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Potential of pumice modified with iron(III) for copper removal from aqueous solutions

Guler U. A., Cebeci M. S.

Environment Protection Engineering

2017

Vol. 43, nr 3

165--180

Iron-modified pumice (Fe-P) was prepared by the ion-exchange method using natural pumice from Kayseri, Turkey at room temperature without calcination. SEM, FTIR, XRD, and S-BET measurement were used to investigate the copper removal mechanism. The results show that the SBET of the pumice increased from 11.88 m2/g to 21.01 m2/g after iron modification. The effects of pH, contact time, initial copper concentration, temperature, and various cations (Na+, K+, Ca2+, Mg2+ and Al3+) at various pH were investigated in batch experiments. More than 92% of Cu(II) was removed after 180 min. Langmuir, Freundlich, Dubinin-Radushkevich and Temkin isotherm models were applied to the equilibrium data at 298, 308 and 318 K. The maximum adsorption capacity at 298, 308 and 318 K was found to be 21.52, 19.48, and 19.67 mg/g, respectively. The kinetics of copper on Fe-P was best described by the pseudo-second order kinetic model. The negative values of free energy change and enthalpy change indicated that the adsorption process was feasible, spontaneous and exothermic.

Removal of reactive blue 29 dye by adsorption on modified chitosan in the presence of hydrogen peroxide

Naghizadeh A., Nabizadeh R.

Environment Protection Engineering

2016

Vol. 42, nr 1

149--168

Industrial effluents that carry dyestuff into natural water systems are serious environmental concern. Complex aromatic structures of dyes make them more stable and more difficult to remove from the effluents discharged into water bodies. In the present study, removal of reactive blue 29 dye with chitosan and modified chitosan with Cu complexes from aqueous solution was investigated in a batch adsorption system with respect to the changes in the contact time, pH of solution and chitosan dosage. Adsorption isotherms of the dye onto chitosan were also studied. The results revealed that the adsorption capacity of chitosan with Cu complexes is lower than that of chitosan without Cu complexes. Also effect of H2O2 on adsorption when we used chitosan without Cu complexes is more considerable. The results also demonstrated that adsorption capacity of reactive blue 29 dye on chitosan was higher at lower pHs. Finally, the Langmuir isotherm showed the best conformity to the equilibrium data.

Preparation of titanium dioxide/attapulgite composites and their application in treating Reactive Black KN-B wastewater

Xie A., Luo S., Chaoyao Y.

Environment Protection Engineering

2014

Vol. 40, nr 1

45--56

Removal of water soluble Reactive Black KN-B from aqueous media by means of titanium dioxide/attapulgite (TiO2/ATP) composites was studied in a batch system. The composites were investigated using X-ray diffraction and surface area analysis. Under UV irradiation, the photocatalytic effect of TiO2/ATP composites, pH and reaction temperature on the decolorization rate of Reactive Black KN-B were investigated in detail. The adsorption experiments of TiO2/ATP composites showed that the isotherms and adsorption kinetics were well followed by the Langmuir model and the zero order equation, respectively. The maximum adsorption capacity of TiO2/ATP composites for Reactive Black KN-B calculated by the Langmuir model was 20.08 mg g-1. It can be concluded that the TiO2/ATP composites could be good photocatalysts/adsorbents for treating Reactive Black KN-B wastewater.