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111/39
Slow sand filters consist of uniform beds of sand generally from one
to three feet deep through \vhich secondary treatment effluent is passed
aot 1mV' hydraulic rates. Since these filters are not equipped \vi th backwash
facilities, cleaning them entails drainage and partial drying of
the bed for the manual removal of the filter cake and the top few inches
of the sand into \vhich the solids have penetratede This requi res periodic
replacement of the sand thus removed.
These filters are characterized by simple construction, large space requirements,
and relatively high costs of operation and maintenance.
They are subject to freezing in cold \veather and to rapid clogging \vhen
receiving occasional high solids loads. Although the slow sand filter
is vlell established for water treatment applications, due to the problems
noted above the process has not been used widely for waste treatment
and performance data are meager. It -is estimated that BOD and
suspended solids removals from a secondary effluent would be in the
ranges of 30 to 50 percent and 50 to 80 percent, respectively, while
the filter r~mains in operation.
Rapid sand filters, as the name implies, are loaded at much greater
hydraulic rates than are slow sand filters. Consequently, they require
m~ch less space for a given volume of \vaste,,7ater, but have considerably
shorter filter runs. The filters consist of sand beds
generally from one to three feet deep and are equipped with backwash
facilities for cleaning. They may be designed for either gravity or
pressure operation.
Object Description
| Title | Master plan for sewers (pt. 3) |
| Alternative Title | Water pollution control plant |
| Contributor |
Henry B. Steeg & Associates Fort Wayne (Ind.). Board of Public Works |
| Topic | Public Utilities |
| Subject | Sewage disposal--Indiana--Fort Wayne |
| Geographical Coverage | Fort Wayne, Indiana |
| Date of Original | January 1972 |
| Time Period | 1900-1999 |
| Source | Print version: Master plan for sewers. Pt. 3: Water pollution control plant. (Indianapolis, Ind.: Henry B. Steeg & Associates, 1972), 1 v. |
| Additional Availability | Print version might be available at IPFW Helmke Library. See online catalog. |
| Relation | Third of three parts of Master plan for sewer. Pt. 1, Relief sewers, digital barcode is 30000126499916; Pt. 2, Sanitary sewers, digital barcode is 30000126499924; |
| Rights | Copyright Indiana University-Purdue University Fort Wayne, 2006- . All rights reserved. May not be reproduced without permission. For information regarding reproduction and use see: http://cdm16776.contentdm.oclc.org/cdm/about/collection/p16776coll1/ |
| Date Digitally Created | April 17 2012 |
| Digital Publisher | Walter E. Helmke Library, Indiana University-Purdue University Fort Wayne |
| Digitization Specifications | This pdf file was derived from 400 dpi, 1-bit, uncompressed TIFF images that were scanned from the originals using a Fujitsu 5750C scanner with Adobe Acrobat 9.0 Professional scanning software, black and white configuration. |
| Content Type | Text |
| Digital Format | text/pdf |
| Collection | Fort Wayne Area Government Information |
| Identifier | 30000126499932 |
| File Name | 30000126499932.pdf |
Description
| Title | Page 120 |
| Transcript | 111/39 Slow sand filters consist of uniform beds of sand generally from one to three feet deep through \vhich secondary treatment effluent is passed aot 1mV' hydraulic rates. Since these filters are not equipped \vi th backwash facilities, cleaning them entails drainage and partial drying of the bed for the manual removal of the filter cake and the top few inches of the sand into \vhich the solids have penetratede This requi res periodic replacement of the sand thus removed. These filters are characterized by simple construction, large space requirements, and relatively high costs of operation and maintenance. They are subject to freezing in cold \veather and to rapid clogging \vhen receiving occasional high solids loads. Although the slow sand filter is vlell established for water treatment applications, due to the problems noted above the process has not been used widely for waste treatment and performance data are meager. It -is estimated that BOD and suspended solids removals from a secondary effluent would be in the ranges of 30 to 50 percent and 50 to 80 percent, respectively, while the filter r~mains in operation. Rapid sand filters, as the name implies, are loaded at much greater hydraulic rates than are slow sand filters. Consequently, they require m~ch less space for a given volume of \vaste,,7ater, but have considerably shorter filter runs. The filters consist of sand beds generally from one to three feet deep and are equipped with backwash facilities for cleaning. They may be designed for either gravity or pressure operation. |
