In-situ synthesised polyaniline - halloysite nanoclay composite sorbent for effective decontamination of nitrate from aqueous streams

• Published in: International journal of environmental analytical chemistry Vol. 102; no. 18; pp. 7274 - 7289
• Main Authors: Parab, Harshala, Chauhan, Komal, Ramkumar, Jayshree, P.S., Remya Devi, Shenoy, N. S., Kumar, Sangita D.
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 28.12.2022; Taylor & Francis LLC
• Subjects: Acidic oxides; Aniline; Aquatic organisms; Aqueous solutions; Chromatography; Clay; Contaminants; Decontamination; ground water; Groundwater; Groundwater treatment; kinetic and equilibrium models; Kinetics; nitrate; Polyaniline -halloysite nanoclay (PAni-HC) composite sorbent; Polyanilines; Removal; Rivers; Sorbents; Sorption; sorption capacity; Streams; Surface properties; Uptake; Water analysis; Water pollution; Water sampling
• ISSN: 0306-7319; 1029-0397
• DOI: 10.1080/03067319.2020.1828390

Nitrate (NO 3 − ) is one of the most common contaminants of water bodies with harmful effects to aquatic life and human beings. There is a need for development of sorbents for effective removal of NO 3 − form aqueous streams. The aim of present study was to develop a Polyaniline modified halloysite nanoclay (PAni-HC) composite sorbent for the uptake of NO 3 − from aqueous medium. Aniline coated on halloysite clay was oxidised in acidic medium at 4ºC to synthesise PAni-HC composite in one pot reaction. Successful incorporation of polyaniline (PAni) in the clay matrix was confirmed by different surface characterisation techniques. The as synthesised PAni-HC composite sorbent was tested for NO 3 − sorption in a batch mode in the initial concentration range of 5-500 mg L −1 . The analysis of NO 3 − was performed using ion chromatography in the suppressed conductivity mode. The experimental data were assessed using different kinetic and equilibrium models for understanding the sorption behaviour of the PAni-HC composite. Sorption followed pseudo second order kinetics and intraparticle diffusion model. The maximum Langmuir sorption capacity of PAni-HC composite for NO 3 − was found to be 27.9 mg g −1 . The composite sorbent when treated with groundwater samples exhibited quantitative removal (> 90%) of NO 3 − thus demonstrating the applicability of the sorbent in real situations.