APPLICATION OF DO PROFILE FOR MONITORING BIOLOGICAL (SBR) TREATMENT OF TOXIC INDUSTRIAL WASTEWATER

摘要

This paper presents results of a study on successful treatment of a toxic industrial (coke) wastewater, using Sequential 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 NH_3-N <1 mg L~(-1) was achieved.rnMonitoring 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 observe 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.