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Nitrate is one of the water contaminants that mainly result from anthropogenic activities. The major causes of nitrate contamination of water resources are anthropogenic activities such as animal or human waste, septic or sewage systems, fertilizer application, concentrated animal farming, industrial waste, and landfill leachates. These man-made activities are the primary sources of nitrate contamination in water resources. Nitrate contamination of water is a global issue that has been increasing over time. According to previous research, exposure to nitrate in water above the world health organization (WHO) guideline limit (50 mg of NO3/L) has been found to induce major health effects such as methemoglobinemia in humans, with the severity depending on the amount consumed. This problem has become a major threat to humans and the environment. Thus, this article presented an overview of nitrate contamination of water resources in Ethiopia, emphasizing anthropogenic activities to indicate the current nitrate water contamination status for the necessary remedial actions.

The need for pulp and paper currently in the whole world has become shooting up massively. The generation of the pulp, as well as paper from woody materials, has a challenge due to deforestation, huge chemical and energy consumptions. Now, an alternative source for paper is lignocelluloses wastes, because of low cost, low energy, and chemical consumption. Among them, the banana pseudostem was best for the input of pulp and paper production. This investigation was on the production and characterization of pulp from Banana Pseudo Stem for Paper Making via Soda Anthraquinone pulping process. The amount of cellulose (41.45%), ash (12.4%), hemicellulose (23.37%), extractive (12.72%), and lignin (10.46%) contents were obtained at the initial compositional evaluation of the pseudostem. It has excellent fiber length (1.75mm), fiber diameter (22.15μm), an acceptable Runkle ratio (0.55), and flexibility coefficient (159.64). The effect of temperature (130,140 and 150 °C), cooking time (45, 60, and 75 minutes), the concentration of soda (10, 12.5, and 15%), were examined. The maximum pulp yield and kappa number was 36.7% and 22.8 respectively obtained at 10% of soda concentration, at 150 °C, and 63 minutes of cooking time from oven-dried raw material. The produced paper from the banana pseudostem has a tensile index, tearing index, smoothness, and porosity were 78.75 Nm/g, 19.1 mN.m2/g, 500-530μm, and 50 sec/100ml air respectively. This study indicates that high strength mechanical property and good surface properties paper can be produced from banana pseudostem pulp with a more environmentally friendly pulping process.

Contamination of water by ciprofloxacin has become a significant concern due to its adverse health effects and growing evidence of antimicrobial-resistant gene evolution. To this end, a chemically modified bamboo biochar was prepared from bamboo sawdust to effectively remove ciprofloxacin (CIP) from an aqueous solution. Under similar adsorption conditions, the modified bamboo biochar (MBC) has an excellent CIP removal efficiency (96%) compared to unmodified bamboo biochar (UBC) efficiency (45%). Thus, MBC was used in batch adsorption experiments, and the process was optimized with the central composite design (CCD) framework of response surface methodology (RSM). Sorption process parameters such as initial CIP concentration, pH, adsorbent dose, and contact time were studied and found to have a significant effect on CIP removal. The optimal CIP removal (96%) was obtained at MBC dose (0.5 g L-1), CIP initial concentration (20 mg L-1), pH (7.5), and contact time (46 min). The adsorption kinetic data were well described by the pseudo-second-order model ( R 2 = 0.999 ), and both Langmuir ( R 2 = 0.994 ) and Freundlich ( R 2 = 0.972 ) models gave the best fit in CIP adsorption isotherm analysis. The maximum monolayer adsorption capacity of the MBC was 78.43 mg g-1 based on the Langmuir isotherm model. These results suggest that CIP adsorption was mainly controlled by chemisorption. Moreover, the CIP adsorption process was endothermic and spontaneous. Overall, MBC is a low-cost, efficient, and recyclable adsorbent for eliminating emerging contaminants such as ciprofloxacin from an aqueous solution.

Due to its widespread consumption, paracetamol (PCT) has emerged as one of the leading contaminants that pollute water. Herein, a PCT removal of 99.6% was achieved using chemically activated carbon (CAC), derived from bamboo sawdust using KOH/FeCl3 as an activating agent, at optimal conditions of PCT (20 mg/L), CAC (0.5 g/L), contact time (90 min), and pH (8). Kinetic study revealed that the PCT adsorption process followed the pseudo-second-order kinetic model (R2 = 0.99), indicating that chemical adsorption dominated the adsorption mechanism. On the other hand, isotherm experimental data were best described by the Langmuir (R2 = 0.98) and Freundlich (R2 = 0.96) models. CAC had a maximum Langmuir monolayer capacity of 188.67 mg/g at a PCT concentration of 120 mg/L. Moreover, the Redlich–Peterson model gave the best fit (R2 = 0.99) to the experimental data, confirming that PCT adsorption was monolayer adsorption onto the heterogeneous surface. Thermodynamically, the PCT adsorption was exothermic, spontaneous, and favorable. The reusability study depicted that CAC can be successfully reused for five consecutive adsorption–desorption cycles. Furthermore, the application of CAC to environmental samples showed interesting results. The overall adsorption study indicated that CAC could serve as a promising adsorbent for eliminating PCT from water.