| The water eutrophication would be caused through the nitrogenous substances ofcoking wastewater, which could be large population of algae, deteriorate and stank,especially having great harmful to the swamps, lakes and other closed waters.Nowadays, there is a little treatment process with the low concentration of ammonianitrogen wastewater in the country; comparatively the emulsion liquid membrane has agood effect to treat the low concentrations of ammonia nitrogen wastewater.The emulsion liquid membrane was investigated for treating the coking wastewaterthrough the main raw material about Span-80, Tween-80and carbon tetrachloride in thispaper. Compared with the Span-80as a single surfactant, emulsion liquid membrane areinvestigated different factors effecting on extraction rate of NH3-N through treatingcoking wastewater, such as the emulsifier type and proportion, HLB value, the volumerate of oil to inner phase, the volume rate of emulsion to wastewater, concentration ofH2SO4, the emulsion-made time, the extraction time and draw optimal conditions: TheHLB of the surfactant is5.19and the amount of surfactant is2.67%, concentration ofH2SO4is0.25mol/L, the volume rate of oil to inner phase is1.5:1, the volume rate ofemulsion to wastewater is3:5, the emulsion-made time is15min, the extraction time is10min, The extraction rate of NH3-N reached99.9%through mixed emulsion liquidmembrane, under optimal conditions ammonia removal efficiency was98%through thesingle emulsion liquid membrane.Furthermore, comparison of two emulsion liquid membrane on measuring the CODin the coking wastewater and breakage rate of membrane, which can be seen that underoptimal conditions mixed emulsion liquid membrane remove COD efficiency reached67%, while the single emulsion liquid membrane remove COD efficiency is53%,ammonia nitrogen has some impact on COD in coking wastewater; concentration ofsulfuric acid in inner water phase have the greatest impact on the membrane breakagerate, In the best conditions the mixed emulsion liquid membrane breakage rate was1%,compared with a single type of emulsion liquid membrane was9%.In summary, mixed emulsion liquid membrane is better than the single type emulsionliquid membrane on the efficiency of ammonia removal, the COD removal and thestability of membrane. |
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