Believe is the plural as they are talking in general.

Some examples of usage:

In alkaline media (pH 9.5) sodium sulfite is a good reducer of hydroperoxides
... hydroxides when treated with excess ammonia in an ammonium medium ...
www.sas.org/E-Bulletin/2002-08-16/features2/body.html - 46k - Cached - Similar pages

Germar Rudolf: The Rudolf Report
... be converted into iron(II)-cyanide, but cannot react with iron(III)-ions to
... Although more strongly alkaline media can accumulate iron(II)-cyanide ...
www.vho.org/GB/Books/trr/6.html - 130k - Cached - Similar pages

[PDF] Evaluation of Croatian Clinoptilolite- and Montmorillonite-rich ...
File Format: PDF/Adobe Acrobat - View as HTML
... ammonium ions removal on the samples was calculated from the difference ...
change in slightly acid, neutral and slightly alkaline media (pH = 3–8). Am- ...
jagor.srce.hr/ccacaa/CCA-PDF/ cca2002/v75-n1/CCA_75_2002_255-269_Rozic.pdf - Similar pages

Bacterial Degradation of Cyanide and Its Metal Complexes under ...
... (ii) the bacterium stoichiometrically converted cyanide into ammonium in ...
The bacterium was able to grow in alkaline media, up to an initial pH of ...
aem.asm.org/cgi/content/full/71/2/940 - Similar pages

[PDF] Chapter 8 Water Quality Requirements and Management
File Format: PDF/Adobe Acrobat
... tank is converted into ammonia. Most of the feed that is ingested by the ...
convert ammonium ions to nitrite, while Nitrobacter spp. convert nitrite to ...



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Note added at 1 hr 14 mins (2005-05-06 22:01:52 GMT)
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i.e. talking in general as a common property to all.........