Enhanced Adsorption of Pb(II) Ions from Aqueous Solution by Persimmon Tannin-activated Carbon Composites

The modification of activated carbon with persimmon tannin and its application for the removal of Pb（II） ions were carried out by batch method. The effects of solution pH, contact time, temperature and initial concentration on the immobilization of persimmon tannin were studied. The experimental results showed that the experimental data of persimmon tannin and Pb（II） fitted better by Langrnuir adsorption isotherm model and pseudo-second order model. The adsorption capacities of adsorbents for persimmon tannin and Pb（II） were calculated from the Langmuir isotherm model, and found to be 42.97 and 12.40 mg/g at optimum pH, respectively. It was noted that the adsorbent exhibited the best adsorption property for Pb（lI） when 1.0 g activated carbon was modified by 17.32 mg persimmon tannin. The modified activated carbon is more effective than the plain activated carbon, and it is expected to be an economic and effective adsorbent for the disposal of wastewater containing Pb（II） ions.

Removal, Recovery and Recycle of Gold (III) from Aqueous Solution Using Persimmon Tannin Gel

In order to recover much amount of gold, gold removal-recovery cycle was examined using immobilized persimmon gel, which could remove much amount of gold (III) from the tetrachloroaurate solution at 30°C. Removal of gold has proceeded different 2 mechanisms stages. At first, gold (III) was adsorbed rapidly on the surface of the persimmon gels until 2 hours and reached adsorption equilibrium. After that, the amount of gold removed was re-increased slowly and also reached equilibrium until 48 hours. The amount of gold removed was affected by the pH of the solution. The amount of Au removed was the highest at pH 5, which was decreased with decreasing or increasing the pH of the solution. The amount of gold removed (mol/g-dry wt. gels) was increased with increasing the gold concentration in the solution, whereas gold removed ratio was decreased. Gold removed ratio was increased with increasing the amount of persimmon gel used, whereas the amount of removed Au (mol/g-dry wt. gels) was decreased. Gold removal-recovery cycles were also examined in detail.

Synthesis and Characterization of Natural Polymer/Inorganic Antibacterial Nanocomposites

In order to increase antibacterial abilities and avoid the aggregation of nanoparticle, Ag- ZnO nanocomposites were studied in the network structure which contains bonds, and these bonds are formed by hydrolysis reaction between Ti（TBOU）4（TBOT） and the water that in Persimmon tannin solution. The size and morphology of Ag-ZnO nanocompos：tes were investigated by scanning electron microscopy （SEM） and field emission scanning electron microscopy（FE-SEM）. The antibacterial properties of nanocomposites were examined by minimal bactericidal concentration（MBC）. Results showed that this kind of antibacterial nanocomposites composites（ANPs） have excellent antibacterial abilities and without aggregation.

Preparation and application of iron oxide/persimmon tannin/graphene oxide nanocomposites for efficient adsorption of erbium from aqueous solution

Rare earth elements(REEs)are used for the developme nt of new energy materials owing to their intrinsic physicochemical property.However,excess REEs in water threaten the safety of animals,plants and humans.An efficient way to separate REEs from the water is therefore needed.In this study,a biosorbent consisting of iron oxide(Fe3 O4),persimmon tannin(PT),and graphene oxide(GO)as Fe3 O4/PT/GO was prepared,and the adsorption of trivalent erbium(Er3+)ions from aqueous solution was investigated.The adsorption process for Er3+ions conforms to pseudo-second order kinetic and the Langmuir isotherm model behavior.Thermodynamic studies indicate that the adsorption process is spontaneous and endothermic.Scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD),thermogravimetric analysis(TGA).Fourier-transform infrared(FT-IR)spectroscopy;Brunauer-Emmett-Teller(BET)analysis,and vibrating sample magnetometer(VSM)were used to assess the adsorption mechanism of Er3+ions onto the Fe3 O4/PT/GO biosorbent.A combination of electrostatic interactions,redox reactivity and chelation are responsible for adsorption of Er3+ions on the Fe3 O4/PT/GO biosorbent,The magnetic Fe3 O4/PT/GO biosorbent can be easily separated under the magnetic field for effective recycle of Er3+ions from aqueous solution.Therefore,this new biomass composite holds great promise for wastewater treatment.