Process Optimization of a Petroleum Refinery Wastewater Treatment Facility Using Process Modeling and Site Specific Biokinetic Constants

摘要

In this project, an old, out-of-service secondary clarifier was converted to a Complete Mix BatchrnReactor (CMBR) and was designed to provide maximum deployment flexibility so that it couldrnbe operated in a number of modes. Simulation analysis with the MantisIW model in GPS-XTMrnwas used to determine the optimal number of batch runs to treat a high strength COD andrninhibitory waste stream to meet predefined effluent criteria for discharge to the Activated SludgernUnit (ASU). The CMBR was also deployed in another instance as an isolated sidestreamrnchemostat reactor to treat a large quantity of floating free oil that was released to the wastewaterrntreatment plant. Simulation analysis of the chemostat reactor was used to determine the optimalrnincubation period for the microbes to consume the free oil under aerobic conditions. A total ofrnfour CMBR batches were required to consume the high levels of free oil. After 24 hoursrnimmediately following the first CMBR effluent blend with the oxidation ditch influent, thernclarifier effluent oil and grease levels were consistently below 15 mg/L. After an MCRT processrncontrol strategy had been effectively implemented at the WWTP, a full-scale Lawrence andrnMcCarty (1970) model field biokinetic study was executed to determine the site-specificrnbiokinetic constants of the existing wastewater treatment facility. The site-specific biokineticrnconstants were determined by fitting the operating data as a function of the microbial growth raternusing statistical regression analysis. For the first time since it began operation, the true organicrnloading capacity of the existing facility was conclusively quantified. The calibrated GPS-XTMrnmodel utilizing the site-specific biokinetic constants is a fully predictive model that can be usedrnto analyze and optimize the wastewater treatment facility operations and accurately predict thernplant performance under hypothetical operating conditions.