Task Group on

The use of water quality and process models for minimizing wastewater utility greenhouse gas footprints

Task group on “The use of water quality and process models for minimizing wastewater utility greenhouse gas footprints” is a newly established group. Two things are remarkable about this TG. Firstly, it is a jointly formed task group by several specialist groups: Sustainability SG, Nutrient Removal SG, Systems Analysis and Integrated Assessment SG, Instrumentation, Control and Automation SG, Urban Drainage SG, Microbial Ecology and Water Engineering SG. This is obviously related to the multiple angles from which the problem can be approached (system understanding, system modeling, process sustainability) and the different scales (treatment plant, sewer, integrated urban water system) that can be considered to define the problem boundaries. Secondly, since the matter is one of the major future challenges of the next generation in the water business, YWPs are involved as key individuals, in close collaboration with the aforementioned specialist groups. These YWPS are also leading the TG under the guidance of the more seasoned members. This approach can help maintain continuity in effective leadership throughout the various IWA groups.

The final objectives of the Task Group are twofold:
a. 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.)
b. 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 can be 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; multi-criteria optimization strategy development, including modeling and ICA for minimizing N20, CH4, and indirect GHG emissions, as well as for maximizing CH4 production in anerobic 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.

The kick-off meeting of the TG is planned at the WWTmod2010 seminar which will be held at the end of March in Quebec City (Canada). At that seminar there will also be a workshop dedicated to the topic. Possible TG activities and meetings are planned at LET2010, WWC2010 and WEFTEC2010. More information concerning these will be made available soon on the TG website which will be announced through IWA.

If you are interested and think you can contribute to the objectives of the TG, please don’t hesitate to contact the group Chair and co-chair.

Jose Porro, Malcolm Pirnie (USA), JPorro@PIRNIE.COM
Ingmar Nopens, BIOMATH, Ghent University (Belgium), Ingmar.Nopens@UGent.be

Core group composition

Aside from the Chair and Co-Chair of the task group, there are several other key individuals who are within the core group:

• Model development and research nitrogen GHG:/Kartik Chandran (Columbia University, USA) and Marlies Kampschreur (TU Delft, Netherlands)
• Model development and research methane: Zhiguo Yuan (University of Queensland, Australia) and Jing Liu (Bioprocess Control, Sweden)
• Plant-wide modelling and Benchmarking: Ingmar Nopens (Ghent University, Belgium) and Andrew Shaw (Black and Veatch, USA)
• Validation and research gaps identification: Bernhard Wett (ARA Consult, Austria) and Sudhir Murthy (DCWASA, USA)
• Facilitating PhD: Jose Porro (Malcolm Pirnie, USA)

A more extended list of professionals, either active in the field of GHG emissions from WWTPs and sewers, or capable of applying key knowledge to this field form the second tier of the TG. This list is currently being compiled and will be finalized in the early stages of the TG.