Wastewater treatment with chemical coagulants has a variety of drawbacks, including sludge management, cost, concerns for human health, and environmental pollution. In light of this, a study was conducted to determine whether banana plant stem (Musa acuminate) made coagulant can effectively reduce turbidity (NTU) of wastewater. In this study, conventional extraction method was used to extract the coagulant from the banana plant stem by using NaCl (0.1, 0.5, 1M) solvent. After extraction, the coagulation efficiency of each produced coagulant was computed in terms of their turbidity removal efficiency () from sampled wastewater. The sampled wastewater had an average turbidity value of 893 NTU. Response surface methodology (RSM) and central composite design (CCD) were used to study the effects of NaCl solvent concentration (M), extraction time (min), and particle size (mm) on the coagulation efficiency () of the extracted coagulant. In addition, the coagulant was characterized such as FTIR analysis, point of zero charge value determination, and inulin compound presence analysis. From all prepared coagulants, the maximum coagulation efficiency obtained was 86.3 at the optimum conditions, such as 0.55M (NaCl) of solvent concentration, 1.25mm particle size, and 20min of extraction time. The characterized coagulant had 6.2 points of zero charge value and also had various types of functional groups. Based on the findings of this study, it can be said that the coagulant prepared from banana stems (Musa acuminate) was an efficient natural coagulant that could be applied to treat wastewater.

The fast nutrient release behavior of chemical fertilizer is becoming a pressing issue in the environment and causes a decrease in agricultural land productivity. This study presents the development of slow-release urea fertilizer (SRUF) using bentonite-starch coating materials as a response to the weak utilization efficiency of conventional urea fertilizer. Production and characterization of SRUF have been carried out using bentonite-starch coating materials at different combination stages. The two-way ANOVA without replication was examined using Microsoft Excel for statistical data analysis to see the significance of the effect of affecting parameters on the response parameters. The SRUF product sample was characterized in terms of water swelling capacity, water retention capacity, strength, and nutrient release in static water. The result has shown, water swelling (%WS) to be in the range of (55.1–89.7%), water retention (%WR) (4.45–93.2%), crushing strength (87.74–99.02%), and nutrient release in static water (8.92-89.00%). The effect of bentonite, starch, and urea particle size on the quality of the SRUF has been discussed in this research study. ANOVA analysis showed that affecting parameters had a significant effect on the response parameters (P value < 0.05). From the experiment carried out, the SRUF sample with 25% bentonite and 10% starch achieved a better-quality product. Additionally, the SRUF sample was subjected to the SEM and FT-IR analysis and revealed, the produced SRUF sample has a better water and nutrient retaining behavior. Generally, the study demonstrates the efficiency of bentonite clay and starch for urea fertilizer coating purposes, and the materials were found to be the best candidates for coating purposes to solve problems associated with the use of chemical fertilizers.

The increasing industrial use of chromium, particularly in the textile sector, presents significant environmental challenges due to the improper disposal of chromium-laden wastewater. This study explores the potential of corncob-derived activated carbon as an effective adsorbent for removing hexavalent chromium (Cr (VI)) from wastewater generated by the MAA Garment Textile Factory in Mekelle, Ethiopia. Corncobs were collected from nearby agricultural fields in Quiha, Mekelle. They were then crushed using an electric grinder to a particle size of less than 100 mesh, followed by carbonization in a furnace at a temperature of 500 ℃. A comprehensive analysis of corncob revealed a moisture content of 7.95%, volatile matter at 75.24%, and an elemental composition of 51.21% carbon, 5.49% hydrogen, 0.3% nitrogen, and 43% oxygen. The functional groups of the activated carbon, chemically activated with potassium hydroxide, were analyzed using FTIR spectroscopy. Experimental results demonstrated a remarkable chromium removal efficiency of 99.45% within 75 minutes at a pH of 6.5 and a dosage of 0.175 grams, with an equilibrium adsorption capacity of 7.67 mg/g. The adsorption characteristics were effectively modeled using the Langmuir isotherm, indicating a maximum adsorption capacity of 515.5 mg/g under optimal conditions, with both pseudo-second-order kinetics and Langmuir model (R² = 0.999) accurately describing the process. This research underscores the feasibility of utilizing agricultural waste for chromium recovery, contributing to environmental management and resource conservation while promoting sustainable industrial practices in Ethiopia and beyond. Future studies should focus on scaling these methods for broader application across various industries to enhance environmental sustainability.