Laserfiche WebLink
Performance of Packed Bed Filters <br /> Terry R. Bounds, Eric S. Ball, and Harold L. Ball' <br /> Introduction <br /> Packed bed filters (PBFs) incorporating naturally occurring treatment media such as sand and gravel <br /> have been used successfully for treating small to medium volume wastewater flows for decades. These <br /> filters—commonly called sand filters--produce high duality effluent that is superior to that discharged <br /> by the majority of our nation's municipal treatment facilities. There are two types of packed bed sand <br /> filters commonly used today the single-pass (or intermittent) filter and the recirculating filter. A <br /> typical single pass intermittent sand filter system is shown in Figure 1 below. <br /> Figure I: Single Pass Sand Filter(ISF) <br /> Intermittent sand filters are capable of treating septic tank effluent to advanced wastewater treatment <br /> levels or better. The following effluent characteristics are typical averages: <br /> CBODS: 5 mg/I <br /> TSS: 5 mg/1 <br /> NO,-n: 30 mg/l <br /> Intermittent filters are typically-used in onsite applications for single-family homes or small offices. <br /> They are most successful when the influent has been pretreated and screened in the septic tank to <br /> sufficiently ensure that the effluent characteristics applied to the sand filter do not exceed the following <br /> criteria shown in Table 1: <br /> 'Authors are Executive Vice President, Vice President of Product Development, and President respectively, Orenco Systems, <br /> Inc.,Sutherlin,Oregon. <br /> NTP-FLT-TRB-ESB-HLB-1 <br /> zM <br /> Page 1 <br />