Effect of operating conditions on benzene removal using aqueous surfactant two-phase (ASTP) system of cationic and anionic surfactant mixtures / Onanong Kunanupap = ผลของภาวะปฏิบัติการในการกำจัดเบนซีนด้วยระบบการแบ่งวัฏภาค ของสารลดแรงตึงผิวผสมชนิดประจุบวกและประจุลบ / อรอนงค์ คุณานุภาพ
A novel class of separation technique utilizing an environmentally friendly surfactant known as an aqueous surfactant two-phase system (ASTP) is a new technique to remove contaminant such as benzene from wastewater. When cationic and anionic surfactants are mixed at certain surfactant concentration and composition, the solution separates into two immisible aqueous phases. One is the surfactant-rich and the other is the surfactant-dilute phase. The organic pollutant will solubilize into the surfactant aggregates and concentrate in the surfactant-rich phase. So, the other phase contains only small amount of surfactant and pollutant as the treated water. The ability of ASTP formed by dodecyltrimethyl ammonium bromide (DTAB) and alkyl diphenyl oxide disulfonate (DOWFAX 8390) to extract benzene from wastewater was investigated in batch experiment. The results showed that the effect of surfactant composition is crucial in which the phase separation only occured in some particular ratios of DTAB:DOWFAX, i.e., 1.6:1, 2:1, 2.2:1, and 2.4:1. However, the pH and operating temperature for extraction did not have significant effects on the extraction efficiency. From this study, the most suitable condition to extract benzene from wastewater was at 2:1 molar ratio of DTAB:DOWFAX, the total surfactant concentration of 50 mM, operating temperature at 30 ํC and at neutral solution (pH 7), in which the surfactant and benzene partition ratio can be as high as 2700 and 48 respectively. Moreover, 72% of benzene was removed within single stage extraction