SILICA SOLUBILITY
Many years ago at L*A Water, we hoped to determine the relative affinity of strong base anion resin for “pure silica”. Instead, we performed a simple experiment in silica polymerization. We went out into the California desert and collected some natural volcanic water that contained about 65 ppm of reactive SiO2. We ran it through cation and weak base ion exchangers, then air sparged to remove carbon dioxide. The solution, when freshly prepared, contained 65 ppm of reactive silica but almost nothing else. About a week later, we retested the solution and found the reactive silica to be less than 10 ppm!