The Composition of Sewer A ir
283
Table 2
Classical Field and Laboratory Procedures
Absorption Media
Application
Procedure
Special Draeger Tubes
Saturated Baryta Water
CdCl 2 -Cd(OH) 2 aqueous
dispersion
ZnCl 2 followed by HgCl 2
carried on fibre glass
discs
Buffered distilled
Sodium bisulphide (1% aq)
Concentrated H 2 S0 4
impregnated on fibre
glass discs
Activated carbon
C0 2 , H 2 S and mercaptans
C0 2
H 2 S
Mercaptans and organic
sulphides
(a)
(b)
alkylamines
aldehydes
aldehydes
organic amines
organic soils and solvents
Direct aspiration
Direct aspiration and back
titration with standard
H 2 S0 4 solution
Formation of methylene
blue and spectrophotometry
(i) Displacement by boiling
HC1 into tetra acetony
mercuri-fluorescein
(ii) transfer to GLC Column
(a) (i) Zitomer-Dahlgren
(1964) formation of
starch - iodine complex
(ii) transfer to GLC Column
(b) method of Sawicki et al
(1961)
Transfer to GLC Column
Transfer to GLC Column
(i) desorption withCH 2 Cl 2
followed by gravimetric
determination
(ii) transfer to GLC Column
The GLC procedures finally developed are summarised in Table 3.