Abstract
In this work, the removal of 4-nitrophenol (4-NP) from water by emulsion liquid membrane (ELM) was investigated. An ELM system is made up of hexane as a diluent, Span 80 as the surfactant, and sodium carbonate as the inner aqueous solution. Effect of volume ratio of emulsion to external phase on the extraction of 4-NP was studied in the range of 5/250-90/250. The influence of 4-NP initial concentration and salt addition on the permeation of the pollutant was also investigated. The obtained results showed that the volume ratio of emulsion to external phase has a significant effect on the removal of 4-NP using ELM. It was found that by appropriate selection of the extraction and stability conditions, a treatment ratio of 30/250 conducted to excellent removal percentage (>99%). The 4-NP transport was influenced by solute initial concentration. The presence of NaCl in the continuous phase had an impact on the removal percentage, especially at high salt concentrations. The ELM treatment process represents a very interesting advanced separation process for the removal of 4-NP from water.