A Canadian chemical plant collects rainwater run-offs into a stormwater pond, which is then transferred to the facility waste treatment plant for processing. The high ambient temperatures and stagnant conditions caused algae growth at the surface of the pond, which led to recurrent plugging of the pump screens.
The algae growth caused the transfer pumps to lose suction and had the potential to damage the pumps. The frequent pump issues prevented the smooth operation of the stormwater pond and hindered the wastewater treatment. Failure to transfer the collected water to the waste treatment plant could cause an environmental concern due to the potential for overflow and loss of containment.
Veolia, in discussion with the site operations team, looked at various options to reduce or eliminate the algal bloom in the stormwater pond.
Mechanical removal was not a practical option due to the complex and costly work involved. Veolia's proprietary product Spectrus CT1300, a high- efficiency quaternary ammonium salt-based biocide, was proposed for the treatment of the stormwater pond based on previous experience treating similar systems successfully. The Spectrus CT1300 treatment was initiated by feeding a daily dose of the product at a mixing inlet, and within only a few days, the algae bloom on the pond was reduced significantly as seen in Figure 2.
Resultado
The control of algae prevented further pumping issues, stabilizing the wastewater treatment operation. It also helped to reduce odors, control environmental risk on the surrounding water bodies and improve the aesthetics of the site. The total savings based on maintenance cost avoidance was estimated at CAD$75,000.