Sorptive removal of arsenate using termite mound

Area of Science:

• Environmental Science
• Geochemistry
• Materials Science

Background:

• Long-term arsenic exposure causes severe health issues.
• Arsenate (As(V)) contamination in drinking water is a significant global health concern.
• Developing effective and economical water treatment methods is crucial.

Purpose of the Study:

• To evaluate the arsenate (As(V)) sorption capacity of termite mound (TM) as a potential adsorbent.
• To investigate the key factors influencing As(V) removal by TM.
• To determine the adsorption mechanism and regeneration potential of TM.

Main Methods:

• Batch adsorption experiments were conducted to study As(V) removal.
• Parameters investigated included contact time, pH, adsorbent dose, initial As(V) concentration, and competing anions.
• Adsorption kinetics and isotherms were analyzed using pseudo-second order, Freundlich, and Dubinin-Radushkevich models.

Main Results:

• Equilibrium As(V) adsorption was achieved within 40 minutes.
• High removal efficiency (∼99%) was observed between pH 3 and 10.
• Adsorption followed pseudo-second order kinetics and was well-described by Freundlich and D-R isotherms, indicating chemisorption.
• Phosphate ions significantly reduced As(V) removal.

Conclusions:

• Termite mound (TM) exhibits excellent arsenate (As(V)) sorption capacity.
• TM is a cost-effective and efficient adsorbent for As(V) removal from drinking water.
• The adsorbent can be regenerated effectively using NaOH solution.