A selective approach for multiple wastewater recovery is nowadays desirable and technologically feasible, to provide water at specific quality standards for each reuse objective. This “fit-for-purpose” approach to water reuse could both save water and would reduce production cost and energy demand by eliminating unnecessary treatment and long-range conveyance, as it typically aims at local reuses. The appropriate choice of technologies for such approaches is perhaps the most critical planning and design decision when evaluating systems for implementation or refurbishing. This article examines wastewater reuse goals (direct potable use, indirect potable use, non-potable uses and industrial uses) and related requirements as relevant case studies, and issues that may arise during implementation. It then proposes an overview of current conventional and advanced technologies and their possible combination to meet foreseen uses under a multiple barrier treatment (MBT) approach, which implies a sequence of complementary processes at an increasing level of protection for both conventional and emerging pollutants according to reuse goals.

如今，选择一种用于多种废水回收的方法是合乎需要的，并且在技术上可行，以便为每个再利用目标提供特定质量标准的水。这种“适合目的”的水再利用方法可以省水，并且通过消除不必要的处理和远程运输（通常针对本地再利用），可以降低生产成本和能源需求。当评估用于实施或翻新的系统时，为此类方法选择合适的技术可能是最关键的规划和设计决策。本文研究了废水再利用的目标（直接饮用水用途，间接饮用水用途，非饮用水用途和工业用途）和相关需求作为相关案例研究，以及在实施过程中可能出现的问题。