ABSTRACT
Hybrid processes of pressure retarded osmosis-membrane distillation (PRO-MD) have been presented for the unique advantages of (1) lower operation costs for desalination, (2) higher water recovery, (3) less membrane fouling, and (4) minimal negative environmental impacts. Based on current proposals reported in the literature and pilot studies, two types of PRO-MD process configuration, namely, close-loop and open-loop, are classified and subsequently discussed in detail. In addition, the general design and operation guidance of the membrane components within a PRO-MD hybrid process are provided. Special considerations catering for the modeling of hybrid processes are also highlighted followed by a brief economic analysis and future perspectives.
