Separation of oil–water emulsion from car washes

Abstract

The potentials of UF and NF membrane processes have been evaluated for separation of oil water emulsion generated from car washing operations. Using membranes, wastewater can be effectively recycled and fresh water usage could be reduced. The parameters studied were membrane type, emulsifier types, pressure and competing compounds. Both an-ionic and non-ionic emulsifiers were used for the experimental runs. The Ca2+ and Mg2+ were used as the main competitive ions. Results indicate that a polysulfone membrane caused more flux reduction than the cellulose acetate and thin film polyamide membranes. Higher concentrations of emulsifier presented negative flux decline in both UF and NF membranes. However, the presence of nonionic emulsifier in oil emulsion caused more significant flux reduction than an anionic emulsifier. The NF membrane produced higher TOC removal and less fouling than UF. The results indicate that increased competitive Ca2+ and Mg2+ ions resulted in significant positive NF flux and TOC removal.

Reuse of carwash water with a cellulose acetate ultrafiltration membrane aided by flocculation and activated carbon treatments

“…Panpanit et al reported that CA UF membranes showed higher permeation flux compared to polysulfone UF membranes in an oil-water emulsion from a carwash [15]. The effect of pure water permeability of the CA membrane on permeation flux in carwash wastewater after flocculation treatment was examined using three kinds of membranes with MWCO of 150,000 Dalton in a laboratory-scale experiment.…”

Applicability of nanofiltration in the carwash industry

“…That is why in literature more attention was given to the first problem of membrane fouling, for example Panpanit et al [5] tried to decrease membrane fouling by adding bentonite to the wastewater. An experimental comparison between the performance of different ultrafiltration and nanofiltration membranes also pointed out that applying nanofiltration to recycle the wastewater would result in less fouling in combination with higher retentions [6,7]. However, a systematic study of the feasibility of nanofiltration in the carwash industry is currently missing in literature.…”

Gas-station Wastewater Treatment using Catalytic and non-Catalytic Ozonation

“…Many particles and chemicals are found in wash water. The concentration and severity of these particulates are usually extrapolated or not considered [1]. Many contaminants of gas-station wastewater have an impact on the environment.…”