Textul licitației

atural organic matter (NOM) removal method when purifying cold surface water. Membrane performance and water quality is compared to that of a clarification and sand filtration. Purchased UF process will be preceded by a separate chemical dozing and flocculation unit to ensure effective NOM removal and membrane applicability in variable conditions. Different precipitation chemicals will be used, but the choice of chemicals and applied dose can be discussed with membrane supplier. In principle, the UF unit would be built in one of the existing sand filter pairs: one of the filters will be used for chemical dozing and flocculation, while the other one is reserved for UF units. Plant block flow diagram is shown in a following picture and sand filters are pointed with a green square. The main targets in piloting are: - Adequate NOM removal - Act as an effective microbial barrier - Stable turbidity level in permeate from membrane filtration HSY have completed several laboratory scale tests for different UF processes, and the Client has decided to perform a full scale UF pilot based on ceramic submerged membrane filtration. Produced permeate from the ceramic UF unit will be further processed in Pitkäkoski WTP prior to distribution to customers. Pilot process lifetime is expected to be at least 50 years and membranes are assumed to be