Analysis of Techniques for Evaluating and Optimizing Existing Full-Scale Wastewater Treatment Plants

This paper presents an analysis of techniques applied to the evaluation and optimization of nearly 40 full-scale wastewater treatment plants. The techniques evaluated included oxygen transfer analysis by off-gas and hydrogen peroxide techniques, clarifier analysis by stress testing and hydraulic analysis, on-line monitoring, and reactor tracer testing. The results indicate that the process performance of full-scale wastewater treatment units can be measured using these techniques. Advantages exist for off-gas testing when applied to the analysis of low to moderate turbulence diffused air systems. Hydrogen peroxide analysis can be applied to essentially all oxygen transfer systems. Stress testing can be used to quantify the treatment capability of clarifier units; hydraulic analysis can then be used to identify clarifier upgrade opportunities and to quantify the impact of any modifications implemented. On-line monitoring is the most powerful technique tested. It has been used successfully to optimize and improve full-scale treatment plants. Reactor tracer testing can be used to identify upgrade opportunities for full-scale units.