SR0033424_ENG DESIGNED PLAN - Laserfiche WebLink

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� • `mss 11-5 OTHER PACKED-SED FILTERS 753 TABLE 11-16 Experimental data for standard nonlayered and layered textile filters used to treat typical residential wastewater' Hydraulic Effluent � uali Fecal Type of loading rate, q ' m1 coliform, operation gaVtt2•d BOD GOD TSS MPIW100 mL Standard nonlayered textile filter$ Single pass 5 6.4 54 5 7012 Single pass 10 12.4 110 10 74,000 I Recirculation 15 3.9 20 2.0 200 Layered textile filter(with capillary breaks)' Single pass 30 9 85 22 9920 Recirculation 45 7 36 11 3480 'From Auger(1997),Chenier(1997),and Roy(1997). tAverage influent characteristics over 18 months:BOD = 162 mg/L,COD = 315 mg/L, and TSS = 92 mg/L =Average over 18 months. I 'Average over 6 months. i mittent filter, the nonlayered textile filter can treat up to 10 gal/ft2•d (400 Llm2•d) ' of septic tank effluent. if nonlayered, the reactor:is operated as a recirculating fil- ter; 15 gallftz•d(600 Um2-d)can be applied.Effluent quality meets secondary stan- dards, and some constituents meet or exceed advanced treatment standards (see Table 11-16). A typical installation is shown in Fig. 11-29 (Roy, 1997). Recent developments that take full advantage of the hydraulic properties of the i textile material show that hydraulic loading rates can be increased significantly. On the basis of-the results of experimental studies, an entirely new filter concept was developed in which the filter bed is subdivided in hydraulically independent layers. Each layer affords complete capillary effects, such that a large volume of water is retained 'in the filter between pump cycles. When operated as,a recirculating filter Spray nozzle k i t 60 in diameter fiberglass lid , Air admittance valve Vent Influent Three layers of Effluent � compacted textile media ' Pea gravel ' Slotted underdrain f - FIGURE 11-29 Schematic of textile packed-bed fiber with external pump basin(courtesy Orenco Systems, Inc.).