Liming acid streams: Aluminium toxicity to fish in mixing zones
| Autor: | N. S. Weatherley, Stephen James Ormerod, S. P. Thomas, G. P. Rutt |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
Fish mortality
geography Environmental Engineering geography.geographical_feature_category Chemistry Ecological Modeling media_common.quotation_subject Environmental engineering engineering.material Particulates complex mixtures Pollution Speciation Hydrolysis Environmental chemistry Toxicity Tributary engineering Environmental Chemistry Water treatment Water Science and Technology media_common Lime |
| Zdroj: | Water, Air, and Soil Pollution. 55 |
| ISSN: | 1573-2932 0049-6979 |
| DOI: | 10.1007/bf00211199 |
| Popis: | Liming to neutralize acidic surface waters involves a possible risk of toxicity to fish due to precipitation or changes in speciation of Al. We report the response of captive brown trout to the experimental liming of an acid stream rich in Al. Within 15 m of lime dosing 0.22 µm filterable Al fell from 580 to 230 µg L−1, and to 120 jig L−1, within 30 m, though total Al was unchanged. After 24 hr, fish mortality was 100% at untreated acidic sites, 80% up to 30 m downstream of liming, declining to zero within 100 m. Mortality was 70% at 15 m below the confluence of an acidic tributary with the limed stream, despite little change in pH or total Al concentration. Mortalities were significantly correlated with concentrations of Al and Fe in gill tissues, and with 0.22 µm filterable Al and Fe in the water, but not with particulate Al or Fe. AI(OH)4 −, precipitating A1 or polymeric hydrolysis products are all possible causes of the observed toxicity. Iron may have also have contributed, but the stream concentrations of this metal were relatively low. The practical conclusion is that changes in Al chemistry, where waters of differing acidity mix, may be important in some circumstances where river systems are limed selectively. |
| Databáze: | OpenAIRE |
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