Ozone-On-Demand™ Reduces Water Treatment Cost By 20%

Pinnacle Ozone Solutions’ new generation of smart Ozone-On-Demand (OOD™) generator and control technology can help significantly reduce the cost and complexity of ozone water treatment. By precisely matching ozone production to real-time demand, the North Burleigh Water Treatment Plant (WTP) near Bismarck, North Dakota increased treatment capacity by 64% while simultaneously reducing unitoperating cost by over 20%. The results clearly demonstrate that newer, more efficient ozone generation and controls technologies are ideally suited for small to medium treatment plants, especially those using membranes.

Since its construction in early 2005, the North Burleigh Water Treatment Plant near Bismarck, North Dakota has used ozone in both its pre-treatment and disinfection process steps. Although many treatment plants experience seasonal variations in raw water quality, the conditions at the Burleigh site are especially challenging. Because the plant draws raw water from a series of angle wells drilled beneath the Missouri River, even slight changes in river water level or quality influence the incoming mix of surface and groundwater. Especially challenging are concentrations of dissolved iron (Fe), manganese (Mn), and dissolved organic carbon (DOC) can often reach 5.0 mg/l, 0.8 mg/l, and 3.4 mg/l, respectively, and can fluctuate by more than 30% throughout any give  day.

To improve treatment, the Burleigh plant uses ozone for both pre-treatment and disinfection. However, managing ozone demand and production was a real challenge. To compensate, the plant often ran its older air-based ozone system at 100% capacity and then dosed 10-15 mg/l of sodium bisulfite to prevent damage to the downstream microfiltration – reverse osmosis (MF-RO) membranes. While effective, this process was difficult to manage, inefficient, and costly to operate.