CRITERIA FOR MICROBIOLOGICAL AND CHEMICAL QUALITY OF WATER REUSE IN DIFFERENT SYSTEMS OF REGENERATION IN REAL SCALE

The main objective of this project is to determine the criteria for microbiological and chemical quality more appropriate for different regeneration systems of treated water to an actual scale, to ensure the sanitary quality according to the uses. In order to do this, it is proposed to analyze the following parameters: 1) bacterial and viral indicators, 2) pathogens (enteroviruses, protozoa and helminth eggs), 3) physical-chemical parameters (COD, AOX, MES, turbidity, residual chlorine) and 4) byproducts of water disinfection (trihalomethanes, acids, haloacetic and derivatives). The research was performed in 4 regeneration systems of actual scale, wich obtained effluent is currently reused for irrigation. The four facilities are: 1) the wastewater treatment plant (WWTP) of Platja de Aro (with a regeneration system consisting of a rapid sand filtration followed by disinfection combined with ultraviolet light and chlorine), 2) Blanes WWTP (with a full regeneration system consisting of the process of coagulation, flocculation, sedimentation, filtration and disinfection combined with ultraviolet light and chlorine), 3) Empuriabrava WWTP (with a regeneration system using wetlands with surface flow) and 4) the WWTP Castelló de Empuries (with a system consisting of a lagooning). The effectiveness of these systems and the quality of reclaimed water obtained will be analyzed over two years by 8 sampling campaigns on a quarterly basis. Each campaign will take punctual samples of influent and effluent for seven consecutive days, from each of the unit processes that comprise the facility. Over the next 6 months, it will be comparatively assessed the physical and chemical quality of reclaimed water, obtained after the regeneration treatment, in order to demonstrate its relationship with the detection of microorganisms (bacterial indicators and pathogenic virus). In addition, the concentrations of the byproducts of water disinfection (trihalomethanes and derivatives) that are generated in the chlorination, as there is currently concern about their carcinogenic, hepatotoxic, or reproductive harm potential. The results of this project will allow an initial assessment of the health risk of reusing treated water with real and reliable data of the sanitary quality (physical-chemical and microbiological) of reclaimed water in our country.