MEMBRANES FOR UNRESTRICTED WATER REUSE

摘要

Water reuse is becoming a key component of the water cycle management.The provision of sufficient and safe water supplies for human and environmental needs is a difficult challenge in many parts of the world, especially in arid regions. In order to manage water resources in an efficient and sustainable way, a wide range of tools and techniques are required. Water recycling and reuse is an increasingly important element of sustainable water management strategies in both water poor and water rich regions. Municipal wastewater, which comprises between 60-80% of municipal water consumption, is one of the most reliable sources of water, since municipal water supply is always of high priority. If treated properly, it can replace potable water and used for unrestricted irrigation, including edible crops. Membrane separation processes such as ultrafiltration (UF) and microfiltration (MF) hold the key to better water treatment as tertiary filtration, after existing biological treatment. Careful evaluation of engineering aspects of these filtration technologies will yield design and operation parameters for applications in Europe. A few case studies will be presented. Economic analysis was carried out, for a system that produces a net effluent capacity of 25,000m~3/day, resulted in a total cost of 8-10 cent per cubic meter. Recently, Membrane Bioreactor Systems (MBR) are becoming an attractive alternative, especially for limited space constrains, taking into advantage their smaller footprint, as compared to conventional wastewater systems. Also, the higher qualities of their effluent, with SDI values lower than 3, indicate the suitability of the process for pre-treatment for desalination by Reverse Osmosis, for effluents with high salinity. The concept of Integrated Membrane Systems (IMS) will be elaborated, and case studies will be described.