The amount of sewage sludge from municipal wastewater treatment plants (MSS) still rising, methods of processing or disposal remains the same. Among them, incineration and export are the major ones. As MSS disposal represent a significant proportion (30-50%) of the OPEX in the operation of the wastewater treatment plant, activities for diminishing quantities of residual MSS are highly justified. As MSS contain mostly water (80%), it is reasonable to give most of the attention to drying. Sludge drying is an extremely challenging process due to their properties like stickiness, slow drying rates and rapidly bad odour development. Pyrolysis process very efficiently contributes to increasing drying rates of the MSS and at the same time provides a possibility of the thermal utilisation of dried sludge. Sludge drying is interesting due to the reduction of sludge quantities (up 60 to 80%) and because of their possibility of usage in a pyrolysis process. The economic process of pyrolysis mandatory needs dry sludge. The pyrolysis process produces carbon which is required in MSS granulation process. Granulation makes MSS and char homogeneous, free flowing material. Such material dries very quickly and in does not cause the development of bad odour and can be dried and stored in piles, bags or the silos. For economical sludge drying, needs of inexpensive heat sources are essential. Sources of heat like solar energy and environment used by heat pumps are available. Pyrolysis also allows the combination of drying and production of energy. Recent process developments allow construction of commercial plants even at smaller capacities (4-8000 t of fresh mud / a). 80-90% reduces the amount of remaining residual solids. Recycling of strategic raw materials like phosphorus becomes more and more real option in the EU.
F.10 Improvements to an existing technological process or technologyCOBISS.SI-ID: 20621590
The several pyrolytic products were tested and on the basis of the results we selected the most suitable for the purpose of alternative rejuvenation, i.e. bitumen from waste car tires. The results showed that the sensitivity of water on asphalt mixtures with the addition of RA is lower. The ITSR volume increased with each level of RA added. With the added rejuvenation, the sensitivity to water did not change. RA improved adhesion in cohesion, and the rejuvenator did not worsen cohesion, although softening bitumen. In all cases, the sensitivity to water relative to the base mixture decreased. The tensile strength increased with a higher proportion of RA, which is consistent with the results of water sensitivity. ITS has decreased in the case of an additional rejuvenator, which can be attributed to slightly worse cohesion. The results of the cooling of the test have shown that RA is a worse property of asphalt mixtures, with crack resistance being improved with the addition of the rejuvenator to the extent that the asphalt mixture with the highest proportion of RA in the rejuvenator has better properties than the basic asphalt mixture. Research on the use of recycled asphalt and its use encourages the use of waste materials, thus contributing to the preservation of the environment and reducing emissions.
F.06 Development of a new productCOBISS.SI-ID: 6250522
Operating permit represents a basic document for each production process and is strongly connected with any investment. In the contribution, some possibilities and conditions for obtaining a permit/license for pyrolysis process of biomass in general and particularly sewage sludge are analysed. A controlling procedure serves as “checklist” enable to declare and clear all environmental and ecological issues connected to the key questions of the whole permit procedure. The process of the pyrolysis is declared as an R3 procedure for waste processing and is literately declared in the legal document. Contribution intends to cover all the areas and issues which may affect and be connected the permit procedure as a whole. End of waste issues about pyrolysis products was observed. Finally, risk and its impact on permit procedure timing are analysed and evaluated.
F.17 Transfer of existing technologies, know-how, methods and procedures into practiceCOBISS.SI-ID: 20621846
Within the environmental symposium, it was published a proceedings of conference of 36 expert papers, presenting actual environmental topic on integrated management of waste and air quality, linking domestic and foreign knowledge in finding opportunities for greater cooperation and knowledge transfer from research institutions to end-users and other relevant subjects.
C.07 Other editorial boardCOBISS.SI-ID: 289499648
Design of technological equipment for extensive drying of biomass and wood for cogeneration using low temperature heat (50 kW). Preparation of design parameters for the production of a drying system for wood chips drying.
F.05 Ability to launch new technological development cycleCOBISS.SI-ID: 26077496