High Iron & Silica Challenges in a 2,000 Hour NF Pilot Study

This paper documents the results of a 2,000 hour nanofiltration (NF) pilot study on very challenging North Carolina well water. The challenges were as followed: Very high iron, up to over 8 mg/L in some wells; Very high silica, up to over 70 mg/L in some wells; A combination of at least two wells is always required to be in operation at all times resulting in both very high iron and very high silica feed water; Silica and iron precipitation in the last elements occurred even at silica concentrations below the published maximum limit for the scale inhibitor used; Experimentation was required using different recovery rates and different scale inhibitors to control silica scaling