Optical and molecular insights into dissolved organic matter release in soils induced by downward migration of biochar colloids

Zhao，Kang1,2; Shang，Jianying1

2024-12-01

10.1007/s44246-024-00136-x

Carbon Research   影响因子和分区

2731-6696

The frequent wildfires and extensive biochar application accumulate biochar colloids in soils. The transport of biochar colloids may influence the release of soil dissolved organic matter (DOM) due to their high mobility and active surface, posing a detrimental impact on carbon cycle, pollutants behaviors, and water quality. Here, we examined the effect of pristine and aged biochar colloids on soil DOM release in three types of soils (black soil, fluvisol, and paddy soil) through adsorption and column experiments combined with fluorescence excitation/emission matrix spectroscopy (EEM) and fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). Adsorption experiment showed that biochar exhibited little effect on soil DOM release, while transport experiment indicated that the downward movement of both pristine and aged biochar colloids significantly enhanced the release of soil DOM, especially black soil and fluvisol. EEM spectra indicated that a humic acid-like substance with large molecular weights was the primary DOM that enhanced release from black soil (10.9–12.0% enhancement) and fluvisol (6–8% enhancement) during biochar colloid transport. Condensed aromatic-like (22.8% and 19.4%) and tannin-like (18.4% and 18.9%) compounds are the primary molecules correlated to the enhanced release of humic acid-like substances. Although chemical aging resulted in a more negative surface of aged biochar colloids and slightly enhanced biochar colloid transport (up to 7.0%), it showed no distinct effect on the release of soil DOM. This study indicates that biochar colloids may cause an increase in DOM release when irrigation and rainfall occur, and more attention should be paid to the environmental impacts of biochar colloids from intensive biochar application and wildfires. Graphical Abstract: (Figure presented.)

Biochar colloids FT-ICR-MS Release Soil dissolved organic matter Transport

英语

其他

2-s2.0-85193800318

Scopus

1.College of Land Science and Technology,China Agricultural University,Key Laboratory of Arable Land Conservation in North China,Ministry of Agriculture and Rural Affairs,Beijing,100193,China
2.State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control,School of Environmental Science and Engineering,Southern University of Science and Technology,Shenzhen,518055,China

Zhao，Kang,Shang，Jianying. Optical and molecular insights into dissolved organic matter release in soils induced by downward migration of biochar colloids[J]. Carbon Research,2024,3(1).

Zhao，Kang,&Shang，Jianying.(2024).Optical and molecular insights into dissolved organic matter release in soils induced by downward migration of biochar colloids.Carbon Research,3(1).

Zhao，Kang,et al."Optical and molecular insights into dissolved organic matter release in soils induced by downward migration of biochar colloids".Carbon Research 3.1(2024).