Department of Chemistry and Biochemistry, Moi University, Kenya.
Munyendo L.L. Were
School of Pharmacy and Health Science, United States International University, Kenya.
Jackson Cherutoi
Department of Chemistry and Biochemistry, Moi University, Kenya and African Centre of Excellence in Phytochemistry, Textiles and Renewable Energy, Kenya.
Mark P. Odero *
Department of Applied Sciences, Rift Valley Technical Training Institute, Kenya.
*Author to whom correspondence should be addressed.
Abstract
Background: Antibiotics are presently considered as emerging contaminants with adverse effects in the environment and the population such as the development of antimicrobial resistant genes (ARG) and antimicrobial resistant bacteria (ARB). This study was guided by objective entailing to determine the seasonal occurrences and removal efficiencies of four antibiotics in Kisii and Kabarnet waste water treatment plants in Kenya.
Place and Duration of Study: Waste water samples were picked from Suneka wastewater treatment plant in Kisii county and Kabarnet Level V Hospital in Baringo County Kenya in the months of June and December 2020
Methodology: Multiple samples were picked in Kisii and Kabarnet waste water treatment plants in the months of June and December correspond to the dry and wet seasons in Kenya. Collected waste water samples were centrifuged and filtered with glass microfiber filter papers and subsequently passed through a Solid phase extractor cartridge. High Performance Liquid Chromatography was used for quantification of antibiotics as per international commission for harmonization and subsequently applied for analysis.
Results: The results revealed that the dry season had higher antibiotic concentrations at 1.29, 0.09, 2.92 and 1.82 µg/l for sulphamethoxazole, trimethoprim, ampicillin and amoxicillin respectively for the Kisii waste water treatment plant and 0.18, 0.05, 1.34 and 0.09 µg/l respectively for Kabarnet waste water treatment plant. During the wet seasons the measured concentrations were 1.11, 0.14, 2.04 and 1.34 µg/l for sulphamethoxazole, trimethoprim, ampicillin and amoxicillin at the Kisii WWTP, and 0.14, 0.06, 1.01 and 0.09 µg/l for Kabarnet WWTP. The removal efficiencies in the WWTPs, ranged from a high of 94 % to a low of 11.11 % depending on the type of antibiotic in both wet and dry seasons.
Conclusion: Amoxicillin, ampicillin, trimethoprim and sulphamethaxazole were found in both Kisii WWTPs and Kabarnet WWTPs with nearly all antibiotics having a higher concentration of in the dry season than in the wet season. The highest calculated percentage removal was 94.03 % while the lowest calculated percentage removal was 7.14 %. The results suggest that the two WWTPs are effective for the removal of different types of antibiotics.
Keywords: Antibiotics, removal efficiency, seasonal variation, HPLC