Development of dual-layer membranes and recycling of reverse osmosis membrane modules for water treatment

Abstract

Nowadays, water scarcity is a problem that important organizations such as the United Nations (UN) warn about, indicating that only less than two-thirds of the world's population has adequate access to safe and drinking water. Membrane technologies and mainly desalination by reverse osmosis (RO) process, are being applied worldwide as mechanisms to obtain drinking water. However, RO has still some problems that require an immediate solution, such as the treatment and management of the produced brines and wastes caused by discarded RO membrane modules. Other membrane processes of emerging interest such as forward osmosis (FO), pervaporation (PV) or membrane distillation (MD), also need focused efforts for their proper development and subsequent large scale application.The main objective of this PhD thesis is twofold. On one hand, dual-layer polymeric membranes (DLMs) are developed using different membrane preparation techniques in order to improve the performance of membrane separation processes of emerging interest such as PV and MD; and on other hand, attempts are made to recycle discarded RO modules in order to extend the useful life of their components making them suitable for water treatment by other membrane processes, contributing therefore to the circular economy of membrane science and protection of the environment...