Cadmium ion adsorption by amine-modified activated carbon

Area of Science:

• Environmental Chemistry
• Materials Science
• Water Treatment

Background:

• Cadmium (Cd) is a highly toxic heavy metal pollutant prevalent in aquatic environments.
• Conventional methods for cadmium removal often face limitations in efficiency and cost-effectiveness.
• Activated carbon (AC) is a widely used adsorbent, but its native capacity for cadmium can be improved.

Purpose of the Study:

• To develop an effective adsorbent for aqueous cadmium removal by modifying activated carbon (AC) with 3-aminopropyltrimethoxysilane (APS).
• To optimize the surface modification process parameters for introducing cadmium-binding amine ligands onto AC.
• To evaluate the adsorption performance of the modified AC for cadmium ions.

Main Methods:

• Surface modification of activated carbon using 3-aminopropyltrimethoxysilane (APS).
• Optimization of preparation parameters (temperature, contact time, APS/AC ratio) using response surface methodology (RSM) with a central composite design.
• Characterization of the modified adsorbent and evaluation of its cadmium adsorption capacity.

Main Results:

• Successful introduction of amine ligands onto AC surfaces via silanol reaction between surface functional groups and APS.
• Optimized preparation conditions determined as 77 °C, 4 hours, and an APS/AC ratio of 2.1.
• The modified activated carbon demonstrated favorable adsorption of aqueous cadmium (Cd(II)).

Conclusions:

• The amino-functionalized activated carbon is an effective adsorbent for removing cadmium from water.
• The optimized modification process enhances the cadmium-binding capacity of activated carbon.
• This approach offers a promising strategy for heavy metal remediation in contaminated water sources.