The efficiency of Pterocarpus Anglolensis sawdust, an abundantly available waste product of the timber industry, capacity as an adsorbent for mercury was investigated. A series of batch experiments was carried out with experimental conditions of metal concentration, adsorbent concentration, pH, and contact time being changed. The concentration of the metal ion was deduced using spectrophotometric means. The adsorption efficiency was found to be pH-dependent with pH 4 being the optimum. 90 minutes was found to be the equilibrium time with particle size range 90-124 μ m being the most efficient. Maximum adsorption of mercury was evaluated at 80. 33 %. The experimental data was best modeled by the Freundlich isotherm and Pseudo second-order kinetic models. The calculated adsorption parameters are Kf = 0. 0002 L/mg, bF = 3. 0 and k2 = 0. 00016 g/μ g. min.

This study aims to report Batch adsorption study of hexavalent chromium, Cr (VI) on zeoliteNaX. Kinetics of Cr (VI) adsorption and adsorption isotherms were determined by varying operating parameters such as pH, initial concentration, temperature and contact time. ZeoliteNaX was found to remove Cr (VI) in acidic solutions down to ppm level at pH of about 4. Removal rate of Cr (VI) was found to decrease as pH rises above 4.0. Langmuir, Freundlich, Temkin and Redlich-Peterson models were applied to adsorption equilibrium data to find the best amongst these models. Langmuir model with R2 = 0.9711 best fits the adsorption data. The kinetics of adsorption was found to follow the first order reversible reaction. The separation parameter, RL values of less than 1.0 i.e., 0.7369, 0.5834 and 0.4828 corresponding to initial concentrations of 10, 20 and 30 mg/L, respectively indicated that adsorption of Cr (VI) on zeoliteNaX is favoured. The estimated values of thermodynamic parameters such as heat of adsorption and standard gibbs free energy confirmed the exothermic nature of adsorption of Cr (VI) on zeoliteNaX.

Background and purpose: Phenol is an aromatic hydrocarbon and one of the banzan derivatives which has a higher dissolution rate in water. Therefore, it must be removed for water pollution prevention. The aim of this study was to investigate the possibility of Pistaciamuticabio mass as an alternative adsorbent for phenol removal from aqueous solution.Materials and Methods: The effect of various parameters including contact time (10-102 min), pH (2-8), adsorbent dosage (0.4-1.5g/L), phenol concentration (50-150mg/L) were investigated in this experimental-lab study. Also, the isotherm and kinetic investigations were performed for phenol adsorption process. The adsorption equilibriums were analyzed by Langmuir, Temkin, Freundlich and Harkins Jura isotherm models.Results: It was found that the data fitted to Langmuir (R2=0.98) better than other isotherm models.Batch kinetic experiments showed that the adsorption followed Pseudo second-order kinetic model with correlation coefficients greater than 0.998.Conclusion: It was revealed that P. mutica was not only an inexpensive absorbent, but also a quite effective factor in removal of phenol from water and wastewater.

Batch experiments were conducted to study the adsorption behaviors of lead ion (Pb2+) onto ferrihydrites prepared using three different procedures which were characterized by textural analysis (BET). The adsorption removal of Pb2+ by the three ferrihydrites (called FH-1, FH-2 and FH-3, respectively) were compared, and FH-3 shows fast adsorption kinetics as well as high adsorption capacities, the adsorption properties of the three ferrihydrites for lead ion depend on the pH value and the optimal pH for Pb2+ adsorption of FH-3 is 6.0. The maximum adsorption capacity of lead ion on FH-3 is 13.75 mg/g and the adsorption isotherms followed Langmuir isotherm model better than the Freundlich isotherm model. The adsorption kinetic data could be described well by pseudo-second-order kinetic equation.

Background and Objectives: Fluoride has both beneficial and detrimental effects on health. Therefore, it is important to determine its concentration in drinking water. Dental fluorosis and skeletal fluorosis are health effects caused by long term exposure to high levels of fluoride in drinking water. The aim of this research was to investigate fluoride removal using modified diatomite-supported ferric oxide nanoparticles and to determine the adsorption kinetics and isotherm.Materials and Methods: This fundamental and practical study was performed at laboratory scale. The effects of pH (3.5-9.5), contact time (20-100 min), adsorbent dosage (1-5 g/L), and initial concentrations of fluoride (5-25 mg/L) on the adsorption efficiency were evaluated. The properties of adsorbent were investigated using XRD, XRF, FTIR and FESEM. Finally, the suitability of pseudo first and second order kinetics, and Langmuir and Freundlich isotherms for the data were investigated.Results: This study showed that the removal efficiency of F- increased with increase in contact time, decrease in pH, increase in adsorbent dose, and increase in initial fluoride concentration. The highest removal efficiency was observed at pH=3.5, 60 minutes contact time, and 3 g/L of adsorbent dose in the initial concentration of 5 mg/L F-. Pseudo first order and Freundlich were the best fitted kinetic and isotherm models, respectively, for describing F- adsorption process.Conclusion: The present study indicates that the modified diatomite-supported ferric oxide nanoparticles can be used as an effective and environmentally friendly bio sorbent for the removal of fluoride ions from aqueous solutions.