Aquatic Chemistry: for Water and Wastewater Treatment Applications
266
Aquatic Chemistry: for Water and Wastewater Treatment Applications
266eBook
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Overview
This book provides chemical concepts as well as crucial steps for inorganic water and wastewater treatment. Examples and tools help to understand and to guide through industrial and natural water process engineering. Chemical and environmental engineers, researchers and professionals, as well as students benefit from this concise and explanatory book.
Product Details
| ISBN-13: | 9783110604092 |
|---|---|
| Publisher: | De Gruyter |
| Publication date: | 05/06/2019 |
| Series: | De Gruyter STEM |
| Sold by: | Barnes & Noble |
| Format: | eBook |
| Pages: | 266 |
| File size: | 31 MB |
| Note: | This product may take a few minutes to download. |
| Age Range: | 18 Years |
About the Author
Ori Lahav, Technion, Haifa, Israel.
Liat Birnhack, Technion, Haifa, Israel.
Table of Contents
Preface v
1 Water chemistry fundamentals 1
1.1 Introduction 1
1.2 Solutions 1
1.3 The chemical structure of the H2O molecule 1
1.4 Dissolution 2
1.5 Solubility 2
1.6 Electrolytes and non-electrolytes 3
1.7 Expressing solute concentrations in environmental engineering 4
1.8 Weight fraction (mass per unit mass) 5
1.9 Weight per volume 5
1.10 Molarity (M) 6
1.11 Normality (N = eq/L) 6
1.12 Weight per volume expressed as a different substance (units: g/L as X) 8
1.13 The p-notation 10
1.14 Chemical equilibrium 11
1.15 The kinetic approach for describing chemical equilibrium 11
1.16 Adjusting the equilibrium constant to a non-ideal system 13
1.17 Acid-base equilibrium in the aqueous phase 16
1.18 The thermodynamic approach for describing chemical equilibrium 19
1.19 Standard free energy offormation 21
1.20 Determining ΔG under non-standard conditions 22
1.21 Temperature effect on the equilibrium constant value 24
2 Acids and bases 27
2.1 Introduction 27
2.2 Basic principles 27
2.2.1 Defining acids and bases 27
2.3 Acid-base pairs 29
2.4 Polyprotic acids 30
2.5 The carbonate system 30
2.6 The strength of an acid or base 32
2.7 The Henderson-Hasselbalch equation 36
2.8 Species distribution of weak-acids/bases as a function of pH 38
2.8.1 Species concentration as a function of pH - the graphical approach 42
2.8.2 Sketching the log (species) curve as a function of pH - a quick procedure 46
2.8.3 Sketching the log (species) curve as a function of pH - important points 47
2.9 The effect of a change in the total species concentration, CT 48
2.10 Interpreting acid/base systems using proton balance equations 48
2.11 Equivalent solutions and equivalence points 54
2.11.1 H2AEP - the equivalence point of H2A 55
2.11.2 HAEP- The equivalence point of HA- 57
2.11.3 A-2EP - the equivalence point of A-2 59
2.12 Buffer capacity 62
2.13 Graphical method for solving problems 63
3 Alkalinity and acidity as tools for quantifying acid-base equilibrium and designing water and wastewater treatment processes 67
3.1 Introduction 67
3.2 Alkalinity and acidity - definitions 67
3.2.1 First verbal definition 68
3.2.2 Second verbal definition 68
3.3 Development of alkalinity and acidity equations for monoprotic, weak-acid (weak-base) systems 70
3.3.1 Developing an equation for the alkalinity of a monoprotic, weak acid with HA as the reference species 70
3.3.2 Deriving an equation for the acidity of a monoprotic, weak acid with A- as the reference species 72
3.3.3 Generalization and elaboration of the concepts alkalinity and acidity and the relationships between them for a monoprotic weak acid 73
3.3.4 Introduction to measuring alkalinity and acidity in the laboratory 74
3.4 Developing equations for the description of alkalinity and acidity values of diprotic weak-acid systems 75
3.5 The carbonate system as an example of a diprotic system 75
3.5.1 Developing alkalinity and acidity equations with respect to the equivalence point of H2CO3 76
3.5.2 Developing alkalinity and acidity equations around the equivalence point of HCO3- 78
3.5.3 Developing the alkalinity and acidity equations around the equivalence point of CO32- 79
3.5.4 Useful notes about the carbonate system and useful relationships between the values of pH, alkalinity, acidity and CT 80
3.6 Determining alkalinity and acidity values in the lab: Characterization of acid-base relationships in natural waters 82
3.7 Standard laboratory alkalinity analysis 83
3.8 More on water characterization through analysis of CT and additional forms of alkalinity and acidity 84
3.9 Buffer capacity of solutions 85
3.9.1 Buffer capacity or buffer intensity 85
3.9.2 Deriving the buffer capacity equation for a monoprotic, weak acid 86
3.9.3 Expansion on the derivation of β to include diprotic and polyprotic systems using the carbonate system as an example for polyprotic systems 88
3.10 Titration curves 89
3.11 Alkalinity and acidity equations composed of several weak-acid systems 92
3.12 Elaboration on laboratory methods for measuring alkalinity and acidity 95
3.12.1 Gran titration for determining alkalinity 97
3.12.2 Mathematical derivation of the Gran method 98
4 Use of alkalinity and acidity equations for quantifying phenomena in chemical/environmental engineering and design of water and wastewater treatment processes 101
4.1 Theoretical background related to acid-base calculations in aqueous solutions from the knowledge of alkalinity and acidity parameters 101
4.2 Examples of acid-base problems from chemical/environmental engineering in which alkalinity and acidity terms can be used 104
4.3 Examples for implementation of the principles of the calculation method for solving problems related to wastewater 111
4.4 Using a method based on alkalinity and acidity mass balances to quantify the change in characterization of acid-base properties of water as a result of chemical dosage (deliberate or unintentional) 117
4.4.1 Solution outline 118
5 Equilibrium between the aqueous and gas phases and implications for water treatment processes 125
5.1 Introduction 125
5.2 Expressions describing concentrations of components in the gas phase 126
5.3 Henry's law 127
5.4 Factors affecting henry's law constant 130
5.4.1 The effect of the solution Ionic strength on Henry's constant 131
5.5 Systems that are closed to the atmosphere 132
5.6 The carbonate system in the context of gas-liquid phase equilibrium equations 133
5.7 Distribution of species as a function of pH for systems that are in equilibrium with the gas phase 137
6 Principles of equilibrium between the aqueous and solid phases with emphasis on precipitation and dissolution of CaCO3(5) 145
6.1 Introduction 145
6.2 The effect of Ionic strength on the solubility constants 147
6.3 Effect of temperature on the solubility constant 148
6.4 Effect of the addition of one of the solid components on the concentration of the other component in equilibrium (common ion effect) 148
6.5 Effect of side reactions on solubility of solids 150
6.6 Precipitation/dissolution of CaCO3: qualitative and quantitative assessment of the saturation state 151
6.6.1 Langelier saturation index (LSI) 151
6.6.1.1 Mathematical development of the formula for calculating pHL 151
6.6.1.2 The inherent problems in the Langelier method 152
6.6.2 Precise quantification of CaCO3 precipitation/dissolution potential (CCPP method) 153
6.6.3 Determination of the precipitation potential (numerical method) 154
6.6.4 Comparison of LSI values and CCPP in a given solution 155
6.6.5 Determining the precipitation potential (CCPP) graphically 156
6.6.5.1 Modified Caldwell-Lawrence (MCL) diagrams 156
6.6.5.2 MCL graph development 156
7 Computer software for calculations in the field of aquatic chemistry and water treatment processes, with an emphasis on the Stasoft4.0 program 163
7.1 Introduction 163
7.2 Principles of calculation and limitations 163
7.3 How to use the software 165
7.4 Simulation of water treatment processes using the Stasoft4 program 174
8 Water softening using the lime-soda ash softening method 179
8.1 Introduction 179
8.2 Deliberate modification of the aqueous-solid equilibrium state characteristics by the addition of chemicals to water 179
8.3 Water softening 181
8.3.1 Softening by lime-soda ash method 183
8.3.2 Basic description of the stages of the lime-soda ash softening process 184
9 Water stabilization and remineralization 193
9.1 Introduction 193
9.2 Overview of existing stabilization/remineralization technologies 193
9.3 Direct dosage of chemicals 194
9.3.1 Ca(OH)2 followed by CO2 addition 194
9.3.2 Ca(OH)2 and Na2CO3 or Ca(OH)2 and NaHCO3 195
9.3.3 CaCl2 and NaHCO3 196
9.4 Blending of low TDS water and other water sources 196
9.4.1 Blending case study 197
9.5 Post treatment methods based on (quarry) calcite dissolution 198
9.6 Acidic chemical agents used to enhance calcite dissolution 198
9.7 Final pH adjustment 200
9.8 Unintentional CO2(g) emission during calcite dissolution 201
9.9 Dolomite dissolution as means of supplying Ca2+, Mg2+ and carbonate alkalinity 201
9.10 Design of stabilization/remineralization processes 205
10 Problems and solutions 213
References 243
Index 247