Extraction of Rhodamine 6G Dye from Liquid Waste Solution: Study on Emulsion Liquid Membrane Stability Performance and Recovery

Abstract

Effluent from industry using coloring material is hazardous to the environment because it is toxic in nature. Thus, it is important to treat the effluent to preserve the environment. In this research, extraction of Rhodamine 6G (R6G) from liquid wastewater using emulsion liquid membrane (ELM) process was studied. ELM formulation consists of kerosene as diluent, bis (2-ethylhexyl) phosphate (D2EHPA) as carrier, sulphuric acid (H₂SO₄) as internal phase, and SPAN 80 as surfactant. Several parameters had been examined to determine the stability of ELM and the recovery of R6G basic dyes from liquid waste solutions. The results show that the most stable emulsion was obtained with formulation consists of 0.1 M D2EHPA, 1.0 M of H₂SO₄ by using 12000 rpm homogenizer speed at 5 minutes emulsifying time. Furthermore, the result of recovery R6G in ELM process shows that the optimum condition of 50 ppm concentration of dye extraction were 5 minutes extraction time with the concentration of Span 80 at 3% w/v, agitation speed at 150 rpm, and the condition of 1:3 treat ratio. At this condition, the percentage of extraction and recovery were 100% and 84% respectively. Hence, the conclusion that ELM is a very promising technique for separating R6G from liquid wastewater.

Keywords:

• emulsion liquid membrane
• extraction
• recovery
• Rhodamine 6G
• wastewater

ACKNOWLEDGEMENTS

The authors would like to acknowledge the Ministry of Science, Technology, and Innovation (Science Fund: 79336) and Universiti Teknologi Malaysia for making this research possible.