Case study: Urban wastewater treatment plant with saline intrusions

Abstract

In this chapter the performance of a wastewater treatment plant (WWTP) treating wastewater with saline content due to seawater intrusions is evaluated. Aspects regarding the effects on the removal efficiency and performance of the different processes are considered as well as the solutions put into practice for the different drawbacks associated with the salt presence. In particular, the increase of reagents needed in the physical-chemical processes, the production of H 2 S due to anaerobic biological processes and the decrease of biomass activity will be evaluated. Two case studies are assessed based on the salinity of the wastewater treated (3,000 and 7,000 µS/cm) in a WWTP installed on the Mediterranean coast of Spain. For both case studies, two possible scenarios are analysed: the direct discharge of the effluent to the sea or its reuse for agriculture irrigation.