Investigation of the usability of sewage sludge ash in geotechnical engineering applications

Environmental pollution occurring in the world with the rapid increase in population is one of the most important problems of humanity. Environmental elements that are vital for living things; air, soil and water are getting more polluted and unusable day by day. For this reason, various improvement studies are carried out in these areas. One of them is wastewater treatment plants built to control water pollution. While the water treated in the sedimentation ponds in these facilities is recycled to the nature, it leaves waste treatment sludge behind. These waste sludge collected in a certain place are evaluated by methods such as composting, drying or destroyed by incineration. In many previous studies, the usability of sewage sludge ash in soil improvement was investigated. In this study, the usability of sewage sludge ash in various geotechnical engineering applications such as road fill, soil improvement, clay cores in dams, garbage and hazardous waste storage areas was investigated. This examination was carried out both for the purpose of soil improvement and to prevent environmental pollution by using a waste material that needs to be disposed of in a beneficial way. Treatment sludge ash was obtained from Bursa Fluidized Bed Sludge Incineration and Energy Recovery Facility. Sieve analysis, consistency limits, standard Proctor test, unconfined pressure test and permeability tests were performed by adding treatment sludge ash at certain rates to the weak soil. The obtained values were compared with the values requested in the standards and it was determined whether they were appropriate. As a result of the laboratory studies carried out within the scope of the thesis, it has been determined that sewage sludge ash can be used in geotechnical engineering applications if added in determined proportions.