Method and Knowledge-Based System for Diagnosis in Biological Wastewater Treatment, 1999 Environmental Conference Proceedings

Amy C. Lo & Stanley R. Megraw

Domtar Innovation

A method and knowledge-based system to generate a holistic health index for diagnosis and decision support in the operational management of biological wastewater treatment processes has been developed for detecting early symptoms of microbial illness. It measures four general categories of parameters in an operating biological treatment plant that includes floc structure, floc activity, floc nutrient and floc settleability. These measurements are compared to benchmark values in a database to generate a comparison value. A holistic health index of the operating microbial population is then derived from the comparison values to provide an evaluation of the operational management of the biological treatment process. Based on such an evaluation, the operating parameters may be adjusted to maintain wastewater treatment at an optimum level. The system has been applied in more than 85 case studies with 3 activated sludge processes and 3 aerated lagoons since 1995 to test its validity as a successful diagnostic tool and performance indicator. Discrepancies between model outputs and operational reality were investigated and used as learning feedback to modify the scoring algorithms. A software program based on the holistic health model is under development.