Browsing by Author "Bakari, Ramadhani"
Now showing 1 - 5 of 5
Results Per Page
Sort Options
Item Catalytic supercritical water gasification of biomass waste using iron-doped alkaline earth catalysts(Springer, 2022) Bakari, Ramadhani; Xiao Huang, Thomas Kivevele; Jande, Yusufu A. C.The objective of this study is to optimise the process of supercritical water gasification of rice husk biomass utilising a low-cost catalyst made from alkaline-earth materials. The interactions between catalyst loading and Fe content on gasification yield were investigated using response surface methodology. The catalyst characterisation findings revealed that the catalysts’ predominant reactive site is on iron oxide, calcium ferrite, and calcium oxide. Under all the conditions tested, the manufactured catalyst was highly active in promoting char gasification, gas volume, and gasification efficiency whilst the tar yield was substantially elevated. The maximum gasification efficiency of 69.57%, gas yield of 402.8 mL/g biomass, char yield 24.68 wt%, and gravimetric tar yield of 57.5 mg/g were obtained under the catalytic conditions of 15% catalyst loading with 5%Fe/limestone, 492 °C, 120-min residence time, and 9.5 wt% feed concentrations. Thus, the manufactured catalyst showed a potential for optimising gasification outputs.Item 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) Ripanda, Asha; Rwiza, Mwemezi J.; Nyanza, Elias Charles; Bakari, Ramadhani; Miraji, Hossein; Njau, Karoli N.; Vuai, Said Ali Hamad; Machunda, Revocatus L.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%.Item Exploring eco-friendly approaches for mitigating pharmaceutical and personal care products in aquatic ecosystems: a sustainability assessment(Elsevier, 2023) Hossein, Miraji; Asha, Ripanda; Bakari, Ramadhani; Islam, Nazim Forid; Jiang, Guangming; Sarma, HemenGlobal water scarcity is exacerbated by climate change, population growth, and water pollution. Over half of the world's population will be affected by water shortages for at least a month annually by 2050 due to a lack of clean water sources. Even though recycling wastewater helps meet the growing demand, new pollutants, including pharmaceuticals and personal care products (PPCPs), pose a health threat since conventional methods cannot remove them and their environmental monitoring regulations are yet in place. Therefore, the current review aims to investigate and propose eco-friendly technologies for removing PPCPs from wastewater and their implementation strategies for ecosystem safety. Findings indicated the absence of a single wastewater treatment technology that can remove all PPCPs in a single operation. Instead, biotechnological methods are one of the alternatives that can remove PPCPs from aquatic environments. In this context, community involvement and knowledge transfer are identified keys to clean water resources' long-term sustainability.Item Removal of lamivudine from synthetic solution using jamun seed (Syzygium cumini) biochar adsorbent(Elsevier, 2023) Ripanda, Asha; Rwiza, Mwemezi J.; Nyanza, Elias Charles; Bakari, Ramadhani; Miraji, Hossein; Njau, Karoli N.; Vuai, Said Ali Hamad; Machunda, Revocatus L.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 ecologyItem Sub- and supercritical water gasification of rice husk: parametric optimization using the I-optimality criterion(American Chemical Society, 2021) Bakari, Ramadhani; Kivevele, Thomas; Huang, Xiao; Jande, Yusufu A. C.In this study, rice husk biomass was gasified under sub- and supercritical water conditions in an autoclave reactor. The effect of temperature (350–500 °C), residence time (30–120 min), and feed concentration (3–10 wt %) was experimentally studied using the response surface methodology in relation to the yield of gasification products. The quadratic models have been suggested for both responses. Based on the models, the quantitative relationship between various operational conditions and the responses will reliably forecast the experimental outcomes. The findings revealed that higher temperatures, longer residence times, and lower feed concentrations favored high gas yields. The lowest tar yield obtained was 2.98 wt %, while the highest gasification efficiency and gas volume attained were 64.27% and 423 mL/g, respectively. The ANOVA test showed that the order of the effects of the factors on all responses except gravimetric tar yield follows temperature > feed concentration > residence time. The gravimetric tar yield followed a different trend: temperature > residence time > feed concentration. The results revealed that SCW gasification could provide an effective mechanism for transforming the energy content of RH into a substantial fuel product.