ABSTRACT
The removal of pollutants or the recovery of valuable molecules with low molecular weight is a current challenge in wastewater treatment. Membrane processes are, as of now, considered to be a viable option to solve these issues. In terms of separation in membranes, the rejection of organic matter and water permeability are two fundamental, coupled aspects to optimize. In general, an increase in the former comes at the expense of the latter; in fact, a high level of rejection is often a cause of membrane fouling, which in turn dramatically reduces water permeability. Thus, membrane fouling constitutes one of the major drawbacks in membrane separation processes, which, unfortunately, is intrinsically connected to the rejection of solutes. In addition to these challenges, two other related aspects have to be considered to obtain efficient membranes for water purification: resistance and lifetime, related to chemical, biological or mechanical degradation, swelling or embrittlement.
