Determination of Urea and Ammonia Influent Limits to Sequencing Batch Reactor (SBR) Using Wastewater Plant Simulator in a Chemical Fertilizer Plant

An industrial wastewater treatment plant at a petrochemical facility in Sabah, Malaysia, was modeled using wastewater treatment plant simulation software. The simulation was initiated to establish contaminant limits in the influent, specifically for urea and ammonia. Additionally, it aimed to optimize molasses injection for sequencing batch reactor (SBR) operation, ensuring the treatment facility’s resilience against plant upsets. The simulation study utilized BioWin Process Simulator 6.2, where a base-case model representing the SBR system was developed and calibrated using actual data to match actual operations. The simulations revealed that the system is able to raise the concentration limits for urea and ammonia treatment to 300 mg/L and 75 mg/L, respectively, by gradually increasing them in the influent. The existing system shows a low denitrification rate, evident from the comparatively high nitrate concentration in the treated effluent. Improving the denitrification process is possible by increasing molasses injection into the SBR to provide a sufficient carbon source.