Solvent Extraction with Cyanex 923 to Remove Arsenic(V) from Solutions

Area of Science:

• Environmental Chemistry
• Separation Science
• Hydrometallurgy

Background:

• Arsenic contamination in water poses significant health risks.
• Effective removal of arsenic(V) from aqueous solutions is crucial for environmental remediation.
• Solvation extractants offer a promising avenue for selective metal ion removal.

Purpose of the Study:

• To investigate the efficiency of Cyanex 923 for arsenic(V) removal from aqueous solutions.
• To determine the optimal experimental conditions for arsenic extraction and stripping.
• To evaluate the selectivity of Cyanex 923 against other metal ions and compare it with other P=O-based extractants.

Main Methods:

• Solvation extraction experiments were conducted varying parameters like acidity, temperature, and concentrations.
• Extraction and stripping isotherms were determined based on experimental data.
• Selectivity studies involved assessing the extraction of co-existing metal ions (Cu(II), Ni(II), Bi(III), Sb(III)).

Main Results:

• Cyanex 923 efficiently extracted arsenic(V) from acidic solutions, forming H3AsO4·nL species.
• The extraction process was found to be exothermic.
• Arsenic and sulfuric acid could be effectively stripped from the organic phase using water.

Conclusions:

• Cyanex 923 is a viable extractant for removing arsenic(V) from acidic industrial effluents.
• The study provides valuable data for designing arsenic removal processes using Cyanex 923.
• Cyanex 923 demonstrates potential for selective arsenic extraction compared to other reagents.