Modeling of gadolinium recovery from nitrate medium with 8-hydroxyquinoline by emulsion liquid membrane.
The extraction equilibrium of Gd(III) from nitrate medium by 8-hydroxyquinoline (HOX) in toluene was studied. Liquid-liquid investigations were first carried out. Based on the equilibrium results, the extraction of Gd(III) from aqueous nitrate medium into an emulsion liquid membrane system (ELM) containing 8-hydroxyquinoline in toluene as extractant, HNO(3) as stripping solution, Span-80 as surfactant was studied. The stability of the prepared ELM was studied in terms of the degree of membrane breakage. The different parameters affecting the permeation of gadolinium (III) were also studied. A general permeation model for the recovery of Gd(III) by the selected membrane is presented. The internal mass transfer in the water in oil (W/O) emulsion drop, the external mass transfer around the drop, the rates of formation and decomposition of the complex at the external aqueous-organic interface were considered.
Carrier Assisted Emulsion Liquid Membrane Process for Recovery of Basic Dye from Wastewater using Continuous Extractor
Nowadays, water pollution has become major issue especially dye contaminated wastewaters from the textile industry. Dye causes serious environmental pollution and health problems. The removal of color from dye-contaminated wastewaters in the related industries becomes a major concern all over the world. In this research, several parameters of dye extraction and recovery in the continuous emulsion liquid membrane (ELM) process were investigated. This process consisted of three phases which are external (feed) phase, membrane phase and internal phase. The membrane phase was prepared by dissolving extractant bis(2-ethylhexyl)phosphoric acid (D2EHPA) and hydrophobic surfactant sorbitan monooleate (Span 80) in kerosene as diluents. The internal phase consisted of an aqueous solution of sulfuric acid (H2SO4). The important parameters governing the extraction process of dye such as stirring speed, initial dye concentration, Span 80 concentration and treat ratio (volume ratio of emulsion to external phase) were studied. The results showed that the optimum condition for 25ppm initial concentration of dye extraction are 250 rpm stirring speed, 5% (w/v) Span 80 and treat ratio 1:5. At this condition, the percentage of dye extraction, stripping and recovery were 98%, 82% and 81% respectively. Hence, continuous ELM technique is proven to be a very promising technique in industrial wastewater treatment and recovery of dye.
Processing of ammoniacal solutions containing copper, nickel and cobalt for metal separation
Abstract Ammoniacal-ammonium sulphate solutions containing copper, nickel and cobalt were treated for the separation of metal values. The solutions were processed for the co-extraction of copper and nickel using LIX64N in kerosene leaving cobalt in the raffinate. The effect of pH and ammonium sulphate concentration on the extraction efficiency of copper and nickel was studied using 5% LIX64N in kerosene. Conditions were established for the co-extraction of copper and nickel, ammonia scrubbing and selective stripping of metal ions with their respective spent electrolytes from a typical solution containing 1.76 kg/m 3 copper, 1.70 kg/m 3 nickel, 0.19 kg/m 3 cobalt, 90 kg/m 3 ammonia and 200 kg/m 3 ammonium sulphate.