Influence of NF membrane properties on water recovery from the dairy industry wastewater

In the paper, the use of three types of polymer nanofiltration (NF) membranes, i.e. the TS80, DL and NP010, to recover water from the dairy industry wastewater is described. The most desired results were obtained for the TS80 membrane with the skin layer made of polyamide. This membrane significantly contributed to the recovery of water to be reused for external cleaning of tank parts, road tankers, and floors. All tested NF membranes were characterised by a relatively low fouling index. This is due to the preliminary treatment of wastewater as part of an integrated system of bag filtration and microfiltration. However, the decrease in the permeate flux for all tested polymer membranes was observed during the NF process, which was mainly caused by an increase in the concentration factor of the dairy industry wastewater components. The presented results are part of the prospective trends in the development of the bioeconomy, especially in a closed circuit.