Experimental verification of tertiary treatment process in achieving effluent quality required by wastewater reuse standards

Modern technologies in wastewater treatment can produce high quality effluents, therefore wastewater is now considered a valuable product suitable for reuse. However, water reuse needs to be regulated based on applicable and legally binding guidelines, therefore the lack of a regulatory framework hampers this practice and its benefits. The Czech Republic, as many other countries, has an absent water reuse legislation. In this study, a pilot-scale tertiary treatment was installed at Milevsko Waste Water Treatment Plant (WWTP) in South Bohemia (20,000 P.E.) to demonstrate the effluent quality that can be achieved and evaluate the reuse potential, especially on non-potable applications, such as industry and irrigation. WWTP secondary effluent was treated by three separated technologies: Dissolved Air Flotation (DAF), sand filter and Filtra-lite® filter; followed by ultraviolet (UV) disinfection. Results on water quality were compared to Czech standards for drinking and non-drinking water, and to some international benchmark regulations for water reuse. Our results have led us to initiate the introduction of legislation regulating wastewater reuse in the Czech water management framework.