Skip to main content


Buy Article:

$9.50 plus tax (Refund Policy)

Or sign up for a free trial

Solids generated in wastewater treatment typically involves separation of a portion of the water from the treated liquid solids mixture, followed by treatment, or disposal, of the resulting cake. These options include Landfill, Drying and Pelletizing, or Incineration. Each of these have costs associated with the quality and quantity of the material being processed. In addition, Drying and Incineration systems achieve better efficiency when processing a consistent, steady-state feed. A thermal process optimization system should generate feedback signals allow for optimization of fuel consumption, solids throughput, and emissions standards.

Automated control and optimization of the unit processes upstream of a thermal system is a valuable tool for making unit processes more efficient, thus reducing O&M costs.

Mass flow unit processes, including thickening and dewatering, have proven difficult to effectively control due to the non-linear nature of the process variables. This meant, when using control systems based on PID control, operators had to frequently re-enter FIXED set points, in order to maintain process control or continually make manual adjustments to accommodate for changing conditions. Fortunately, in recent years, algorithms have been developed which create DYNAMIC set points. The use of dynamic set points allows the optimization process to be automated which in turn allows greater control in producing a consistent feed product to a downstream thermal process.

This paper will focus on the Automation of process control and optimization of the thickening and dewatering process in order to produce the optimum product to the downstream thermal process. The optimization and control includes parameters such as dryness of cake and/or feed rate.

The author has been providing comprehensive control systems for numerous wastewater thermal processes since 1988. He provided a SCADA mass flow control system for a new furnace and centrifuge at the Hatfield WWTP in 1991. In the mid 1990s he furnished a control system upgrade for the Fitchburg WWTP. Equipment included a wet ESP, and a multiple venturi scrubber. In 1998 he was chosen as a controls consultant for the WERF 98-REM-3 project on dewatering automation. Two of the four test sites had Fluid Bed and Multiple Hearth furnaces.

The effective results for the recommended thermal control process include reduced fuel cost, consistent throughput, better emissions and reduced Operator attendance.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
No Metrics

Document Type: Research Article

Publication date: 01 January 2003

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
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