# ISO 9509:1989 — Withdrawn and superseded ISO standards

For ISO 9509:1989, item title is Water quality — Method for assessing the inhibition of nitrification of activated sludge micro-organisms by chemicals and waste waters; status code is 9599; successor is ISO 9509:2006; withdrawn / published date is 1989-10-12, recorded from its source on 2026-08-05.

- **Identifier:** ISO 9509:1989 _(verified: appears in the quote below)_
- **Item title:** Water quality — Method for assessing the inhibition of nitrification of activated sludge micro-organisms by chemicals and waste waters _(verified: appears in the quote below)_
- **Status code:** 9599 _(verified: appears in the quote below)_
- **Successor:** ISO 9509:2006
- **Withdrawn / published date:** 1989-10-12 _(verified: appears in the quote below)_

## What the source says

> 17241,IS,,ISO 9509:1989,Water quality — Method for assessing the inhibition of nitrification of activated sludge micro-organisms by chemicals and waste waters,Qualité de l'eau — Méthode pour l'évaluation de l'effet inhibiteur sur la nitrification par des micro-organismes de boues activées par des produits chimiques ou des eaux résiduaires,1989-10-12,1,['13.060.70'],ISO/TC 147/SC 5,9599,,[34812],"['en','fr']",6,

## Source

- https://isopublicstorageprod.blob.core.windows.net/opendata/_latest/iso_deliverables_metadata/csv/iso_deliverables_metadata.csv

Last verified: 2026-08-05. Review by: 2027-02-01.
Part of [Withdrawn and superseded ISO standards](https://referencesource.org/iso-standard-supersessions/).