Skip to main content

GRIT HANDLING SYSTEM IMPROVEMENTS: A CASE STUDY AT DECATUR, ILLINOIS

Buy Article:

$17.50 plus tax (Refund Policy)

Or sign up for a free trial

Abstract:

The Sanitary District of Decatur owns and operates a 41-mgd (125 peak mgd) wastewater treatment plant. The service area includes a collection system that is partially combined. The wastewater treatment plant includes a headworks facility with catenary mechanical bar screens and Dorr-Oliver “Detritor” grit removal equipment. The headworks area of the plant has been chronically plagued with reliability problems. The District's goal for this project was to improve overall system reliability.

Plugging of the “catenary” screens has been a recurring problem during the fall months, and clogging of the grit pumping systems frequently occurs after significant rainfall events. In addition, the District has experienced maintenance and reliability problems with the headworks equipment. The improvements for this project focused on the grit removal equipment.

A detailed listing of the facility improvements implemented as part of this project is as follows:

Increase “Detritor” rake tip speed from 19 fpm to 38 fpm.


Two new grit washer-classifiers.


Four new variable speed grit pumps.


A new shaft-less screw conveyor for transporting the clean grit into a roll-off container.


All new grit slurry piping was added. The grit piping's interior surfaces were custom-coated with abrasion-resistant KanigenĀ® coating used to help withstand the deteriorating effects of pumping abrasive grit from the wastewater.


A new flow control vane gate on the headworks' influent channels systems, for uniformly directing the influent grit load to the facility's two grit chambers.


A new screenings handling unit that grinds, washes, and compacts the screenings.


A new masonry grit loading building. The building features included low-maintenance, interior walls that constructed of structural glazed tile that do not require painting.


Additions to the Intellution-based SCADA system to merge the new grit and screenings equipment controls into the existing system.


The improvements noted above have dramatically reduced system downtime and increased reliability.

Document Type: Research Article

DOI: https://doi.org/10.2175/193864705783867620

Publication date: 2005-01-01

More about this publication?
  • Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed.

    A subscription to the Proceedings of the Water Environment Federation includes access to most papers presented at the annual WEF Technical Exhibition and Conference (WEFTEC) and other conferences held since 2000. Subscription access begins 12 months after the event and is valid for 12 months from month of purchase. A subscription to the Proceedings of the Water Environment Federation is included in Water Environment Federation (WEF) membership.

    WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access. Access begins 12 months after the conference or event
  • Subscribe to this Title
  • Membership Information
  • About WEF Proceedings
  • WEFTEC Conference Information
  • Learn about the many other WEF member benefits and join today
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more