Oily Wastewater Recycling Using Membranes

Client: Confidential

Summary

Oilfield brine intrusion into an aquifer threatened the supply of fresh water to a Midwest community and refinery. In response, our team planned and designed one of the largest wastewater reclamation projects for a domestic refinery.

The wastewater reclamation facility has reduced the migration of chlorides toward the community’s fresh water supply, eliminated the need for temporary rental units, and improved cooling and boiler water quality. The refinery’s action has ensured the community and refinery have a sustainable supply of fresh water while meeting the facility’s cooling and steam demands.

The 3,800-gpm unit treats remediation water and water from a local sanitary treatment plant and the refinery wastewater treatment plant. The project included piloting membranes to evaluate scaling, chemical pretreatment options, recovery, flux rates and long-term operational costs. Finished water is used for cooling tower makeup and boiler feed water within the refinery.

A 25,000-square foot building houses most of the wastewater reclamation equipment. The cooling water treatment system has a capacity of approximately 2,300 gpm. Inert and organic compounds are removed using automated strainers, chemical pretreatment, microfiltration, cartridge filtration and nanofiltration. The cooling tower makeup is held in a storage tank and directly fed to refinery cooling towers. The cooling tower makeup water has less than 0.5 mg/L and 50 mg/L of organic carbon and hardness, respectively. The boiler water feed treatment system has a capacity of approximately 1,500 gpm. Suspended solids, organics and dissolved solids are removed using the same technologies employed for cooling water except reverse osmosis is substituted for nanofiltration. The treated water has less than 0.5 mg/L and 2 mg/L of organic carbon and hardness, respectively. The reclaimed water is pumped to the boiler house zeolite filters for polishing ahead of the refinery boilers.

Our team designed and constructed several ancillary systems adjacent to the water reclamation facility. The team constructed chemical storage tanks, chemical feed equipment and water storage tanks outside the main process building. Chemicals used in the water treatment process include: sulfuric acid, biocide, caustic, hypochlorite, bisulfite, anti-scalant and citric acid. The team also constructed a 4,800-square-foot operations building and a 10/11.2 MVA substation adjacent to the reclamation facility. The blast-hardened building services the reclamation facility and nearby refinery units.

Services

  • Front-end planning
  • Detailed design

Features

  • Industrial wastewater reclamation
  • Ultrafiltration (UF)/reverse osmosis (RO) treatment
  • Boiler and cooling water
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