A Green Method for Preparing Robust and Sustainable Cellulose-polyaniline based Nanocomposite for Effective Removal of Fluoride from Water and a Purifier thereof

Category- Green Technology

Industry Classification:

NIC (2008)- 28195- Manufacture of filtering and purifying machinery or apparatus for liquids and gases; 11043- Manufacture of mineral water; 36000- Water collection, treatment and supply; 20299– Manufacture of various other chemical products n.e.c.

Applications:

Water treatment and purification and fluoride removal from groundwater.

Market drivers:

water treatment market size is expected to rise from US$ 69.73 billion in 2024 to US$ 137.17 billion by 2034 with a CAGR of 7%

Natural fluoride (F-) content of water between 1 to 1.5 mg/L is essential for good dental health. However, higher fluoride content of 1.5-4 mg/L can lead to dental and skeletal fluorosis which effects over 200 million people across the globe.
Conventional methods of using alumina-based coagulants, membrane technology and electrocoagulation either leave an unpleasant taste or are too expensive for public use.
There is a need for an eco-friendly polymer based nano-cellulose adsorbent with metallic oxyhydroxides to get a robust composite for an improved synergistic performance towards F- removal.

Cellulose Nanofibers-Polyaniline template Ferrihydrite (CNPFH) nanocomposite was prepared by a green method involving a one pot synthesis process via an in-situ polymerization method.
The ferrihydrite nanoparticles incorporated in the polymeric confinement of cellulose nanofibers and doped N sites of blended PANI function as active sites which operate synergistically for enhanced Fluoride removal
The CNPFH composite exhibited a maximum Fluoride adsorption capacity of 50.8 mg/g
The developed CNPFH composite was also tested for the effect of interfering ions to simulate usage for groundwater applications. CNPFH is able to remove more than 80% of Fluoride in presence of most interfering anions while remaining unaffected by the presence of interfering cations.

The simple synthesis process yielded a sustainable composite which was used for F- removal from water by means of adsorption.
CNPFH composite has maximum F- adsorption capacity of 50.8 mg/g which is higher than other PANI based composites.
Though low cost and bio-based adsorbents such as alumina and chitosan are available, they are not completely eco-friendly or effective due to issues such as non-plant based source and high polycrystallinity when compared to cellulose based composites.
The robustness of the composite keeps it free from leaching. Moreover, CNPFH works efficiently in a wide range of pH with fast adsorption kinetics making it a superior option for an industrially feasible green material for delivering affordable water in Fluoride affected communities worldwide.

Prof. T Pradeep

Department of Chemistry

TRL 5

Technology Validated in Relevant environment

Technology Transfer