Browsing by Author "Miraji, Hossein"

Now showing 1 - 4 of 4

Antibiotic-resistant microbial populations in urban receiving waters and wastewaters from Tanzania
(Elsevier, 2023) Ripanda, Asha; Rwiza, Mwemezi; Nyanza, Elias; Miraji, Hossein; Bih, Numfor; Mzula, Alexanda; Mwega, Elisa; Njau, Karoli; Vuai, Said; Machunda, Revocatus
Antimicrobial resistance against certain medications in the pathogenic microbial community is globally increasing due to the continual discharge and disposal of pharmaceuticals in the environment. The phenomenon resulted in significant antibiotic resistance among several exposed Enterobacteriaceae species, with wastewater treatment plants (WWTPs) and rivers serving as significant reservoirs. Despite antibiotic resistance being a tragedy, particularly in treating diseases by using antibiotics, local and regional studies indicating the severity, resistant species and the molecular level insight into these pathogens are scarce, thus requiring immediate intervention. This study, therefore, investigated wastewater from wastewater treatment ponds and receiving waters for the presence of resistant pathogens through phenotypical and molecular approach screening of their genes. Among the 57 analyzed samples, 18 (67%, n = 27) isolates of Klebsiella spp.., 4 (80%, n = 5) isolates of Proteus spp., 1 (100%, n = 1) of isolated Pseudomonas aeruginosa and 6 (18%, n = 34) of E. coli found were resistant to at least 1 among the tested antibiotics. E. coli had an 83% higher proportion of multi-drug resistance (MDR) than Klebsiella spp.., which had 68.5%, and no MDR was shown by P. aeruginosa isolates. Among the 20 bacterial isolates of antibiotic-resistant genes, showed that E. coli harboured 39%, followed by 22% of Klebsiella spp. Eleven (11) isolates of these 20 (55%) contained sulphonamides resistant genes: Sul 1 (n = 4) and Sul 2 (n = 7). Ten (10) isolates (50%) contained the tetracycline-resistant genes in which 4 isolates showed the Tet A, Tet B – 1 and 5 isolates contained Tet D. β-lactamases (bla CTX-M and bla SHV) were found in 7 isolates (35%). The existence of these antibiotic-resistant species in the urban receiving and wastewater presents a threat of transmission of diseases to humans and animals that are not cured by the existing medications, jeopardizing public health safety.
Data from the batch adsorption of ciprofloxacin and lamivudine from synthetic solution using jamun seed (Syzygium cumini) biochar: Response surface methodology (RSM) optimization
(Elsevier, 2023-02) Ripanda, Asha; Rwiza, Mwemezi; Nyanza, Elias; Bakari, Ramadhani; Miraji, Hossein; Njau, Karoli; Vuai, Said; Machunda, Revocatus
This dataset expresses the experimental data on the batch adsorption of ciprofloxacin and lamivudine from synthetic solution using jamun seed (JS) (Syzygium cumini) biochar. Independent variables including concentration of pollutants (10-500 ppm), contact time (30–300 min), adsorbent dosage (1-1000 mg), pH (1-14) and adsorbent calcination temperature (250,300, 600 and 750 °C) were studied and optimized using Response Surface Methodology (RSM). Empirical models were developed to predict the maximum removal efficiency of ciprofloxacin and lamivudine, and the results were compared with the experimental data. The removal of polutants was more influenced by concentration, followed by adsorbent dosagage, pH, and contact time and the maximum removal reached 90%.
Jamun Seed (Syzygium Cumini) Biochar as a Potential Adsorbent for Environmental Applications
(Engineered Science Publisher, 2025-02-18) Ripanda, Asha; Rwiza, Mwemezi; Giridhar Reddy, S.; Nyanza, Elias; Bakari, Ramadhani; Miraji, Hossein; Ravikumar, C. R.; Ananda Murthy, H. C.; Vuai, Saidi; Machunda, Revocatus; Annamareddy, Sri Hari
This study investigates the properties and adsorption performance of jamun seed biochar (JS biochar) produced through calcination at varying temperatures. Elemental analysis reveals that the carbon content significantly increases from 64.25 to 87.93 wt.% as calcination temperature rises from 400 to 600 °C, while nitrogen content remains within the range of 2 to 2.29 wt.%. The biochar's surface characteristics, with a maximum specific surface area of 261.2 m²/g, demonstrate strong adsorption capacity for small organic molecules, including ciprofloxacin (555.55 mg/g) and lamivudine (400 mg/g). The identified functional groups, including hydroxyl and carbonyl groups, enhance adsorption through mechanisms such as hydrogen bonding and electrostatic interactions. The observed porous, rough surface morphology supports the material's effectiveness as an adsorbent. The results demonstrate JS biochar’s high adsorption capacity, governed by a synergistic interplay of physisorption and chemisorption. This research underscores the potential of JS biochar as a sustainable and effective solution for environmental remediation, particularly in mitigating aqueous pollutants. The findings offer valuable insights for optimizing biochar properties to improve adsorption efficiency, thereby promoting sustainable waste management and environmental remediation.
Removal of lamivudine from synthetic solution using jamun seed (Syzygium cumini) biochar adsorbent
(Emerging Contaminants, 2023-09-01) Ripanda, Asha; Rwiza, Mwemezi; Nyanza, Elias; Bakari, Ramadhani; Bakari, Ramadhani; Miraji, Hossein; Njau, Karoli; Vuai, Said; Machunda, Revocatus
Antiviral drugs such as lamivudine have been globally identified in the environment and marked as emerging pollutants of concern due to their bioactive extremity. Following therapeutic uses, approximately 70% of the oral dose of lamivudine is eliminated renally as the parent drug. Concerns has been raised for neighbouring aquatic bodies due to effluent produced from production plants containing high concentrations of antiviral drugs. Antiviral drugs, such as lamivudine, are extremely bioactive, prompting interest in their urgent removal from the environment. The purpose of the present study was to optimize the removal of lamivudine from the synthetic solution using jamun seed (JS) (Syzygium cumini) biochar. The influence of sorption parameters such as pH, lamivudine concentration, adsorbent dosage, contact time, and calcination temperatures on the removal of lamivudine was investigated and optimized using a response surface methodology (SRM) based on optimal design. The results indicated that, a quadratic model best fits data with a model regression coefficient R2, adjusted R2, and predicted R2 of 0.9934, 0.9761 and 0.8340, respectively. The JS biochar calcined at 750 °C, at pH 8, initial lamivudine concentration of 10 ppm and contact time of 30 min indicated a maximum experimental removal efficiency of 84.9%. The residual standard error (RSE) value was 3.5% implying that the model was reliable. Isotherm data for the adsorption of lamivudine on JS biochar followed the Freundlich isotherm, with an R2 value of 0.9977 while R2 for the modified Langmuir model was 0.9852. These findings indicated that JS biochar is potentially useful for removal of lamivudine, and other organics from contaminated water and wastewater effluents. Therefore, this study presents an environmentally friendly remedy against lamivudine for a healthier ecology.