Adsorption Performance on As(III) from Aqueous Solution Using the Complex Nickel-Aluminum Hydroxides

Area of Science:

• Materials Science
• Environmental Chemistry
• Inorganic Chemistry

Background:

• Arsenic contamination in water poses significant health risks.
• Effective adsorbents are needed for arsenic removal from aqueous media.
• Nickel-aluminum hydroxides are explored for their adsorption properties.

Purpose of the Study:

• To synthesize and characterize nickel-aluminum hydroxides.
• To evaluate their adsorption capability for arsenic ions (As(III)).
• To investigate factors influencing As(III) adsorption and elucidate the mechanism.

Main Methods:

• Synthesis of nickel-aluminum hydroxides at various molar ratios (NA12-NA41).
• Characterization using techniques like X-ray diffraction and surface area analysis.
• Adsorption experiments evaluating contact time, temperature, pH, and isotherm models.

Main Results:

• NA41 exhibited the highest As(III) adsorption capacity.
• Adsorption equilibrium was reached within 24 hours, following pseudo-second-order kinetics.
• Optimal As(III) removal occurred at pH 6-8.
• Electrostatic interaction and ion exchange were identified as key adsorption mechanisms.

Conclusions:

• NA41 is a promising adsorbent for As(III) removal from aqueous solutions.
• Physicochemical properties like surface area did not solely determine adsorption efficiency.
• The study provides insights into the adsorption mechanism for effective water treatment strategies.