RESUMEN
Removal of cadmium as a hazardous heavy metal is studied by applying a new design of hybrid cell for liquid membrane process. Tri-iso-octyl amine (TIOA) is used as the carrier in the organic phase. The concentration of cadmium in the samples is measured by atomic absorption spectroscopy. The effect of various parameters including type of supporting membrane, pH of feed and stripping phases, initial concentration of cadmium, carrier concentration, solvent nature, and also organic film resistance on mass transfer rate and removal efficiency are studied. The effect of temperature on mass transfer flux is studied by proposing a prediction model. The optimum carrier concentration is found to be about 0.05 M. The appropriate values of pH for feed and stripping phases are about 3 and 13, respectively.
Asunto(s)
Cadmio/aislamiento & purificación , Membranas Artificiales , Solventes/química , Sustancias Peligrosas/aislamiento & purificación , Concentración de Iones de Hidrógeno , TemperaturaRESUMEN
Removal of cadmium from wastewater using emulsion liquid membrane (ELM) is studied in the present study. A polyamine-type surfactant was used for stabilizing the emulsion phase. Tri-iso-octyl amine (TIOA) has been used as a carrier for transferring of cadmium through the membrane. The results show good performance in the separation process. To determine the optimum operation conditions, the effect of several parameters such as surfactant concentration, carrier concentration, pH of external and internal phases, oil to internal phase volume ratio, emulsion to external phase volume ratio, solvent type, solute concentration, presence of iodide and chloride in external phase, and mixing conditions have been investigated.
Asunto(s)
Cadmio/aislamiento & purificación , Residuos Industriales/prevención & control , Contaminantes del Agua/aislamiento & purificación , Emulsiones , Indicadores y Reactivos , Membranas Artificiales , TensoactivosRESUMEN
Removal of phenol from wastewater using emulsion liquid membrane (ELM) is studied in present study. A new polyamine-type surfactant was synthesized and used for stabilizing of the emulsion phase. The results for the emulsion made by the synthesized surfactant showed much better stability and performance in the separation process compared to that by conventionally used Span 80. To determine the optimum operation conditions, the effect of several parameters such as emulsifier concentration, concentration of NaOH in the internal phase, oil to internal phase volume ratio, mixing intensity, temperature, solvent type, and stabilizer concentration have been investigated. It was found that under the optimum conditions, more than 98% of phenol can be removed in a single-stage process. The removal efficiency can be increased to 99.8% in a two-stage process.