Toxicity analysis of coke wastewater treated in a rotating biological contactor and a membrane bioreactor

Abstract

To investigate the effectiveness of a rotating biological contactor (RBC) and a two-stage membrane bioreactor (MBR) for the treatment of coke wastewater, samples were collected three times (Batches I, II, III) from the “Jadwiga” coke plant in Zabrze, Poland at two-week intervals. The wastewater was then diluted with tap water (1:3 ratio, wastewater: tap water) and then treated at retention times of 4.1 days (RBC) and 7 days (MBR). For phytotoxicity and genotoxicity tests, the wastewater was sampled from various points in the treatment systems and further diluted to produce a range of concentrations. In the phytotoxicity tests (growth inhibition), Lemna minor and Vicia faba were used. A low concentration of wastewater (6.25%) often stimulated growth. © UNIVERSITY OF WARMIA AND MAZURY IN OLSZTYN ABBREVIATIONS CA chromosome aberration EC50 half maximal effective concentration Embr effluent, after wastewater treatment in MBR Erbc effluent, after wastewater treatment in RBC Fmbr flow between two units of MBR reactor INF influent, wastewater after preliminary treatment, diluted four times with tap water before biological treatment MBR two-stage membrane bioreactor