The paper describes results of experiments performed with supersaturated silica feed solutions, aiming to elucidate basic silica scaling phenomena with and without the presence of antiscalants. The experimental program covered a wide range of silica feed concentrations. Most experiments were performed at relatively low silica supersaturation levels in the range of practical applications (supersaturation ratio, s/s, up to about 2). Silica scaling under such conditions was characterized by a deposition mechanism of monomeric silica. The experiments carried out at high silica supersaturation levels (around s/s = 4) displayed a strikingly different mechanism involving colloidal particles deposition followed by some monomeric deposition. Concomitantly, permeate flux decline was also significantly different at low and high silica supersaturation levels, respectively.
- Reverse osmosis
- Silica scale