REMOVAL OF HARDNESS FROM GROUNDWATER BY NANOFILTRATION

In this paper the softening of groundwater with drinking-water quality using nanofiltration is studied. Experiments were carried out with th ree commercial nanofiltration membranes. The UTC 20 membrane was chose n for further experiments. The influence of water temperature was stud ied on both permeate flux and ion retention. Also, the effect of a hig her recovery was studied: experimental and predicted values were compa red for recoveries of 0 to 70%. Finally, experiments were carried out to study membrane fouling. The use of hydrochloric and sulphuric acid was compared and the effect of an ultrafiltration pretreatment on the water flux was examined.