Sensitivity of green and blue-green algae to methyl tert-butyl ether

The toxicity of methyl tert-butyl ether (MTBE) to Chlorella ellipsoidea and Aphanizomenon flos-aquae was tested and assessed for a 15-d incubation with concentrations of MTBE from high (2.00×10⁴ mg/L) to low (2 mg/L). The results showed that the toxicity was low when the concentration of MTBE was in the range 1.00×10⁴?2.00×10⁴ mg/L (the greatest inhibition of growth-rate was 70%–71%, occurred during the day 1–5). Low concentrations (2–500 mg/L) stimulated algal growth up to the greatest effect of 85%–200% when the concentration of MTBE was 50–100 mg/L during day 3–5. The toxicity of MTBE (72–120 h EC₅₀) was 6.65×10³–9.58×10³ mg/L for C. ellipsoidea and that is 1.14×10⁴–2.00×10⁴ mg/L for A. floc-aquae. We found that the toxicity and ecological risk of MTBE for the algal community structure were low and the toxicity was influenced by the duration time of the test.