Circular economy of wastewater streams by means of membrane technologies

In this Chapter the circular economy possibilities on membranes used for wastewater treatment processes are exploited. Circular economy in this case can be performed on two different aspects of the same technology: on the product streams and on the membrane modules. The first is performed by valorization of the waste stream, that is the stream separating in the membrane module and that is not considered to be the process one. In most cases, this stream correspond to the concentrate, and in the past was always discharged as a waste. The latter one can be achieved by increasing the longevity of the membrane module and, once exhausted, to think about after life applications. In the past, exhausted membrane modules were seen as a solid waste in line with consumables. Achieving circular economy in membrane technology is therefore not a simple task, and requires proper process design to be achieved.