Ponovna uporaba mulja s uređaja za pročišćavanje otpadnih voda u betonskoj industriji - od mikrostrukture do inovativnih proizvoda

In the wastewater treatment process, a by-product is generated, as additional waste called sewage sludge (0.5 kg of sludge per 1 m3 of wastewater). Adequate wastewater management implies collection and treatment of wastewater, but also adequate management of waste substances generated in the treatment process. Joining the European Union Croatia has made the commitment to construct all treatment plants of capacities over 10.000 PE by 2018. This will result in putting into operation of treatment plants with the total load of about 4.000.000 PE (250.000.000 m3 of wastewater), which will generate about 215.000 tons per year of raw sewage sludge and after incineration around 49.000 tons per year of incinerated sewer sludge ash (ISSA). Taking into account that EU Directives are limiting the amount of sewage sludge waste to be landfilled, and Waste Framework Directive (2008/98/EC) puts reuse and recycling of waste into the most favorable position, it is evident that enormous amount of ISSA will become available for appropriate management. The composition of the generated sewage sludge and ISSA is dependent on the technology of wastewater and sludge treatment. Reviewing the available knowledge in this field leads to the conclusion that the influence of the method of incineration on physical properties of ISSA and the technology of preparing and processing of concrete and concrete elements has not been fully analysed. The main objective of the project is to investigate the possibilities of recycling the sludge from WWTPs in preparing of new innovative products in concrete industry. Based on comprehensive experimental research and multidisciplinary knowledge of the partners (hydrotecnical, materials and chemical engineering), a strategy will be proposed for the comprehensive and sustainable management of ISSA and its transformation from unwanted waste material into valuable resource for production of construction products with ecological, economical and technological benefits.