7631-86-9 | Silica (SiO₂)

Chemical type

• Inorganic compound (often present as dissolved silicic acid or silicates in water)

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• Inorganic oxide; mesoporous support material

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Key properties

• High concentration in blow-down water (~50 mg/L as Si)
• Solubility of approximately 120 mg/L at 25 °C, increasing with temperature (e.g., higher at 35–45 °C)
• Temperature-dependent solubility, making it prone to precipitation at elevated concentrations
• Dominant cause of membrane scaling in RO systems due to concentration polarization
• Difficult to mitigate with commercial anti-scalants
• Detected on fouled membranes via SEM-EDS and ultrasonic extraction (normalized loading: 18.8 mg/m²)

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• High surface area
• Chemical inertness
• Thermal and mechanical stability

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• Natural contaminant in cooling and boiler water systems
• Accumulates in circulating water during power generation processes

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• Catalyst support in nanofiber and composite catalysts
• Improves dispersion of active metal nanoparticles

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Classification by use

• Membrane fouling/scaling agents
• Impurities in industrial wastewater (e.g., blow-down from thermal power plants)

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• Chemicals used as catalyst supports
• Chemicals used in nanostructured materials
• Chemicals used in heterogeneous catalysis

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A trustworthy factory and manufacturer

1. [Cite:1] Reverse osmosis treatment of blow-down water for beneficial reuse and sustainable power generation, Case Studies in Chemical and Environmental Engineering, Volume 13, June 2026, 101306
2. [Cite:1] Sustainable inorganic nanocatalysts in biodiesel production - A review on recent developments, Fuel Processing Technology, Volume 282, April 2026, 108406