Adsorption of cationic dye onto Raphanus seeds: optimization, adsorption kinetics, thermodynamic studies.

Dyes are one of the common contaminants in industrial wastewater. Adsorption is the most widely method which used to treat dye-contaminated water due to their easy use, cost-effectiveness, and their efficiency was high. The aim of this study is the investigating of the utilization of the activated carbon which prepared from Raphanus seeds solid residual (ACRS) as a low cost adsorbent for removing of cationic Methylene Blue dye (MB)from wastewater. measuring the surface area using BET methods and SEM. The FT‒IR and XRD was measured. Different variables (e.g.: initial concentration of the dye, pH, contact time, and dosage) have been studied. Process has been systematically investigated experimentally at (25 ± 1 °C). The % removal of MB reached 99.4% after 90-min MB adsorption (40 mg/L) was observed within 5 min of contact time for the Raphanus seeds solid residual (ACRS) dosage of 4 g/L. MB initial concentration (10 ppm) Raphanus seeds solid residual (ACRS) effectively adsorbed MB (> 99%) over a widely range of pH (from pH 2 to pH 8). However, a swift decline in removal was observed when the pH was set at 7. The results of the adsorption kinetics analysis indicate a strong correlation with the pseudo-second-order model, as evidenced by the high regression coefficients. However, the adsorption capacity diminished with a rise in temperature. Thermodynamic calculations of (MB) onto Raphanus seeds solid residual (ACRS) is an exothermic reaction. The results have been indicated that the effectiveness of MB removal by activated carbon prepared from Raphanus seeds solid residual is favorable under neutral conditions, Raphanus seeds solid residual (ACRS) can be considered an efficient, environmentally friendly, readily available, and economical adsorbent that could treat industrial wastewater contaminated with cationic textile dyes. The objective of the experiments was to investigate the impact of various factors on the response of a process or formulation. To accomplish this goal, response surface methodology (RSM) has employed as a statistical model. RSM is an efficient and effective method for optimizing processes through the use of a quadratic polynomial model. The utilization of RSM allows for a reduction in the number of experiments needed, thus minimizing the associated costs of extensive analysis. This method has been done using Box-Behnken Design (BBD) to optimize % removal of MB. The optimal conditions as obtained from the RSM is pH 7,contact time 120 min, initial concentration 10 ppm, ACRS dosage 1 g, adsorption temperature 45 °C.

Electrical conductivity and thermodynamic studies on Sodium Dimethyldithiocarbamate in non aqueous solvents Dimethylformamide (DMF), at different temperatures.

This paper threw some light on the behavior of Sodium N,N-Dimethyldithiocarbamate as an electrolyte. The effect of solvents on the conductance of this salt would be discussed via measurements of Λo, ao and KA, since it can be assumed that the different solvents have a little chance to impose great variations on the solvation processes. The conductance method was chosen as a tool to illustrate the electrolyte-solvent interactions. Fuoss-Onsager equation would be tested using Sodium Dimethyldithiocarbamate in presence of dimethylformamide solvent at different temperatures. The conductance of dilute solutions of Sodium N,N-Dimethyldithiocarbamate is measured in Dimethylformamide, at different temperatures (25, 30, 35 and 40 °C). Accurate values of Λo were obtained by applying the (Fuoss-Kraus-Shedlovsky) equation. Finally, the (Fuoss-Onsager) equation was solved to give the correct values of the constants Λo, J, KA and a° (the closest distance of approach) for Sodium N,N-Dimethyldithiocarbamate salt in Dimethylformamide solvent. Λo and a° (solvation) increase with increasing temperatures. Thermodynamic parameters (∆G°, ∆H°, ∆S° and ∆Es) of Sodium N,N-Dimethyldithiocarbamate in Dimethylformamide were calculated from conductance measurements, the activation energy (∆Es), the enthalpy change (heat of association) (∆H°) and the entropy change (∆S°) are positive, however The free energy change (∆G°) values was negative for Sodium N,N-Dimethyl dithiocarbamate in DMF systems studied with increasing the temperature.

Removal of iron, zinc, and nickel-ions using nano bentonite and its applications on power station wastewater.

Removal of high concentrations of toxic heavy metals from wastewater is very important within the environmental field because heavy metals pollution a serious environmental problem due to them being nonbiodegradable. This study shed some light on the use of Nano bentonite as an adsorbent for the elimination of Iron, Zinc, and Nickel ions from wastewater, and the optimum conditions were evaluated to find out thermodynamic and kinetic parameters and equilibrium adsorption models have been applied. The results showed that adsorption percentage increases with increasing temperature, speed of rotation, and volume of solution, but decreases with adsorbent dose and initial concentration increase. The adsorption process has fit pseudo-second-order kinetic model Langmuir and Freundlich adsorption isotherm models were applied to analyze adsorption data and both were found to apply to these adsorption processes. Thermodynamic parameters e.g., ΔGo, ΔSo, and ΔHo of the adsorption process were found to be endothermic. Finally, the Nano bentonite was observed to be more powerful for the removal of Fe (III), Zn (II), and Ni (II) at the same experimental conditions.