AbstractsMathematics

A wide variety of trace organic compounds (TOrCs) used in pharmaceuticals, personal care products and food additives discharged to sewerage collection systems and treated by wastewater treatment plants in the United States. Within the past few years, concerns have increased regarding their potential effects on human and environmental health despite their low concentrations. Several mathematical models and evaluation tools have been developed to predict TOrC concentrations in wastewater treatment plant effluents and aquatic receiving environments, but few have focused on sludge digestion and final biosolids concentrations. Thus, objective of this study was to develop a new mathematical model for predicting TOrC concentrations in sludge digestion. The newly developed model was then incorporated into the existing ASTREAT model, which simulates TOrC removal in conventional activated sludge treatment. The model algorithm was programmed in C++ and the interface was developed in Excel using Visual Basic. An available dataset consisting of several TOrCs were used in the model development process. Results showed the digestion model predictions to be within an acceptable range compared to actual measurements. Due to inherent fluctuations of the input parameters, sensitivity and uncertainty analysis were performed for the model. This assessment identified the most sensitive parameters for accurate model predictions and supported the model as a successful assessment and evaluation tool. Due to the object oriented program structure, the current model can easily be modified for specific wastewater treatment plant configurations following a similar approach.