Alternative methods for dissolved oxygen removal from water: a comparative study

Different methods for removing dissolved oxygen from water on the laboratory scale have been studied. They are membrane modules, membrane reactors and ion-exchange columns. The membrane modules and membrane reactors have basically a shell and tube type of construction with hollow-fibre polymeric (polypropylene) membranes acting as the tubes. The main difference in the membrane reactor compared to the membrane module is the presence of catalyst (palladium doped anion-exchange resin based on styrene and divinyl benzene) in the shell side. The ion-exchange column was fabricated from glass and packed with a type-II anionic resin (Purolite A-310) regenerated in the sulphite form. These methods use either physical stripping or chemical reduction or a combination of both for the removal of dissolved oxygen from water. The performance of each of these methods was analyzed, and it was found that the membrane reactor which reduced the dissolved oxygen in water by both physical stripping and chemical reduction gave the best results in terms of the outlet dissolved oxygen level.