Performance evaluation of a full-scale ABS resin manufacturing wastewater treatment plant: a case study in Tabriz Petrochemical Complex

Background: The measurement data regarding the influent and effluent of wastewater treatment plant (WWTP) provides a general overview, demonstrating an overall performance of WWTP. Nevertheless,these data do not provide the suitable operational information for the optimization of individual unitsinvolved in a WWTP. A full-scale evolution of WWTP was carried out in this study via a reconciled data.Methods: A full-scale evolution of acrylonitrile, butadiene and styrene (ABS) resin manufacturingWWTP was carried out. Data reconciliation technique was employed to fulfil the mass conservation law and also enhance the accuracy of the flow measurements. Daily average values from long-termmeasurements by the WWTP library along with the results of four sampling runs, were utilized for data reconciliation with further performance evaluation and characterization of WWTP.Results: The full-scale evaluation, based on balanced data showed that removal efficiency based on chemical oxygen demand (COD) and biochemical oxygen demand (BOD5) through the WWTP were80% and 90%, respectively, from which only 28% of COD and 20% of BOD5 removal had occurred in biological reactor. In addition, the removal efficiency of styrene and acrylonitrile, throughout the plant,was approximately 90%. Estimation results employing Toxchem model showed that 43% of acrylonitrile and 85% of styrene were emitted into the atmosphere above water surfaces.Conclusion: It can be concluded that the volatilization of styrene and acrylonitrile is the main mechanism for their removal along with corresponded COD elimination from the WWTP