Preparation Of Hydrophobic Materials And Environmental Pollutants Recovery Application Research

Liquid membrane separation technology is applied widely in extraction and separation of metal ions and organic pollutants from the industrial wastewaters, based on their characteristics of simple, efficient, fast, high selectivity and so on. The membrane material as the core of the liquid membrane separation technology has become more and more attractive. Polypropylene (PP) microporous membrane synthesizing using thermally induced phase separation (TIPS) method is the widely used membrane material. However, the commercial membranes are not suitable for the individual requirement because their specifications are relatively fixed. In view of this, we developed a simple, convenient method for membrane preparation, and investigated the application of the prepared polypropylene microporous membrane in separation and extraction of heavy metal ions and phenolic substances in aqueous solutions. Higher extraction efficiencies are obtained. In consideration of the oil spill in ocean petroleum exploitation, we also explored the synthesis of a kind of super hydrophobic cotton for the oil recovery. Better oil recovery efficiency was achieved.The details are summarized as follows:1. Several methods for membrane preparation and the kind and the application of liquid membrane were introduced. 2. Polypropylene flat microporous membrane (PPFMM) was prepared via TIPS with PP as the membrane material, polyethylene glycol (PEG) as the pore-forming agent, and xylene as the diluents. Scanning electron microscope and contact angle measurement were employed to characterize the surface morphology and the hydrophobic performance of the membrane. The optimal parameters were as fellows,3:1:70of the mass ratio of polypropylene and xylene and polyethylene glycol,145℃of the synthesis temperature,60min of the stirring time, heating4min in the oven temperature of95℃, extracting5days in constant temperature water bath of45℃.Study on the extraction of metal ions, Cu(Ⅱ), Zn(Ⅱ), Cd(Ⅱ), and Ni(Ⅱ), through the strip dispersion hybrid liquid membrane (SDHLM) with the above synthesized PPFMM as the membrane material coupled atomic absorption spectroscopy analysis is developed. Kerosene, di-(2-ethylhexyl) phosphoric acid (D2EHPA), and hydrochloric acid are used as the membrane solvent, the carrier, and the stripping phase, respectively. The optimized experimental conditions are as fellows:0.5mol/L of carrier concentration, pH4.2in the feed solution,4mol/L of HCl as stripping solution,50:30of volume ratio of the liquid membrane phase and the stripping solution, and5h of the transport time. Under the optimized experimental conditions, the transport efficiencies are47.50%,38.76%,70.81%, and60.05%, respectively, for Cu(Ⅱ), Zn(Ⅱ), Cd(Ⅱ), and Ni(Ⅱ). The results show the developed SDHLM exhibits excellent extraction selectivity for the investigated four metal ions.3. Study on the extraction of phenolic compounds, phenol (PhOH), p-nitrophenol (PNP), and2,4,6-trichlorophenol (TCP), through SDHLM with the above synthesized PPFMM as the membrane material coupled high performance liquid chromatography analysis is developed. Kerosene, Trioctylamine (TOA), and sodium hydroxide are used as the membrane solvent, the carrier, and the stripping phase, respectively. The optimized experimental conditions are as fellows:0.8mol/L of carrier concentration, pH4.7in the feed solution,0.02mol/L of NaOH as the stripping solution,50:30of volume ratio of the liquid membrane phase and the stripping solution, and12h of the transport time. Under the optimized experimental conditions, the higher transport efficiencies,50.12%,62.58%, and54.30%for PhOH, PNP, and TCP are reached, respectively.4. Sol-gel method was used to prepare SiO2nanoparticles, and then the prepared nanoparticles were modified through silanization. The hydrophobic cotton was obtained by coating the cotton with the nanoparticles silane. Scanning electron microscope and contact angle measurement are employed to characterization of the surface morphology and the performance of the hydrophobic cotton. More than150°of static water contact angle indicates the prepared hydrophobic cotton owns super hydrophobic properties. The prepared super hydrophobic cotton exhibits8.333g/g of oil recovery efficiency in application of oil recovery.