An integrated “process modelling-life cycle assessment” tool for the assessment and design of water treatment processes

PurposeThe application of Life Cycle Assessment (LCA) to the design of water treatment plants is hampered by: (1) a large diversity of unit processes, (2) the high variability of the operation conditions in relation with the water quality input, and (3) the range of possible technical solutions to fulfil the treatment needs. For a consistent prospective assessment, the LCA should be based on the simulated functioning of the unit processes rather than on average data, as it is most often the case when no real data are available. Here, a novel, integrated and flexible process modelling-life cycle assessment (PM-LCA) tool for design and LCA of water treatment technologies is presented.MethodsThe tool (EVALEAU) was developed in Umberto® (v5.5) using the Python language for code scripting. A library of unit process (UP) modules was built. Each module is a detailed and highly parameterized model of a specific water treatment process, which is further linked with the software PHREEQC® for water chemistry calculation. Input data are: water composition, design, operation parameters, including literature or user-defined values. The modules are linked to Ecoinvent datasets (v2.2) for background processes. By combining the modules, water treatment chains can be designed and evaluated in Umberto® with a high level of detail and specifications. A sensitivity analysis toolbox (Morris method) was included for the identification of the process parameters mainly affecting the impact results.Results and discussionThe tool was successfully applied to the test bed case of an existing drinking water plant located in the Paris region. The conventional LCA results, based on average recorded data, were compared with the results obtained using the PM-LCA tool. Modelling results for technical parameters were also compared with data collected on site. An overall good agreement between simulations and real data was obtained, proving the relevance of the developed tool. Sensitivity analysis indicated that ozone production and transfer into water are the main technological parameters influencing climate change (taken as example since it is of high interest for stakeholders), which have therefore to be fine-tuned.ConclusionsThe EVALEAU tool successfully solves the challenge of linking LCA results to the related engineering design choices, from the assessment and eco-design perspectives. The concepts and methodologies embedded within the tool provide the user with complementary views of the designed system, in terms of potable water quality, design and operation parameters and environmental impacts generated over its life cycle.

[1]  Gerald Rebitzer,et al.  IMPACT 2002+: A new life cycle impact assessment methodology , 2003 .

[2]  J. G. Petrie,et al.  Life cycle assessment applied to process design: Environmental and economic analysis and optimization of a nitric acid plant , 1996 .

[3]  D. L. Parkhurst,et al.  User's guide to PHREEQC (Version 2)-a computer program for speciation, batch-reaction, one-dimensional transport, and inverse geochemical calculations , 1999 .

[4]  Ligia Tiruta-Barna,et al.  Cost-performance indicator for comparative environmental assessment of water treatment plants. , 2013, The Science of the total environment.

[5]  Gregory J. McRae,et al.  Integrating Life Cycle Analysis ( LCA ) with Process Modeling , 2004 .

[6]  Andrea Saltelli,et al.  An effective screening design for sensitivity analysis of large models , 2007, Environ. Model. Softw..

[7]  Manuele Margni,et al.  IMPACT 2002+: User Guide , 2015 .

[8]  Faisal Khan,et al.  GreenPro: a new methodology for cleaner and greener process design , 2001 .

[9]  Réjean Samson,et al.  Optimal greenhouse gas emissions in NGCC plants integrating life cycle assessment , 2012 .

[10]  P. Hiemstra,et al.  Environmental impact assessment of groundwater treatment with nanofiltration , 1997 .

[11]  Luis M. Serra,et al.  Life Cycle Assessment of Water Production Technologies - Part 1: Life Cycle Assessment of Different Commercial Desalination Technologies (MSF, MED, RO) (9 pp) , 2005 .

[12]  Adisa Azapagic,et al.  A Methodology for Integrating Sustainability Considerations into Process Design , 2006 .

[13]  Gonzalo Guillén-Gosálbez,et al.  Life cycle assessment coupled with process simulation under uncertainty for reduced environmental impact: application to phosphoric acid production , 2008 .

[14]  Konrad Hungerbühler,et al.  Decision framework for chemical process design including different stages of environmental, health, and safety assessment , 2008 .

[15]  Adisa Azapagic,et al.  The application of life cycle assessment to process optimisation , 1999 .

[16]  E. Friedrich,et al.  Life-cycle assessment as an environmental management tool in the production of potable water. , 2002, Water science and technology : a journal of the International Association on Water Pollution Research.

[17]  Jean-Pierre Birat,et al.  Physicochemical modelling of the classical steelmaking route for life cycle inventory analysis , 2010 .

[18]  David L. Parkhurst,et al.  USER'S GUIDE TO PHREEQC A COMPUTER PROGRAM FOR SPECIATION, REACTION-PATH, ADVECTIVE-TRANSPORT, AND INVERSE GEOCHEMICAL CALCULATIONS , 1995 .

[19]  Max D. Morris,et al.  Factorial sampling plans for preliminary computational experiments , 1991 .

[20]  François Maréchal,et al.  LCA tool for the environmental evaluation of potable water production , 2008 .