Ballast Water Treatment on Alaskan Coastline

An Alaskan oil terminal had to deal with contaminated ballast water that needed to be collected and treated before discharge. They had a biological treatment process on site, but it was difficult to operate in the temperature and contaminant loading extremes the site experiences and they struggled to get it to work consistently. The plant is also required to treat spring snowmelt and rain that falls within the site boundaries, creating extremes of liquid temperatures and contaminant concentrations. QED ran through many different scenarios using our on-line air stripper performance model. Optimization of the various conditions led the site to select four of the largest 1000 gallon per minute E-Z Tray® (U.S. Patent Number 5,518,668) units. Additionally, QED added a custom seventh stage to the units for additional capacity.

Alaskan Ballast Water Treatment Overview

• VOC treatment of tanker ballast water.
• Air Strippers replaced an aging activated sludge treatment process that was unable to handle changes in flow and concentration.
• Process string includes free-phase removal and air treatment.
• Pilot testing used prior to design.