2.3. Biodegradation test
The method for biodegradability determination was established
according to ‘‘Water Quality – Evaluation in an Aqueous Medium of
the Aerobic Biodegradability of Organic Compounds’’ (ISO 7827-
1984; Qin et al., 2006). Biodegradation cultures were prepared in
1 L shaking flasks. The composition of medium used was as follows
(in g L1 distilled water): ammonium chloride (3.0), potassium
hydrogen phosphate (1.0), magnesium sulfate (0.25), potassium
chloride (0.25), ferrous sulfate (0.002), and yeast extract (0.3). With
pH of about 7.4. The test compounds were added to the culture
medium to give a concentration of 30 mg L1. Each medium
(0.5 L) was inoculated with 5 mL of activated sludge with