D Dusenflo™ Gravity Filter Since 1948, Veolia Water Technologies Canada has developed an expertise second to none in water and wastewater treatment. Among the numerous processes that the company offers to meet various treatment objectives, the Dusenflo™ gravity filter has proven to be an efficient and reliable filtration system. Filtration M Mangaflo™ Mangaflo™ is a manganese and iron removal treatment process of water for human consumption. Filtration O Opus™ The Opus™ technology is a proprietary Optimized Pretreatment and Unique Separation process for desalination of feed water with high concentrations of silica, organics, hardness, heavy metals, boron and particulates. Membrane Filtration - reverse osmosis