Standard Methods for the Examination of Water and

Normality is an older unit of concentration that, although once commonly used, is frequently ignored in today s laboratories. Normality is still used in some handbooks of analytical methods, and, for this reason, it is helpful to understand its meaning. For example, normality is the concentration unit used in Standard Methods for the Examination of Water and Wastewaterf a commonly used source of analytical methods for environmental laboratories. 

Method 3500-Mg D as published in Standard Methods for the Examination of Water and Wasteveater, 18th ed. American Public Health Association Washington, DC, 1992, pp. 3-73 to 3-74. 

American Public Health Association, Standard Methods for the Examination of Water and Waste Water, 16th edn. 

Clesceri, L.S. Greenberg, A.E. Trussell, R.R. Eds. Standard Methods for the Examination of Water and Wastewaters 17th Edition, American Public Health Association, American Water Works Assoc., Water Pollution Control Federation, Baltimore, MD. 1989. 

APHA, Standard methods for the examination of water and wastewater, 16" edition, American Public Health Association, Washington, DC, 1985... 

Traditionally, the definition of suspended solids as used in the characterization of wastewater is defined according to the method used in the analysis of total suspended solids (TSS), e.g., as described in Standard Methods for the Examination of Water and Wastewater (1998). This definition of suspended solids is based on a filtration—or sometimes also centrifugation—procedure and is, therefore, appropriate for particles having a diameter > 1-0.5 pm (Figure 3.5). 

The VFAs, primarily formate, acetate, propionate, n-butyrate and isobutyrate, can be determined analytically on an ion chromatograph (Standard Methods for the Examination of Water and Wastewater, 1998). Determination of fermentable, readily biodegradable substrate, SF, and fermentation products, SA, in units of COD requires that the VFA components be converted to this unit. The following example using formate demonstrates this ... 

Total sulfide can be measured photometrically by the methylene blue method (Cline, 1969 Standard Methods for the Examination of Water and Wastewater, 1998). Reliable sensors exist for the measurement of hydrogen sulfide in air. 

APHA-AWWA-WPCF, Clesceri, Greenberg and Trussel (Eds.), Standard Methods for the Examination of Water and Wastewater, 17th Edn., 1989. EEC Directive 92/32/EEC (1992/04/30) Seventh amendment of Directive 67/548/EEC. C.3 Microalgae growth inhibition test. 

APHA/AWWAAVPCF. 1985. Standard methods for the examination of water and wastewater. 

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