The adsorption of Pb(II) and Cd(II) ions from aqueous solution was studied by Common Reed (CR) activated with NaOH solution of 0.5 M. CR materials obtained were characterized using XRD, SEM and FT-IR. The adsorption data were studied for adsorption isotherms of Langmuir and Freundlich models. Adsorption of Pb(II)  and Cd(II) ions was best fitted with Langmuir adsorption isotherm. The maximum adsorption capacity of Pb(II)  and Cd(II) ions were 19.84 mg/g and 17.33 mg/g, respectively. Experimental data were also performed to the pseudo-first-order and pseudosecond-order kinetic models. The results indicated that the biosorption of Pb(II)  and Cd(II) ions on activated CR biomass followed well the second-order kinetics. The results indicated that CR can be used as a low-cost adsorbent for the removal of heavy metal ions in wastewater.

In the present study, MIL-53(Al) metal-organic framework material dopping with iron (denoted as Fe-MIL-53(Al)) had been synthesized and applied as a catalyst to degrade rhodamine B (RB) in aqueous solution by H2O2. The obtained materials were characterized using X-ray diffraction (XRD), thermogravimetry analysis (TG), transmission electron microscopy (TEM), and energy dispersive X-ray (EDX). The influence of iron content on the structure of MIL-53(Al) and treated temperature of Fe-MIL-53(Al) were investigated. The results showed that the obtained Fe-MIL-53(Al), which was synthesized at mole ratio of Fe/Al = 1/9, had high catalytic activity for RB oxidation reaction by H2O2, RB degradation efficiency was 92%, and achieved 100% under UV radiation ([RB] = 10 mg/L). The treatment at 280 ºC had almost no effect on the structure of the material, but also slightly enhanced the catalytic activity.

In the present study, zeolitic imidazolate framework-8 (ZIF-8) is synthesized quickly in methanol solvent with the support of ultrasound, and application of photocatalyst for methylene blue (MB) decomposition reaction under UV radiation. The obtained ZIF-8 was characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and UV-Vis diffuse reflectance spectra (DR-UV-Vis). The influence pH and kinetics of photocatalytic MB decomposition and reusability of ZIF-8, were also investigated. The results indicated that ZIF-8 could work effectively in the wide pH range from 4 to 12. When the initial pH of the solution increases to 12, the adsorption capacity and MB decomposition efficiency are both high. The MB decomposition on the ZIF-8 photocatalyst followed a pseudo-first-order kinetics model. The structural strength of ZIF-8 as well as the relatively high photocatalytic efficiency after reuse three times shows that ZIF-8 has good reusability and can be applied to treatment of organic pollutants in aqueous solution.

In the present study, the synthesis of ZnO/LSAC through pyrolysis of the carbonized material prepared from longan seed, zinc acetate in alkaline medium. The obtained materials was characterized by means of XRD, SEM, TEM, BET and UV-Vis-DRS. The XRD patterns of ZnO/LSAC nanocomposites were assigned to wurtzite structure of ZnO with crystallite size about 15 to 30 nm. SEM and TEM observations showed the spherical ZnO particles formed on the activated carbon. The band gap energy and specific surface area of ZnO/LSAC were found to be 2.79 eV and 294.4 m2/g, respectively. The photocatalytic activities of the prepared materials were evaluated for the degradation of Rhodamine B (RhB) dye. The removal of RhB was found to be pH dependent, and the optimized removal efficiency reached to 93.75% and the mineralization level was over 84,09% at initial RhB concentration of 40 mg.L-1 andpH 7 following 120 min under visible-light illumination. The kinetic studies showed the decolorizationof RhB followed pseudo first-order kinetics with the rate constant were determined kapp= 1.67Í10-2 min−1

Fe-doped TiO2 nanotubes were prepared by hydrothermal method using ferric nitrate and commercial TiO2 powder. The obtained materials were characterized by means of XRD, TEM, BET, FT-IR and UV-Vis-DRS. The photocatalytic activity was evaluated based on photodegradation of methylene blue under visible light irradiation. The results show that Fe3+ ions might incorporate into the lattice of TiO2 nanotubes. Fe-doped TiO2 materials showed narrower band gap energies, higher specific surface areas, more hydroxyl groups on the surface and significantly improved photocatalytic activity. The optimum Fe doping at the molar ratios of Fe/Ti = 0.5% showed the highest photocatalytic activity and was 3.08 times higher than that of undoped TiO2. The kinetic studies showed the decomposition of MB followed pseudo first-order kinetics with the rate constant were determined kapp = 5.64×10-2 min−1.