Removing heavy metals from polluted surface water with a tannin-based flocculant agent

Area of Science:

• Environmental Science
• Water Chemistry
• Chemical Engineering

Background:

• Heavy metal contamination in surface water poses significant environmental and health risks.
• Effective removal of toxic metals such as zinc (Zn2+), nickel (Ni2+), and copper (Cu2+) is crucial for water quality management.

Purpose of the Study:

• To evaluate the efficacy of a novel commercial tannin-based flocculant for removing Zn2+, Ni2+, and Cu2+ from surface water.
• To assess the flocculant's performance under varying pH conditions, isolating its effect from hydroxide precipitation.

Main Methods:

• Coagulation-flocculation process was employed to test the tannin-based flocculant.
• Experiments were conducted with controlled pH adjustments to differentiate flocculant-driven metal removal from metal hydroxide precipitation.

Main Results:

• The tannin-based flocculant demonstrated significant removal of Zn2+, Ni2+, and Cu2+ across tested conditions.
• A minimum of 75% metal removal was achieved in all experimental cases, with efficiency varying based on pH.
• Optimal flocculant dosage was determined to be in the range of 100-150 ppm.

Conclusions:

• The commercial tannin-based flocculant is effective for removing key heavy metals from surface water.
• The study highlights the potential of tannin-based materials as sustainable solutions for industrial and environmental water treatment.
• Controlled pH is essential for maximizing flocculant efficiency and ensuring accurate assessment of heavy metal removal.