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Valuable product recovery from sewage sludge

Periodic Reporting for period 1 - reNEW (Valuable product recovery from sewage sludge)

Reporting period: 2016-07-01 to 2016-12-31

The treatment of sewage sludge represents one of the biggest problems for small and medium sized wastewater treatment plants. Sludge use on land is the most common solution in Europe, however the heavy metal and nutrient concentration is strictly regulated. As the sludge production is increasing due to stricter wastewater treatment regulations the land use has some limitations as the volume is continuously increasing. To solve the problem landfilling, incineration and digestion is used, however these methods are either expensive or have environmental concerns. The problem of sewage sludge treatment will increase with population growth and urbanisation in the future. Our objective is to commercialize the reNEW technology. In this process, the sewage sludge is biologically transformed into volatile fatty acids (VFA) and valuable nutrients (NPK), which are recovered.
Our company, UTB Envirotec Zrt, is one of the regional market leaders in engineering services for wastewater treatment. In the past 8 years, we developed a technology for sustainably treating sewage sludge. This technology is based on a biological process resulting in two valuable products from sewage sludge: Volatile Fatty Acids (VFA) and Nutrients (NPK). VFAs have antimicrobial, pesticide and in some cases odorant effects. Nutrients (NPK), containing macro and micro elements, are mainly inorganic compounds in an environmentally friendly form. These compounds can be used directly as an environmentally friendly fertilizer. During this Phase 1 feasibility study we verified the technological challenges as well as the economic viability of the envisaged project.
Existing solutions are mainly focusing on exploiting the sewage sludge as a whole, due to either its calorific value or organic matters. However, in many cases (e.g. incineration, landfilling) most of the value within is lost. According to our knowledge there is no technology available commercially, that recovers the valuable components of sewage sludge, while neutralising its toxicity. Our solution is unique, the key element of the process is the biological hydrolysis and acidification of organic matter. The reNEW process is economically and environmentally sustainable by creating a product cycle. reNEW technology will have important socio-economic advantage (as compared to existing solutions). Its application leads to less waste generation from wastewater treatment and at the same time it contributes to the circular economy.