The removal of toxic and harmful dyes like methylene blue (MB) from textile wastewater is necessary to reduce environmental pollution. Therefore, this study is aimed at removing MB from an aqueous solution using magnetite-doped biochar of parthenium hysterophorus. Biochar was prepared through pyrolysis techniques at 500 ℃ for 2 h whereas the magnetite and composite material were developed using coprecipitation methods. Herein, NaNO3 and FeSO₄. 7H₂O were utilized as precursor materials and NaOH as a precipitating agent for preparation of magnetite. Furthermore, pH point of zero charge (pHpzc), Scanning Electron microscope (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray Diffraction (XRD) are characterization techniques used to evaluate the nature of the composite material. On the other hand, a full factorial design involving four factors at two levels (2⁴) such as pH (3 and 9), contact time (10 and 40 min), initial dye concentration (100 and 150 mg/L) and adsorbent dosage of 0.01 and 0.04 g/100 mL was used to design and optimize the batch adsorption of MB from an aqueous solution. As a result, a maximum removal efficiency of 99.99% was attained at optimum operating conditions of pH 9, contact time 40 min, initial MB concentration 100 mg/L and adsorbent dosage of 0.04 g/100 mL. Langmuir, Freundlich and Temkin isotherm models were used to investigate the adsorption isotherm in which Freundlich isotherm with a maximum R² of 0.98 was found to describe the adsorption process inferring multilayer and heterogeneous surface interaction. Additionally, the thermodynamics study depicts that the nature of the adsorption is spontaneous, endothermic and feasible. On the other hand, the chemosorption nature is revealed by the pseudo second kinetics model with a maximum R² of 0.99. Finally, the remarkable reusability ranging from 99.98% to 97.6% for five consecutive cycles proved that the magnetic biochar derived from parthenium hysterophorus can be used as an effective adsorbent for the decolourization of MB saturated effluent at an industrial scale.

This work focused on the decolorization of methyl red (MR) from an aqueous solution utilizing Rumex abyssinicus-derived biochar (RAB). RAB was prepared to involve unit operations such as size reduction, drying, and carbonization. The pyrolysis of the precursor material was carried out at a temperature of 500 °C for two hours. After that, the prepared RAB was characterized by the pH point of zero charge (pHpzc), the Brunauer–Emmett–Teller (BET) method, Scanning Electron Microscopy (SEM) and Fourier-Transform Infrared (FTIR) spectroscopy. On the other hand, a batch adsorption experiment of MR removal onto RAB was conducted, considering four operating parameters: pH, contact time, adsorbent dose, and initial dye concentration. The characterization of the adsorbent material revealed a porous and heterogeneous surface morphology during SEM, a specific surface area of 45.8 m²/g during the BET method, the presence of various functional groups during FTIR, and a pHpzc of 6.2. The batch adsorption experiment analysis results revealed that a maximum removal efficiency of 99.2% was attained at an optimum working condition of pH 6, contact time of 40 min, initial dye concentration of 70 mg/L and adsorbent dosage of 0.2 g/100 mL. Furthermore, Freundlich isotherm (R² = 0.99) and pseudo-second-order kinetics (R² = 0.99) models confirmed the heterogeneous surface interaction and chemisorption nature. Generally, this study highlighted that RAB could be a potential adsorbent for the detoxification of MR-containing industrial effluents.

This study dives into the essential issue of sustainable water management techniques in East Africa. Recognizing water as a key component of sustainable agricultural development, the study highlights the importance of a complete approach that takes into account technological, socio-economic, and environmental issues. A detailed, comprehensive review of 109 scientific research articles published between 1993 and 2024 was conducted to acquire a thorough grasp of current sustainable water resource management techniques in East Africa. This in-depth investigation sought to uncover major regional trends, challenges, and opportunities in water resource management. Furthermore, the evaluation aimed to identify specific knowledge gaps impeding the region’s implementation of sustainable water management techniques. As East Africa faces rising problems from climatic variability and change, which have a direct impact on water availability and agricultural output, the need for comprehensive policies becomes clear. The review reveals significant gaps in previous research, including a lack of focus on the socio-economic consequences of water management methods, gender dynamics, long-term assessments, indigenous knowledge integration, and climate change adaptation. By highlighting these areas, the study emphasizes the necessity of future research in addressing these gaps and developing more effective and sustainable water management solutions for East Africa.

An untreated biosorbent derived from the leaves of Cordia africana was utilized in this study for the first time to remove malachite green (MG) dye from aqueous solutions via batchwise adsorption. Comprehensive characterizations of the biosorbent were conducted, including Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and determination of the pH point of zero charge (pHpzc). The adsorption process was investigated under varying operational conditions: biosorbent dosage (0.25–0.65 g/100 mL), contact time (25–50 min), initial pollutant concentration (15–45 mg/L), and solution pH (4–9). Kinetic and isothermal models were employed to evaluate the adsorption mechanism. Characterization revealed an amorphous, heterogeneous surface. The biosorbent achieved an impressive MG removal efficiency of 98.9%, with a maximum Langmuir adsorption capacity (Q _max ) of 6.25 mg/g, indicating a monolayer chemisorption process in agreement with Langmuir and pseudo-second-order kinetics models. This study highlights the cost-effectiveness and potential of Cordia africana leaf-based biosorbent as a sustainable and efficient solution for the decolorization of MG-laden industrial effluents, providing a pathway for practical, large-scale applications.

Phenol and its derivatives in water and wastewater are highly toxic and challenging to degrade, posing serious environmental and health risks. Therefore, this research focuses on the removal of phenol from aqueous solutions using activated carbon made from Catha edulis stems. The activation process involved impregnating the Catha edulis stems with phosphoric acid followed by thermal treatment at 500 °C for 2 h. The resulting adsorbent was extensively characterized using various techniques, including Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) surface area analysis, and proximate analysis. Batch adsorption experiments were designed using a full factorial approach with four factors at two levels, resulting in 16 different experimental conditions. The characterization results showed that the activated carbon has a high surface area of 1323 m²/g, a porous and heterogeneous structure, and an amorphous surface with multiple functional groups. Under optimal conditions of pH 2, a contact time of 60 min, an adsorbent dosage of 0.1 g/100 mL, and an initial phenol concentration of 100 mg/L, the adsorbent achieved a phenol removal efficiency of 99.9%. Isotherm and kinetics analyses revealed that phenol adsorption fits the Langmuir model and pseudo-second-order kinetics, indicating a uniform interaction and chemisorptive process. This study highlights the effectiveness of Catha edulis stem-based activated carbon as a promising material for phenol removal in water treatment applications.