Mercury ions removal from aqueous solution using an activated composite membrane.

Area of Science:

• Environmental Chemistry
• Materials Science
• Separation Science

Background:

• Mercury (Hg(II)) is a toxic heavy metal pollutant in aqueous solutions.
• Effective removal of Hg(II) is crucial for environmental protection and water safety.
• Composite membranes offer a promising platform for heavy metal remediation.

Purpose of the Study:

• To investigate the efficacy of activated composite membranes (ACMs) for Hg(II) ion removal.
• To explore the role of di-(2-ethylhexyl)dithiophosphoric acid (DTPA) as a ligand in Hg(II) removal.
• To optimize parameters influencing Hg(II) removal efficiency by ACMs.

Main Methods:

• Preparation of activated composite membranes (ACMs) incorporating di-(2-ethylhexyl)dithiophosphoric acid (DTPA).
• Experimental studies on Hg(II) removal from aqueous solutions under varying conditions (pH, acid type, mercury concentration, ligand content, membrane surface area).
• Monitoring of mercury concentration changes over time using solution sampling and analysis.

Main Results:

• ACMs demonstrated high efficiency in removing Hg(II) ions, achieving over 93% removal under optimal conditions.
• Optimal conditions included a 1.0 M DTPA casting solution and a feed solution of 2.49 x 10(-4) M Hg(II) in 0.1 M HCl.
• Control experiments with free-DTPA membranes confirmed that Hg(II) removal was solely due to the presence of the DTPA ligand.

Conclusions:

• Activated composite membranes (ACMs) functionalized with di-(2-ethylhexyl)dithiophosphoric acid (DTPA) are highly effective for Hg(II) removal.
• The study identified key parameters for maximizing mercury removal efficiency using ACMs.
• ACMs represent a viable technology for the remediation of mercury-contaminated water sources.