Task Groups & Working Groups

Table of Contents

Tasks Groups
Working Groups
Finished Tasks Groups

Task Group on Design Operation Uncertainty (DOUT)

The goal of the IWA task group is to summarise the work that has already been done on the topic of uncertainty evaluation in wastewater treatment and identify gaps in available methods or knowledge. It will build on the knowledge already acquired by certain key efforts in the wastewater field. In addition, the project intends to incorporate work done in related fields such as water resources management. The study intends to bring together the collective knowledge of engineers, academics and plant owners, from several countries and continents.

The goals of the group can be summarised as follows:

  1. Propose a common language for communicating on the subject.
  2. Propose a comprehensive list of the sources of uncertainty.
  3. Document and evaluate existing methods for assessing and evaluating uncertainty (quantitative and qualitative).
  4. Incorporate knowledge from other fields (water resources, atmospheric science, nuclear industry, etc.) on applications of uncertainty evaluation methodologies.
  5. Identify gaps in current knowledge. Define the developments required to provide adequate tools to implement uncertainty evaluations in projects.

Task Group on Greenhouse Gas Emission (GHG)

Use of modelling for minimising wastewater utility greenhouse gas footprints. The final objectives of the Task Group are twofold:

  1. Understand the processes that are responsible for the major contributions to GHG emissions from WWTP and sewer systems (e.g. heterotrophic denitrification, autotrophic nitrification, autotrophic denitrification, methanogenesis, etc.)
  2. Translate this knowledge into mathematical models that can be embedded in system/plant-wide models allowing multi-criteria optimisation

In order to achieve this, the following sub-objectives are embedded in a strategic overall approach to tackle the problem:

  1. Determine state-of-the-art, key players and ongoing projects in all scientific areas below; research gap identification: use existing facilitating channels like the Global Water Research Coalition (GWRC) as a means of coordination of research outputs from ongoing work, and providing research needs for future work
  2. Basic research nitrogen GHGs: build consensus on process mechanisms (preferably assisted by process modeling) and GHG yields under different conditions
  3. Model development nitrogen GHGs: translate research knowledge into mathematical models and embed them in ASM; design experiments needed for calibration of  the additional model parameters; note that this needs close interaction with basic research (perhaps working through GWRC)
  4. Basic research methane: quantify methane emissions in sewers and those fractions introduced into the WWTP via the sewer and digester reject water; quantify methane stripping in biological reactors
  5. Model development methane: embed knowledge into ASM and hydraulic network models; design experiments needed for model calibration; note that this needs close interaction with basic research
  6. Full-scale monitoring: what can be measured with which accuracy; identify cases for detailed GHG measurement campaigns
  7. Plant-wide model – Benchmarking: full-scale model integration and calibration; multicriteria optimisation strategy development, including modeling and ICA for minimising N20, CH4, and indirect GHG emissions, as well as for maximising CH4 production in anaerobic digestion; testing of control strategies using a benchmark
    approach extending the efforts of the current TG on Benchmarking of control strategies; and guidance on coupling with existing LCA tools

Task Group on Physical Chemical Modelling (P&C)

The task group was established to enhance our understanding and representation of physicochemical processes. These reactions occur naturally in aquatic environments, without the need for a microbial mediator. They are commonly used across the water industry cycle. Important examples include the use of alum for coagulation and phosphorous removal, unintentional scaling, gas transfer, and acid-base reactions. While an enormous amount of effort has been expended in developing and applying biological process models, models of physicochemical reactions are generally rudimentary and empirical. This greatly limits our ability to effectively manipulate and utilise these processes. In fact, the fundamentals are reasonably well known, but have not been systematically assessed in the water and wastewater area. The task group will develop a physicochemical framework with high predictive capacity that is usable across the range of unit operations by both modelers and end-users.

The task group composition is currently being finalised, but includes representatives from Europe, Asia, Africa, and the USA, and is well represented by both industrial practitioners and academics.

Task Group on Membrane Bioreactor Modelling and Control (MBR_MC)

Several models for MBR-based systems have been presented in the literature in order to explain the peculiarities of these systems. Despite the efforts performed in MBR modelling, this topic is not fully matured yet and need further work. There is not a consensus regarding the use of a “standard” and well established mathematical model able to describe also the fouling phenomena.
The main motivation for the initiation of the Membrane Bioreactor Modelling and Control Task Group (TG) is to lead the research community towards standardised criteria to model MBR systems. The final objectives of the TG are threefold:

  • Propose standardised criteria to integrate biological, filtration and energy models for modelling of MBR-based systems
  • Set-up a database that can be used for plant-wide modelling, control and optimisation of MBR-based systems.
  • Propose guidelines to apply appropriate models to be used for different purposes, such as: academic research, environmental and economic sustainability assessment, and control and multi-criteria optimisation of MBR systems.

The Task Group is also related to the activities of the IWA Specialist Group: Instrumentation, Control and Automation (ICA).

Working Group on Life Cycle Assessment (LCA)

The Working Group for Life Cycle Assessment of Water and Wastewater Treatment (LCA-Water WG) will facilitate the exchange of ideas, and develop consensual methodologies, to promote better use of LCA in the urban water systems.

Working Group on Modelling Integrated Urban Water Systems (MIUWS)

The interest of the WG comprises the integration of models of all components of the water cycle in urban areas, including the waste, nutrients and energy cycles for the various operational processes as they relate to the water cycle. The main focus lies on model and software integration issues, e.g. on how to solve integration problems and how to exploit integration opportunities. Modelling is in this context mostly intended for decision support, not for process understanding.

The main aims of the WG are to promote the exchange of ideas and experiences regarding the use and development of tools and methods for MIUWS, and to build a network of experts in the field. Collaboration will be sought with other IWA groups focused on closely related topics, e.g. urban drainage, LCA, etc. and with WEF committees (e.g. Collection Systems).

Working Group on Computational Fluid Dynamics (CFD)

The main aims of the WG are to:

  1. promote the exchange of ideas and experiences regarding the use of Computational Fluid Dynamics in the field of water and wastewater treatment and
  2. build a network of experts in the field.

Working Group on Good Modelling Practice (GMP)

The scope of the Good Modelling Practice (GMP) Working Group (WG) is to continue the work of the former IWA GMP TG in promoting the use of numerical modelling of wastewater treatment plants in general and of activated sludge plants in particular. The GMP WG is the platform for promoting GMP in the long-term perspective.
The objectives of the GMP WG are

  • To organise and run courses on Modelling Activated Sludge Plants (in conjunction to IWA conferences) to promote “Good Modelling Practice” (see IWA STR No.22),
  • to disseminate the content of the GMP STR to the field

Based on the objectives, the tasks and responsibilities of the GMP WG are
1. Courses on Modelling Activated Sludge Plants
2. Initiate and support a follow-up IWA Task Group on the topic of “Good Modelling Practice”

Task Group on Benchmarking of control strategies for wastewater treatment plants (BSM)

The goal of the Task Group was to promote the use of the benchmark simulation protocols (BSM1, BSM1_LT and BSM2) and produce a Scientific and Technical Report (as part of IWA Publishing’s series). In the mid-90s, the IWA Task Group on Respirometry began the work on the development of a simulation-based protocol (a ‘simulation benchmark’) that would be used for the objective comparison and evaluation of wastewater treatment plant control strategies. The main reason for initiating this work was the discovery that over the years numerous WWTP control strategies had been proposed in the literature, however, the literature did not provide a clear basis for comparison of these strategies because of the many confounding influences that have an impact on the systems.

The ‘benchmark protocol’, is defined in terms of a comprehensive description of
a standardised simulation and evaluation procedure including plant layout, simulation models and model parameters, a detailed description of disturbances to be applied during testing and evaluation criteria for testing the relative effectiveness of simulated control and monitoring strategies. The success of the BSMs in terms of publications (already more than 500) and the large number of research groups world-wide requesting access to the tools are strong indications of the need for this research.

The Scientific and Technical Report (STR) was published in 2014 and the 15 associated Technical Reports are currently being polished and thereby the efforts of the BSM Task Group are finished. In addition, the software is being ‘polished’. Matlab versions of BSM1 and BSM2 are available for free download and also an updated version of the ADM1 including ionic strength, activity and ion pairing (contact Ulf Jeppsson).
An associated tool – the influent wastewater generator model (Matlab) – is also freely available (contact Dr Krist V. Gernaey). A preliminary software version of an extended BSM2 including a catchment model and sewer system model (published in Environmental Modelling and Software, volume 78, pp. 16-30) is also available. However, as there are so many ongoing activities and development related to the BSM framework and its extensions (greenhouse gas emissions, micro-pollutants and illicit drugs, physico-chemical activity, pH, precipitation, phosphorus, sulphur, inclusion of sewer and receiving water quality models, resource recovery) it is our intent to set up another ‘umbrella’ for organising the BSM efforts by all the different research groups involved. At a workshop at the WWC2014 in Lisbon, Portugal there was consensus on the need for creating an IWA Working Group on “Benchmarking of control and monitoring strategies for urban wastewater systems”. Support for such an initiative has been granted by both the ICA and the MIA specialist groups.