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Study On Elimination Of Trace Cr(â…¥) In The Solution By Emulsion Liquid Membrane And Model

Posted on:2007-02-03Degree:MasterType:Thesis
Country:ChinaCandidate:Y F ShiFull Text:PDF
GTID:2121360185966865Subject:Applied Chemistry
Abstract/Summary:PDF Full Text Request
The separation of trace components in the dilute solution have gained great intrest in academe. A lot of valuable materials often exist with very low concentration in solution, and we require that the concentration of all harmful substance as the heavy metal ion and the organic matter should be very low, and the concentration of some matters must be in a rank of ppm in environmental protection. The great challenge we faced with is that how we can separate these trace components in dilute solution in the view of the separation and purifying industry. At present, the problem that the trace components are extracted in the dilute solution can not been solved by use of the traditional separation methods, such as extraction, coagulation, oxidation-reduction and exchange resin, etc.. Emulsion liquid membrane spearation method is a new type of separation methods, and it can simulate the enrichment of biology cells, and also utilizes theories of biology chemistry and physical chemistry and organic chemistry, etc. Its separation process can include extraction and counter-extraction at one time. It has such many virtues as high rate of mass transfer and very good character of selection and high separation efficiency and low energy consumption and multiple utilization of membrane phase,etc, so it is a kind of new separation which can use in enrichment and decontamination. But there are some defects which are properly solved, for example, membrane phase is evaporable easily and its stability is not good, and model can not simulate entire spearation process of emulsion liquid membrane spearation.In this dissertation, many experiments are carried out about abstraction of Cr(VI) in the waste water, and a lot of operation parameters are studied, for example, the concentration of surfactant, the pH of internal or external phase, the temperature of environment, Rew , and the kinds of surfactant, etc. The experimental results show that the best condition of abstraction of Cr(VI) is that the concentration of surfactant is 5%, the proportion of Span80 and oleic acid is 7:1, the temperature is from 16 to 20 centigrade degree, pH in internal phase is from 12.80 to 13.15, pH in external phase is 1.0, and Rew is 1:4. At last, the concentration of Cr(VI) is 0.35mg/L in wasterwater, and less than 0.5mg/L which is our country standard about discharging polluted water, the separation percentage is 96% when the experiment is over.On the base, temperature affecting the separation efficiency of Cr(VI) is studied. The experimental results show that the separation efficiency is low when...
Keywords/Search Tags:emulsion liquid membrane, separation percentage, temperature, mixed surfactant, mathmathical model
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