Hi,
I was wondering if anyone here is any experience with the extraction of oil and grease from wastewater in which surfactants have been used (either cationic, anionic, non-ionic or a combination). The extraction I'm performing is with n-hexane according to ISO 11349. The wastewater I'm using contains lipids and surfactants. After extraction and evaporation there are no significant amount of lipids left, which I know for sure must be in there. I'm getting the impression that the surfactants are withholding the lipids from entering the hexane phase. Is there any one that has any experience with this and knows how to counteract the effect?
Kind regards,
André
Hi André
it is obvious that the surfactants you are using are emulsifying the lipids or converting them into water soluble salts. Try using non-ionic surfactants with low emulsifying properties (HLB value is in the range 3-10)
If you have solid deposit or floating organic fatty precipitates of try using higher HLB values to degrease the surface.
Hi Wadah,
Thank you for your anwser. The problem is that I don't have any influence on the input. The wastewater comes my way and I have to figure out a way to measure the Hexane Extractable Matter (HEM). Any other suggestions?
Sorry I misunderstood the situation, I thought the surfactants were added as a part of the extraction process. Then the only suggestion I have is changing the pH . Try altering the pH with an acid or alkaline to break the emulsion and convert the fatty salts into their corresponding free lipids.
- Badges
- Science topic
- Similar topics
- Social Psychology
- Attitude