Occurrence and Removal Efficiencies of Four Antibiotics in Kisii and Kabarnet Waste Water Treatment Plants, Kenya

Joseph K. Wendott — 2024-04-15

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.

Optimization of Tannin’s Extraction from Cashew (Anacardium occidentale L.) Nut Testa for Use in Leather Tanning

Sharif Zuberi Mwangi — 2024-04-26

Extensive researches have been conducted over the years, focusing on the use of vegetable tannins to reduce pollution caused by mineral tanning. Vegetable tannins have been utilized commercially, but they remain costly and are not easily accessible. The purpose of this study was to optimize the tannin’s extraction from cashew (Anacardium occidentale L.) nut testa using water in order to determine their suitability in leather tanning. Samples of cashew nut testa were collected randomly from cashew nut processors in Mtwara region, Southern Tanzania. They were shade-dried and ground into powder. Various ratio of powder/water (1:6, 1:9, 1:12 and 1:15) -on weight basis were made for extraction, maintained at a temperature of 70 ⁰C for 90 minutes. Results showed that, depending on the extract ratios, different tannin concentrations were obtained which had an implication on tannin extracted from powder. Experiment was found solution with ratio 1:9 have shown to extract about 50.73% of total tannins presented on cashew nut testa powder followed by solutions with ratio 1:12, ratio 1:15, and ratio 1:6 extracted about 46.27%, 43.51% and 38.95% respectively. Suitability of various tannins solution extracted from cashew nut testa was tested using conventional tanning process on sheepskins. The physical properties of the resultant leathers were determined using the standard methods (TBS/ISO). Under given condition, it has shown that using the ratios of 1:6, 1:9, 1:12 and 1:15 resulted in leather with tensile strength ranging between 19.41+6.36 MPa and 43.00+8.18 MPa and elongation at maximum load in the range of 34.48+10.12 % to 77.56+10.96 %., average shrinkage temperatures were above 75^oC, and flexing test gave no damage of leather at 100,000 flexes. The physical properties of leather recorded have shown to meet the minimum recommended values from the standard (ISO 14931-2021). The mixing ratio 1:9 of cashew nut testa powder/water has been recommended for extracting tannin for vegetable tanning.

Asian Journal of Applied Chemistry Research

Occurrence and Removal Efficiencies of Four Antibiotics in Kisii and Kabarnet Waste Water Treatment Plants, Kenya

Optimization of Tannin’s Extraction from Cashew (Anacardium occidentale L.) Nut Testa for Use in Leather Tanning