(Downloads - 0)
For more info about our services contact : help@bestpfe.com
Table of contents
Aknowledgements/Remerciements
CHAPTER I – General introduction
1.1 Pesticide use, worldwide occurrence, threats and regulation
1.2 State of the art: pesticide persistence in surface waters
1.3 Multi-scale and multi-tool approaches to assess pesticide fate at the SWI.
1.4 Research questions and overall approach of the thesis
1.5 Graphical abstract of the thesis work
1.6 Publications and author contributions
CHAPTER II – Pesticide degradation pathways at the sediment-water interface
2.1 Analytical section: Sample processing, Quantification and Compound- Specific Isotope Analysis
2.2 Pesticide hydrolysis
2.2.1 Introduction
2.2.2 Material and Methods
Chemicals and Solution Preparation
Experimental Setup
2.2.3 Results and Discussion
Hydrolysis of chloroacetanilides and isotopic fractionation
Mechanistic insights from AKIE values and C−N isotope plots
2.2.4 Environmental implications
2.3 Pesticide photodegradation in agriculturally impacted surface waters
2.3.1 Introduction
2.3.2 Material and method
Chemicals and preparation of solutions
Experimental Section
Analytical section
2.3.3 Results & Discussion
Effects of the Hydrochemistry on the Photodegradation
Rates under Simulated Sunlight
Formation of Phototransformation Products
C and N Isotope Fractionation to Trace Atrazine and S-
metolachlor Photodegradation
2.3.4 Environmental implications
2.4 Pesticide oxic and anoxic biodegradation in water-sediment systems
2.4.1 Introduction
2.4.2 Material and method
Sediment sampling and characteristics
Experimental set-up
Control experiments
Pesticide extraction, quantification and CSIA
Suspected screenings of transformation products
Phase-transfer and biodegradation modelling
2.4.3 Results and discussion
Dissipation kinetics and isotope fractionation
Water–sediment phase-transfer and implications for interpreting
degradation kinetics
Water–sediment phase-transfer and implications for interpreting
isotope signature
Pesticide degradation pathways
2.4.4 Environmental implications for water–sediment studies
CHAPTER III – Pesticide transport at the sediment-water interface
3.1 Introduction
3.2 The FRT numerical model
3.2.1 Governing equations
3.2.2 Numerical resolution
3.3 Tracer recirculation in bench-scale river channel
3.3.1 Experimental setup
3.3.2 Conservative and sorptive tracer experiments
3.3.3 Data acquisition
3.3.4 Experiment conditions
3.4 Model validation vs experiment
3.4.1 Numerical simulations: Conceptual model, parameterization and domain discretization
3.4.2 Comparing numerical and experimental results
3.5 Pollutant transport at the sediment-water interface
3.5.1 Velocity field in the bench-scale river channel and transport processes
3.6 Transport processes governing mass exchange in the bench-scale river channel
3.6.1 Understanding and predicting the effect of sorption on mass exchange at the SWI
3.7 Towards a comprehensive understanding of hyporheic process at the SWI
3.8 Implication and perspectives for conservative and sorptive pollutant transport at the SWI
3.9 Investigation of the influence of water flow on pollutant degradation
3.9.1 Material and Methods
Adjustments to the bench-scale river channel
Experimental conditions
Adjustments to the FRT model
3.9.2 Results and discussion
Influence of water flow on the depth of the oxic sediment layer
Influence of water flow on caffeine degradation at the SWI
3.10 Implications and perspectives for pollutant degradation at the SWI
CHAPTER IV – S-metolachlor dissipation alongside a river reach
4.1 Introduction
4.2 Material and methods
4.2.1 Study site
4.2.2 S-metolachlor application
4.2.3 Soil, water and sediment collection
4.2.4 Chemical analyses
4.2.5 Data analysis
4.3 Results and discussion
4.3.1 Hydrological response and AVB hydrological functioning
4.3.2 S-metolachlor sources and export to the AVB
4.3.3 S-metolachlor dissipation in the AVB: transport dominates over degradation
4.4 Environmental significance and outlook for CSIA use in rivers
CHAPTER V – General conclusions
5.1 Introduction
5.2 Laboratory testing procedures to understand pesticide fate in surface waters
5.2.1 General discussion
5.2.2 Implications and perspectives
5.3 A robust and parsimonious mathematical framework tailored to the studied system
5.3.1 General discussion
5.3.2 Implications and perspectives
5.4 CSIA from molecular to river scales to characterize pesticide fate at the SWI: potential, limits and perspectives
5.5 Perspectives
5.6 Implications for water resource managers
Appendices
CHAPTER A – Supporting information to chapter II
A.S1 Photodegradation
A.S1.1 List of chemicals
A.S1.2 Main Properties of Selected Pesticides and Origin of the Substances Used
A.S1.3 Chemical Composition of Irradiation Solutions
A.S1.4 Organic Matter Photobleaching
A.S1.5 PNA/Pyr Actinometer System
A.S1.6 Irradiation conditions and correction of degradation rates .
A.S1.7 Light Spectrum Homogeneity within the Light-proof Box
A.S1.8 Atrazine and S-metolachlor transformation products
A.S1.9 Optical properties of chemicals and irradiation solutions
A.S1.10 Simulated sunlight characteristics
A.S1.11 Prediction of Degradation Rates and Identification of Dominant Photodegradation Mechanisms
General methodology
Calculation of Short-lived Reactive Intermediates Steady
State Concentrations
Identification of Main Photosensitizers
Calculation of Light Absorption Rates and Screening Factors
Detailed Results
A.S1.12 Presentation of Experimental Datasets
A.S1.13 Comparison of C and N isotope fractionation during atrazine
photodegradation, biodegradation and abiotic hydrolysis
A.S2 Biodegradation
A.S2.1 Appendices for material and methods
List of chemicals
Sediment sampling and characteristics
Hydrochemistry characterization
Batch sorption isotherm
Mass balance accounting for the phase-transfer process
A.S2.2 Appendices for results and discussion
Sediment characteristics
Hydrochemistry
Control experiments
Batch sorption experiments
Pesticide dissipations
CHAPTER B – Supporting information to chapter III
B.S1 Current developments at the SWI
B.S2 Sand characterization
B.S3 Characterization of FB291 adsorption from the batch equilibrium method – OECD
B.S4 Compensation of tracer concentrations for evaporation and ion release
B.S5 Scaling methodology of concentrations for inter-comparison of experiments
B.S6 Mesh sensitivity analysis
B.S7 Fit of modelled velocities with the log-law profile
B.S8 Darcy’s velocities calculation
B.S9 Characterization of the transport regime with Pe
B.S10 Characterization of the transport regime with Deff
CHAPTER C – Supporting information to chapter IV
C.S1 S-metolachlor applications
C.S2 S-metolachlor and main TPs summary of physicochemical properties
C.S3 Hydrochemistry of the AVB river measured at S1 and S2
C.S4 Example of GC-IRMS chromatogram with soil sample
C.S5 Riverbed sediment texture
C.S6 Temporal evolution of S-metolachlor concentrations within top soils surrounding S1 and S2
C.S7 Test of isotopic signatures shift within the AVB river reach
C.S8 Averaged transit time and degradation within the AVB river reach
C.S9 Evidences of S-metolachlor release from the riverbed from monitoring of the regional water agency
C.S10 Temporal evolution of S-metolachlor concentrations in the riverbed sediment
C.S11 Excepted isotope fractionation with increasing residence time
