Purified Recycled Water for Drinking: The Technical Issues

After more than a year in the making, the Queensland Water Commission recently published a 270 page report titled Purified Recycled Water for Drinking: The Technical Issues.

Associate Professor Greg Leslie and I were invited to co-author Chapter 4 of the report titled ‘Advanced Water Treatment Technologies’. I’d be grateful for any feedback or questions from anyone who takes the time to read it...



Purified Recycled Water for Drinking: The Technical Issues
Table of Contents

Foreword
Acknowledgements
Contributors
Reviewers

1 Introduction and report overview
1.1 Background
Drought
Population growth and climate change
Meeting future water demands
1.1.1 Objectives of the technical papers
1.2 Synopsis of technical papers
1.2.1 Introduction to potable water treatment – Chapter 2
Introduction
Synopsis
1.2.2 Current wastewater treatment processes – Chapter 3
Introduction
Synopsis
1.2.3 Advanced water treatment technologies – Chapter 4
Introduction
Synopsis
1.2.4 Risk management of chemicals in recycled water – Chapter 5
Introduction
Synopsis
1.2.5 Management of microbial contaminants for indirect potable reuse – Chapter 6
Introduction
Synopsis
1.2.6 Current indirect potable reuse schemes – Chapter 7
Introduction
Synopsis
1.3 References

2 Introduction to potable water treatment
Summary
2.1 Introduction
2.2 Australian drinking water guidelines
2.3 Why treat water?
2.4 Conventional water treatment
2.4.1 Dissolved air flotation
2.5 Disinfection
2.5.1 Chlorine
2.5.2 Chloramine
2.5.3 Ozone
2.5.4 Ultraviolet disinfection
2.6 Other treatment options
2.6.1 Adsorption processes
2.6.2 Oxidation
2.6.3 Biological filtration
2.6.4 Anionic resins
2.6.5 Membrane filtration
2.7 Monitoring
2.8 Potable water treatment in south east Queensland
2.9 Conclusions
2.10 Acknowledgements
2.11 References

3 Current wastewater treatment processes
Summary
3.1 Introduction
3.1.1 Outline of this chapter
3.1.2 Compounds in wastewater
3.1.3 Overview of wastewater treatment
3.2 History of wastewater treatment
3.2.1 The need for wastewater collection and treatment
3.2.2 Early wastewater treatment methods
3.2.3 The development of secondary treatment
3.2.4 The development of tertiary treatment
3.3 Steps in wastewater treatment
3.4 Nutrient removal processes
3.4.1 Biological nitrogen removal
3.4.2 Biological phosphorus removal
3.4.3 BNR operation
3.4.4 Common BNR plant configurations
3.4.5 Developments in BNR technology
3.5 Removal of micropollutants in wastewater treatment
3.5.1 Factors affecting biological removal of micropollutants
3.5.2 Performance of micropollutant removal
3.6 Reliability of modern wastewater treatment plants
3.6.1 Reliability of WWTPs in meeting licence conditions
3.6.2 Existing and future monitoring and controls
3.6.3 Importance of source control
3.7 Treatment processes in South East Queensland
Bundamba wastewater Centre
Oxley Creek wastewater treatment plant
Gibson Island wastewater treatment plant
Luggage Point wastewater treatment plant
Goodna wastewater treatment plant
South Caboolture wastewater treatment and reclamation plants
3.8 Conclusions
3.9 References

4 Advanced water treatment technologies
Summary
4.1 Introduction
4.2 Multiple barrier approach to water treatment
4.3 Objectives of advanced water treatment process
4.4 Technologies for removal of suspended solids
4.4.1 Membrane technologies
4.4.2 Monitoring the effectiveness of membranes
4.5 Removal of dissolved chemicals
Rationale for removal of organics
Rationale for residual nutrient removal
Rationale for removal of residual salt
4.5.1 Removal technologies for dissolved chemicals
Semi-permeable membranes for reverse osmosis processes
Adsorptive treatment processes
Advanced oxidation processes
Ion Exchange processes
4.6 Disinfection Processes
Chlorination
Ozonation
Ultraviolet light
Oxidation
4.7 Stabilisation
Rationale for stabilisation
Addition of sodium hydroxide
Lime stabilisation
4.8 AWT processes in South East Queensland
4.9 Conclusions
4.10 Acknowledgements
4.11 References

5 Risk management of chemicals in recycled water
Summary
5.1 Introduction
5.1.1 Scope of this chapter
5.2 Risk assessment framework
5.2.1 Issue identification
5.2.2 Hazard assessment - toxicological
5.2.3 Exposure assessment
5.2.4 Risk characterisation
5.3 Risk perception and risk communication
5.3.1 The case of endocrine disruption
5.4 Assessment guidelines
5.4.1 Australian drinking water guidelines (2004)
5.4.2 enHealth Council guidelines
5.4.3 National guidelines for water recycling (2006)
5.5 Hazard assessment for chemicals
5.5.1 Recognised chemical contaminants
5.5.2 Unknown chemicals and/or complex mixtures
5.5.3 Chemicals in water
Natural and synthetic hormones
Synthetic Industrial chemicals
Pharmaceuticals and personal care products
Antiseptics
Cyanotoxins
Treatment by-products
Radiological water quality
Pesticides and heavy metals
5.5.4 Dose-response relationships
5.6 Exposure assessment
5.6.1 Measurement methods
Chemical analyses of individual compounds
Complex mixtures and detecting ‘unknown chemicals’
5.6.2 Source controls
Trade waste controls
Hospital waste
5.6.3 Removal of organic contaminants in wastewater
Fate and partitioning
Removal of selected endocrine disruptors from WWTPs in SE Queensland
5.6.4 Removal of chemicals during AWT
5.7 Risk characterisation
5.7.1 Epidemiology
Cohort (longitudinal) studies
Case-control
Cross-sectional studies
Ecological studies
5.7.2 Experimental toxicology
Biomarkers of exposure and/or effect
Whole animal testing
Toxicological Studies on IPR
5.7.3 Combining observational epidemiology with experimental toxicology
5.7.4 Other methods for monitoring and assessment
Biosensors
Sampling techniques
Quantitative structure–activity relationship (QSAR)
Integration of chemical and bio-analytical methods
5.8 Conclusions
5.9 References
Appendix 1
List of regulated chemicals from ADWG and their identification as EDCs
Regulated pesticides from ADWG and their identification as EDCs

6 Management of microbial contaminants for indirect potable reuse
Summary
6.1 Introduction
6.2 Pathogenic microorganisms potentially present in wastewater
6.2.1 Bacteria
6.2.2 Viruses
Box 6.1 Can I get AIDS from drinking water?
6.2.3 Protozoa
6.2.4 Prions
Box 6.2 Can I get mad-cow disease from drinking water?
6.3 Removal of microorganisms from water
6.3.1 Wastewater treatment
6.3.2 Disinfection processes
6.3.3 Environmental buffer
6.3.4 Potable water treatment
6.4 Monitoring the removal of microorganisms from purified recycled water
6.5 Guidelines for water quality and microbial contaminants
6.5.1 Australian drinking water guidelines
6.5.2 National guidelines for water recycling
6.5.3 EnHealth guidelines
6.6 The management of microbial risks in water
6.6.1 Risk management in the National Guidelines for Water Recycling
6.6.2 Risk management in the enHealth guidelines
6.7 Acknowledgements
6.8 References

7 Current indirect potable reuse schemes
Summary
7.1 Introduction
7.2 United States of America
7.2.1 Upper Occoquan Sewage Authority, Northern Virginia
7.2.2 Groundwater Recharge in California
Box 71 Presence of N-nitrosodimethylamine (NDMA) in recycled water
7.2.3 Scottsdale Water Campus, Arizona
7.2.4 Gwinnett County Georgia
7.3 Singapore
7.4 Windhoek, Namibia
7.5 Veurne-Ambacht, Belgium
7.6 Berlin, Germany
7.7 United Kingdom
7.7.1 Thames River
7.7.2 Essex and Suffolk Water
7.8 Examples within Australia
7.9 Relevance to South East Queensland
7.10 Acknowledgements
7.11 References

Appendix
Abbreviations and glossary
Glossary