SPECTRUM MICRO MEDIA FILTER - Eco-Tec

Particle Count /LFiltrate Turbidity (NTU)Filtrate Turbidity (NTU)1,000,000800,000600,000400,000200,0000.350.300.250.200.150.100.05Filtrate Turbidity < 0.1 NTUPurge10 ppm Feed25 ppm Feed0.000.0 1.0 2.0 3.0 401.00.90.80.70.60.50.40.30.20.1Column VolumeFiltrate Particle Size = 1 µm nominal10 ppm FeedFiltrate00 5 10 15Diameter (µm)Filtrate TurbiditySPECTRUMFEED: Suspended Solid = 10 ppmCoagulant Dose = 3 ppmConventional Dual Layer Media Filter(Anthracite/Fine Sand)0.00 5 10 15 20Onstream Volume (CV)Figure 3Figure 4Figure 5Performance ...High quality filtrate...All water sources contain fine particlesthat are typically in the form of colloidalsilt or microorganisms (e.g., algae, bacteria).If not addressed, these solids willfoul downstream reverse osmosis or ionexchange equipment, resulting in poorperformance and an increase in operatingcosts.The Spectrum Micro Media Filter isdesigned to remove these very fine particlesthat would otherwise pass throughother media filters. The filter effectivelyfilters turbid raw waters containing suspendedsolids concentrations of greaterthan 50 ppm to produce a filtrate of lessthan 0.1 NTU, with a particle size of lessthan 1 µm nominal (Figures 3 and 4)and a filtrate silt density index (SDI) ofless than 3.Minimal initial ripening...The Spectrum Micro Media Filter doesnot exhibit the ripening effect typicallyseen with other filters. A drawback ofrapid media filters is the poor qualitywater produced at the beginning of thefilter run. Fine matter passes throughthe filter during the initial period in substantialquantities and for an extendedperiod of time (Figure 5).In order to overcome this problem andprevent the improperly filtered waterfrom going downstream, it has been thepractice to send a large volume of theinitial filtrate to waste. This requirementresults in large amounts of waste waterand poor unit productivity. As shown inFigure 5, the Spectrum Micro MediaFilter produces a filtrate quality of lessthan 0.1 NTU after the purge of only asingle column volume. A conventionalmedia filter requires a purge of 10 columnvolumes or more in order to attainthe same filtrate quality.