TY - JOUR

T1 - Use of the Dynamic Technique DGT to Determine the Labile Pool Size and Kinetic Resupply of Pesticides in Soils and Sediments

AU - Li, Y.

AU - Han, C.

AU - Luo, J.

AU - Jones, K.C.

AU - Zhang, H.

N1 - This document is the Accepted Manuscript version of a Published Work that appeared in final form in Environmental Science and Technology, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/10.1021/acs.est.1c01354

PY - 2021/7/20

Y1 - 2021/7/20

N2 - The diffusive gradients in thin films (DGT) technique has been successfully and widely applied to investigate the labile fractions of inorganic contaminants in soils and sediments, but there have been almost no applications to organic contaminants. Here we developed and tested the approach for the pesticide Atrazine (ATR) in a controlled soil experiment and in situ in an intact lake sediment core. The soil study explored the relationships between soil solution, DGT measured labile ATR and solvent extractable ATR in dosed soils of different organic matter, pH status and incubation times. The results are further interpreted using the DIFS (DGT-induced fluxes in soils and sediments) model. Resupply of ATR to the soil solution was partially sustained by the solid phase in all the soils. This was due to small labile pool size and slow kinetics, with soil pH being an important controlling factor. The in situ sediment study successfully used a DGT probe to examine labile ATR distribution through the core on the subcm scale. It demonstrated-for the first time-an easy to use in situ technique to investigate the effects of redox on resupply kinetics and biogeochemical processes of trace organic contaminants in sediments.

AB - The diffusive gradients in thin films (DGT) technique has been successfully and widely applied to investigate the labile fractions of inorganic contaminants in soils and sediments, but there have been almost no applications to organic contaminants. Here we developed and tested the approach for the pesticide Atrazine (ATR) in a controlled soil experiment and in situ in an intact lake sediment core. The soil study explored the relationships between soil solution, DGT measured labile ATR and solvent extractable ATR in dosed soils of different organic matter, pH status and incubation times. The results are further interpreted using the DIFS (DGT-induced fluxes in soils and sediments) model. Resupply of ATR to the soil solution was partially sustained by the solid phase in all the soils. This was due to small labile pool size and slow kinetics, with soil pH being an important controlling factor. The in situ sediment study successfully used a DGT probe to examine labile ATR distribution through the core on the subcm scale. It demonstrated-for the first time-an easy to use in situ technique to investigate the effects of redox on resupply kinetics and biogeochemical processes of trace organic contaminants in sediments.

KW - atrazine

KW - desorption

KW - fine scale

KW - in situ sampling

KW - passive sampling

KW - pore water

KW - sediment profile

KW - Biogeochemistry

KW - Kinetics

KW - Pesticides

KW - Soil moisture

KW - Biogeochemical process

KW - Controlling factors

KW - Diffusive gradients in thin films

KW - Inorganic contaminants

KW - Lake sediment cores

KW - Organic contaminant

KW - Soils and sediments

KW - Trace organic contaminants

KW - Sediments

U2 - 10.1021/acs.est.1c01354

DO - 10.1021/acs.est.1c01354

M3 - Journal article

VL - 55

SP - 9591

EP - 9600

JO - Environmental Science and Technology

JF - Environmental Science and Technology

SN - 0013-936X

IS - 14

ER -