DS/EN ISO 9509:2006
Water quality - Toxicity test for assessing the inhibition of nitrification of activated sludge microorganisms

Standard No.

DS/EN ISO 9509:2006

Release Date

2006

Published By

Danish Standards Foundation

Latest

DS/EN ISO 9509:2006

Replace

DS/EN ISO 9509:1996

Scope

This International Standard specifies a method for assessing the short-term inhibitory effect of waters, waste waters or test substances on nitrifying bacteria in activated sludge. The inhibitory effect is estimated over an exposure period of usually 4 h or up to 24 h with weakly nitrifying sludge.The method is applicable with nitrifying activated sludge derived from domestic and synthetic sewage and also to sludges from industrial and mixed domestic and industrial waste waters.The nitrifying activity of the sludge is verified by testing in the presence and absence of a specific inhibitor (e.g. N-allylthiourea; see Annex A). If the nitrification rate is wit

DS/EN ISO 9509:2006 history

• 2006 DS/EN ISO 9509:2006 Water quality - Toxicity test for assessing the inhibition of nitrification of activated sludge microorganisms
• 0000 DS/EN ISO 9509:1996