Backgrounds and Objective: Usage electrocoagulation methods for removal chemical contaminants are widely used in the recent years. The aim of this research is to investigate fluoride removal, agent dental and skeletal fluorosis, from drinking water by BATCH electrocoagulation reactor with using aluminum electrode. Materials and Methods: In this study, the drinking water sample is prepared by plastic BATCH reactor by monopole electrode. Removal efficiency is studied in different conditions, included pH (4, 7, and 10), reaction time (5, 10, 15, 30, and 45 min), distance between electrode (2 cm), and current density (1.5, 3, and 4.5 mA/cm2). Results: In electrocoagulation reactor, percentage of removal fluoride 2 mg/L, current density 4.5 mA/cm2 and reaction time 30 min in pH 4, 7 and 10 are obtained 96.5%, 100% and 90.5%, respectively. In electrocoagulation reactor, percentage of removal fluoride 12 mg/L removal in distance 2 cm, current density 4.5 mA/cm2, and reaction time 30 min in pH 4, 7, and 10 are obtained 60.7%, 64%, and 56%, respectively. Conclusion: The findings indicated that fluoride removal efficiency is increased with increasing current density and reaction time. The results indicate that increasing the concentration of fluoride ions, the time required to achieve good efficiency should also increase. It can be concluded that the electrocoagulation technology is an effective process for defluoridation of drinking waters.

Effective use of low-grade coal is crucial for meeting global energy needs and mitigating environmental impacts, making the study of its thermal decomposition a key focus for sustainable energy development. Understanding the pyrolytic degradation process of coal is crucial for optimizing its use in eco-friendly energy solutions. It is hypothesized that the isothermal pyrolysis of low-rank coal at different temperatures will exhibit different kinetic behaviors and produce valuable condensable products. This research investigates the pyrolytic behavior, kinetics, and BATCH pyrolysis of low-rank coal. Thermo-gravimetric analysis was conducted under isothermal conditions at temperatures ranging from 350 to 500 °C, with a 25 °C increment, for 2 hours in an inert atmosphere. The data were analyzed using model-fitting methods, testing a total of 21 models to calculate the reaction kinetics. The results revealed that weight loss increased with temperature, reaching a maximum at 18. 61% (450 °C), with activation energies of 5. 817–123. 51 kJ/mol. The D2 diffusion model best described the process (Ea = 7. 267 kJ/mol, A = 0. 022 min⁻¹). The pyrolysis index rose from 0. 0113 (350 °C) to 0. 051 (500 °C). At 450°C, 18. 9% condensable products formed, containing alkanes, alicyclics, and aromatics (FTIR/GC-MS). These findings facilitate the optimization of sustainable pyrolysis of low-rank coal for the production of valuable outputs.

Quantity lack of required water resources for agriculture and quality decreasing caused by entrance of poor quality drain water resulted environmental threatens in the resources. Inappropriate application of nitrogen fertilizers that are one of the most important required nutrients for plants causes entrance of nitrogen components more than allowed limits to the water resources. Modified natural zeolite usage for nitrate reduction from aqueous solutions in BATCH and dynamic EXPERIMENTS investigated in this research. Equilibrium time and the amount of nitrate adsorption resulted from physical model were compared to the results of BATCH tests. Equilibrium time resulted from both conditions was about 60 minutes but the portions of nitrate adsorption and removal percent were different. While the different observed results caused by physical drain channel model, effects of two flow rates including 0.05 and 0.08 (lit/s) and three sorption box widths including 2, 3 and 5 cm on nitrate removal were surveyed. Results showed 8 to 16 percent better zeolite efficiency in more flow rate. About 19 percent removal increase observed by reduction of adsorption box widths from 0.33 to 0.13 of adsorption box length.

One of the key influencing parameters in the safe management of nuclear waste repositories is the distribution coefficient ( ) of radionuclides on bedrock. In this study,  of uranium and thorium ions in intact bedrock were determined using BATCH EXPERIMENTS on crushed bedrock at seven different particle size fractions as well as three different initial concentrations of ions. Sorption EXPERIMENTS have been performed on crushed bedrock prepared from intact drill core samples and an aqueous solution containing desired ions from the local water (LW) near Anarak Nuclear Waste Repository. The results showed that both factors of the initial ions concentration as well as the size of the crushed bedrock particles significantly affect the value of the distribution coefficient so that (  value increases with decreasing particle size and increasing ion concentration. Also, ( calculated at three studied concentrations showed that the difference in the ( values in smaller particles is large but decrease with increasing particle size and ( ) curves for two concentrations of (100 and 10) ppm overlap at the end of the chart. Therefore, it can be concluded that for accurate calculation, it is better to use large particles and low concentrations of ions to determine ( ) in intact bedrock. In this report, different mechanisms including chemical interactions, physical adsorption, and ion exchange were presented for ion adsorption by bedrock. The proposed mechanisms were related to the type of metal speciation of ions in the solution. Based on the obtained data, the preferred mechanism to describe the adsorption of uranium and thorium ions is composed of chemical interactions and physical adsorption.

This study reports the usage of chemically impregnated coconut coir waste (CICCW) as a low-cost adsorbent for the desulfurization of feed diesel. The characterization of the developed adsorbent was focused on quantitative analysis (carbon yield %, proximate, ultimate, carbon surface functionalities, BET surface area and porosity distribution, and particle size analysis), qualitative analysis (FTIR), and optical analysis (SEM). BATCH EXPERIMENTS with feed diesel having a total sulfur concentration of 2,050 mg L-1 were conducted to optimize the adsorption parameters such as adsorbent dose, temperature, and contact time. The adsorption process shows an optimum dose of 1 g/20 mL, and the equilibrium is attained in 3 h. The adsorption of sulfur onto the adsorbent at optimum temperature 293 K is regulated by external mass transfer (diffusion into mesopores) followed by a steady adsorption phase with intra-particle diffusion in micropores. A Fickian mechanism controls the diffusion of sulfur molecules from the solution onto the surface of the adsorbent. Freundlich adsorption isotherm illustrates the equilibrium adsorption data very well. The negative value of ΔGo (-27.61 kJ mol-1) and ΔSo (-44.56 J K-1 mol-1) indicates the feasibility, spontaneity of the adsorption process and justified the decrease in the randomness of adsorbed sulfur molecules onto the adsorbent surface, respectively. The exhausted CICCW can be effectively regenerated by methanol and reutilized for three adsorption–desorption cycles. The approximate cost of preparation of the adsorbent was USD 10.714 per kg. These results clearly proved the feasibility of the developed low-cost adsorbent (CICCW) as a good candidate for the desulfurization of feed diesel.

BATCH sizing in different planning period is categorized as a classical problem in production planning, that so many exact & heuristic methods have been proposed to solve this problem, each of which considering various aspects of the original problem. The solution obtained from majority – e.g. MRP – is in this format that there may be some periods of idleness or each period should produce as needed in different adjacent periods. If there are more the one final independent product to be produced in a factory, this makes the production planning experience strong variations in BATCH sizes for different periods, which production managers are opposed to these proposed production plans. In this paper, some of the models are proposed to solve this shortcoming of the production plan to smooth the variation of BATCH sizes and consequently to meet the managers ideal. Finally all of the proposed models are used in a real case problem and the best model is introduced in that case.