Mercury in river, estuarine and seawaters - Is it possible to decrease realist environmental concentrations in order...

Area of Science:

• Environmental Science
• Materials Science
• Analytical Chemistry

Background:

• Mercury contamination poses significant risks to aquatic ecosystems and human health.
• Effective removal of mercury from diverse water bodies is crucial for environmental protection.
• Developing efficient and cost-effective sorbent materials is essential for water remediation.

Purpose of the Study:

• To investigate the efficacy of dithiocarbamate-functionalized magnetite nanoparticles (Fe3O4@SiO2/SiDTC) for mercury removal.
• To evaluate the performance of these nanoparticles in various water matrices (river, estuarine, sea).
• To assess the ability of the sorbent to meet new environmental quality standards for mercury.

Main Methods:

• Synthesis and characterization of dithiocarbamate-functionalized magnetite nanoparticles (Fe3O4@SiO2/SiDTC).
• Sorption experiments using different water samples spiked with Hg(II).
• Kinetic studies using the Elovich model to understand sorption mechanisms.
• Evaluation of sorbent dose and distribution coefficients.

Main Results:

• Fe3O4@SiO2/SiDTC nanoparticles demonstrated high efficiency in mercury removal, exceeding 99.9% in estuarine and sea waters.
• Residual mercury concentrations were reduced below the new environmental quality standard of 70 ng/L.
• Sorption kinetics followed the Elovich model, with initial rates dependent on sorbent dose.
• High distribution coefficients (Kd > 10^3 mL/g for river water, Kd > 10^5 mL/g for estuarine/sea water) indicated strong binding affinity.

Conclusions:

• Dithiocarbamate-functionalized magnetite nanoparticles are a promising material for effective mercury remediation.
• The sorbent's performance is influenced by the water matrix composition.
• These nanoparticles offer a viable solution for achieving stringent mercury environmental quality standards in diverse aquatic environments.