Application of polypyrrole nanofibers in the selective extraction of methotrexate and its polyglutamate metabolites from hospital effluents

A novel solid-phase extraction(SPE)strategy based on polypyrrole(Ppy)nanofibers was developed for the determination of trace methotrexate and its polyglutamate metabolites(MTXs)in hospital effluents.Ppy was coated on the surface of electrospun polystyrene nanofibers by in situ oxidative polymerization to form Ppy electrospun nanofibers.The mechanism of adsorption on MTXs was explored through static adsorption studies.The MTX contents,after extraction,were determined by liquid chromatography-tandem mass spectrometry analysis.Results show that the physical/chemical adsorption of targets occurs on the surface of Ppy nanofibers,which is most likely dominated by multiple adsorptions and heterogeneous adsorption sites.Ppy nanofibers exhibit satisfying extraction performance.The content of targets detected in medical wastewater samples ranges from 21 to 2908 ng/L.The novel strategy based on Ppy nanofiber SPE can extract trace MTXs effectively,guarantee analytical accuracy,and circumvent the storage and transportation of water samples during on-site sampling operations.

Microbiological Quality of the Effluents Produced by the University and Hospital Centres in the Department of Littoral, Republic of Benin

Introduction: The effluents generated by hospital activities pose a potential danger to health and the environment. This study aimed to study the microbiological quality of the effluents produced by the university and hospital centres of Littoral department. Methods: This was a descriptive cross-sectional study of 60 samples of hospital effluents from sewage treatment plants and septic tanks carried out during the period from April to June 2019. Samples at the station were made at the entrance and exit of the station. Samples for microbiological analysis were collected in pre-sterilized 500 mL glass bottles. Samples were kept between at 2°C - 8°C and in the dark to ensure satisfactory preservation. ANOVA one-way analysis of variance was performed for each microbiological parameter and principal component analysis (PCA) was also performed. Results: The bacteriological analyses carried out on the 60 samples taken showed a significant microbiological load. In fact, the bacteriological parameters measured and compared to the pollutant release standards in the environment show that the number of germs identified is above the recommended guideline values. The average values for total coliforms, faecal coliforms, faecal streptococci and staphylococci were: 3.91 × 105 UFC/100 mL, 0.52 × 105 UFC/100 mL, 3.92 × 105 UFC/100 mL and 1.36 × 105 UFC/100 mL, respectively. The most isolated bacteria were: Klebsiella pneumoniae, Klebsiella oxytoca, Escherichia coli, Enterococcus faecalis, Enterobacter cloacae, Pseudomonas horizyhabitans, Staphylococcus aureus and Staphylococcus saprophyticus. Most strains were resistant to at least 3 families of antibiotics (beta-lactams, aminoglycosides and fluoroquinolones). Conclusion: These effluents therefore present health and environmental risks. It is of utmost importance to develop methods for the treatment of these effluents before their release into the natural environment.