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The occurrence of multidrug-resistant (MDR) bacteria in ground-water samples from Osogbo, southwest Nigeria was investigated in this study. Bacteria isolated from the water samples were tested against antibiotics by disc diffusion method. Out of the 113 gram-- negative bacteria isolated, E. coli (28.32%) was the most predominant and the least was Serratia spp. (2.65%). All the isolates were 100% resistant to cefuroxime and <20% susceptible to ceftazidime and cefixime. More than 99% of the isolates were MDR and 33 (29.20%) were resistant to at least five classes of antibiotics. High prevalence of MDR bacteria in the groundwater indicates that the water sources are reservoirs of antibiotic resistance. [ABSTRACT FROM AUTHOR]

Environmental and public health concerns grow on the interaction of municipal solid waste (MSW) leachates from unlined waste disposal sites with aquifers in many developing countries. This study investigated the environmental pollution impacts of an unlined MSW landfill at Ajakanga area, Ibadan, southwest Nigeria. Analytical studies indicated that the concentrations of NO3−, SO42−, PO43−, NH4−, Cl−, Na, Fe, Mn, Cr, and Mo in the leachate samples exceeded the WHO wastewater discharge limits. Hydrochemical parameters of the groundwater and surface water were within WHO allowable thresholds, except for EC, TDS, Fe, Mn, and Pb in the groundwater and Pb, Cd, and Cu in the surface water, indicating major geogenic and minor MSW leachate impacts on the groundwater and surface water chemistry. Bacteria found in the leachate include Enterobacter cloacae (16.67%), Pseudomonas spp. (14.28%) and Bacillus spp. (9.52%). The geoelectrical imaging data indicated substratum leachate infiltration greater than 10 m deep, which is consistent with the low resistivity values of the topsoil-weathered basement layers. The health risk assessment showed high hazardous index values, indicating health risks of Mn, Cd and Pb in the surface water for the residents around Ajakanga landfill. Hydrochemical data indicated greater impact of the MSW leachates on the surface water than the groundwater, while geophysical data showed greater propensity of the surrounding aquifer to leachate interaction through fractured basement zone with increasing abstraction. Waste site closure and hydrochemical monitoring are suggested measures to mitigate environmental pollution in the study area. [ABSTRACT FROM AUTHOR]

Aim: Di-(2-ethylhexyl) phthalate (DEHP) has been identified as an endocrine-disrupting chemical, commonly found in the environment. The aim of this study was to isolate bacteria from municipal solid waste (MSW) leachates in Nigeria and its ability to degrade DEHP. Methodology and results: The DEHP degrading bacterium was isolated and identified. The degradation process was monitored aerobically at varying temperature and pH and the metabolites were determined using High Performance- Liquid Chromatography and Gas Chromatography-Mass Spectrometry, respectively. Based on the morphology and the 16S rDNA sequence, the bacterial isolate was identified as Bacillus aquimaris. B aquimaris was able to degrade 99% of 200 mg/L DEHP within 12 days. The optimum pH and temperature for its biodegradation were 8 and 25 °C, respectively and the intermediate metabolites were identified as butyl octyl phthalate and phthalic acid. Conclusion, significance and impact of study: This study showed that B. aquimaris could be a useful tool for the biodegradation of DEHP in the environment. [ABSTRACT FROM AUTHOR]

A ceramic water filter (CWF) coated with plant-based nanoparticles was used as household water purifier in a rural community. Silver nanoparticles (AgNPs) were produced from the stem bark of Bridelia ferruginea plant, and their efficacy to enhance the physical, chemical, and microbial quality of raw stream water sample was determined using analytical probes and pour-plate techniques, respectively. The pH of the filtered water sample ranged 7.6 to 8.1, which is within the WHO permissible limit for drinking water, and the electrical conductivity values were also reduced from 110 to 70 µS/cm. The CWF coated with AgNPs (CWF-AgNPs) removed Klebsiella pnuemoniae, Pseudomonas aeruginosa, Staphylococcus aureus , and Entamoeba histolytica from the stream water sample. The highest percentage of coliform reduction in the CWF and CWF-AgNPs were 93.18% and 99.64%, respectively. The raw data showed that the CWF-NPs enhanced the quality of the stream water. The surface and internal structure of the CWF-AgNPs can be modified by varying the concentration of the composite materials, so as to determine the most effective combination. The improved CWF-AgNPs will enhance achieving United Nations Sustainable Development Goal #6, which focuses on clean water and sanitation., Competing Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2024.)