266
A. NELSON-SMITH
V. REMOVAL OF SPILT OIL
A. Bacterial degradation and other biological processes
Orton recognized in 1925 that bacteria play an important part in
removing oil from the sea. Although Adam (1936) later ignored biodegradation in his otherwise full discussion of the dispersal of oil at sea,
Pilpel (1968) concluded from the work of Dzyuban ( I 958) and others
that bacterial oxidation could proceed as much as ten times as fast as
auto-oxidation. There is no doubt that bacteria can utilize a variety
of hydrocarbons under field conditions. Their activities in industrial
cutting and fuel-oils are frequently troublesome (see Birkholz et al.,
1961-62). Ludzack et al. (1957) observed that the amount of oil in a
stretch of river receiving a refinery effluent diminished by 40-80y0
below the discharge point, according to the season, and in laboratory
experiments a t summer temperatures 50-80y0 of the oil in their water
samples underwent biological degradation within a week. ZoBell and
Prokop (1966) found that, although oil was continually polluting bays
and creeks on the Louisiana coast, its concentration in bottom deposits
was generally low (see above), reaching 1% only in localized areas of
recent pollution and persisting there only for a few weeks. Oil-oxidizing
bacteria were detected in 94% of their mud samples.
Prokop (1 950) concluded that the presence of acclimated cultures
was essential to the degradation of crude oil and McKee (1956) gave
values for the biochemical oxygen demand of various organic compounds in cultures seeded with sewage organisms in which pure hydrocarbons gave low figures (no BOD from toluene, xylene or benzene over
five days ; 1-20 g BOD/g benzene over ten days ; 0.53 g from kerosine
and 0.078 g from gasoline over five days), although those containing
oxygen or nitrogen had much higher demands. ZoBell ( 1 964) obtained
higher figures (1.4-4.0 mg oxygen/mg sample) using mixed cultures of
hydrocarbon oxidizers. I n a 35-day test a t 25"C, the samples were 4785% oxidized. Comparable BOD values for other substances are 1.07
(glucose), 1.18 (starch, cellulose), 1.5-1.8 (protein), 2.5-2.9 (vegetable
and animal oils). However, Stone et ab. (1942) used ordinary soil
" seeds " on a selection of light oils, crudes and residues to obtain after
a few days cultures capable of attacking all the samples they tested.
The American Petroleum Institute's manual on biological treatment for
oil refinery wastes (McKinney, 1963) says, of recommended sources,
" The engineer need only look under his feet to find suitable organisms."
ZoBell (1946) and Voroshilova and Dianova (1950) have shown that
over 100 organisms can decompose pure hydrocarbons. Pseudomonas
is thc outstanding type for crudes and is represented by several marine
A. NELSON-SMITH
V. REMOVAL OF SPILT OIL
A. Bacterial degradation and other biological processes
Orton recognized in 1925 that bacteria play an important part in
removing oil from the sea. Although Adam (1936) later ignored biodegradation in his otherwise full discussion of the dispersal of oil at sea,
Pilpel (1968) concluded from the work of Dzyuban ( I 958) and others
that bacterial oxidation could proceed as much as ten times as fast as
auto-oxidation. There is no doubt that bacteria can utilize a variety
of hydrocarbons under field conditions. Their activities in industrial
cutting and fuel-oils are frequently troublesome (see Birkholz et al.,
1961-62). Ludzack et al. (1957) observed that the amount of oil in a
stretch of river receiving a refinery effluent diminished by 40-80y0
below the discharge point, according to the season, and in laboratory
experiments a t summer temperatures 50-80y0 of the oil in their water
samples underwent biological degradation within a week. ZoBell and
Prokop (1966) found that, although oil was continually polluting bays
and creeks on the Louisiana coast, its concentration in bottom deposits
was generally low (see above), reaching 1% only in localized areas of
recent pollution and persisting there only for a few weeks. Oil-oxidizing
bacteria were detected in 94% of their mud samples.
Prokop (1 950) concluded that the presence of acclimated cultures
was essential to the degradation of crude oil and McKee (1956) gave
values for the biochemical oxygen demand of various organic compounds in cultures seeded with sewage organisms in which pure hydrocarbons gave low figures (no BOD from toluene, xylene or benzene over
five days ; 1-20 g BOD/g benzene over ten days ; 0.53 g from kerosine
and 0.078 g from gasoline over five days), although those containing
oxygen or nitrogen had much higher demands. ZoBell ( 1 964) obtained
higher figures (1.4-4.0 mg oxygen/mg sample) using mixed cultures of
hydrocarbon oxidizers. I n a 35-day test a t 25"C, the samples were 4785% oxidized. Comparable BOD values for other substances are 1.07
(glucose), 1.18 (starch, cellulose), 1.5-1.8 (protein), 2.5-2.9 (vegetable
and animal oils). However, Stone et ab. (1942) used ordinary soil
" seeds " on a selection of light oils, crudes and residues to obtain after
a few days cultures capable of attacking all the samples they tested.
The American Petroleum Institute's manual on biological treatment for
oil refinery wastes (McKinney, 1963) says, of recommended sources,
" The engineer need only look under his feet to find suitable organisms."
ZoBell (1946) and Voroshilova and Dianova (1950) have shown that
over 100 organisms can decompose pure hydrocarbons. Pseudomonas
is thc outstanding type for crudes and is represented by several marine