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SUEZ Environnement’s Densadeg XRC™ is a high throughput water clarification unit capable of removing total suspended solids (TSS) with the aid of a high density ballast material. The ballast material is separated from the waste solids through a hydrocyclone and recycled into the system. Separation is inefficient and the unit experiences loss of ballast at 7 to 14 lbs per million gallons of treated water through the overflow of the hydrocyclone. Currently, ballast must be added at the loss rate to maintain the proper concentration to remove TSS. This requires that water treatment plants must provide storage space for ballast material, manpower to add the ballast, and a method to measure ballast concentration. To recover ballast material, a scale model of the overflow of the hydrocyclone was constructed and an angled pipe was added to settle the ballast into a collection sump. The effects of angle and linear flow velocity in the settling pipe were tested in a Design of Experiment (DOE) analysis to determine the critical process parameters. The maximum linear velocity in the settling pipe to settle ballast was also determined and used as the design criteria for the pilot scale. The results of this study will provide a basis for engineers from SUEZ to begin a long-term study of the economic impacts of using this ballast recovery method. Success in this project will allow SUEZ to provide this solution as an addition to the existing and future Densadeg XRC™ units.

Publication Date



Chemical and life science engineering, Water treatment, ballast recovery, DOE, hydrocyclone


Chemical Engineering | Engineering

Faculty Advisor/Mentor

Dr. B. Frank Gupton

Faculty Advisor/Mentor

Rudy Krack

Faculty Advisor/Mentor

Temple Ballard

VCU Capstone Design Expo Posters


© The Author(s)

Date of Submission

August 2016

Improved Ballast Recovery in Water Treatment