Water reuse as a secure pathway to deal with water scarcity

摘要

An adequate access to water supply systems is crucial for a sustainable future. Climate change is expected to increase water shortage problems worldwide. Reuse/recycling of treated wastewater for domestic and/or agricultural purposes can be considered an interesting water supply: it is independent from seasonal drought and meteorological variability and able to cover the peak of water demand. In the case of direct reuse, the parameter of treated water must comply with the reuse limits for biological oxygen demand, chemical oxygen demand and suspended solids. In case of indirect reuse, the regulatory approach changes as the dilution ratio between discharge and flow of the irrigation canal is taken into account too. There are many interventions that are considered useful for the purpose of promoting the development of an enhanced water recovery and recycling: legislation improvements, modification in the water storage management, prevention in pollution discharged into sewerage systems, improving the efficiency of WWTPs, incentive the adoption of rainwater storage tanks and interventions for the separation of gray water, establish a “blue certificate” for financing investments. In the present paper those aspects are analysed referring to some cases found in an Italian region.