Speciation of Aluminium in the Water and Bottom Sediment of Fish-Breeding Ponds

Abstract

Water and bottom sediment samples collected from a few fish-breeding ponds/reservoirs were subjected to tests. The aim of this paper was to determine the total content of aluminium and its fractions in the samples tested to estimate the potential risk to fish caused by the toxic forms of aluminium. The monomeric inorganic aluminium in waters was determined using the ion exchange and extraction-colorimetric method with oxychinoline according to Barnes's-Driscoll's procedure. The bottoms were fractionated using a three-step sequential extraction procedure and the microwave mineralisation. The total content of aluminium in waters and extracts was determined using the spectrophotometric method with eriochromocyanine R, and comparatively using the ICP OES technique. The results were subjected to statistical analysis. The level of concentration of labile Al in the waters about 26-34 µg/dm 3 and content of exchangeable Al 5-34 mg/g range in bottom sediments are possibly hazardous to aquatic organisms.

The Toxicity of Aluminium Salts to Lecane Inermis Rotifers: Are Chemical and Biological Methods Used to Overcome Activated Sludge Bulking Mutually Exclusive?

“…The most interesting result was the signifi cant interaction between temperature and the concentration of Al-salts on the 12 th day of experiment. At 20°C, the chemicals were more toxic to the rotifers than at lower temperatures, and the effect was more distinct for AlCl 3 (Fig. 1A, B).…”

“…The EC50 (the effective concentration caused 50% mortality in mg dm -3 ) was calculated from a log-linear model [13]. After the EC50 was determined, we measured effects of low concentrations of AlCl 3 and Al 2 (SO 4 ) 3 on the rotifer reproduction and population growth rate. Single individuals of Lk1 or Lk3 strains (age <1 day) were transferred into separate wells, and 1 ml of 0.0005 or 0.005 mg dm -3 of Al-salt solutions with molasses were added.…”

“…Next, the effects of the experimental treatments on particular variables measured in low-concentration experiment were tested. These variables included the following separately for AlCl 3 and Al 2 (SO 4 ) 3 on each day of the experiment: the number of alive rotifers, the number of eggs, the mortality rate and the internal growth rate (r). All statistical analyses were conducted using Statgraphics Centurion XVI.…”

“…The addition of fl occulants improves the settlement characteristics of the sludge. On the other hand, fl occulants could also increase the production of excessive sludge [1,2] or could interfere with nitrifi cation process [2]; the disadvantage of chemical methods is also high cost and aluminium toxicity to non-target organisms [3]. Soddell Seviour [4] mentioned some attempts of using different microorganisms, among them ciliates, bacteria or even commercially available bacteria mixture, to control foaming.…”

“…The aim of presented study was to assess the toxic effects of aluminium chloride, AlCl 3 , and aluminium sulphate, Al 2 (SO 4 ) 3 , fl occulants typically used to overcome the bulking problem, on themonogonont rotifer, Lecaneinermis. The experiments presented here comprised of testing the toxicity of Al-salts to L. Inermis at three temperatures (8, 15 and 20°C) that refl ect the annual temperature distribution in the majority of municipal wastewater treatment plants in the temperate climate zone.…”