Adsorption kinetic characteristics of molybdenum in yellow-brown soil in response to pH and phosphate

Zhaojun Nie,Hongen Liu,Jinfeng Li,Daichang Wang,Shiliang Liu,Haiyang Liu,Peng Zhao

doi:10.1515/chem-2020-0501

Abstract

AbstractMolybdenum (Mo) adsorption by acidic yellow-brown soil was investigated as a function of a pH (1–13) and the equilibrium of P solution (0, 3.1, and 31 mg L−1) concentration. Mo adsorption by acidic yellow-brown soil increased within the pH range from 1 to 4. Above pH 4, Mo adsorption decreases with an increase in pH. The maximum adsorption was found between pH 2 and 4. Competitive adsorption experiments showed that the equilibrium sorption data fitted into Langmuir and Freundlich isotherms. The sorption data of Mo on the acidic yellow-brown soil fitted well with the Langmuir isotherm model due to the higher R2 value. A reduction in Mo adsorption by the acidic yellow-brown soil was noticed at higher addition levels of P (3.1 and 31 mg L−1). Therefore, P increasing the bioavailability of Mo and enhancing Mo uptake by plants might be related to the inhibition of Mo absorption by the acidic yellow-brown soil.

Highlights

Molybdenum (Mo) is a trace element found in soil and is essential for plant growth
Mo is present in soil at an average level of up to 2.3 mg kg−1, which is lower than the lithosphere levels of up to 2.5–15 mg kg−1 [3]
The adsorption of Mo by the acidic yellow-brown soil was a strong function of pH and showed a maximum adsorption in the acidic pH range of 2–4

Summary

Introduction

Molybdenum (Mo) is a trace element found in soil and is essential for plant growth. As an important cofactor of more than 50 Mo enzymes found in all organisms, Mo participates in diverse metabolic processes, such as carbon metabolism, nitrate assimilation, ascorbate– glutathione cycle metabolism, and so on in plants [1,2]. Mo is present in soil at an average level of up to 2.3 mg kg−1, which is lower than the lithosphere levels of up to 2.5–15 mg kg−1 [3]. Mo in soil ranges from 0.11 to 6 mg kg−1 and at an average level of up to 1.7 mg kg−1, Mo deficiency in soil is very common. Mo deficiency is notably serious especially in the acidic yellow-brown soil from the Middle–Low Reaches of the Yangtze River in Hubei, Anhui and Jiangsu Provinces [5,6]

Objectives

Methods

Results

Conclusion