In order to categorize a city as smart city, we must look into their sewers and landfills. The rate of water purification and recycling of municipal solid waste can give us an idea of a city’s modernity and the quality of life of its citizens. The Viennese in that sense are very proud of the high level of results achieved in both their wastewater treatment of 95% as in the full use of their waste.
In times of economic crisis it is hard to think of the development of new projects, but for Lukas Magg, communications director Tina Vienna, and responsible for the creation of the Office for the development of Smart Cities in Vienna , the economic crisis is a unique opportunity for the development of the smart cities’ industry . This opportunity is based on the European Union forecasts, which provide that by 2050 70% of the population will settle in large cities and only 30% will remain in rural areas or towns of less than 10,000 inhabitants. To house new neighbors does not mean just building new areas in the city, but to efficiently manage the resources that are available.
Water treatment
The Danube, one of Europe’s most abundant rivers, passes through Vienna displacing 500,000 m3 per second. Vienna uses its resources for its supply through an underground artificial channel starting from the River Danube and connecting all their sewage.
6,000 m3 of wastewater enter the ebswien Hauptklaranlage treatment plant as a result of daily water consumption per capita of 150 liters. The plant consumes about 1% of Vienna’s overall electrical energy, representing a 50w/hour consumption per capita per day. The plant’s enormous annual consumption, which is 63 GW / hour, can be offset by producing biogas from the sewage sludge within the frame of a project that plans to produce around 87 GW / hour per year.
Vienna’s water treatment plant is part of Austrian environmental program aimed at preserving the quality of its rivers, definitely contributing to the sustainable development of the city. Twenty hours of treatment suffice to return the water purified at a rate of 95% to the Danube.
Municipal Solid Waste (MSW) treatment
There are three incineration plants for municipal solid waste in Vienna, which together are responsible of recycling 40 % of the one million tons of garbage generated by the city’s 1.8 million inhabitants. The remaining 60%, namely 600,000 tons are burned to produce hot water for the city’s weatherization. This hot water is circulated through a district heating plant along about 1,000 km. of pipes that supply one third of the population. We had the opportunity to visit one of these plants during our trip to Vienna, the Pfaffenau plant which receives about 200 trucks a day and is capable of burning 32 tons per day in two incineration lines. One of the plant’s key elements is that in charge treating contaminated gases which through a triple filtration process is able to eliminate all particles that are hazardous to health.
The ashes resulting from the process are also used in the cement industry.
