The Toxic Effect of Conventional Treated Mine Water on Aquatic Organisms

The present paper aims to evaluate the toxic effects generated by conventional treated mine water as well as freshwater samples (Macris river) on primary producers (green algae, Selenastrum capricornutum) and primary consumers (planktonic crustaceans, Daphnia magna). Those organisms could be very realiable biological models to assess the toxic effect of mine waters on the environment. The green algae growth inhibition test (performed according to OECD201) and the acute immobilization test of freshwater crustaceans (Daphnia magna) (performed according to OECD 202) showed no growth inhibition or Daphnia magna immobilization / mortality during 72h and 48h incubation in presence of surface water samples from Macris river. The aqueous system with 1.89 g/L sulphate ion (SO42-) concentration, containing treated mine water mixed with freshwater sample (ratio 2.4:1), generated 100% toxic effect on crustaceans (Daphnia magna) after 48h incubation.

Toxicity of coke wastewater treated with advanced oxidation by Fenton process supported by ultrasonic field

The aim of the presented study was to determine the toxicity of wastewater from the production of coke. The wastewater was treated with advanced oxidation involving ultrasonic field with Fenton’s reagent (the amplitude was 61.5 μm and sonication time 8 min). Two doses of iron and four doses of hydrogen peroxide were used. The amount of hydrogen peroxide was proportional to the value of the chemical oxygen demand of raw wastewater, ranging from COD/H2O2 ratio of 1:2.5 to 1:20. Two tests were used to determine the toxicity (algae growth inhibition test and Lepidium test). It was found that more toxic to algae was wastewater treated by Fenton’s reagent containing a higher dose of iron. A similar inhibitory effect was observed on the germination of cress seeds.