Micropollutants in Large Lakes

From Potential Pollution Sources to Risk Assessments

Nathalie Chevre

• Publisher: EPFL Press
• Year: 2018
• ISBN:
  9781351240284
• Edition: 1
• Topic: Biological Sciences
• Subtopic: Science General
• Index: Biological Sciences

Scientists, regulators, and the general public are now more and more aware of the chemicals present in surface waters worldwide. Agrochemicals, such as herbicides or insecticides, pharmaceuticals and cosmetics can be detected at low to medium concentrations in seas, groundwaters and rivers. Among freshwaters, lakes are of particular concern. These large reservoirs are used as sources of food and drinking water, but also serve for recreational activities.

This book aims in presenting insights into the physical, chemical, and ecological dynamics of large lakes that enable proposing recommendations for sustainable lake management regarding chemicals. Lake Geneva, Switzerland, is used as a case study, but the developed methodologies and tools can be useful for lake water quality management in general.

A first chapter is dedicated to the chemicals entering the lake through agriculture. These are mainly pesticides. After a review of the different types of compounds, the authors present the main pathways these compounds follow to enter the lake. The case of glyphosate, an herbicide largely used worldwide, is presented. A second chapter illustrates the urban source of pollutants with the case of pharmaceuticals and biocides. Two models are presented that allow estimating the load and the dynamic of these chemicals that may exit from an urban catchment and therefore reach a lake. Special attention will be paid to the 'end of pipe' removal of these compounds at a WWTP. A third chapter is dedicated to the lake circulation. The aim of this chapter is to present an overall description of the lake's hydrodynamics, which is driven by three factors: wind, temperature and Coriolis forces. To achieve this aim, a hydrodynamic model is presented that allows describing the behavior of the top layer of the lake based on the wind direction. The importance of stable hydrogen and oxygen isotopes for characterizing the sources of water and the mixing processes in the lake is also described.

The next chapters are dedicated to a Bay, called the Vidy Bay, that receives the treated effluents of the largest wastewater treatment plant of the lake catchment. This latter represents therefore one of the major point sources of contaminants for lake Geneva. These two chapters will focus on the various processes that control the transfer of chemicals (associated to particles or in a dissolved state) discharged into the bay and transported to the lake's main water body.

Then, a next chapter focuses on one major issue of chemicals in aquatic systems like lakes, i.e. the risk of the mixture of chemicals. The evaluation of the risk of mixture is not trivial and the models that allow doing it are presented in a critical way. Their validity as predictive tools is illustrated with the example of herbicides mixture in Lake Geneva.

A final chapter synthesizes the main findings and discusses some recommendations for the management of large lakes regarding micropollution.

Table of content

1. Introduction

1.1 Lakes as a resource

1.2 Micropollutants in surface waters: a worldwide recognition of the issue

The history of organic chemistry

Chemical regulations

Chemical pollution of Lake Geneva: case of pesticides, pharmaceuticals and heavy metals

1.3 Book chapters

1.4 References

2 Agricultural Sources of Micropollutants: from the Catchment to the Lake

2.1 Agricultural sources of micropollutants of the catchment

2.1.1 Generalities

2.1.2 Pesticides: definitions, types and usages

2.1.3 Fate of pesticides in the environment

2.1.4 Environmental risk of pesticide use

2.2 Source and transport dynamics of glyphosate: a case study in Swiss vineyards

2.2.1 Introduction

2.2.2 Methodology

Study area

Field equipment

Chemical analysis

Risk assessment

2.2.3 Field results

Soil column and parcel level

Catchment level

Mass balance

Interactions with DOM

2.2.4 Risk assessment of glyphosate

2.3 Synthesis and conclusions

2.4 References

3 Urban Sources of Micropollutants: from the Catchment to the Lake

3.1 Introduction

3.2 Micropollutants found in urban waters

3.2.1 Surfactants

3.2.2 Pharmaceuticals

3.2.3 Personal care products

3.2.4 Household and industrial chemicals

3.2.5 Biocides and pesticides

3.2.6 Heavy metals

3.2.7 Polycyclic aromatic hydrocarbons

3.2.8 Volatile organic compounds

3.3 Fate of micropollutants in WWTPs

3.3.1 Removal mechanisms of micropollutants in conventional WWTPs

Sorption

Biological transformation

Volatilization

Abiotic degradation

3.3.2 Fate of selected classes of micropollutants in conventional WWTPs

Surfactants

Pharmaceuticals

Personal care products

Household and industrial chemicals

Biocides and POPs

PAHs and VOCs

Heavy metals

Synthesis and risk evaluation

3.3.3 Enhanced treatment of micropollutants in WWTP

Optimization of conventional treatments

Improvement of hydrophobic pollutant removal

Improvement of biodegradable pollutant removal

Advanced treatments

Ozonation

Activated carbon adsorption

Others technologies

Treatment of surface runoff water

3.4 Conclusions

3.5 References

4 Currents of Lake Geneva

4.1 Introduction

4.2 Wind patterns on Lake Geneva

4.2.1 Description of wind data sets

4.2.2 k-means and hierarchical clustering

4.2.3 Procedure and results

4.3 Hydrodynamic modelling

4.3.1 Hydrodynamic modelling with Delft3D-Flow

4.3.2 Grand Lac flow patterns

Overview

Current circulations of Lake Geneva for different wind patterns

4.4 Vidy Bay current patterns

4.5 Transport of water within Lake Geneva based on the stable isotope compositional variations of water in Lake Geneva

4.5.1 Isotopes of water

4.5.2 Transport patterns of Rhône River water within Lake Geneva

4.6 Summary and conclusion

1.4 References

5 Occurrence, Fate and Ecotoxicological Relevance of Micropollutants in Vidy Bay

5.1 Introduction

5.2 The Vidy Bay – morphology and pollution source

5.3 Vidy Bay hydrodynamics

5.4 Spatio-temporal occurrence of micropollutants in Vidy Bay

5.4.1 Measured micropollutant concentrations in Vidy Bay

5.4.2 Measured micropollutant concentrations above the WWTP outfall

5.4.3 Conductivity as an indicator for elevated micropollutant concentrations above the WWTP outfall

5.5 Ecotoxicological risk associated with wastewater-derived micropollutants

5.6 Dilution and degradation processes affecting micropollutant concentrations in Vidy Bay

5.7 Modelling the micropollutant plume in Vidy Bay

5.7.1 Coupled hydrodynamic-photolysis model

5.7.2 Susceptibility towards direct and indirect photolysis processes

5.7.3 Effect of sunlight on plume extension for representative compounds

5.7.4 Extent of ecotoxicological risk zone and contribution of photolysis to its attenuation

5.8 Environmental implications

5.9 References

6 Sediment-bound Contaminant Transport Dynamics in and Around Vidy Bay

6.1 Introduction

6.2 Hydrodynamics within the bay

6.3 Contaminant path tracing and sediment focusing

6.4 Colloid and aggregate characterisation

6.5 Vertical and lateral sedimentation pathways in Vidy Bay

6.5.1 Sediment accumulation and composition

6.5.2 Spatial and temporal radionuclide flux dynamics

6.5.3 Vertical sedimentation model with lateral component

6.6 Hydrodynamic conditions of Vidy Bay’s BBL

6.7 Conclusions

6.8 References

7 Mixture Risk Assessment of Chemical: from the Theory to the Application

7.1 Introduction

7.2 Mixture effect assessment theory

7.2.1 Mixture effects models

7.2.2 Accuracy of the CA and IA models

7.2.3 Mixture risk assessment

7.3 Risk assessment of chemical mixtures in the Lake Geneva catchment

7.3.1 Lake Geneva, Rhône River and Vidy Bay

7.3.2 Limits of the mixture risk assessment approaches

7.4 Comparison with ecological data

7.5 Conclusion

7.6 References

8 Synthesis and Perspectives

Sources of chemicals: the catchment

Understanding lake hydrodynamics as a prerequisite for the assessment of micropollutant behaviour

Behavior of dissolved chemicals in a lake

Behavior of sediment-bound chemicals in a lake

Risk assessment of the micropollutants present in a lake

8.1 References

CHAPTER 1

Introduction

Nathalie Chèvre

Faculty of Geosciences and Environment, University of Lausanne, 1015 Lausanne, Switzerland

Andrew Barry

School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland

Florence Bonvin

School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland

Silwan Daouk

Faculty of Geosciences and Environment, University of Lausanne, 1015 Lausanne, Switzerland

Neil Graham

Institute F.-A. Forel, University of Geneva, 1211 Geneva-4, Switzerland

Jean-Luc Loizeau

Institute F.-A. Forel, University of Geneva, 1211 Geneva-4, Switzerland

Hans-Rudolf Pfeifer

Faculty of Geosciences and Environment, University of Lausanne, 1015 Lausanne, Switzerland

Luca Rossi

School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland

Torsten Vennemann

Faculty of Geosciences and Environment, University of Lausanne, 1015 Lausanne, Switzerland

1.1

Lakes as a resource

Freshwaters represent less than 3% of the total water present on Earth, rivers and lakes around 0.01% (UNEP/DEWA, 2004). However these systems are crucial for human well-being. Indeed, they are used as resources for both fisheries and drinking water, and serve as recreational areas. Furthermore, they constitute sensitive ecosystems with a multitude of species contributing to their equilibrium. A sustainable protection and management of freshwaters is therefore necessary.

Mid-sized lakes exemplify particularly several key challenges for sustainable freshwater management over the next decades. The ever-increasing population will heighten drinking water demand, but will also exacerbate the release of pollutants to aquatic systems. This is especially true in terms of emerging micropollutants that may affect water quality (Schwarzenbach et al., 2006). Furthermore, the expected increase in average temperature and changing precipitation patterns linked to climate change may alter physical, chemical and biological dynamics of lakes and could also impact future water quality in ways that are still unknown. Increasing recreational use of lakes, changes in catchment land use, the use of thermal energy from lakes and other developments will also affect water quality. Living organisms and human inhabitants will bear the consequences of these rising pressures on lake ecosystems.

In this book, we will present insights into the physical, chemi...

Table of contents

• Cover
• Title Page
• Copyright Page
• Table of Contents