CHEMICAL CLEANING OF REVERSE OSMOSIS MEMBRANE FOULED BY APPLE JUICE

Abstract

ABSTRACTThe effects of several chemical agents on cleaning of RO BW30 membrane fouled by apple juice were investigated. Resistance removal (RR) and flux recovery (FR) were calculated for all the seven chemical cleaning agents (HCl, HNO3, NH3, NaOH, ethylenediaminetetraacetic acid [EDTA], cetyl three methyl ammonium bromide and sodium dodecyl sulfate[SDS]) which were used at 1% (w/v) concentration. For high cleaning efficiency agents, the effect of chemical factors (pH and concentration) and physical factors (velocity, temperature and time) were studied. SDS showed the highest (about 90%) cleaning efficiency. EDTA and NH3 were also quite effective in reacting with organic foulants. The treatment of fouled membrane by distilled water as cleaning agent showed high cleaning efficiency. Investigations of the chemical and physical factors on membrane cleaning indicate that the cleaning efficiency is dependent on these parameters. Increasing the pH of 1.5% SDS solution up to 11.8 showed the highest cleaning efficiency, i.e., approximately 100%.PRACTICAL APPLICATIONSReverse osmosis (RO) is a very useful technology in fruit juice concentration due to maintaining the taste and fresh juice flavors. In contrast, the conventional processes applied for this concentration, e.g., evaporation, have the disadvantage of adding a cooking taste to the product and lowering itsquality, in addition to the high energy consumption. However, fouling by carbohydrate components is the most important problem associated with the RO application. Finding high efficiency cleaning agents for regeneration of membranes is one of the industrial interests, which is proceeded in this work.