Optimization studies of chromium biosorption by carbon nanoparticles of Cocos nucifera

Saravana Raj, Adimoolam; Karuppaiah Subramanian, Aakaash; Perumal, Vinosh Muthukumar; Balasubramanian, Bharathiraja; Jayabalan, Veeramalini; Ganesan, Saravana Kumar; Akilan, Meenakshi Sundar

doi:10.22104/aet.2026.6958.1948

Optimization studies of chromium biosorption by carbon nanoparticles of Cocos nucifera

Document Type : Research Paper

Authors

Adimoolam Saravana Raj ¹

Aakaash Karuppaiah Subramanian ¹

Vinosh Muthukumar Perumal ¹

Bharathiraja Balasubramanian ²

Veeramalini Jayabalan ¹

Saravana Kumar Ganesan ³^{, 4}

Meenakshi Sundar Akilan ⁵

¹ Department of Chemical Engineering, Vel Tech High Tech Dr. Rangarajan Dr. Sakunthala Engineering College, Avadi, Chennai, Tamil Nadu, India

² Department of Biotechnology, Easwari Engineering College, Ramapuram, Tamil Nadu, Chennai, India

³ Department of Computer Science and Engineering, Karpagam Academy of Higher Education, Coimbatore-641021, IndiaCentre for Artificial Intelligence and Autonomous Aerial Systems (CAAAS), Karpagam

⁴ Centre for Artificial Intelligence and Autonomous Aerial Systems (CAAAS), Karpagam Academy of Higher Education (Deemed University), Coimbatore-641021, India

⁵ Department of Chemical Engineering, V.S.B. Engineering College, Karur, Tamil Nadu, India

10.22104/aet.2026.6958.1948

Abstract

Carbon nanoparticles (CNPs) were produced from the leaves of Cocos nucifera and chemically activated using phosphoric acid. The activated CNPs were characterized using Brunauer-Emmett-Teller (BET) (surface area: 122.53 m²/g; mean pore diameter: 16.29 nm) and Field Emission Scanning Electron Microscopy (FE-SEM) (particle size: 20-30 nm). Batch adsorption experiments were conducted to optimize chromium (VI) removal from leather industry effluent. Response surface methodology with Central Composite Design (CCD) was employed to investigate the effects of four parameters: Cr concentration (10-100 ppm), CNP dosage (1-10 g/L), contact time (10-60 min), and pH (1-7). Under optimized conditions (Cr concentration 100 ppm, CNP dosage 10 g/L, contact time 30 min, and pH 2), the maximum removal efficiency achieved was 83% with an adsorption capacity of 83 mg/g. ANOVA analysis confirmed the quadratic model adequacy (F-value = 74.65, p < 0.0001, and R² = 0.9896). CNP concentration emerged as the most influential parameter. Isotherm modeling analysis demonstrated that the chromium biosorption process follows Langmuir isotherm behavior with an R² value of 0.9951, a Chi-squared error (χ²) value of 0.2452, and a root mean square error (RMSE) of 1.0002 mg/g, indicating monolayer adsorption. The Cocos nucifera carbon nanoparticles demonstrated high efficiency for chromium removal from tannery effluents under acidic conditions.

Graphical Abstract

Keywords

Carbon nanoparticles

Cocos nucifera

Leather effluent treatment

Response Surface optimization

Langmuir isotherm

Subjects

Adsorption

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