PROJECT DESCRIPTION
BACKGROUND
Water Resource Recovery Facilities (WRRFs) are essential for achieving the objectives of the Water Framework Directive but they also represent a significant source of three greenhouse gases (GHGs): carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). Direct emissions come from the biological processes taking place within WRRFs while indirect emissions are associated with the energy produced outside the WRRF and imported to supply treatment units. Aeration of the biological tanks is known to be responsible for 50-60% of the total energy consumption on average and can reach up to 80% of the total energy demand in biological WRRFs, accounting for most of the indirect emissions of GHGs from these facilities. According to Eurostat data, wastewater treatment is still inadequate, especially in southeast European countries. Pollutant loads treated in aerobic plants in Europe are predicted to continuously increase in the coming years. This brings increasing energy requirements and the need for sustainable solutions for wastewater treatment. Therefore, the carbon footprint of WRRFs needs to be significantly reduced by optimising treatment steps and lowering energy requirements.
OBJECTIVES
LIFE LESSWATT aimed to target both the environmental issues related to the energy consumption of WRRFs and their direct GHG emissions. The project aimed to develop an innovative tool for assessing and minimising both direct and indirect contributions of aerated compartments in WRRFs to the facility’s overall carbon footprint. This tool incorporates two innovative elements: the LESSDRONE, an automated, wireless and self-moving device for monitoring Oxygen Transfer Efficiency (OTE) and GHG emissions under normal operating conditions; and a model-based user-friendly tool (protocol) for converting complex information into concrete actions aimed at minimising the carbon footprint.The tool’s effectiveness would be demonstrated and validated in the WRRFs of tannery CUOIODEPUR and in five other plants, three in Italy and two in the Netherlands.
The LIFE LESSDRONE tool would also facilitate the implementation of EU and national environmental policies by:
- Effectively evaluating the impact of new climate-related environmental policies;
- Making the implementation of environmental policies less costly;
- Facilitating compliance with the European regulation establishing a European Pollutant Release and Transfer Register; and
- Providing widely applicable guidelines for European WRRFs located in climatically similar regions, identifying the best equilibrium between OTE and GHG emissions.
RESULTS
The LIFE LESSWATT project team developed an innovative wireless tool for assessing and minimising energy consumption, and reducing both direct and indirect greenhouse gas (GHG) emissions, in water resource recovery facilities (WRRFs).
The tool combines two innovative elements: i) the LESSDRONE, an automated, wireless, self-propelled drone for monitoring Oxygen Transfer Efficiency (OTE) and greenhouse gas (GHG) emissions; and ii) a user-friendly protocol, which uses the measurements taken by the drone to model the plant and define concrete actions (e.g. maintenance of the blowers, amount of air insufflation, and strategies to mitigate the impact of the GHG emitted). The project team demonstrated the tool's effectiveness and validated its operation in the WRRFs of the Italian tannery Cuoiodepur and in five other plants, three in Italy and two in the Netherlands. Questionnaires and networking activities also enabled the collection of information from additional companies and interest groups, to help fine-tune the tool for different types of plant, thus contributing to its transferability and commercialisation.
A number of environmental benefits (both direct and indirect) were confirmed: an increase in aeration efficiency from 10% to 30% for WRRFs; a reduction in the range of 10-30% of indirect GHG emissions linked to aeration; and a substantial reduction of costs for water services and energy consumption. The beneficiaries recorded large energy saving (ca. 10.5 GWh/year) by project end. This was supported by monitoring of electricity consumption, carried out within the six pilot WRRFs over periods ranging from weeks to more than 1 year. The project team also recorded large reductions in the GHGs emitted by aerated tanks, namely carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), and also for PM10 emissions.
By decreasing energy consumption, the tool also delivers significant cost saving for water services. This should ensure the continuation and replication of the project’s approach. Indeed, by project end, seven further WRRFs had signed an agreement for using the project's drone and associated protocol, and further business activities are envisaged thanks to a solid business plan.
The tool serves as an effective means to help WRRFs measure (and thus respect) emissions ceilings, therefore helping them implement EU policies in which emission limits are set, particularly for methane, carbon dioxide and nitrous oxides.
The project team engaged with regulatory bodies in Italy (i.e. Ministry for Environmental Transition, Tuscan Regional Government), water service regulatory and control bodies (ARERA, AIT), and major research institutes in the sector (ENEA). This facilitated the possibility of introducing incentives aimed at reducing energy consumption and GHG emissions, and the use of carbon credits to combat pollution and foster sustainable development. The project also prepared a report for the IPCC bureau to consider the prototype as a candidate BAT, in line with the JRC Reference Report on Monitoring of Emissions to Air and Water from IED Installations.
Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).
