Global NEST Journal

Estimation of annual peak flood flow has considerable financial influence, as this can pave numerous ways for water resources planning, design of hydraulic structures, and sustainable management of these valuable resources at an optimum benefit. Six standard plotting position methods coupled with Linear Log-regression Model (LLM) are employed for the Return Period (RP) of 15, 20, 25, 30, 60, and 1000 years to forecast peak flood flow magnitudes and for this daily annual peak flood flow data for the periods of 24 years were used to illustrate the proposed methods. Another method, Gumbel's Analytical Approach (GAA), is also used to forecast the peak flood flow magnitude for the same RP, and it was taken as the benchmark to compare all the six methods of plotting position. The degree of accuracy of the plotting position is based on the coefficient of determination R2. The R2 values for Adamowski, Hazen, Beard, Chegodajev, Tukey, and Benard, are 0.9073, 0.9284, 0.9119, 0.9111, 0.9135, and 0.9111, respectively. Out of the six-plotting position methods, Hazen method predicted a very closer value in comparison with GAA. It is advantageous to have the additional method to forecast peak flood flow for longer RP. The achieved result assuredly facilitates effective planning, regulation, and maintenance of huge reservoirs across the frequent occurrence of floods in river basin areas, considering safety and particularly downstream inhabited areas to save loss of human life, animals, damages to properties, and an impair of cultivated crops.

The coconut shell-derived biochar was employed in this study to remediate Remazol Black B from aqueous solutions. For efficient dye remediation, preliminary batch investigations focused on adjusting temperature, biochar dosage, initial dye concentration, and pH. The results shown that dosage of biochar had a considerable effect on the potential of dye absorption, with 1 g/L performing well. In addition, the data revealed that a pH of 2.0 was employed to attain equilibrium. Different temperature ranges from 30°C to 45°C were used to explore the influence of temperature, with 35°C being found to be the optimal value. The characteristics of biochar were investigated using Fourier Transform Infrared Spectroscopy, thermogravimetric analysis, and a Scanning Electron Microscope. In addition, the potential of biochar desorption was investigated by varying the solid to liquid ratio for different elutants. Adsorption and kinetic study revealed that the adsorption was favoured by physical adsorption. According to the findings, it was found coconut shell-derived biochar can treat dye-bearing aqueous solutions with a removal efficiency of 69.67%.

Dewatered sludge is the main by-product from wastewater treatment and it contains various types of hazardous substances which can cause environmental pollution. The alternative utilization of sludge waste is for covering the landfill or as liner for the landfill. Landfill cover is a critical component to protect the surrounding environment from leachate contamination produced by landfills and it has specific characteristics. This study analyzes the optimum water content, permeability coefficient, and stability of the material consisting of a mixture of dewatered sludge, bentonite, and quicklime. The test results show that the optimum water content in the three composite variables meet the requirements; the highest optimum value was 28%, a mixture with a ratio of 84% sludge, 15% bentonite, and 1% quicklime. The results also show that mixing sewage sludge with bentonite significantly reduces the permeability value with a ratio of 80% sludge, and 20% bentonite produces the lowest permeability coefficient of 1.979 x 10-7 and this has reached the hydraulic conductivity limit of 1 x 10-7. The shear strength and safety factor results test show that V3 had the best results, with a cohesion value of 22.40 kPa, a shear angle of 31.97°, and a safety factor of 5.297. The addition of bentonite tends to reduce the value of the safety factor. This safety factor can reach a high value because of the ratio of the total shear resistance to the working soil shear stress.

Biosorption of azo dyes (RO-16, RB-120 & RB-19) from the aqueous solutions was investigated using the activated sugarcane bagasse charcoal adsorbent. The characteristics of the prepared adsorbent were analyzed by SEM, EDX, FTIR, XRD, TG & DT analysis, and the BET surface area of the sugarcane bagasse adsorbent was examined by N2 adsorption and desorption techniques. Batch adsorption studies were performed to determine the optimum pH, azo dye concentration, sugarcane dose & temperature, and both Langmuir & Freundlich isotherm studies fit well with the adsorption process. Packed bed column adsorption studies confirmed the earlier breakthrough of the adsorption process, and the column adsorption studies fitted with Thomas, Yoon-Nelson, BDST and Adams-Bohart models. The desorption studies were conducted by adding various concentrations of sulfuric acid, and regeneration of spent azo dyes was done by different cycles.