Question: What is driving the trend toward increased water reuse and how is membrane technology addressing this? Furthermore, what does the future hold for water reuse?
Answer: Meeting water demands and ensuring a plentiful supply of water for future generations is a top-of-mind issue for the water industry today. Adequate, safe and accessible water supplies are essential to sustaining life and economic development. Improving access to clean water benefits human health and industry, and as such, every effort should be made to achieve a water quality that is as safe as possible. Water reuse is one way to increase access to clean water, and it is becoming increasingly important around the world.
Membrane technology enables the treatment of wastewater for further beneficial use and several trends are driving the use and development of membrane technology for water reuse. First, the availability and affordability of freshwater are influenced by the natural environment and climate, contamination of freshwater and the increasing price of freshwater. Second, growing populations, urbanization, higher living standards and expansion of water-intensive industries are causing local imbalances between water supply and demand. These imbalances lead to increased demand for municipal and industrial wastewater treatment. Finally, at the system level, the fact that membrane bioreactor technology produces high-quality water in water reuse applications is driving demand and further development of ultrafiltration membranes.
Nanofiltration and reverse osmosis are two types of membrane technologies used for residual and trace contaminant removal of reclaimed water. In recent years, emerging organic pollutants have been a focus in water treatment. Emerging organic pollutants are chemicals used in everyday life that enter the environment either through point-of-source contamination or environmental discharge of wastewater that is not fully treated. Emerging organic pollutants of particular interest include endocrine disruptors, human and animal antibiotics, disinfection byproducts, pesticides, insecticides, herbicides and various pharmaceutical drugs. The challenge is to reduce these pollutants and prevent their presence in drinking water, and membrane technology is an important part of meeting that challenge.
Efficient and affordable water reuse will help solve global water shortages, and to this end, innovation in membrane technology will continue. The future holds further developments in ultrafiltration, nanofiltration, reserve osmosis and related technologies that will support cleaner, safer and more plentiful supplies of water across the globe.
Peter Aerts is a senior research specialist at Dow Water & Process Solutions (Midland, Mich.; www.dow.com) and the global application development leader for wastewater and water reuse applications.