IN-SITU COAL PIT LAKE TREATMENT OF ACIDITY WHEN SULFATE CONCENTRATIONS ARE LOW 1

摘要: Pit lakes (abandoned flooded mine pits) represent a potentially valuable resource to mining companies, the environment and community, if appropriate water quality can be achieved. However, is often of low pH with high dissolved metal concentrations. In Western Australia coal pit are acidic (pH 3-5) but concentrations sulfate metals. Low prevent microbial reduction from reducing acidity in these lakes. stimulation primary production associated alkalinity generating processes may provide cost effective sustainable solution problems. A field-scale experiment (with control) involving treatment in-situ macrocosms (~600 m 3 ) small south-west, Australian lake municipal mulch phosphorus additions enhance was undertaken between June 2003 2004. One macrocosm treated P additions, another mulch, third P, untreated formed control. Physico-chemical algal (chlorophyll a) sampling occurred at monthly intervals. The decomposition reduced nitrogen very levels necessitated supplementation urea fertilizer. Phosphorus dropped rapidly after addition as it became bound iron, organic matter sediment. Although there virtually no difference treatments control for most physico-chemical parameters measured (including pH), PCA data showed that sent on different trajectory This reflected observations increased abundance diversity biofilms macroinvertebrates within macrocosms. conclusion, alone not sufficient increase Collie lakes, although does number benefits biota water. We therefore recommend liming used pH, followed by nutrient stimulate production.