The role of membrane processes in municipal wastewater reclamation and reuse

Wastewater reuse presents a promising solution to the growing pressure on water resources. However, wastewater reuse implementation faces obstacles that include insufficient public acceptance, technical, economic and hygienic risks and further uncertainties caused by a lack of awareness, accepted standards, uniform guidelines and legislation. So far, there are no supra-national regulations on water reuse in Europe and further development is slowed by lack of widely accepted standards, e.g. in terms of required water quality, treatment technology and distribution system design and operation. Treatment technology encompasses a vast number of options and membrane processes are regarded as key elements of advanced wastewater reclamation and reuse schemes and are included in a number of prominent schemes world-wide, e.g. for artificial groundwater recharge, indirect potable reuse as well as for industrial process water production. For dual reticulation purposes in urban areas two types of systems have been built, a centralised type of treatment with dual membrane processes, including e.g. microfiltration (MF) and reverse osmosis (RO), and small scale systems using membrane bioreactors. This paper will provide an overview of the status of membranes processes in wastewater reclamation and reuse world-wide and will depict their potential role in promoting more sustainable water use patterns.