Biological treatment of urban wastewater at the Beniel WWTP (Murcia)

This article outlines the methodology and results of a study carried out at the Beniel WWTP (Murcia). The study analysed the treatment of real wastewater using a mixed system that combines a unit of reactors with sludge supported on a biomedia of polyvinyl alcohol (PVA) spheres and an activated sludge reactor acting as the refining stage of the process. This treatment enables the biological removal of nitrogen as well as simultaneously resulting in lower sludge production than an activated sludge system. It also enables a reduction in the reactor volumes required. The study analysed system efficiency for the removal of COD, SS, total N and total P, as well as excess sludge production. The system achieved good treatment performance, with specific excess sludge production being significantly lower than the WWTP reference value.
One of the most significant WWTP operating costs is related to the management of sludge generated in the treatment process. This sludge typically undergoes a costly mechanical dewatering process to reduce volume and also has associated transport and management costs, whether it is used for agricultural purposes or goes to landfill. For this reason, research into treatment processes that enable lower sludge production at source is of vital importance to more cost effective management of treatment plants.

Moreover, current environmental legislation sets out discharge limits on nitrogen and phosphorus for WWTP effluent. Therefore, new treatment systems must be capable of removing these elements.

Pedro J. Simón Andreu, Technical Director ESAMUR
Carlos Lardín Mifsut, Technical Director of Operations ESAMUR
Miguel Ángel Martínez Muro, Technical Director URDEMASA-RED CONTROL consortium
Juan Antonio Vicente González, Head of Operations URDEMASA-RED CONTROL consortium
Claudia Llosá Llácer, Plant Manager Beniel WWTP URDEMASA-RED CONTROL consortium
Lucas Benac Vegas, Technical Dept. WWTP Control RED CONTROL

Article published in: FuturENVIRO June 2013