BS ISO 20468‑3:2020 pdf download.Guidelines for performance evaluation of
treatment technologies for water reuse systems.
3? Terms,? definitions? and? abbreviated? terms
For the purposes of this document, the following terms and definitions given in ISO 20670 and the following apply.
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3.1 Terms and definitions
3.1.1
ambient? ozone? concentration
concentration of ozone existing in the air or surrounding the ozone treatment apparatus
3.1.2
exhaust residual ozone concentration
ozone concentration (3.1.6) at the outlet of an off-gas ozone treatment unit
3.1.3
generated ozone amount
mass of ozone generated in a unit time
3.1.4
generated ozone concentration
ozone concentration (3.1.6) in the gas phase at the outlet of an ozone generator
3.1.5
off-gas ozone concentration
ozone concentration at the outlet of an ozone contactor
3.1.6
ozone concentration
volume, mass or mole of ozone in a unit volume or mass of gas or liquid
3.1.7
ozone concentration monitor
instrument capable of measuring ozone concentration in samples continuously
3.1.8
ozone demand
amount of ozone consumed to oxidize material in water
3.1.9
ozone dose
mass of ozone injected into a unit volume of water
Note 1 to entry: Ozone dose is expressed in units of mass-per-volume concentration (g/m 3 or mg/l).
3.1.10
residual ozone concentration
dissolved ozone concentration measured after a given contact time
Note 1 to entry: It is expressed in mg/l.
3.1.11
transferred ozone dose
mass of ozone applied into a unit volume of water
Note 1 to entry: Transferred ozone dose is expressed in units of mass-per-volume concentration (g/m 3 or mg/l).
4.2 Ozone system for water treatment
4.2.1 Feed gas supply unit The feed gas supply unit is using either air or oxygen gas to the ozone generation unit. An air-fed ozone system uses compressed air directly from the atmosphere. An oxygen-fed ozone system uses LOX or concentrated oxygen fed by an oxygen concentrator. Typically, the oxygen concentrator increases oxygen concentration by adsorbing nitrogen selectively from air.
4.2.2 Ozone generation unit
The ozone generation unit typically consists of:
— ozone generator(s)
— a power supply
— a cooling system
Corona discharge is currently the most common ozone generation method.
5 Principles and general guidelines for performance evaluation
5.1 General
Based on the principles and general guidelines for performance verification described in
ISO 20468-1:2018 [1] , this document also specifies two kinds of performance requirements:
— functional requirements
— non-functional requirements
5.3 Non-functional requirements
5.3.1 Performance characteristics
The following two performance characteristics are provided.
a) Environmental and economic key factors (5.3.2)
b) Safety requirements (5.3.3)
BS ISO 20468‑3 pdf download.