Case Study: Wastewater plant in Como, Italy, upgrades Ozone for significant savings

Reducing energy and maintenance costs, expanding treatment capabilities in the heart of the fabric district

By: Alex Bettinardi, Product Technology Manager, De Nora

The Lariana Depur wastewater treatment plant in Fino Mornasco, Italy, treats wastewater from multiple textile manufacturers in the Como region, known as the heart of the textile industry. Since 1994, ozone has been used effectively as a polisher to remove the dark blue-purple color - the result of the dyes used in the textile dyeing and printing process - from the water. Because the aging ozone system used an old technology that made spare parts difficult and costly to acquire, Lariana Depur put out a bid for a modern ozone system that would be more cost-effective and also meet new discharge standards.  

De Nora supplied a complete package of engineering and equipment for an upgraded ozone system, optimizing the plant for lower specific energy consumption (SEC) and less costly spare parts, a result of innovative technologies including De Nora’s proprietary dielectric design. 

The new ozone system, installed in early 2018, consists of two Capital Controls® DTPF 182XTL-O ozone generators with a liquid oxygen feed system; De Nora ozone destruct units; De Nora power supply units; and redesigned De Nora porous diffusers system to optimize ozone transfer efficiency. Each ozone generator is designed for a maximum capacity of 1,322 lbs/day.  

In addition to removing color from the wastewater, the new system is now addressing additional treatment needs including COD for sludge reduction, surfactants, and disinfection before discharge to the Como River, all at significantly lower energy usage. Later this year, Lariano also plans to work together with De Nora to study the use of ozone to reduce of contaminants of emerging concern.