| With the increasing development of modern economic, the contamination of ourcountry’s environment become more and more serious and harm to human health.Heavy metal pollution has become a major problem. There is an urgent to develop anefficient and recycling functional materials to remove heavy metals from wastewater.For it’s structure-activity scheduled、specific recognition and extensive practicability,molecularly imprinted polymers(MIPs) has gradually became an important functionalmaterials of wastewater treatment. The wastewater of heavy metal ions is seriouslyharmful to human. However, the synthesis of molecularly imprinted polymers withtraditional method is too difficult to recycling and with low selectivity, functionalmaterials to selective adsorption Pb(II) and Hg(II) were developed in order to solveabove problems, and their recognition characteristics and binding mechanism of thefunctional materials were also investigated. The details are summarized as follows:1. In the present work, a novel Pb(II) ion imprinted polymers (Pb(II)-IIP) werefirstly synthesized by inverse emulsion technology, and try to used to enrich andadsorb Pb(II) in wasterwater.4-vinylbenzo-18-crown-6as a functional monomer,which used to good selectivity and adsorption capacity for Pb(II). Moreover, Theeffect of concentration and pH value of Pb(II) solutions were optimized. Theadsorption experiments showed that the maximum adsorption amounts of Pb(II)-IIP toPb(II) is27.95mg/g, and the adsorption behaviors of Pb(II)-IIP for Pb(II) is fitted tothe Langmuir adsorption isotherm model and the pseudo-second-order kinetics model.the selectivity coefficients of Pb(II)-IIP for Pb(II) with respect to Zn(II), Co(II),Ni(II), and Cd(II) are very high, and they are617.79,500.56,52.28and201.15, thanNIP, respectively, which indicated the higher binding ability of Pb(II)-IIP for Pb(II)ion with respect to the competitor species. Moreover, The Pb(II)-IIP particles showsalmost100%removal efficiencies in real water，suggesting that Pb(II)-IIP particleshas a strong anti-interference ability in real environment water.2. The application of above IIPs needs a very complicated procedure such asfiltration or centrifugation. This is the first time use thymine as a functional monomer,Fe3O4magnetic nanoparticles as carriers, magnetic imprinted polymers (Hg(II)-MIIP)were prepared by an precipitation polymerization to remove Hg(II) from contaminatedwater with thymine as a new functional monomer. Main factors affecting the removalof Hg(II) such as initial Hg(II) concentration, adsorption time, solution pH, co-anionsand the actual water samples were investigated. TEM analysis shows that the Fe3O4with narrow size distribution and Hg(II)-MIIP were wrapped in the surface ofmagnetic Fe3O4. The adsorption experiments showed that the adsorption behaviors ofHg(II)-MIIP for Hg(II) were fitted to the Langmuir adsorption isotherm model and thepseudo-second-order kinetics model. At pH=6-7, the maximum adsorption amounts ofHg(II)-MIIP for Hg(II) is162mg/g.3. Up to date, we must undergo a cumbersome process to elution template ion before the IIPs used to adsorption of heavy metal ions. Reduce graphemeoxide-thymine(rGO-Thy) Complexes were prepared by diazotization reaction, usingthe graphene oxide as carrier, thymine-phenylenediamine derivative as a ligand,which capable of selective adsorption of Hg(II). The adsorption efficiency wasinvestigated by static、 dynamic adsorption experiment、 selective adsorptionexperiments and pH effects. Experimental results showed that the rGO-Thy has astronger affinity and more adsorption sites for Hg(II) than rGO, and the maximumabsorption capacities are128and60mg/g for rGO-Thy and rGO, respectively.rGO-Thy exhibited a much larger adsorption capacity for Hg(II) when other ionscoexistence(Pb(II)、Ni(II)、Co(II)、Cd(II), which means that rGO-Thy selectiveadsorption of Hg(II) for it specificity. These results suggest that rGO-Thy can be usedas a water absorbent material handling Hg(II) contamination for it excellentperformance. |
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