An expert system for selecting and sequencing wastewater treatment processes

Wastewater treatment system design involves selecting and sequencing various treatment processes. The design becomes complicated when a large number of processes and various contaminants are considered. In this work, an expert system is developed to find an appropriate treatment process design for a given waste stream. The knowledge base of the system is established with a treatability database to select suitable treatment techniques for specified contaminants and concentration levels. Also, a preliminary fuzzy logic based approach is proposed to express the user's preference of treatment techniques in a linguistic form. The preference is defined on the basis of the treatment efficiency and the cost of a technique. The system is intended to serve as a decision support tool for a designer to determine optimal treatment process sequences for various contaminants at different concentration levels. Finally, the developed system is demonstrated in a case study for a chemical processing waste stream.