posted on 2001-09-06, 00:00authored byLindsay J. Sherwood, Robert G. Qualls
Addition of iron and aluminum compounds has become
an increasingly popular method to regulate phosphorus
eutrophication in lakes and reservoirs. It has been proposed
that ferric chloride addition to agricultural runoff entering
the northern Everglades could provide a means for
enhancing natural mechanisms of phosphorus removal
from the wetland. In this study we added ferric chloride
to Everglades water spiked with 32PO4, incubating the resulting
precipitates in microcosms simulating the Everglades
ecosystem. 32P activity and reduction−oxidation (redox)
potentials were monitored to determine if the 32P was released
into the overlying water column due to iron reduction.
Results of redox potential measurements and 32P activity
indicate that although reducing conditions exist in the soil,
on average less than 1% of the added 32P was measured
in the water column during the 139-day incubation.
Ferric chloride addition thus might prove an effective
means of long-term phosphorus retention in the Florida
Everglades and perhaps other wetland systems.