| With the fast developing of economy, environmental problems are increasing serious, one of themost serious pollution is water pollution. There are various pollutants in the water, because of toxicityand difficult in degrading, heavy metals has become a hot issue. And it is popular to develop anefficient method to removal of metal ions from wastewater.SA composite membrane was prepared with sodium alginate as the main body and modified bypolyvinyl alcohol (PVA), polyethylene glycol (PEG). Experiment was conducted to discuss theperformance of the composite membrane by loading the different amounts of PVA and PEG. It wasshowed that when m(PVA):m(PEG):m(SA)=1:0.6:3, the air permeability could achieve the bestvalue with rather small water absorption and swelling of SA composite membrane.A batch ofexperiments were performed to investigate the effects of experiment parameters on removal rate byconsidering the concentration of Cu2+, dosage of composite membrane, contact time, pH andtemperature. The results showed that the removal rate of Cu2+reached90%by SA compositemembrane when the time was about60min.A composite membrane TiO2-SA was prepared by nano-TiO2and sodium alginate (SA), whichwas used to remove Cu2+from wastewater. Experiment was used sol-gel method to prepare TiO2nano-particles and XRD, TEM, BJH were used to characterize the performance of TiO2. It turned outthat the particle size of TiO2material was about100nm. TiO2-SA composite membrane was preparedby blending method. From SEM photo, the composite membrane was observed clear porosity andpore size was uniform when the dosage of TiO2was0.02g. TiO2-SA composite membrane was used toremove Cu2+, a batch of experiments were performed to investigate the effects of experimentparameters on removal rate by considering the concentration of Cu(II) ions, dosage of compositemembrane, contact time, pH and temperature. It took about120min for TiO2-SA composite membraneto achieve95%.Based on SA composite membrane and TiO2-SA composite membrane removal of Cu2+fromwastewater, thermodynamics analysis, adsorption experimental data could be better described byLangmuir isotherm model. The Linear degree reached more than0.996. Kinetics analysis showed thepseudo-second-order model displayed the best correlation with kinetic date. Expressions of SAcomposite membrane and TiO2-SA composite membrane were: y=0.0725x+0.0373, y=0.137x+0.0198respectively. Thermodynamics and Kinetics analysis indicated that two types of composite membranes mainly belong to monolayer adsorption process and the chemical adsorption played animportant role. |
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