Paper No. 86002 of the Water Resources Bulletin. Discussions are open until August 1, 1987.
EFFECTIVENESS OF ALUM IN A WEEDY, SHALLOW LAKE1
Article first published online: 8 JUN 2007
JAWRA Journal of the American Water Resources Association
Volume 22, Issue 6, pages 921–926, December 1986
How to Cite
Welch, E. B., DeGasperi, C. L. and Spyridakis, D. E. (1986), EFFECTIVENESS OF ALUM IN A WEEDY, SHALLOW LAKE. JAWRA Journal of the American Water Resources Association, 22: 921–926. doi: 10.1111/j.1752-1688.1986.tb00764.x
- Issue published online: 8 JUN 2007
- Article first published online: 8 JUN 2007
- sediment phosphorus release;
- internal phosphorus loading;
- lake restoration
ABSTRACT: An alum treatment in Long Lake (mean depth, 2 m) in 1980 has been effective at controlling internal loading of phosphorus for four years. The fifth summer after treatment, the lake returned to its pro-treatment state. Lake P content decreased from a summer average of 65 μg/L during 1976–1978 to about 30 μg/L during four years following treatment. In 1985, summer P content was 61 μg/L. Algal abundance, species composition, and transparency have responded proportionately with P.
Alum effectiveness apparently declined because the floe layer tended to sink and become dispersed at a deeper level in the sediment, as well as become covered with new, P-rich sediment. Iron-reduction may be the principal mechanism for internal P loading, although the lake is unstratified and anoxia is usually not pronounced.