Drinking Water Treatment, Volume 3, Organic and Mineral Micropollutants E-Book

Kader Gaid

• Herausgeber: John Wiley & Sons
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 553

Veröffentlichungsjahr: 2023

Beschreibung

Today, hundreds of millions of people drink contaminated water without knowing it. Yet water treatment technologies can effectively eliminate contamination and can supply urban and rural populations with safe drinking water in a secure way. For almost two centuries, the huge number of treatments available to guarantee water quality has grown alongside technological progress, the strengthening of industry norms and the reinforcement of consumer expectations. New treatment methods have been developed according to the advancement of knowledge and new sanitary regulations. This five-volume book sets out to clearly present the variety of treatments available along with their performance, limitations and conditions of use as well as ways to combine them to produce safe drinking water, which is a basic need essential to everyday life. The author shares his expertise acquired at Veolia, a company that is a world leader in water services and sanitation, desalination of sea water and the recycling of wastewater. Founded in France in 1853 to bring safe water to populations and to protect them from waterborne epidemics which ravaged cities, its history is intertwined with that of water treatment.

Leseprobe

Contents

Cover

Title Page

Copyright Page

Chapter 10. Removal of Micropollutants

10.1. Introduction

10.2. Pesticides

10.3. Pharmaceuticals and industrial waste

10.4. Pesticide removal technologies and emerging MPs

10.5. Frogbox

®

: an effective monitoring and control tool

10.6. The evolution of micropollutants in drinking water plants

10.7. References

Chapter 11. Removal of Perfluorinated Compounds

11.1. Physicochemical properties

11.2. Presence in the water

11.3. Drinking water regulations

11.4. Treatments

11.5. Conclusion

11.6. References

Chapter 12. Biological Removal of Ammonia

12.1. The principle of biological nitrification

12.2. Design parameters

12.3. Factors limiting oxygen

12.4. Implementation

12.5. Biofilters (Biocarbon

®

process)

12.6. Water treatment stations

12.7. References

Chapter 13. Nitrate Removal

13.1. Biological treatment

13.2. Treatment with ion exchange resins

13.3. Nitrate removal by high pressure membranes

13.4. References

Chapter 14. Removal of Perchlorates

14.1. General aspects

14.2. Main processes for removing perchlorate ions

14.3. Conclusions regarding the removal of perchlorates

14.4. References

Chapter 15. Water Softening

15.1. Water hardness

15.2. Alkalinity

15.3. Langelier index (LI or LSI)

15.4. Drinking water hardness goals

15.5. General principles of water softening

15.6. Water softening chemical processes

15.7. Veolia water softening technologies

15.8. Saphira

®

process

15.9. Water softening using high-pressure membranes

15.10. Water softening using ion exchange resins

15.11. Comparison between the four water softening solutions discussed

15.12. References

Chapter 16. Metal Removal

16.1. Iron and manganese removal: general aspects

16.2. Arsenic removal

16.3. Removal of selenium (Se)

16.4. Nickel removal

16.5. References

Index

Summaries of other volumes

List of Tables

Chapter 10

Table 10.1.

Main families and organic compounds

Table 10.2.

List of hazardous priority substances

Table 10.3.

Design magnitudes of AC reactors

Table 10.4.

Adsorption of pesticides onto activated carbon

Table 10.5.

Freundlich model parameters k and 1/n

Table 10.6.

Semi-structural formula of chloroacetamides and their metabolites considered to be relevant

Table 10.7.

Characteristics of metolachlor, alachlor and metabolites (ESA and OXA)

Table 10.8.

Characteristics of the powdered activated carbons tested

Table 10.9.

Adsorption parameters of activated carbons in relation to metolachlor and metolachlor ESA

Table 10.10.

Characteristics and adsorption parameters of micrograin activated carbon

Table 10.11.

Freundlich parameters (k and 1/n) for some drugs

Table 10.12.

Characteristics of some granular activated carbons used for the removal of micropollutants

Table 10.13.

Characteristics of granular activated carbons

Table 10.14.

Adsorption conditions of some pharmaceutical residues onto activated carbon

Table 10.15.

Ozonation performances on pharmaceutical residues

Table 10.16.

Performance of two PACs in combination with ozone

Table 10.17.

Operating conditions and oxidation of atrazine with an H

2

O

2

/O

3

ratio

Table 10.18.

Pore diameter of some nanofiltration and low-pressure reverse osmosis membranes

Table 10.19.

Percentage retention of NF 90 (DOW), Toray TMHA and XLE (DOW/Filmtec) as a function of molecular weight and effective diameter for some pesticides

Table 10.20.

Influence of the physical characteristics of some pesticides on their rejection by the NF 200 membrane

Table 10.21.

Efficacy of nanofiltration and low pressure reverse osmosis membranes in relation to medicinal products

Chapter 11

Table 11.1.

Classification and chemical structure of perfluoroalkylated molecules

Table 11.2.

Physicochemical characteristics of PFOS and PFOA. For a color version of this table, see www.iste.co.uk/gaid/watertreatment3.zip

Table 11.3.

Characteristics of some granular activated carbons tested

Table 11.4.

Langmuir and Freundlich parameters for PFOA and PFOS adsorption onto powdered activated carbon (Veolia tests)

Table 11.5.

Physicochemical composition of leachate contaminated with fluorinated compounds (Veolia tests)

Table 11.6.

Feed water chemical composition

Table 11.7.

Efficacy of LPRO on perfluorinated substances (Veolia tests)

Table 11.8.

Efficiency of NF on perfluorinated substances (Veolia tests)

Table 11.9.

Effectiveness of various treatments: <10% shown in yellow; 10–60% shown in green; >90% shown in purple. For a color version of this table, see www.iste.co.uk/gaid/watertreatment3.zip

Chapter 12

Table 12.1.

Theoretical quantity of biologically nitrifiable ammonia (mg·L

–1

)

Table 12.2.

Characteristics of biological sand filters

Table 12.3.

Biocarbon

®

design parameters

Chapter 13

Table 13.1.

Theoretical consumptions and those observed at the treatment station for Biofilters

Table 13.2.

Theoretical cell production and actual production observed at the treatment station for Biofilters

Table 13.3.

Applied volumic loads as a function of temperature

Table 13.4.

Contact time (min) as a function of temperature

Table 13.5.

Filtration velocity (m·h

–1

) as a function of temperature and nitrate concentration

Table 13.6.

Summary of design and exploitation conditions for biological denitrification

Table 13.7.

Weight and average concentrations of the different anions released in eluates

Table 13.8.

Concentrations of various anions following a global treatment and a partial treatment

Table 13.9.

Hydrated radius and hydration energy for various ions

Chapter 14

Table 14.1.

Characteristics of the resins tested

Table 14.2.

Physicochemical qualities of the raw water used during the tests

Table 14.3.

Pilot testing results on previously denitrified water

Table 14.4.

Pilot testing results on raw water

Table 14.5.

Experimental parameters

Chapter 15

Table 15.1.

Hardness concentrations and corresponding water quality

Table 15.2.

Carbonate and bicarbonate identification using AT and Alk

Table 15.3.

Langelier index correspondences

Table 15.4.

Correspondences between various reagents and calcium carbonate

Table 15.5.

Physicochemical characteristics of the water to be treated (first case)

Table 15.6.

Rapid estimation of lime quantities for water softening (first case)

Table 15.7.

Physicochemical characteristics of the water to be treated (second case)

Table 15.8.

Rapid estimation of lime quantities for water softening (second case)

Table 15.9.

Physicochemical characteristics of the water to be treated

Table 15.10.

Rapid estimation of caustic soda quantities for water softening

Table 15.11.

Chemical reagents used in various water softening processes

Table 15.12.

Summary of reagents required for water softening with lime

Table 15.13.

Removal of TOC with Actiflo

®

softening

Table 15.14.

Solubilities of various salts at 15°C

Table 15.15.

Sand height calculation depending upon the hardness to be removed

Table 15.16.

Sand consumption for the chemical reagents lime and soda

Table 15.17.

Comparison of the characteristics of the two materials: sand and garnet

Table 15.18.

Operating parameters with caustic soda and lime

Table 15.19.

Percentage of pellet expansion along the reactor depending on pellet diameter

Table 15.20.

Comparative removal of Ca and Mg by various processes

Table 15.21.

Partial water softening with a “loose” nanofiltration membrane

Table 15.22.

Advantages and limitations

Chapter 16

Table 16.1.

Summary of different iron and manganese processing techniques and operating conditions

Table 16.2.

Forms in which iron may be present

Table 16.3.

Stoichiometric ratios for various oxidants

Table 16.4.

Summary of iron treatment characteristics

Table 16.5.

Optimal conditions for biological iron removal

Table 16.6.

Limits defining the biological process standard conditions

Table 16.7.

Oxidation tower design

Table 16.8.

Filtration design parameters

Table 16.9.

Chlorine and ozone neutralization by reducers

Table 16.10.

Design parameters for biological iron removal on a sand filter

Table 16.11.

Stoichiometric ratios for various oxidants

Table 16.12.

Summary of manganese treatment characteristics

Table 16.13.

Characteristics of various MnO

2

supports available in the market

Table 16.14.

Mangagran technical specifications

Table 16.15.

Possible solutions integrating MnO

2

depending on the quality of the water (Fe and Mn) to be treated

Table 16.16.

Performances as a function of Mn

2+

concentration and pH > 7.2

Table 16.17.

rH and pH conditions for biological iron and biological manganese removal

Table 16.18.

Main forms of arsenic

Table 16.19.

Chemical reactions of As depending on the nature of the water environment

Table 16.20.

Oxidation reactions with various oxidants

Table 16.21.

Influence of aluminum salt used for the removal of As

5+

Table 16.22.

Physical characteristics and composition of activated alumina

Table 16.23.

Characteristics of some arsenic-adsorbing media

Table 16.24.

Adsorption capacity of GFH in relation to arsenic

Table 16.25.

Adsorption capacity of GFH as a function of contact time

Table 16.26.

BV on GFH media for different pH and arsenic concentrations

Table 16.27.

Comparison between adsorption onto MnO

2

and GFH

Table 16.28.

Advantages and disadvantages of different arsenic removal processes

Table 16.29.

Choice of complexing agent, operating pH and molar ratios for various heavy metals

Guide

Cover

Table of Contents

Title Page

Copyright

Begin Reading

Index

End User License Agreement

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Drinking Water Treatment 3

Organic and Mineral Micropollutants

Kader Gaid

First published 2023 in Great Britain and the United States by ISTE Ltd and John Wiley & Sons, Inc.

Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced, stored or transmitted, in any form or by any means, with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms and licenses issued by the CLA. Enquiries concerning reproduction outside these terms should be sent to the publishers at the undermentioned address:

ISTE Ltd27-37 St George’s RoadLondon SW19 4EUUK

John Wiley & Sons, Inc.111 River StreetHoboken, NJ 07030USA

www.iste.co.uk

www.wiley.com

© ISTE Ltd 2023The rights of Kader Gaid to be identified as the author of this work have been asserted by him in accordance with the Copyright, Designs and Patents Act 1988.

Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s), contributor(s) or editor(s) and do not necessarily reflect the views of ISTE Group.

Cover illustration:© imageBROKER.com/Matton Images

Library of Congress Control Number: 2022945176

British Library Cataloguing-in-Publication DataA CIP record for this book is available from the British LibraryISBN 978-1-78630-785-9

10Removal of Micropollutants

10.1. Introduction

Since aquatic environments have always been intimately related to economic growth (which, in turn, involves population growth, industrial development, intensive agriculture and mass tourism), they have become the ultimate dump for the waste generated by our lifestyles. Nowadays, micropollutants (MPs) in the aquatic environment are a major problem, not only for the human population who uses water resources, but also for aquatic ecosystems.

Estimates for the European Community have shown that among the more than 110,000 chemical substances placed on the market, more than 100,000 substances have little information concerning the hazards they may pose. These substances are involved in the composition of many formulations and take part in a number of processes (industrial, agricultural practices, etc.). They also appear in the daily activities of households.

MPs present in water comprise a multitude of mineral and organic compounds likely to have a toxic action on humans and/or aquatic organisms, even at very low concentrations in water (ranging from 1 ng to 100 µg/L).

These MPs may have various origins (Table 10.1):

– craft or industrial economic activities (plasticizers, flame retardants, electrical insulators, etc.);

– agricultural (e.g. use of phytosanitary products, veterinary drugs);

– domestic use: cleaning products, detergents, cosmetics, drugs, etc.;

– contamination provoked by atmospheric fallout and transfer made by water runoff on urban surfaces;

– natural origin (metals relating to environmental geology).

Figure 10.1.Constituents present in water. For a color version of this figure, see www.iste.co.uk/gaid/watertreatment3.zip

10.2. Pesticides

Agriculture is largely the primary pesticide consumer. The list of biocides chiefly reveals three main families: insecticides, fungicides and herbicides. Insecticides can have an action on the nervous system (neurotransmission), the respiratory system or molting. Fungicides act selectively on the respiratory route, biosynthesis (sterols, RNA, melanin), cell growth or cell permeability. Finally, herbicides can have a deleterious impact on photosynthesis, on the synthesis of lipids and amino acids, on cell division or growth. Among the most widely represented families of pesticides, we can find:

– organophosphates (chlorpyrifos, malathion), which have an insecticidal effect by inhibiting the acetylcholinesterase enzyme (disruption in the transmission of nervous impulses);

– organochlorines (DDT, chlordecone, lindane), insecticides affecting the nervous system by disrupting nervous impulses at the synapse level. Although at present these compounds are all banned in France, they are highly persistent in the environment (e.g. the problem of chlordecone exposure in the West Indies); <pg/>

– carbamates (aldicarb, carbofuran), which have an effect on the nervous system in the same way as organophosphates;

– triazines (atrazine, simazine), which have a herbicidal effect by blocking the transport of electrons and light energy;

– phenylureas (diuron, isoproturon), which have a comparable mode of action to that of triazines;

– chloroacetanilides (metolachlor, acetochlor), which act on plants by inhibiting elongases, the enzymes involved in lipid synthesis (long chain fatty acids);

– aryloxyacids (2,4 D, mecoprop, dichlorprop), disrupting the regulation of the AIA auxin (indole-3-acetic acid), an essential phytohormone responsible for plant growth;

– sulfonylureas (chlorsulfuron, nicosulfuron), which affect the synthesis of branched amino acids (valine, leucine, isoleucine) via the inhibition of acetolactate synthetase (ALS).

Table 10.1.Main families and organic compounds

Main families

Compounds

Drug molecules

Anxiolytics, analgesics, anti-inflammatories, antibiotics, hypolipidemics, antihypertensives, antiepileptics, anticancers, iodinated contrast agents, etc.

Cosmetics and personal hygiene products

Musks (galaxolide, tonalide), triclosan, etc.

Endocrine-disrupting compounds

Hormones, alkyl phenols, bisphenol A (BPA), phthalates, flame retardants, etc.

Illegal drugs

Cocaine and metabolites, THC, amphetamines, etc.

Pesticides

Insecticides, herbicides

Priority substances (Annex X of the European Directive) and dangerous substances (European circular on the Reduction of Dangerous Substances Discharged into Water 050109)

Polycyclic aromatic hydrocarbons (PAHs), dichloromethane

Disinfection by-products

Trihalomethanes, haloacetic acids

Agricultural activity is not the only source of pesticide emissions. Among the secondary sources, we can mention the maintenance of public open spaces, golf courses, individual use, annual mosquito management in wetlands, the veterinary sector, road maintenance, etc.

10.3. Pharmaceuticals and industrial waste

France is one of the world’s largest consumers of medicinal products. More than 3,000 pharmaceutical molecules for human use are commonly used in medicines and 300 veterinary drugs are currently available on the French market. The biologically active substances contained in each pharmaceutical product feature a great diversity of chemical structures. The parent compounds of pharmaceutical residues are essentially excreted via the stool and urine, or in the form of one or more active/inactive metabolites, and then emitted to the sewage system and the soil.

The main sources of water pollution due to pharmaceutical products are:

– diffuse sources, which represent the majority of drugs discharged into the environment; this includes the improper storage and disposal of expired or unused medicines; the metabolic excretion of drugs consumed by humans and animals, via the urinary or digestive tract;

– point sources, which are the cause of far more concentrated, but geographically limited, emissions. The point sources include the direct discharge of medicinal products (and chemical products used during drug manufacture) into the wastewater from pharmaceutical and chemical factories, the direct or indirect disposal of the pharmaceutical agents used in healthcare establishments, the direct dispersion of veterinary medicinal products released to the environment from use in aquaculture and treatment of pasture animals, or indirectly during the land application of manure and slurry from livestock facilities, the direct dispersion of therapeutic molecules in the form of feed additives poured directly into fish ponds.

Drug substances are grouped into several classes, reuniting a wide range of chemical families as well as degradation metabolites produced by humans or in the environment:

– analgesics and anti-inflammatories are the most widely consumed molecules in France for human use, such as diclofenac and ibuprofen, acetylsalicylic acid and paracetamol;

– psychotropics include antidepressants, anxiolytics and sleeping pills;

– anticonvulsants;

– lipid-lowering agents from the fibrate family, whose role is to lower the plasma concentration of cholesterol and triglycerides;

– due to their action, beta-blockers reduce blood pressure and the fixing of adrenaline on receptors. They are cardioselective, in that they act specifically by reducing the nervous impulses toward the heart;

– antibiotics destroy, inactivate or block the action of bacteria by disrupting, for example, the synthesis of proteins associated with bacterial growth;

– the action of bronchodilators stimulates the beta-2 receptors of bronchi, provoking their short-term dilation.

Other classes can be mentioned, such as diuretics, antifungals, antivirals and laxatives.

The use of different antibiotics for animal production and for human medicine may explain the observation of distinct correlations between the composition of the bacterial community and antibiotic-resistant populations, due to the concentration of tetracyclines, sulfonamides and penicillins or fluoroquinolones in wastewater. In fact, the antibiotic resistance of bacteria has been detected in several raw and treated wastewater sources.

These substances are found in the various environmental compartments (water, air, soil), by direct or indirect emission (surface runoff, drainage, atmospheric fallout, etc.), with potential direct or indirect effects on human health and ecosystems, namely due to contaminants in the food chain (Figure 10.2). Concentration levels in natural waterways vary depending on chemical stability, biodegradability, the physicochemical characteristics of molecules and treatment station performances.

In general, the concentration of pesticides and pharmaceutical products in the environment vary not only from one compound to another, but also from site to site. Regional differences in the use of medicinal products, as well as the biodegradability of pharmaceuticals and their metabolites, could explain the differences in concentrations.

The analysis campaigns performed (Veolia) have detected the presence of some of these substances at the inlet and outlet of wastewater treatment stations, as well as in the resources used for the production of drinking water.

Due to the diversity and complexity of the substances considered, data are still limited on the effects of pharmaceutical residues and endocrine-disrupting compounds (EDCs) on the environment, as well as their occurrence patterns in water resources. The great diversity of the molecules considered and the difficulties related to their analysis – which have sometimes been associated with their low concentrations – as well as the studies carried out until now to assess the presence of these compounds in the environment, have been limited to a few groups of molecules. These molecules were chosen on the basis of production amounts and their estimated persistence in the environment (for pharmaceutical residues [PRs]), as well as the potential endocrine activity for EDCs. In point of fact, some of these molecules have an effect on the hormonal balance of many living species, in which case they are qualified as EDCs. Recent toxicological studies have shown that in males, EDCs influence the number of spermatozoa, genital malformations, impaired sexual functions, neuronal development, obesity and even cancer.

Figure 10.2.Different categories of micropollutants. For a color version of this figure, see www.iste.co.uk/gaid/watertreatment3.zip

The harmful effects of EDC and PR discharges into the environment of aquatic and terrestrial organism populations (from simple gastropods to mammals) are now definitely beyond doubt. Numerous examples demonstrate the impact of these substances on fish (e.g. incomplete development of genital organs, hermaphroditism, modification of the male/female ratio), birds (e.g. thinning of egg shells) and mammals (e.g. decline in seal populations feeding on PCB-contaminated fish). Many questions remain among the scientific community regarding this cause-andeffect relationship, which is often difficult to determine (still fragmented knowledge about the toxic and ecotoxic effects of metabolites, substance cocktails, disturbance mechanisms, etc.).

Figure 10.3.Example of the evaluation of micropollutant concentrations in waterways. For a color version of this figure, see www.iste.co.uk/gaid/watertreatment3.zip

Figure 10.4.Simplified diagram of the cycle of water containing pesticides, pharmaceutical residues, endocrine-disrupting compounds. For a color version of this figure, see www.iste.co.uk/gaid/watertreatment3.zip

According to the European Commission, an endocrine disruptor is “an exogenous substance or mixture that alters function(s) of the endocrine system and consequently causes adverse health effects in an intact organism, or its progeny, or (sub)populations”.

In humans, the connection between the presence of pharmaceutical residues and EDCs in the environment is a subject of major concern for populations. European authorities have admitted the link between EDCs and increasingly frequent pathologies, such as testicular, breast and prostate cancers, a drop in the number of spermatozoa, malformations of the reproductive organs, thyroid disorders. Their massive use, as well as their discharge during the manufacturing process, makes them present in concentration levels ranging from a few tens of nanograms per liter to a few micrograms per liter.

The presence of pharmaceutical residues in drinking water is a major concern for the scientific community, the public authorities and the public. Everybody wonders about the presence of pharmaceutical residues in aquatic environments (surface water, groundwater, transfer media, soil) and drinking water, in trace amounts, as well as their effects on the environment and human health. This question is set against a broader context involving the preservation of the environment and water resources, particularly in relation to MPs, substances likely to have a toxic action, even at low doses, in a given environment (ranging from nanogram to microgram per liter of water).

The French public authorities have prioritized source reduction to the point of completely banning the emission of certain substances. Source reduction is essential to prevent the dissemination of substances in the environment, but its effectiveness will take many years to be demonstrated, and will not suffice to control all the risks involved by the use of MPs. This is not only due to the large number of molecules, uses and practices, but also to the fact that many MPs mostly result from the diffuse pollution emitted by individuals (pharmaceutical residues, hormones, biocides, etc.), and will thus become difficult to fully remove.

In Europe, the establishment of a regulatory framework aims to reduce the discharge of hazardous substances into natural environments and to monitor their course within the biosphere. The numerous efforts carried out, particularly on a European scale, focus on the scrutiny of the environmental (chemical) quality of the various water resources available, as well as their evolution.

In France, the regulatory requirements aimed at reducing the emissions of chemical substances and their presence in the natural environment arise from European regulations and directives such as the REACH regulation and the regulations on biocidal and phytopharmaceutical products, the EU Water Framework Directive (WFD), the Industrial Emissions Directive (IED), etc. In essence, these regulations aim to regulate the launch on the market of potentially hazardous substances, to reduce their emissions in the various environmental compartments and to achieve environmental quality goals. These increasingly restrictive requirements will tend to be reinforced in the upcoming years, with the further development of scientific knowledge and with the impact on health and the environment becoming more and more evident.

Apart from transcribing these fundamental European texts into French law, the government has implemented an MP plan aiming to preserve water quality and biodiversity. This plan aims to reduce MP emissions whose toxicity has been proven, to consolidate knowledge and to compile a list of pollutants that require monitoring.

Despite having significantly improved from a technical point of view, wastewater treatment stations have not been designed to remove the entirety of pharmaceutical molecules. For example, even if paracetamol is degraded to more than 90% in treatment stations, traces of this substance can be found in treated wastewater, which is then discharged into surface water. Some compounds, such as diclofenac (anti-inflammatory) or carbamazepine (an anti-epileptic), only poorly degrade. These pharmaceutical product residues, discharged into surface waters, can pose a significant environmental risk due to the fact that their metabolites or degradation by-products are sometimes even more hazardous than the original product.

For this reason, it is necessary to implement so-called “high-performance” sectors, including the use of activated carbon (AC) in its different forms, chemical oxidation with ozone or advanced oxidation (O3/H2O2, UV/H2O2) or high-pressure membranes, such as nanofiltration or low-pressure reverse osmosis (LPRO).

These treatments (AC and high-pressure membranes) are well known in this era because they have already been tried and tested for the treatment of drinking water. As described in Chapter 7, they have proven their effectiveness against organic matter (humic substances) after being tested in the field. In France, the use of ozone for pesticide removal is discouraged due to the by-products generated.

Table 10.2.List of hazardous priority substances

The French Government Resolution of July 8, 2010, enlisting priority substances and establishing the procedures and deadlines for the gradual reduction and removal of discharges, spills, direct or indirect discharges, respectively, of priority substances and hazardous substances referred to in article R. 212-9 of the Environmental Code, consolidated version as of May 8, 2018.

Alachlor

Hexachlorobenzene

Naphthalene

Anthracene

Dicofol

Nickel and its compounds

Atrazine

Perfluorooctanesulfonic acid and its derivatives (perfluorooctane sulfonate PFOS)

Nonylphenols

Benzene

Quinoxyfen

Octylphenols (6)

Brominated diphenyl ethers

Dioxins and dioxin-like compounds

Lead and its compounds

Cadmium and its compounds

Aclonifen

Pentachlorobenzene

Chloroalkanes, C10-13

Cypermethrin (10)

Pentachlorophenol

Chlorfenvinphos

Dichlorvos

Polycyclic aromatic hydrocarbons (PAHs) (7)

Chlorpyrifos (ethylchlorpyrifos)

Bifenox

Simazine

1,2-Dichloroethane

Cybutryne

Tributyltin compounds

Dichloromethane

Hexachlorobutadiene

Trichlorobenzene

Di(2-ethylhexyl)phthalate (DEHP)

Hexachlorocyclohexane

Trichloromethane (chloroform)

Diuron

Isoproturon

Trifluralin

Endosulfan

Mercury and its compounds

Hexabromocyclododecanes (HBCDD)

Fluoranthene

Heptachlor and heptachlor epoxide

Terbutryne

Figure 10.5.The evolution of some substances in wastewater treatment stations. For a color version of this figure, see www.iste.co.uk/gaid/watertreatment3.zip

10.4. Pesticide removal technologies and emerging MPs

Within their structure, MPs have functional groups which determine their reactivity toward adsorption or chemical oxidation. The most important groups are as follows:

– -OH functional groups (hydroxyl, phenol);

– C-O functional groups (carboxyl, carbonyl);

– -N- (amino) functional groups.

Reactivity is strongly influenced by the polarity of the functional groups and the positive or negative charge acquisition when dissociation or a proton association takes place within these functional groups. The hydroxyl group is present in alcohols and phenols. Alcohols are considered hydroxyl-alkene compounds. In most cases, alcohols are neutral, because the hydroxyl group does not ionize easily. Phenols include hydroxyl components that are attached to the aromatic ring.

The phenol group is made of a hydroxyl group directly attached to the carbon of an aromatic ring. In general, phenols are highly reactive.