Arsenic removal from water using lignocellulose adsorption medium (LAM)

Area of Science:

• Environmental Science
• Materials Science
• Water Treatment

Background:

• Arsenate contamination in drinking water poses significant health risks.
• Effective and economical water purification methods are crucial for public health.
• Lignocellulosic materials offer a sustainable and abundant resource for adsorbent development.

Purpose of the Study:

• To develop and evaluate an iron(III)-coated lignocellulose adsorption medium (LAM) for arsenate removal.
• To determine the adsorption capacity and isotherm model for arsenate on LAM.
• To assess the regenerability and cost-effectiveness of the developed adsorbent.

Main Methods:

• Cotton-based lignocellulose was coated with iron(III) chloride.
• Batch adsorption experiments were conducted to determine arsenate removal efficiency.
• Freundlich and Langmuir isotherms were applied to model the adsorption process.
• Adsorbent regeneration was performed using dilute sodium hydroxide.

Main Results:

• LAM demonstrated an average adsorption capacity of 32.8 mg As/g.
• Adsorption followed a Freundlich isotherm model (R2 = 0.993).
• The adsorbent retained over 88% of its capacity after five regeneration cycles.
• Regenerated adsorbent removal cost is approximately $3.20/ton, excluding media costs.

Conclusions:

• Iron(III)-coated LAM is a highly effective adsorbent for removing arsenate from water.
• The adsorbent is regenerable, offering a sustainable and potentially cost-effective water treatment solution.
• Further investigation into concentrating and recycling arsenate from regeneration effluent is warranted.