Biocomposite based electrode for effective removal of Cr (VI) heavy metal via capacitive deionization

Abstract

This study focuses on the fabrication of biocomposite electrode and removal of Cr (VI) ions from wastewater using a capacitive deionization (CDI) method. The activated carbon (AC) was synthesized from Bael fruit shell (BS). The synthesized AC surface has a macroporous and mesoporous structure with the large specific surface area (617.72 m² g⁻¹) and high adsorption capacity. The cyclic voltammetry and CDI were performed for the detection and for the removal of chromium (VI) ions, respectively. The lower level of detection of Cr (VI) by a modified electrode was found to be 10 ppt. SEM, BET, and FTIR analyses were performed to explore the surface properties of electrode materials. The removal efficiency was achieved 100% by using biocomposite electrode with an applied potential of 15 V. The highest percent removal mechanism consists of electrosorption and electroreduction due to the affinity between polyvinyl alcohol modified electrode and Cr (VI) ions, under electrochemically faradic process.

Keywords:

• Adsorption
• Biocomposite electrode
• Capacitive deionization
• Chromium (VI) ion
• Faradic process
• Polyvinyl alcohol

Additional information

Funding

It is grateful to acknowledge the financial support of National Institute of Technology Calicut, India, KSCSTE, Thiruvananthapuram, Kerala Project (Ref No.:ETP/16/2015/KSCSTE) and DST, SREB (Ref No.:EEQ/2018/001261).