Chapter 10
Organic compounds in sludges
10.1 HYDROCARBONS
10.1.1 Aliphatic hydrocarbons
Gas chromatography
Copin et al [1] determined aliphatic C 16 and C 26 hydrocarbons present at low vapour
pressure in sewage by gas chromatography. Recoveries of 95–102% were achieved for
concentrations of 20–30 mg L
−1 . The levels of the hydrocarbons were 200–500 mg L
−1
(dry basis) in urban treatment sludges and less than 150 mg L
−1 in the agro-industrial
effluent sludge.
Bohne-Mabusall et al [2, 4] studied problems connected with the determination of emulsified hydrocarbons in domestic sewage. A liquid chromatographic
method is described for the separation of anionic and non-ionic detergents, following which the simultaneous determination of hydrocarbons, fats and fatty acids could
be accomplished by infrared spectroscopy.
Column chromatography
In a method described by Ryzhova et al [3] for the determination of aliphatic hydrocarbons in wastewater sludges the hydrocarbons were extracted from sludge using a
mixture of pentane and hexane. Metal salts and compounds containing oxygen were
removed by successive treatment with 30% sodium hydroxide and 85% phosphoric
acid. After concentration and drying extracts were evaporated under nitrogen. Hydrocarbons were separated by eluent-adsorption chromatography on silica. Hydrocarbons
formed 95% of the total organic content of the extracted material. Quantitative
gas chromatographic results for 41 compounds are presented. Saturated compounds
present in the locally treated sludge and water were principally alkanes. Cycloalkanes
did not exceed 1%. Over 25 Alkyl benzenes were also quantified.
Millson et al [5] investigated components of sewage sludge and found that elementary sulphur was present in the hydrocarbon fractions eluted from liquid adsorption
columns. By using a solid adsorbent such as alumina, silica gel, or Florisil, and heptanes as eluent, the sulphur could be separated from weakly adsorbed hydrocarbons,
e.g. squalane or biphenyl, but not from more strongly adsorbed hydrocarbons such as
phenyldodecane.
Organic compounds in sludges
10.1 HYDROCARBONS
10.1.1 Aliphatic hydrocarbons
Gas chromatography
Copin et al [1] determined aliphatic C 16 and C 26 hydrocarbons present at low vapour
pressure in sewage by gas chromatography. Recoveries of 95–102% were achieved for
concentrations of 20–30 mg L
−1 . The levels of the hydrocarbons were 200–500 mg L
−1
(dry basis) in urban treatment sludges and less than 150 mg L
−1 in the agro-industrial
effluent sludge.
Bohne-Mabusall et al [2, 4] studied problems connected with the determination of emulsified hydrocarbons in domestic sewage. A liquid chromatographic
method is described for the separation of anionic and non-ionic detergents, following which the simultaneous determination of hydrocarbons, fats and fatty acids could
be accomplished by infrared spectroscopy.
Column chromatography
In a method described by Ryzhova et al [3] for the determination of aliphatic hydrocarbons in wastewater sludges the hydrocarbons were extracted from sludge using a
mixture of pentane and hexane. Metal salts and compounds containing oxygen were
removed by successive treatment with 30% sodium hydroxide and 85% phosphoric
acid. After concentration and drying extracts were evaporated under nitrogen. Hydrocarbons were separated by eluent-adsorption chromatography on silica. Hydrocarbons
formed 95% of the total organic content of the extracted material. Quantitative
gas chromatographic results for 41 compounds are presented. Saturated compounds
present in the locally treated sludge and water were principally alkanes. Cycloalkanes
did not exceed 1%. Over 25 Alkyl benzenes were also quantified.
Millson et al [5] investigated components of sewage sludge and found that elementary sulphur was present in the hydrocarbon fractions eluted from liquid adsorption
columns. By using a solid adsorbent such as alumina, silica gel, or Florisil, and heptanes as eluent, the sulphur could be separated from weakly adsorbed hydrocarbons,
e.g. squalane or biphenyl, but not from more strongly adsorbed hydrocarbons such as
phenyldodecane.