Selective recovery of nickel from waste water In the stainless steel industry by hollow fiber supported liquid membrane

摘要

Heavy metal ions very often appear in high concentrations in all kind of effluents giving rise to hazards of pollution because of their high toxicities and wide environmental spreading. This research deals with the recovery of nickel ions from waste water in the stainless steel industry, examined optimum conditions by hollow fiber supported liquid membrane. Which experiment is batch process or recovery extraction. The extractants are dissolved in kerosene as a membrane solution. The membrane solution was supported by a microporous hydrophobic hollow fiber membrane extractor. The research was studied as a function of several variables.Types of extractants were investigated such as pH of the feed. Which extractant by using D2EHPA, LIX 860-I, Cyanex 272 and Cyanex 301. And effects of concentration of extractants in membrane, concentration of sulfuric solutions which are strip solution, flow rate of system and ratio of the feed volume to stripping volume. After that the system is applied via Connection of two module consecutive hollow fiber. PH=4 of feed by using is LIX 860-I was most successful for percentage of extraction and selectivity of nickel. The percentage of nickel increases in accordance with an increase in the concentration of LIX 860-I. But percentage of nickel decreases when concentration of LIX 860-I is higher than 0.8 mol/l. And the percentage of stripping is increased in accordance with an increased concentration of sulfuric solutions. However the percentage of nickel ions extraction is not much different when concentration of sulfuric acid is higher than 2.0 mol/l . The supported liquid membrane to become unstable is the loss of the liquid membrane phase to come from increased flow rate of system. The module consecutive hollow fiber to result percentage of nickel increased. The highest percentage of nickel ions extraction in optimum condition was 57.869% for single-module and 87.347% for double-module