Potentially migrating and residual components of biochar: Effects on phosphorus adsorption performance and storage capacity of black soil

Ping Xue; Renjie Hou; Qiang Fu; Tianxiao Li; Jinwu Wang; Wenqi Zhou; Weizheng Shen; Zhongbin Su; Yijia Wang

doi:10.1016/j.chemosphere.2023.139250

Potentially migrating and residual components of biochar: Effects on phosphorus adsorption performance and storage capacity of black soil

Chemosphere. 2023 Sep:336:139250. doi: 10.1016/j.chemosphere.2023.139250. Epub 2023 Jun 19.

Authors

Ping Xue¹, Renjie Hou¹, Qiang Fu², Tianxiao Li¹, Jinwu Wang³, Wenqi Zhou³, Weizheng Shen⁴, Zhongbin Su⁴, Yijia Wang⁵

Affiliations

¹ School of Water Conservancy and Civil Engineering, Northeast Agricultural University, Harbin, Heilongjiang, 150030, China; Key Laboratory of Effective Utilization of Agricultural Water Resources of Ministry of Agriculture, Northeast Agricultural University, Harbin, Heilongjiang, 150030, China; Heilongjiang Provincial Key Laboratory of Water Resources and Water Conservancy Engineering in Cold Region, Northeast Agricultural University, Harbin, Heilongjiang, 150030, China.
² School of Water Conservancy and Civil Engineering, Northeast Agricultural University, Harbin, Heilongjiang, 150030, China; Key Laboratory of Effective Utilization of Agricultural Water Resources of Ministry of Agriculture, Northeast Agricultural University, Harbin, Heilongjiang, 150030, China; Heilongjiang Provincial Key Laboratory of Water Resources and Water Conservancy Engineering in Cold Region, Northeast Agricultural University, Harbin, Heilongjiang, 150030, China. Electronic address: fuqiang0629@126.com.
³ School of Engineering, Northeast Agricultural University, Harbin, Heilongjiang, 150030, China.
⁴ School of Electrical and Information, Northeast Agricultural University, Harbin, Heilongjiang, 150030, China.
⁵ Department of Industrial and Manufacturing Systems Engineering, The University of Hong Kong, Hong Kong, 999077, China.

PMID: 37343640
DOI: 10.1016/j.chemosphere.2023.139250

Abstract

Biochar has great potential to increase the soil nutrient storage capacity. However, with aging, biochar gradually disintegrates and releases fractions with migration potential, resulting in unknown effects on soil nutrient regulation. Based on this problem, we used ultrasound to separate original biochar (TB) into potentially migrating biochar (DB) and residual biochar (RB). The elemental composition and pore characteristics of TB, DB and RB were analyzed. Different fractions of biochar were applied to black soil, and the kinetic model and isothermal adsorption models were used to explore the adsorption characteristics of different treatments. Then, the effects of initial pH and coexisting ions on adsorption were compared. The adsorption mechanism and potential leaching process of phosphorus in soil were investigated. The results showed that RB had higher O and H contents and was less stable than TB, while RB was more aromatic. The phosphorus adsorption capacity of different treatments was SRB (1.3318 mg g^-1) > STB (1.2873 mg g^-1) > SDB (1.3025 mg g^-1) > SCK (1.1905 mg g^-1). SRB had optimal phosphorus adsorption performance and storage capacity, with a maximum adsorption capacity of 1.6741 mg g^-1 for the Langmuir isotherm, and it also showed excellent applicability in a pH gradient and with coexisting ions. The main adsorption mode of phosphorus by different treatments was monolayer chemisorption, related to electrostatic repulsion and oxygen-containing functional groups. DB was less effective in inhibiting soil phosphorus migration, with the cumulative leaching of SDB reaching 8.99 mg and the percentage of phosphorus in the 0-6 cm soil layer reaching only 15.42%. Overall, the results can help elucidate potential trends in the adsorption performance and migration process of soil phosphorus by biochar, and improve the comprehensive utilization efficiency of biochar.

Keywords: Adsorption; Biochar; Phosphorus; Potentially migrating component; Residual component.

MeSH terms

Adsorption
Charcoal / chemistry
Phosphorus / chemistry
Soil Pollutants* / analysis
Soil* / chemistry

Substances

biochar
Soil
Phosphorus
Soil Pollutants
Charcoal