size were only evident in those particles incu-
cle. In three instances, one at each temperature
bated at moisture contents below saturation. Al-
tested, the particle was located without sieving,
most all particles were translucent, and there
and the sediment in direct contact with particle
was no evidence of the oxidized coating that
was analyzed. P4 concentrations in this associated
sediment were 0.2 (4C), 0.5 (15C) and 6.6 g/g
forms when P4 is stored in water. Some particles
(20C).
developed an orange tinge over part of the sur-
face, similar to the color that develops when P4
Residual mass of P4 particles. P4 particles were re-
covered from all samples incubated at 4C. At this
is exposed to light. This color change may have
been an artifact from the microscope light used
low temperature, there were no significant reduc-
to locate the particles.
tions of the masses of P4 particles found, except
The particles were difficult to locate. The moist
the particles isolated at the last sampling interval
sediment surrounding the particles was not visi-
(58 days) at the lowest moisture content (Fig. 10a),
bly changed. Some unsaturated samples (s = 0.64)
where the mass for each particle was approxi-
that were incubated at 20C for 10 days were al-
mately half that of the original mass.
For samples incubated at 15C (Fig. 10b), there
lowed to air-dry. Then a razor blade was used to
slice through the region where the particle was
were no changes in particles incubated at satura-
tion or above; however, there were significant re-
ductions in particles incubated at the two lowest
moisture contents (s = 0.45 and 0.64) during 30
days of incubation. Following incubation for 57
days at 15C, no P4 was detected in the samples at
the two lowest moisture contents. At s = 0.82, P4
loss was inconsistent. P4 was undetectable in
some samples after only one week of incubation