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Phosphate inactivation with iron chloride during sediment resuspension
Author(s) -
Wísniewski Ryszard
Publication year - 1999
Publication title -
lakes and reservoirs: research and management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.296
H-Index - 39
eISSN - 1440-1770
pISSN - 1320-5331
DOI - 10.1046/j.1440-1770.1999.00081.x
Subject(s) - sediment , sorption , precipitation , environmental chemistry , phosphate , chemistry , chloride , sediment–water interface , environmental science , mineralogy , geology , adsorption , geomorphology , physics , organic chemistry , meteorology
The present study undertook laboratory and in situ experiments in two hypertrophic lakes in order to determine the possibilities for the effective PO 4 precipitation by means of FeCl 3 , applied directly to organic sediments (at a specific depth) previously subject to resuspension. The study also aimed to test, modify and improve a device constructed previously. This made the direct application of FeCl 3 to organic sediments possible, while generating resuspension in the surface layer of sediments to a specified thickness. The results of both laboratory and field experiments, and tests of the prototype device, showed that linking a dosage of FeCl 3 with the initiation of controlled resuspension led to a decrease of seven‐fold in the concentration of PO 4 in interstitial water, and changed other physical and chemical parameters in the water only slightly. The effectiveness of PO 4 precipitation relied mostly on initial conditions in the interface of water–organic sediment phases, and especially on the sorption capacity of sediments for phosphates, on the gradient of PO 4 concentration, and on the concentration of oxygen in the layer of water above the sediment. It could be an effective method of over‐eutrophied lakes reclamation, and an alternative to the expensive removal of sediments.