Evaluation of Kinetic and Isotherm Models for Adsorption of Boron Under Different Soil Orders in Oil Palm Plantations of India

ABSTRACT

Adsorption isotherm and kinetic models are essential in predicting the adsorption mechanisms, which helps in boron (B) recommendation at appropriate doses. This study is formulated with the objective of assessing different kinetic and adsorption models for the adsorption of B in different soil orders (Entisol, Alfisol, Inceptisol and Vertisol) in Oil Palm plantations in India. The B adsorption in soils followed the order: Vertisol > Alfisol > Inceptisol > Entisol. The results revealed that, the Langmuir adsorption model fitted well for alfisol (part1 R² = 0.9912 & part2 R² = 0.9678), entisol (R² = 0.9862) and inceptisol (R² = 0.9924), while the Freundlich model fitted well for vertisol (R² = 0.9943). The soils under entisol and inceptisol showed linear isotherms whereas, the vertisol and alfisol had curvilinear isotherms and the split Langmuir isotherm was worked out. High bonding energy at the lower part of split isotherm represented stronger retention of B at lower B concentrations. The B equilibrium was attained in 24 h in alfisol and inceptisol, and 12 h in entisol, whereas in vertisol, the equilibrium was not completed until 72 h. From the correlation coefficients obtained from all models, the pseudo-second-order kinetic model explained the B sorption in a better way followed by elovich and power function kinetic models in different soil types. Desorption of B is higher in entisol in most of the added B concentrations. The study suggests a higher rate of B fertilizer application than the recommended in soils having high B adsorption capacity for optimum crop growth and yield.

KEYWORDS:

• Adsorption
• boron
• desorption
• kinetics

Acknowledgements

The authors acknowledge the staff members of the Soil & Leaf analysis lab at ICAR- Indian Institute of Oil Palm Research, Pedavegi, Andhra Pradesh for their assistance provided during the experiment period. We are grateful to the editor and the anonymous reviewers for their constructive suggestions for improving the quality of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data presented in the article is available within the article.