Optimisation of water savings and membrane processes

The Centre for Industrial Water Management is a co-operation between several technology service institutes, university institutes and water consuming companies in Denmark to promote concepts for cleaner production, water treatment and reduction of effluents in industrial production processes. This investigation focuses on two case studies from two of the industrial partners participating in this centre. The first case study is a texturiser of polyester yarn. Nanofiltration and reverse osmosis (RO) have been tested to clean the water streams from a dyeing bath and a reductive bath. It was shown that only the RO-process guaranteed a high rejection of salts under the process conditions. Furthermore, fouling could be analysed and reduced. The second case study is a manufacturer of functional proteins. An ultrafiltration system was used to concentrate the proteins from pig rind. It could be proved that the declining flux was caused by the adsorption of proteins on the membrane surface. To control fouling, a concept involving operation below the critical flux and a cleaning strategy is presented.