Ultrafiltration of Micellar Solutions Containing Phenols.

Area of Science:

• Environmental Science
• Water Treatment Technologies
• Separation Science

Background:

• Wastewater contamination by phenolic compounds like phenol and 4-nitrophenol poses environmental risks.
• Conventional treatment methods may be insufficient for complete removal of these persistent organic pollutants.

Purpose of the Study:

• To evaluate the efficacy of micellar-enhanced ultrafiltration (MEUF) for removing phenol and 4-nitrophenol from aqueous solutions.
• To investigate the influence of different surfactants and electrolyte concentrations on filtration performance and contaminant rejection.

Main Methods:

• Ultrafiltration of micellar solutions containing phenol or 4-nitrophenol using various surfactants: Sodium dodecyl sulfate (SDS), hexadecyltrimethyl ammonium sulfate, alkyl polyglucoside Glucopon 215 SC UP, and oxyethylated methyl dodecanoates.
• Sodium bicarbonate (NaHCO3) was employed as an electrolyte and alkalizing agent.
• Filtration rates and contaminant rejection percentages were measured under different conditions.

Main Results:

• Filtration rate and phenol rejection were significantly influenced by the presence of NaHCO3 and the type of surfactant used.
• Cetyltrimethylammonium bromide (CTAB) and alkyl polyglucoside micellar solutions exhibited the highest filtration rates.
• CTAB micellar solutions achieved nearly 100% rejection of both phenol and 4-nitrophenol across a pH range of 3 to 11. Nonionic surfactants and SDS showed limited effectiveness.

Conclusions:

• Micellar-enhanced ultrafiltration, particularly with CTAB, is a highly effective method for removing phenol and 4-nitrophenol from wastewater.
• The choice of surfactant and electrolyte conditions are critical factors for optimizing MEUF performance.
• MEUF offers a promising advanced oxidation process for treating phenolic wastewater.