ISO 4789:2023
(Main)Guidelines for wastewater treatment and reuse in thermal power plants
Guidelines for wastewater treatment and reuse in thermal power plants
This document specifies guidelines for wastewater treatment and reuse in thermal power plants, including the types and characteristics of wastewater and the technologies of wastewater treatment and reuse. In this document, thermal power plant drainage systems are divided into fuel supply, chemical water treatment, boiler and auxiliary, recirculating cooling, flue gas processing, gasification scrubber and ash handling. Wastewater from these systems is classified in accordance with its system sources. In addition, technical guidelines for wastewater treatment and reuse are provided according to the water requirements of systems in the thermal power plant. This document is formulated to provide feasible technical guidance for the treatment and reuse of wastewater in thermal power plants. It is applicable to coal-fired, oil-fired, gas-fired (including gas turbine), biomass-fired, waste incineration and integrated gasification combined cycle (IGCC) thermal power plants.
Lignes directrices pour le traitement et la réutilisation des eaux usées dans les centrales électriques thermiques
General Information
Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 4789
First edition
2023-06
Guidelines for wastewater treatment
and reuse in thermal power plants
Lignes directrices pour le traitement et la réutilisation des eaux usées
dans les centrales électriques thermiques
Reference number
© ISO 2023
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and abbreviated terms . 1
3.1 Terms and definitions . 1
3.2 Abbreviated terms . 2
4 General principles . 3
5 Types and characteristics of wastewater in thermal power plants .3
6 Wastewater treatment and reuse technologies . 7
6.1 Water quality requirements for reuse water in thermal power plants . 7
6.2 Fuel supply system wastewater treatment and reuse . 8
6.2.1 Coal wastewater . 8
6.2.2 Oily wastewater . 9
6.2.3 Leachate . 9
6.3 Chemical water treatment system wastewater treatment and reuse . 10
6.3.1 RO concentrated water . 10
6.3.2 Membrane washing wastewater and resin reclaimed wastewater
treatment and reuse . 11
6.4 Boiler and auxiliary system wastewater treatment and reuse . 11
6.4.1 Boiler blowdown . . . 11
6.4.2 Boiler chemical cleaning wastewater .12
6.4.3 Auxiliary equipment cooling water blowdown .12
6.5 Recirculating cooling system wastewater treatment and reuse .12
6.6 Flue gas processing system wastewater treatment and reuse .13
6.6.1 WESP blowdown .13
6.6.2 FGD wastewater . 14
6.7 Gasification scrubber system wastewater treatment and reuse . 14
6.8 Ash handling system wastewater treatment and reuse . 15
Annex A (informative) Cases of water balance in thermal power plants .16
Annex B (informative) Cases of wastewater reuse in thermal power plants .25
Bibliography .28
iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
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ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO document should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use
of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed
patent rights in respect thereof. As of the date of publication of this document, ISO had not received
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www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 282, Water reuse, Subcommittee SC 4,
Industrial water reuse.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
Introduction
Global water scarcity is becoming increasingly pronounced as a result of the massive demand for water
caused by population growth, public life and industrial growth. Due to the increasing cost of water and
sewage disposal, wastewater reuse in thermal power plants is being initiated. The number of wastewater
recycling projects in thermal power plants is increasing and water treatment and reuse technologies
are being developed. Studies have shown that electric power plants account for approximately half the
[1]
global industrial water withdrawal , which means the problem of water shortage will be aggravated
with the expansion of thermal power plants.
Although the generation of electricity from renewable sources (e.g. wind, hydro and solar photovoltaic)
with almost zero water consumption is growing, the proportion of world gross electricity generated
[2]
by combustible fuels still accounted for 64,1 % in 2020 . In addition, the wastewater from thermal
power plants (power plants that generate electricity from combustible fuels) is diverse, with a high
[3]
volume and complex pollutant components , and its discharge poses a threat to the ecology of water
environments. Therefore, the reuse of wastewater from thermal power plants has dual benefits of
water saving and environmental protection.
The increasing efforts to control water scarcity and water pollution in some countries have made
industrial wastewater reuse a valuable means of augmenting the existing water supply and reducing
wastewater discharge to the environment. In terms of wastewater treatment and reuse in thermal
[4] [5] [6] [7]
power plants, the United States , China , Japan and International Energy Agency (IEA) have all
introduced relevant policies to encourage wastewater reuse or even zero discharge in thermal power
plants.
However, the reclaimed water quantity of wastewater in thermal power plants is not high, and the
different characteristics of wastewater generated from different systems are ignored. Therefore, it
is necessary to strengthen the classification and characteristic analysis of wastewater, adopt more
reasonable and efficient treatment and reuse technologies in thermal power plants to optimize the
reclaimed water quantity of wastewater, to realize zero liquid discharge of wastewater and to improve
the benefits of water saving and environmental protection and ultimately achieve the sustainable
development goals (see www.un.org/sustainabledevelopment).
v
INTERNATIONAL STANDARD ISO 4789:2023(E)
Guidelines for wastewater treatment and reuse in thermal
power plants
1 Scope
This document specifies guidelines for wastewater treatment and reuse in thermal power plants,
including the types and characteristics of wastewater and the technologies of wastewater treatment
and reuse.
In this document, thermal power plant drainage systems are divided into fuel supply, chemical water
treatment, boiler and auxiliary, recirculating cooling, flue gas processing, gasification scrubber and
ash handling. Wastewater from these systems is classified in accordance with its system sources. In
addition, technical guidelines for wastewater treatment and reuse are provided according to the water
requirements of systems in the thermal power plant. This document is formulated to provide feasible
technical guidance for the treatment and reuse of wastewater in thermal power plants.
It is applicable to coal-fired, oil-fired, gas-fired (including gas turbine), biomass-fired, waste incineration
and integrated gasification combined cycle (IGCC) thermal power plants.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 20670, Water reuse — Vocabulary
3 Terms, definitions and abbreviated terms
For the purposes of this document, the terms and definitions given in ISO 20670 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1 Terms and definitions
3.1.1
advanced treatment for TDS
advanced treatment for total dissolved solids
process of further reducing the salt content in wastewater by using advanced treatment technology
after pretreatment to achieve certain reuse water targets
3.1.2
ash handling system
system that includes all the equipment, pipelines and monitoring devices for collecting bottom ash and
fly ash from combustion or gasification of fuel in boilers and transferring it out of the power plant
3.1.3
boiler and auxiliary system
system that includes primary production equipment for the combustion or gasification of fuel and other
auxiliary machinery
3.1.4
chemical water treatment system
system that treats the raw water to achieve water quality requirements for the different water
applications in the power plant
Note 1 to entry: A chemical water treatment system includes the raw water pretreatment, boiler replenishment
water treatment, condensate polishing treatment and wastewater treatment
3.1.5
flue gas processing system
system that purifies boiler flue gas and reduces pollutants such as sulfur dioxide, nitrogen oxides,
particulate matter and organic gas in flue gas
3.1.6
fuel supply system
system that collects, stores, pre-treats and transports combustible fuels fo
...
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