Monitoring of the biological activity in activated sludge treatment plant: analyzer for PH/DO-STAT automation

The possibility to conduct the continuous monitoring of the bacteria activity in a waste water treatment plant, can become a useful instrument for the activated sludge process management. The treatment efficiency trend, in terms of substrates removal rate and estimation of toxicity of the influent waste (for toxic waste addition, highly concentrated discharge, etc.), guarantees the punctual monitoring of biomass, allows to indicate the real-time events that could affect the biological processes efficiency and allows the activation of appropriate corrective actions. This paper describes the experimentation conducted by automated titrator TITAAN (TITration Automatic ANalyser) that is able to carry out a continuous monitoring of bacteria in biological treatment plants for civil and industrial wastewater. The experimentation was conducted at the waste water treatment plant of Imola Santerno (75.000 EA), which also treats an amount of leachate from Tre Monti di Imola landfill site. The titrator was implemented with analytical procedures that automate the well-known and consolidated pH/DO-stat titration. In this first step of experimentation, in according to a daily and weekly scheduling, the results obtained automatically, allowed the monitoring of the nitrification activity inside the biological reactor. Shortly, it will also be possible to monitor any inhibition events of the influent wastewater. The tests were performed on effluent biomass samples from two biological oxidation reactors. During the 3 months in the winter period of experimentation, a considerable amount of information was collected and analyzed. This enabled the verification of the robustness and reliability of the application.