Reverse osmosis (RO) and nanofiltration membrane technologies have been used effectively for water treatment in a number of applications. The cost of using RO for applications such as desalination is mostly lower than using more expensive distillation techniques and it is also simple and modular to operate.

Scott J. Bury and colleagues, The Dow Chemical Company, Midland, MI, USA, focus on the design of optimized RO-based water treatment systems with spiral wound membranes. They use a mathematical programming-based approach to predict a minimum capital and operating cost RO membrane network that is able to meet both product demand and quality requirements of customers. This overcomes the limitations of simulation-based software tools like ROSA (RO system analysis) and CADIX (computer-assisted design for ion exchange) which are industry standards for design assistance.

The new approach is highly useful for identifying minimum cost robust designs for membrane-based water purification systems, which are especially important in desalination applications.

• Optimal Design of Reverse Osmosis-Based Water Treatment Systems,
  Ramkumar Karuppiah, Scott J. Bury, Adriana Vazquez, Gregg Poppe,
  AIChE J. 2012.
  DOI 10.1002/aic.13880