Abstract
Drinking water utilities in the Netherlands aim to reduce the CO2 footprint in order to become CO2 neutral in the coming years. A preferred route to achieve this is by reducing the CO2 footprint in the primary drinking water production processes. This can be done by using more sustainable chemicals, recycling residual/waste streams and by modifying the production process, for example by applying central softening.
We recently published a paper in which we demonstrate that central softening in drinking water production leads to a net reduction of the carbon footprint. The full life cycle assessment shows that the detrimental contributions to the carbon footprint, due to the use of chemicals and energy for central softening, are outweighed by the beneficial contributions at the household level, where reduced scaling leads to prolonged lifespan of appliances, reduced energy consumption and reduced use of cleaning agents. We estimate that the net total carbon footprint of drinking water softening in the Netherlands is around -0.11 Mtons CO2 equivalent per year.
Nevertheless, CO2 neutrality cannot be achieved by only focusing on reduced emissions in the primary production processes. Part of the CO2 footprint reduction needs to come from compensation, one way to achieve this is by employing floating solar panels. However, little is known on the effects of floating solar at large scale on water quality and ecology. We therefore designed a floating solar pilot and installed this on one of the water reservoirs (depth <4m) at Evides Water Company, a company based in the south of the Netherlands. Evides relies mostly on surface water for the production of drinking water, and river water is stored in large reservoirs. Several quality parameters have been monitored over multiple years, which include: 1) physico-chemical (oxygen, temperature, organic carbon, heavy metals, etc.), 2) microbiological (fecal bacteria) and 3) (hydro)biological (birds, water plants, plankton. Biography
Dr. Albert van der Wal currently leads the R&D team for drinking water production at Evides Water Company and is professor at Wageningen University (NL), specialized in sustainable (drinking) water production with focus on membrane filtration, capacitive deionization (CapDI) for water softening and desalination, removal of organic micropolltants and sand and biological activated carbon filtration. He obtained a PhD in Physical Chemistry and Microbiology.

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