Major Papers


STP-EX model, Ionizing chemicals, Wastewater Treatment, STP-EX Model Testing



When new chemicals are created or introduced to the market in countries around the world, most of them require that these chemicals be assessed for their treatability in sewage treatment plants (STPs). In this study, the expanded version of the STP model (the STP-EX model) is tested for its ability to predict the fate of chemicals of concern. The STP-EX model is algebraically simple, robust and is used for screening level assessment. Inputs for the model include the influent wastewater characteristics, chemical properties and the plan operating parameters. The model predicted sludge-water partition coefficient and the biodegradation constant are the 2 uncertain parameters in this study. The process used to estimate these 2 parameters are also elucidated. A group of 16 pharmaceuticals including 8 acidic, 6 basic, and 2 amphoteric are considered in this study. They were run in the model and a sensitivity analysis was conducted to determine what input parameters affect the removal of the chemical from the plant. The results show that the STP-EX model is an advantageous tool for the prediction of the sludge water partition coefficient for ionizing acids and bases.

Primary Advisor

Dr. Rajesh Seth

Program Reader

Dr. Nihar Biswas

Degree Name

Master of Applied Science


Civil and Environmental Engineering

Document Type

Major Research Paper

Convocation Year


Available for download on Monday, July 31, 2023