| Water is such a valuable natural resource that people pays more and more attention to heavy metal pollution besides the organic compounds in wastewater. Cr(VI) is a kind of carcinogen, famous for its toxicity and harmfulness. In respect to electroplating industry, a large amount of wastewater containing Cr(Vl) and its compounds which are important industrial raw materials is discharged every year, so it is very urgent to find one fast, high-efficient method to dispose it.In this paper, the several methods such as Liquid membrane separation, solvent extraction-, reduction and adsorption were studied for the wastewater treatment containing Cr(VI), respectively. The effects of various conditions on the transport rate of Cr(VI) were investigated and the optical conditions were obtained. Then the several methods were applied to the simulated electrodynamics wastewater containing Cr(VI) and other metal ions. Finally, the advantage and disadvantage of each method was appraised. The experimental results in detail is as follows:(1) Emulsion liquid membrane separationFirstly, the transport rate of Cr(VI) through ELM used TBP as the mobile carrier and Span80 as the surfactant, was studied by the Emulsion liquid membrane system. The effects of various parameters, such as the pH values in external water phase, the concentration of NaOH in inner water phase, carrier concentration, surfactant concentration, the Roi values and Rew, values were investigated; Secondly, the transport process of Cr(VI) through ELM used TBP and TOA as multiple carriers, Span80 as thesurfactant was studied. The results showed this ELM system was effective on Cr(VI) enrichment, and the transport rate could be attained to 94.1%, when Vkerosene : VTB?: VTOA: Vspan80: Vweited paraffin wax is 85:5:3:3:4; NaOH is 0.5mol/L; The pH value is 1.0; the Roi is 1:1 and Rew is 20:100. According to interfacial chemistry theory and solute diffusion theory, the mathematical model of ELM was established and validated.(2) Solvent extraction separateionThe solvent extraction system employed kerosene as solvent, TBP as extractant, CTMAB as scandium, is researched. Factors including the extractant concentration, acidity and extraction time, etc, which influenced the extraction rate of Cr(VI) were studied. Under the conditions of 40% TBP, 1.8mol/L H2SO4,0.1mol/L K2SO4,8.0 10-5mol/L CTMAB and 40min extracting, the extraction rate of Cr(VI) was 83.4%.(3) Reduction methodEffecting factors in the system used Na2SO3 as reducer, including the pH values, dosage was investigated. Experimental results showed that, when the pH value is 2.74, Cr(VI):Na2SO3 is 1:6, the remove rate of Cr(VI) in the wastewater containing 40.0mg/LCr(VI), 25.0mg/LCu(II), 15.0mg/LZn(II) and 10.0mg/LNi(II) reached 100.0%.(4) Adsorption separationIn this section, the experiments were conducted in the static and dynamic forms. The results indicated, the absorption rate of Cr(VI) in the water containing 40.0mg/L Cr(VI) was up to 92.0% after 5h, while the quality of activated carbon is 0.45g in the static experiment. And this adsorption behavior model obeyed Freundlich equation: q =55.8c0,3158; in the dynamic experiment, when the velocity of flow is ImL/min, the concentration of Cr(Vj) is 100.0mg/L, the result that penetrated time is 6h has been achieved. Applied the dynamic absorption to simulated wastewater, the absorption rate of Cr(VI) was 98.3%. The activated carbon could be regenerated by 20.0% NaOH washing, and the absorption results have no changes after repeating 3 times. At the same time, this thesis studied the absorption performance of activated carbon which its surface was modified.
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