For wastewater treatment plant owners, the full value of effective design, control and operation of environmental technology results from in-depth understanding of process behaviour. Process models which mathematically describe processes are powerful tools which increase and consolidate process knowledge.

Many environmental technology systems rely on (bio)chemical and microbial processes which are highly complex. Their behaviour is often difficult to predict. Plant operation is influenced by variations in waste composition, the composition of the groups of micro-organisms which constitute the treatment process and their activities. Physical and chemical processes are also influenced by climatic and other conditions.

A good model will yield a close match between a simulation and observations on working plants. Waste Solutions has successfully created models for a number of processes involving treatment of wastewater and solid waste and has many of the internationally recognised modelling packages. The models are used for design of new plants and to investigate what-if scenarios for the operation of existing plants.

Some process models can also be used to operate plants by encoding the model into software. The software is then integrated with process control systems to supervise the automatic operation of treatment plants.