Removal of Mercury from Aqueous Environments Using Polyurea-Crosslinked Calcium Alginate Aerogels

Area of Science:

• Environmental Science
• Materials Science
• Chemistry

Background:

• Mercury(II) contamination in aquatic environments poses significant risks.
• Effective and sustainable removal methods are crucial for environmental protection.

Purpose of the Study:

• To investigate the efficiency of polyurea-crosslinked calcium alginate (X-alginate) aerogels for mercury(II) removal.
• To evaluate the adsorption capacity, kinetics, and reusability of X-alginate aerogels.

Main Methods:

• Batch-type adsorption experiments were conducted using X-alginate aerogels.
• Adsorption isotherms (Langmuir) and kinetics (pseudo-first-order) were analyzed.
• Energy-dispersive X-ray spectroscopy (EDS) was used for post-adsorption analysis.

Main Results:

• X-alginate aerogels achieved high mercury(II) retention (85% to quantitative) at low concentrations (50-180 μg·L⁻¹).
• The maximum sorption capacity was 4.4 mmol kg⁻¹ (883 mg kg⁻¹) at pH 3.3, following Langmuir isotherm.
• The adsorbent was regenerated with Na₂EDTA and reused multiple times with minimal capacity loss.

Conclusions:

• X-alginate aerogels show significant potential for sustainable mercury removal from aquatic environments and industrial wastewater.
• The material's stability and reusability make it a promising candidate for practical applications.