Regeneration of brewery waste water using nanofiltration

The brewing industry is a large consumer of groundwater for brewing, rinsing and cooling purposes. As regulations become more and more stringent and the cost of water increases, water recycling gains interest. This paper investigates the possibilities of nanofiltration for the treatment of brewery waste water streams in view of recycling. Four different water streams (waste water after biological treatment, bottle rinsing water, rinsing water of the brewing room and rinsing water of the bright beer reservoir) were filtered with four different nanofiltration membranes (UTC-20, UTC-60, Desal-HL-51 and Desal-5-DK). The results for the biologically treated waste water were the most promising. For the other streams, rejection of organics was insufficient to obtain the required quality, mainly due to the high concentrations of organics such as ethanol in the feed water. Over the periods considered (3 h) only moderate flux decline (10–40%) was observed for most membranes and feed solutions. For Desal-5-DK at high pH, an increase of the flux was observed.