114 lakes treated with aluminum (Al) salts to reduce internal phosphorus (P) loading were analyzed to identify factors driving longevity of post-treatment water quality improvements. Lakes varied greatly in morphology, applied Al dose, and other factors that may have affected overall treatment effectiveness. Treatment longevity based on declines in epilimnetic total P (TP) concentration averaged 11 years for all lakes (range of 0–45 years). When longevity estimates were used for lakes with improved conditions through the end of measurements, average longevity increased to 15 years. Significant differences in treatment longevity between deeper, stratified lakes (mean 21 years) and shallow, polymictic lakes (mean 5.7 years) were detected, indicating factors related to lake morphology are important for treatment success. A decision tree developed using a partition model suggested Al dose, Osgood index (OI, a morphological index), and watershed to lake area ratio (related to hydraulic residence time, WA:LA) were the most important variables determining treatment longevity. Multiple linear regression showed that Al dose, WA:LA, and OI explained 47, 32 and 3% respectively of the variation in treatment longevity. Other variables (too data limited to include in the analysis) also appeared to be of importance, including sediment P content to Al dose ratios and the presence of benthic feeding fish in shallow, polymictic lakes.
a Swedish University of Agricultural Sciences, Department of Aquatic Sciences and Assessment, Box 7050, 75007, Uppsala, Swedenidb University of Southern Denmark, Department of Biology, Campusvej 55, DK-5230, Odense M, Denmarkid="aff3">c ERD Environmental Research & Design, 3419 Trentwood Blvd., Suite 102, Orlando, FL, USAid="aff4">d Leibniz Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germanyid="aff5">e Barr Engineering, 4077 77th Street, Minneapolis, MN, 55304, USAid="aff6">f Erken Laboratory, Dep. of Ecology and Genetics, Uppsala University, Norra Malmavägen 45, SE 761 73, Norrtälje, Sweden
Recommended Citation:
Brian J. Husera,,,et al. Longevity and effectiveness of aluminum addition to reduce sediment phosphorus release and restore lake water quality[J]. water Research,2016-01-01,Volume 97