Mobility of biochar-derived dissolved organic matter and its effects on sulfamerazine transport through saturated soil porous media

Abstract

Dissolved organic matter (DOM) released from biochar may impact antibiotic mobility and environmental fate in subsurface environments. Here, DOM samples derived from biochars (BDOM) generated by pyrolyzing corn straw at 300, 450, and 600 °C were employed to elucidate the mobility characteristics of these organic substances and their influences on the transport of sulfamerazine (SMZ, a typical sulfonamide antibiotic) in soil porous media. The results demonstrated that BDOM produced at a lower pyrolysis temperature exhibited greater mobility owing to the weaker hydrophobic and H-bonding interactions between BDOM and soil particles. Additionally and importantly, BDOM facilitated the promotion of SMZ mobility owing to the increased electrostatic repulsion between SMZ forms and soil grains, the steric hindrance effect induced by the deposition of organic matter, and the competitive retention between SMZ molecules and BDOM. Meanwhile, the promotion effects of BDOM enhanced with improving pyrolysis temperature owing to the promoted deposition of organic matter on soil surfaces and the strengthened electrostatic repulsion. Moreover, the facilitated effects of BDOM on SMZ mobility declined as the solution pH values were raised from 5.0 to 9.0 or the flow rate increased from 0.18 to 0.51 cm min−1. This trend was due to decreased deposition competition and the steric effect caused by decreased retention of BDOM on soil particles. Furthermore, the cation-bridging effect emerged as an important mechanism contributing to the promotion effects of BDOM when the solution contained divalent cations (Cu2+ or Ca2+). Moreover, a two-site non-equilibrium model was used to interpret the controlling mechanisms for the effects of BDOM on the transport of SMZ. Findings from this work highlight that biochar-derived dissolved organic matter can remarkably affect the environmental behaviors of antibiotics in aquatic environments.

Graphical abstract: Mobility of biochar-derived dissolved organic matter and its effects on sulfamerazine transport through saturated soil porous media

Supplementary files

Article information

Article type
Paper
Submitted
18 Mar 2024
Accepted
31 Oct 2024
First published
31 Oct 2024

Environ. Sci.: Processes Impacts, 2024, Advance Article

Mobility of biochar-derived dissolved organic matter and its effects on sulfamerazine transport through saturated soil porous media

M. Liu, X. Liu, Y. Hu, Q. Zhang, U. Farooq, Z. Qi and L. Lu, Environ. Sci.: Processes Impacts, 2024, Advance Article , DOI: 10.1039/D4EM00143E

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements