Tertiary Wastewater Treatment using Ultrafiltration

Each year our demand fresh water continues to increase and the market for water re-use technology has grown steadily. In response to this demand, Pure Aqua, Inc. has developed a standard product line of packaged Ultrafiltration (UF) membrane systems. The systems are added to existing (secondary) domestic wastewater treatment plants; UF provides tertiary treatment, providing high quality water for re-use applications like irrigation or cooling water. Furthermore, the high quality water may be used to feed reverse osmosis systems for process water requirements. Water re-use limits demand on existing desalination plants which operate at 500-900 PSI (35 – 62 bar) while UF runs at approximately 35 PSI (2.5 bar); the energy savings are clear.

UF is a pressure driven membrane separation process that removes suspended particulate matter from water. In addition, it removes some dissolved compounds with high molecular weight, including organics and colloids. UF membranes efficiently remove bacteria and most viruses present in water. The ability of UF systems to remove bacteria and most viruses makes the technology ideal for tertiary treatment of sewage. The membrane provides an absolute barrier, protecting the public from pathogens. As well, disinfection requirements are greatly reduced as dosing rates of chlorine, UV and/or ozone are much lower since there is essentially no suspended solids left in the filtered water.