Recovery of contaminated single-phase detergent by means of membrane filtration

The results of the purification of contaminated cleaning solutions (acidic single-phase detergent), emanating from a diary industry, with the use of NF and UF flat-sheet membranes have been reported. The studies have shown potential usefulness of membrane filtration for the recovery of spent acid single-phase detergent. The NF (NP030 and NP010) and the tight UF (PS1) membranes provided high separation of specific milk components (protein and lactose) and organic matter, expressed as TOC and COD. The purified detergent maintained its low pH value and high value of acidity. However the surface tension slightly increased as a result of the high separation of the anionic surfactant.