Inorganic aluminium species (Al_i) in acidic water are toxic to fish (Gensemer Playle 1999) due to accumulation of Al on fish gills causing ionoregulatory and/or respiratory failures (Neville 1985, Wende-laar Bonga 1997). To counteract the toxicity of Al_i, a number of acidified waters are limed (Sandoy Langaker 2001). Liming increases pH and initiates an Al-transformation process (Teien et al. 2004) that can cause increased Al toxicity for a time-limited period (Rosseland et al. 1992). This increased toxicity is due to the instantaneous formation of transient polymeric Al-species. Because polymeric Al-species are transient, colloidal Al-species having low reactivity to gills are formed over time. Thus, the Al toxicity decreases by increasing time after liming.
展开▼
