Influence of Coagulant Salt Addition on the Treatment of Oil‐in‐Water Emulsions by Centrifugation, Ultrafiltration, and Vacuum Evaporation

Effect of α-tocopherol on the oxidative stability of horse oil-in-water emulsion during storage

Horse oil-in-water (O/W) emulsions were prepared and α-tocopherol was added at 0, 100, 200, and 500 ppm (α-T0, α-T100, α-T200, α-T500) to enhance its oxidative stability. Mean particle diameters of the O/W emulsions were 243-299 nm. Zeta potential values increased with the addition of α-tocopherol; however, they decreased during storage at 40 °C for 30 days. Particle size distribution of the O/W emulsion with α-tocopherol remained the same as that of α-T0. For lipid oxidation, the peroxide values of α-T0 and α-T500 were greatly increased from 2.96 and 2.89 to 13.76 and 12.46 mmol/kg oil, respectively, after 30 days. The α-T100 and α-T200 maintained lower peroxide values than other emulsions. Thiobarbituric acid-reactive substance values of α-T0 and α-T500 were higher than those of α-T100 and α-T200. These results indicate that the addition of α-tocopherol from 100 to 200 ppm to the horse oil-in-water emulsion effectively improves its oxidative stability during storage.

Optimization of a High-Performance Poly(diallyl dimethylammonium chloride)-alumina-perfluorooctanoate Intercalated Ultrafiltration Membrane for Treating Emulsified Oily Wastewater via Response Surface Methodology Approach

This research aimed to investigate the ultrafiltration of water from emulsified oily wastewater through the application of surface-functionalized ceramic membrane to enhance its water permeability based on optimized parameters using a cross-flow filtration system. The interactive effects of feed concentration (10–1000 ppm), pH (4–10), and pressure (0–3 bar) on the water flux and oil rejection were investigated. Central composite design (CCD) from response surface methodology (RSM) was employed for statistical analysis, modeling, and optimization of operating conditions. The analysis of variance (ANOVA) results showed that the oil rejection and water flux models were significant with p-values of 0.0001 and 0.0075, respectively. In addition, good correlation coefficients of 0.997 and 0.863 were obtained for the oil rejection and water flux models, respectively. The optimum conditions for pressure, pH, and feed concentration were found to be 1.5 bar, pH 8.97, and 10 ppm, respectively with water flux and oil rejection maintained at 152 L/m²·h and 98.72%, respectively. Hence, the functionalized ultrafiltration ceramic membrane enables the separation efficiency of the emulsified oil in water to be achieved.

Formulation and stability of horse oil-in-water emulsion by HLB system

Optimal condition was determined to prepare horse oil-in-water (O/W) emulsion stabilized by different HLB system. Span 60 and Tween 60 were used to achieve the predetermined HLB values ranging from 10 to 14 and the surfactant concentrations were adjusted to 10-20%. Fifteen formulated O/W emulsions were characterized by mean particle diameter, zeta-potential (ZP), polydispersity index, and encapsulation efficiency (EE, %). Mean particle diameter decreased with increasing HLB value and surfactant concentration. Particles of the emulsion with HLB 12 and surfactant concentration at 15% were distributed in the size of below 500 nm. The particle diameter and EE (%) of the emulsion with HLB 11 or 12 and surfactant concentration at 15 or 20% were not significantly changed during storage at 40 °C for 15 days. These results suggest the characteristics of horse oil O/W emulsion are dependent on HLB values and surfactant concentration so that affect to emulsion properties during storage.

Effect of NaCl concentration on stability of a polymer–Ag nanocomposite based Pickering emulsion: validation via rheological analysis with varying temperature

Schematic for the impact of NaCl on droplet stabilization in Pickering emulsions.

Simulation of phase separation with large component ratio for oil-in-water emulsion in ultrasound field

This paper presents an exploration for separation of oil-in-water and coalescence of oil droplets in ultrasound field via lattice Boltzmann method. Simulations were conducted by the ultrasound traveling and standing waves to enhance oil separation and trap oil droplets. The focus was to the effect of ultrasound irradiation on oil-in-water emulsion properties in the standing wave field, such as oil drop radius, morphology and growth kinetics of phase separation. Ultrasound fields were applied to irradiate the oil-in-water emulsion for getting flocculation of the oil droplets in 420kHz case, and larger dispersed oil droplets and continuous phases in 2MHz and 10MHz cases, respectively. The separated phases started to rise along the direction of sound propagation after several periods. The rising rate of the flocks was significantly greater in ultrasound case than that of oil droplets in the original emulsion, indicating that ultrasound irradiation caused a rapid increase of oil droplet quantity in the progress of the separation. The separation degree was also significantly improved with increasing frequency or irradiation time. The dataset was rearranged for growth kinetics of ultrasonic phase separation in a plot by spherically averaged structure factor and the ratio of oil and emulsion phases. The analyses recovered the two different temporal regimes: the spinodal decomposition and domain growth stages, which further quantified the morphology results. These numerical results provide guidance for setting the optimum condition for the separation of oil-in-water emulsion in the ultrasound field.

Treatment of a waste oil-in-water emulsion from a copper-rolling process by ultrafiltration and vacuum evaporation

A process is proposed for the treatment of a waste oil-in-water (O/W) emulsion generated in an industrial copper-rolling operation. The use of demulsifier agents improves the subsequent treatment by techniques such as ultrafiltration (UF) or evaporation. The effluent COD is reduced up to 50% when the O/W emulsion is treated by UF using a flat 30 nm TiO(2) ceramic membrane (ΔP = 0.1 MPa) and up to 70% when it is treated by vacuum evaporation, after an emulsion destabilization pretreatment in both cases. Increases in the UF permeate flux and in the evaporation rate are observed when a chemical demulsifier is used in the pretreatment step. A combined process consisting of destabilization/settling, UF, and vacuum evaporation can yield a very high-quality aqueous effluent that could be used for process cooling or emulsion reformulation.