Modelling degradation kinetics of metformin and guanylurea in soil microcosms to derive degradation end-points

Briones, Rowena M.; Sarmah, Ajit K.

doi:10.1016/j.envpol.2018.11.045

Cited by 18 publications

(5 citation statements)

References 32 publications

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“…The DFOP model assumes that the compound is initially distributed between solution and sorbed phases and that the degradation of the compound in both phases is described by first-order kinetics . The SFO, FOMC, and DFOP models were selected to fit the measured LNG and QUN degradation data because of their simplicity and previous successful application in describing the degradation of organic compounds. , Furthermore, the SFO and DFOP models have been used by the European Food Safety Authority (EFSA) and the United States EPA in evaluating degradation kinetics of compounds in soil. , …”

Section: Resultsmentioning

confidence: 99%

“…37 The SFO, FOMC, and DFOP models were selected to fit the measured LNG and QUN degradation data because of their simplicity and previous successful application in describing the degradation of organic compounds. 37,38 Furthermore, the SFO and DFOP models have been used by the European Food Safety Authority (EFSA) and the United States EPA in evaluating degradation kinetics of compounds in soil. 39,40 The selection of the optimal model for LNG and QUN degradation in soil was based on GFIs and degradation endpoints (DT 50 and DT 90 ).…”

Section: ■ Materials and Methodsmentioning

confidence: 99%

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Degradation Kinetics and Transformation Products of Levonorgestrel and Quinestrol in Soils

Tang

et al. 2019

J. Agric. Food Chem.

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Levonorgestrel (LNG) and quinestrol (QUN) are typical endocrine disruptors that enter the soil via sewage irrigation and sludge return. However, the fates of both compounds in soil are not well-understood. Laboratory microcosm studies were conducted to fill the gap of understanding of LNG and QUN behavior in soils. High values of goodness-of-fit indices (GFIs) were obtained using the double-first-order in parallel (DFOP) model and the single-first-order (SFO) model to fit the degradation kinetics of LNG and QUN in soils, respectively. The end-points (DT 50 and DT 90 ) of LNG and QUN were positively correlated with soil total organic carbon (TOC). Soil water content and temperature were observed to be critical factors in degradation of LNG and QUN. The degradation rates of LNG and QUN were very slow under sterile and flooded conditions, indicating that the aerobic microbial degradation was dominant in the degradation of LNG and QUN. Moreover, major transformation products were identified, and biodegradation pathways of LNG and QUN were proposed. The present study is expected to provide basic information for ecological risk assessment of LNG and QUN in the soil compartment.

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Section: Resultsmentioning

confidence: 99%

Section: ■ Materials and Methodsmentioning

confidence: 99%

Degradation Kinetics and Transformation Products of Levonorgestrel and Quinestrol in Soils

Tang

et al. 2019

J. Agric. Food Chem.

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“…The unextractable concentrations of MCs in soil were assessed at the time of initial spiking, and the recovery rates of MC-LR and MC-RR were 79.6–104% and 76.3–103%, respectively (Table S2). It has been reported that the unextractable concentrations of organic pollutants may increase over time and influence the measured residual concentrations in the solution phase . Another reason for abiotic MC degradation is oxidization because of the presence of the β, γ–double bond in the Adda side chain .…”

Section: Discussionmentioning

confidence: 99%

Variant-Specific Adsorption, Desorption, and Dissipation of Microcystin Toxins in Surface Soil

Liu

et al. 2021

J. Agric. Food Chem.

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Microcystins (MCs) are hepatotoxic heptapeptides identified in cyanobacterial bloom-impacted waters and soils. However, their environmental fate in soils is poorly understood, preventing reliable site assessment. This study aims to clarify the variant-specific adsorption, desorption, and dissipation of MC-LR and MC-RR in agricultural soils. Results revealed that their adsorption isotherms followed the Freundlich model (R 2 ≥ 0.96), exhibiting a higher nonlinear trend and lower adsorption capacity for MC-LR than for MC-RR. The soils had low desorption rates of 8.14−21.06% and 3.06−34.04%, respectively, following a 24 h desorption cycle. Pairwise comparison indicated that soil pH and clay played key roles in MC-LR adsorption and desorption, while organic matter and cation exchange capacity played key roles in those of MC-RR. MC-LR dissipation half-lives in soils were 27.18− 42.52 days, compared with 35.19−43.87 days for MC-RR. Specifically, an appreciable decrease in MC concentration in sterile soils suggested the significant role of abiotic degradation. This study demonstrates that the minor structural changes in MCs might have major effects on their environmental fates in agricultural soil and indicates that the toxic effects of MCs should be of high concern due to high adsorption, low desorption, and slow dissipation.

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“…bi-phasic kinetics or bi-exponential or double first-order in parallel (DFOP) kinetics (Fantke and Juraske, 2013;Torabi et al, 2021), which might be attributed to slow sorption, limited microbial activities, seasonal changes, and diffusion processes. The variations of first-order degradation rate constants with different soil/plant sub-compartments and description of rate-coefficients by gamma-distribution depict the bi-phasic pattern of pesticide degradation, which often considers the pattern of decline of total pesticide concentrations through time-or concentration-dependent endpoints (trigger value or modeling input) (Briones and Sarmah, 2019;Sathishkumar et al, 2021;Torabi et al, 2021). The respective regression (and integrated) equations and corresponding model descriptions (of kinetic models) for deriving estimates of parameters to plot and calculate the half-lives (t 1/2 ) for pesticide isomers and metabolite on harvested single compartment (either fruits or leaves) are shown in Table S3.…”

Section: Dissipation Kinetics and Waiting Period Calculationmentioning

confidence: 99%

Dissipation Kinetics, Residue Modeling and Human Intake of Endosulfan Applied to Okra (Abelmoschus Esculentus)

Nath

Komala

Fantke³

et al. 2022

SSRN Journal

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Modelling degradation kinetics of metformin and guanylurea in soil microcosms to derive degradation end-points

Cited by 18 publications

References 32 publications

Degradation Kinetics and Transformation Products of Levonorgestrel and Quinestrol in Soils

Degradation Kinetics and Transformation Products of Levonorgestrel and Quinestrol in Soils

Variant-Specific Adsorption, Desorption, and Dissipation of Microcystin Toxins in Surface Soil

Dissipation Kinetics, Residue Modeling and Human Intake of Endosulfan Applied to Okra (Abelmoschus Esculentus)

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