Synthesis of Industrial Water Networks

A. Pennati, Alberto Quaglia, Rafiqul Gani

Research output: Contribution to conferenceConference abstract for conferenceResearch


Water is a valuable resource of great relevance for industrial activities. As water will become scarcer, optimization of its use is of key importance. The issue of water allocation and reuse through mathematical optimization has been addressed in various literature works [1, 2]. However most of the water networks proposed comprise few contaminants and do not consider critical parameters for wastewater treatment equipment, such as limiting inlet concentrations, flow rates, and other specific design constraints. Thus, these networks are arguably not fit to manage the complexity of a real industrial case (in terms of number of contaminants, number of processing options, design constraints etc.).
In this work, a systematic framework for the formulation and solution of water networks problems is proposed, based on the modification of an earlier work [3]. The optimization problem is formulated as a Mixed Integer Non Linear Programming (MINLP), which is solved to identify the best wastewater treatment process among a set of predefined alternatives, according to selected optimum criteria. The optimum criteria may be minimum operating, capital, or total cost, freshwater consumption, treated water discharge and/or concentration of a selected contaminant. The final design can then be refined through a more detailed model with any appropriate process simulator.
The methodology employed is as follows. First, the sources of wastewater and treatment objectives need to be identified. A superstructure of available technologies is used in order to identify process alternatives. The superstructure is built dividing the treatment operation in tasks to remove the various pollutants and considering process units currently used in industry. Then, the objective function is chosen and the problem is formulated as a MINLP optimization problem, which is solved in GAMS.
In order to demonstrate and highlight the features of the tool, a case study dealing with refinery wastewater purification is presented. A superstructure containing technological alternatives for water purification is built, and the optimization problem is formulated and solved for different scenarios.
With respect to the superstructures presented in literature, the one developed here accommodates a more detailed modeling of the water treatment units and a wider range of contaminants. This makes it flexible for various applications and can be used to provide guideline for the process design of the treatment of different types of wastewater sources.
This approach constitutes a useful and flexible tool to design wastewater treatment systems for new plant or retrofit or expansion of existing plants. The tool also allows for the evaluation of the effect of different scenarios e.g. different optimum criteria, wastewater sources, environmental regulations on water discharge, contaminant loads on purified water to recycle etc.
Original languageEnglish
Publication date2012
Publication statusPublished - 2012
EventANQUE ICCE 2012: Innovation for the future - Sevilla, Spain
Duration: 24 Jun 201227 Jun 2012


ConferenceANQUE ICCE 2012
Internet address

Bibliographical note

Oral presentation.

[1] Galán, B., & Grossmann, I. E. (2011) – Optimal design of real world industrial wastewater treatment networks;
Computer aided chemical engineering, 21st European symposium on computer aided process engineering (pp.1251-1255), Elsevier.
[2] Ponce-Ortega, J., Nápoles-Rivera, F., El-Halwagi, M., & Jiménez-Gutiérrez, A. (2012) – An optimization approach for
the synthesis of recycle and reuse water integration networks; Clean Technologies and Environmental Policy, 14(1), 133-151.
[3] Quaglia, A., Sarup, B., Sin, G., & Gani, R. (2011) – Integrated business and engineering framework for synthesis and design of enterprise-wide processing networks; Computers & Chemical Engineering.


  • Process and systems engineering
  • Water integral management

Cite this

Pennati, A., Quaglia, A., & Gani, R. (2012). Synthesis of Industrial Water Networks. Abstract from ANQUE ICCE 2012, Sevilla, Spain.