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Silicate Removal in Aluminum Hydroxide Co-Precipitation Process
Chiharu Tokoro1, Shinya Suzuki2, Daisuke Haraguchi3
1Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan. tokoro@waseda.jp.
Materials (Basel, Switzerland)
|August 10, 2017
Summary
Aluminum hydroxide co-precipitation effectively removes silicate from wastewater through adsorption and precipitation. Controlling pH and aluminum concentration is key for efficient silicate removal, offering a validated method for water treatment.
Area of Science:
- Environmental Chemistry
- Water Treatment Technologies
Background:
- Silica is a common contaminant in wastewater.
- Effective silicate removal is crucial for various industrial applications and environmental protection.
Purpose of the Study:
- To investigate and compare silicate removal mechanisms using aluminum hydroxide co-precipitation and adsorption.
- To establish an effective and validated method for silicate removal from wastewater.
Main Methods:
- Investigated silicate removal mechanisms via aluminum hydroxide co-precipitation and adsorption.
- Utilized adsorption isotherms, X-ray Diffraction (XRD), and Fourier-Transform Infrared (FT-IR) analyses.
- Analyzed silicate uptake in relation to initial Si/Al molar ratios.
Main Results:
- Silicate uptake occurred via adsorption to boehmite (Si/Al < 2) or precipitation of kaolinite (Si/Al > 2).
- Silicate removal proceeded in two steps: rapid uptake (seconds) and slow uptake (hours).
- Co-precipitation showed a higher initial uptake rate than adsorption, attributed to enhanced adsorption and precipitation.
Conclusions:
- Aluminum hydroxide co-precipitation is an effective method for silicate removal from wastewater.
- Strict control of pH and aluminum concentration is essential for optimizing silicate removal efficiency.
- The study provides a validated approach for managing silicate contamination in water.
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