Characterization and Biological Treatment of O-Nitrobenzaldehyde Manufacturing Wastewater

O-nitrobenzaldehyde (ONBA) manufacturing wastewater not only contains significant amount of oil-like substance, but also high salinity, total nitrogen (TN) content and concentration of dissolved organics resulting in high COD load. Oil-like substance could be removed from the wastewater by physical methods. However, dissolved COD compounds and TN could only be removed by biological or chemical treatments. Effluent from physical treatment stage was characterized. After characterization and nutrient balancing of the wastewater, an activated sludge unit was used in laboratory to investigate the effects of major process variables, such as sludge age (SRT) and hydraulic residence time (HRT), on performance of the system. The optimal 86% of COD and 40.9% of TN removal efficiencies were obtained at a SRT of 16 days and HRT of 12 hours. By using the experimental data, kinetic coefficients were determined and design equations were developed.