Ten key research issues for integrated and sustainable wastewater reuse in the Middle East.

Wastewater management is not limited to the technology used to collect and treat wastewater. It begins with the early planning phase of building a society and includes considerations of how that society will grow. Therefore, history, culture, religion, and socioeconomy are important components to include in any relevant and integrated studies of wastewater management and reuse. Engineering, health, chemistry, biology, food production, cultural heritage, and the needs of people of all ages should be considered together when making management decisions regarding issues so intimately tied with humanity as water and sanitation. Other escalating challenges such as poverty, food, and water scarcity, migration and instability, flooding and catastrophes, diseases and mortality, etc. should also be considered as part of wastewater management and reuse planning. Emerging contaminants could be associated with the urbanization, modernization, and industrialization of several countries. Several arid countries have developed water security strategies where wastewater reuse is a major component. The existing wastewater treatment technologies in these countries are, in most cases, unable to remove such contaminants which may affect irrigation waters, industrial products, groundwater, etc. People would have to accept that the food on their tables could be irrigated with treated wastewater that they generated a few months ago, even if very advanced technologies were used to treat it. The purpose of this review is to highlight multidisciplinary areas of research on wastewater and to propose applicable and affordable mechanisms by which we may consider wastewater as a legitimate resource.