Aeration control on a nitrifying biofilter system by using on-line analyzers

Abstract

Two new ways of controlling the aeration in nitrifying biofilters, by measuring on-line dissolved oxygen and ammonia concentration in the effluent of the filter, are compared to the standard control using time tables with constant air flow. Both on pilot and large scale, the new process control concepts proved to be very efficient in optimizing operation costs for aeration (up to 70% during rainy days) and to guarantee a demanded effluent quality.

Biological Fixed Film Systems

“…Biofilms were grown at 0.1, 0.2, and 0.6 meters below the surface in a dairy farm waste stabilization pond in an effort to improve nitrification rates before release of Effluent quality was improved and operating costs were lowered in pilot and large scale nitrifying biofilters using new aeration process controls (Puznava et al, 2000).…”

Aeration control for simultaneous nitrification-denitrification in a biological aerated filter using internal model approach

“…A reduction of up to 50% with respect to the quantity of air injected can be achieved (Puznava et al, 1999). However, without appropriate control and instrumentation, the control of the air flow rate for good and stable process performance remains difficult (Puznava et al, 2000). This is closely linked to the non-linearity of the biological system and to the fact that the overall system is characterised by an important time delay.…”