Coconut coir-derived nanocellulose as an efficient adsorbent for removal of cationic dye safranin-O: a detailed mechanistic adsorption study

Venkatalakshmi Jakka; Anandarup Goswami; Anil Kumar Nallajarla; Uttariya Roy; Koigoora Srikanth; Shubhalakshmi Sengupta

doi:10.1007/s11356-023-29075-7

Coconut coir-derived nanocellulose as an efficient adsorbent for removal of cationic dye safranin-O: a detailed mechanistic adsorption study

Environ Sci Pollut Res Int. 2023 Aug 22. doi: 10.1007/s11356-023-29075-7. Online ahead of print.

Authors

Venkatalakshmi Jakka¹, Anandarup Goswami¹, Anil Kumar Nallajarla¹, Uttariya Roy², Koigoora Srikanth³, Shubhalakshmi Sengupta⁴

Affiliations

¹ Department of Chemistry, School of Applied Science and Humanities, Vignan's Foundation for Science, Technology and Research (Deemed to Be University), Vadlamudi, Guntur, Andhra Pradesh, India.
² Department of Environmental Studies, Budge Budge College (Affiliated to University of Calcutta), 7, Deshbandhu Chittaranjan Road, Budge Budge 24 Paraganas (South), Kolkata, 700137, India.
³ Department of Biotechnology, School of Biotechnology and Pharmaceutical Sciences, Vignan's Foundation for Science, Technology and Research (Deemed to Be University), Vadlamudi, Guntur, Andhra Pradesh, India.
⁴ Department of Chemistry, School of Applied Science and Humanities, Vignan's Foundation for Science, Technology and Research (Deemed to Be University), Vadlamudi, Guntur, Andhra Pradesh, India. drsls_sh@vignan.ac.in.

PMID: 37608172
DOI: 10.1007/s11356-023-29075-7

Abstract

Coconut (Cocos nucifera) coir is an abundant agricultural waste prevalent worldwide. Utilization of this waste has been carried out in this study by obtaining nanocellulose (NC) fibres for wastewater remediation purposes. Nanocellulose was obtained from coconut coir using bleaching and acid-alkali treatments followed by ultrasonication and lyophilization. The structural, compositional, surface and thermal properties of the synthesized material were identified using transmission electron microscopy (TEM), scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT-IR), N₂ adsorption/desorption, differential thermal (DT) and derivative thermogravimetric (DTG) analyses. These analyses confirmed the synthesized NC with enhanced thermal stability and porosity which was further used for adsorption process. After synthesis, NC was used for the removal of cationic dye safranin-O from water under ambient conditions through batch adsorption studies. The batch adsorption studies revealed that at 10 ppm of dye concentration, above 99% removal was achieved by 100 mg dosage of NC within 4.5 h at room temperature with q_e (maximum adsorption capacity at equilibrium) value of around 83 mg g^-1. The corresponding adsorption process fitted well with Langmuir isotherm and pseudo-second order kinetics. The primary mode of adsorption from the thermodynamic studies was found to be chemisorption. The adsorption process was achieved through response surface methodology (RSM) study which revealed that at optimized conditions of temperature 35 °C with a dose of 137.50 mg and contact time of 180 min, above 99% of dye (conc. 0.01 mg mL^-1) was removed. In addition, the adsorbent can be recycled up to six cycles without any significant loss of its adsorption capacity. The present comprehensive study revealed that a greener eco-friendly synthesis of NC from waste material coconut coir was an effective nanoadsorbent for dye removal with high efficacy. This surely opens up opportunities to develop sustainable protocols for efficient environmental remediation.

Keywords: Coconut coir; Dye removal; Nanocellulose; Safranin-O.

Grants and funding

SP/Y0/2019/1283/Department of Science and Technology, Govt. of India