The Arrigorriaga plant is one of the largest water treatment plants in Spain with a capacity of 7m3/s. Each Aquadiox chlorine dioxide generator has a treatment capacity of 15 kg/h (750 ppd) to supplement two existing systems, each with a treatment capacity of 7.2 kg/h (360 ppd). The systems produce chlorine dioxide on site to oxidise reduced iron, manganese, sulphur compounds and odour-causing organic substances in raw water. Chlorine dioxide also provides residual disinfection preventing bacteria from forming in the plant’s distribution network.
“Water and wastewater treatment plants across Europe have increasingly turned to on-site chlorine dioxide generation for their disinfection needs,” said Enric Cardoner, operations director of Severn Trent Services’ European Water Purification business. Severn Trent has won contracts for these systems from the CABB, including the provision of disinfection systems to treat water from the River Nervion in 2007, the original disinfection system updates to the Venta Alta plant in 2008, and the disinfection system for a water treatment plant in Durango in 2010.