WET at petrochemical facilities has been attributed, to emulsified hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), amines, phenols and inorganic materials. The case study presented focuses on toxiciry attributed to PAHs associated with fine particles. Activated sludge treatment, secondary clarification and tertiary filtration were ineffective at removing the pollutants. As a result, chronic toxicity to fathead minnows (Pimephales promelas) was observed, and treatment modifications were implemented to meet WET regulatory requirements.
Application of PAC to remove organic material from wastewater is a relatively proven technology in the textile, pulp & paper, pharmaceutical, chemical, and petrochemical industries. PAC was selected because of its ability to reliability attenuate toxic organic material in an existing bio-treater. There is limited published information on application of the technology; therefore, benchmarking against otheT facilities and lessons learned by wastewater operators were heavily relied upon to design and implement the project.
The time from concept to operation was approximately seven months and effectively doubled the facility's treatment capacity. The modified treatment plant has reliably met WET requirements for approximately two years. Information presented should benefit petrochemical owners, industrial wastewater operators, and consultants that are preparing facilities for crude slate changes and modifications to upstream petroleum processing units.