IL AWWA Best Paper Award
ArticlesThe Thurston E. Larson Best Paper Award was presented to Robert Spon for his presentation of
"Do you Really Have a Free Chlorine Residual?"
at the 2005 Annual Meeting of the Illinois Section American Water Works Association held in Springfield,…
Phosphate Treatment FAQs - Part 1
ArticlesWhat is phosphate treatment?
Phosphates are water treatment chemicals (dry or liquid solutions) used to correct problems resulting from inorganic groundwater contaminants (iron, manganese, calcium, etc.) and also to maintain water quality (inhibit…
Phosphate Treatment FAQs - Part 2
ArticlesHow are phosphate dosages controlled?
Since phosphates do not change basic water chemistry, measuring phosphate residuals in the raw and finished water is necessary to monitor the dosage rate. Orthophosphate ion (PO4) is the most common species…
NSF Std. 60 Listed Orthophosphate Chemicals
ArticlesApproximate % active as PO4
Approximate pH value (1% solution)
Name: Phosphoric Acid
Formula: H3PO4
% active: 75% (pH 1)
Name: Monosodium orthophosphate
Formula: NaH2PO4
% active: 79% (pH 4.5)
Name: Monopotassium orthophosphate
Formula:…
NSF Std. 60 Listed Polyphosphate Chemicals
ArticlesApproximate % active as PO4
Approximate pH value (1% solution)
Name: Sodium acid pyrophosphate
Formula: Na2H2P2O7
% active: 86% (pH 4)
Name: Tetrasodium pyrophosphate
Formula: Na4P2O7
% active: 72% (pH 10.5)
Name: Tetrapotassium…
Manganese (Mn) Fraction Analysis
Articles1. Total Mn: Analyze raw water or system water samples for total Manganese.
2. Soluble Mn: Analyze water samples using the PAN Method, but delete the use of the ascorbic acid reagent (reducing agent) in the Hach Step #6 to identify the initial…
Iron (Fe) Fraction Analysis
Articles1. Total Fe: Analyze raw or finished water sample using Ferrover #8008 for total Iron.
2. Soluble Fe: Analyze raw or finished water sample using the 1,10 Phenanthroline Method #8146 to determine soluble iron. Soluble unbound (ferrous) iron…
Phantom Free Chlorine Residuals
ArticlesA growing number of water systems have naturally occurring ammonia (NH3-N) and organic contaminants (TOC) in their water supplies. These contaminants react with chlorine treatment to form combined chlorine residuals (chloramines, chlororganics),…