| Summary: |
This paper presents results of a study on successful treatment of a toxic industrial (coke) wastewater, using Se-quential Batch Reactor (SBR) technology. The wastewater contained a high nitrogen load (NH3-N = 640 mg L-1, total Kjeldahl nitrogen (TKN) = 760 mg L-1) as well as phenols, thiocyanate, cyanide and arsenic. The removal of NH3-N, TKN and phenols was about 100%. Concentrations of soluble chemical oxygen demand (SCOD), thiocyanate, cyanide and arsenic were reduced by 92.5, 99.2, 98.8 and 89.9%, respectively. The desired discharge limit of NH3-N <1 mg L-1 was achieved.Monitoring the DO profile during the fill and react phases was used to optimize (HRT and temperature) the SBR operation. The selected conditions were applied to ob-serve the biomass response to an induced upset, which simulated a malfunction of the pH adjustment system. It has been demonstrated that changes in the DO profile during fill and react phases allow detecting pre-upset conditions, indicating a potential problem in the treatment system. Monitoring the DO profile during the SBR treatment of wastewater is proposed as a convenient and inexpensive method, providing useful information about the biomass activity and warning about upset conditions. |