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Separation And Recovery Of Wastewater Containing Phenol By Supported Liquid Membrane On Modified Surface Of Polypropylene Membrane

Posted on:2017-01-30Degree:MasterType:Thesis
Country:ChinaCandidate:Q LiFull Text:PDF
GTID:2271330509957455Subject:Environmental engineering
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As a new separation recycling technology of phenolics, supported liquid membrane extraction technology has lots of advantages such as low energy consumption, less dosage of extraction solvent, easy operation and so on. But the problems about the serious loss of liquid membrane and unstable operation restrict its industrial application.The paper has been studied in two aspects. At first, the process of separation and recovery of phenol from high concentration coal gasification wastewater containing phenol has been studied by using polypropylene(pp) hollow fiber membrane as supported body, 0.1M sodium hydroxide solution as stripping phase. The influence of different diluents such as kerosene, sesame oil and olive oil on extraction process of phenol from coal gasification wastewater has been studied, the results show that the extraction effect gets the best with the kerosene as the diluent; The influence of different mixture extraction agents such as the mixture of octyl alcohol and tributyl phosphate(TBP), the mixture of TBP and 2(2-ethyl hexyl) phosphoric acid(P204) and the mixture of trialkyl phosphine oxide(TRPO) and P204 on extraction effect of phenol from coal gasification wastewater has been studied, the results show that the extraction effect gets the best with P204 and TRPO as the extraction agent; The influence of the mass transfer means of supported liquid membrane system such as the choices about gallery and flow direction of feed phase and the stripping phase, the stirring rate of feed phase and temperature of stripping phase on the phenol extraction effect in the supported liquid membrane extraction system has been surveyed. The results show that whenthe feed phase gose the tube, stripping phase gose the shell of the membrane module, the stirring speed of feed phase is 100 rpm, the temperature is 20℃, the extraction effect gets the best.In addition, in order to improve the stablilty of the supported liquid membrane system, the PP hollow fiber membrane has been modification by coating the fluoro-alkyl silanes and nano-silica, then the determined hydrophobic modification conditions are as follows: the concentration of the FAS-C8 was 0.03 M, the mass concentration of nano-silica was 0.15%, the solvent was n-hexane, the time of circulation vacuum coating was 1 h; The modified PP membrane has been characterized by SEM, EDS, FTIR,WCA and mechanical strength test; The pilot test has been studied by using the modified PP membrane module, and the stability of supported liquid membrane system has been discussed in pilot test. The results show that the concentration of phenol in the treated waste water could control in 423.3 mg/L, meet the requirements of the subsequent biochemical treatment.
Keywords/Search Tags:supported liquid membrane, coal gasification, phenol, membrane modification, stability
PDF Full Text Request
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