Effect of high solid loading on the process efficiency of aerobic stabilizastion

Sewage sludge may cause the spread of illnesses via multiplying of microorganism due to containing of organic materials, and when they are not dewatered after stabilization, they may cause surface and groundwater. After that, it may also cause some harmful effects like undesired smell, decomposition and deformation. When we consider these reasons, it submits that stabilization of treatment sludge has an obligation. There are many ways to stable treatment sludge. One of the biological stabilization method is aerobic stabilization. The scope of this thesis is to determine appropriate mixing ratio of primary and final sedimentation sludges, the most appropriate initial solid content for providing autothermal thermophilic conditions, and achieving high stabilization efficiency. A result of the experiments performed with different sludge mixing ratio and initial sludge contents, it was identified that providing the high solid content and high oxygen was insufficient for providing autothermal conditions. However, it is observed that high solids loading increased the stabilization efficiency. The most appropriate sludge mixing ratiowasdetermined as 25%of primary sedimentation sludge and 75% final sedimentation sludge as a result of determination of dewaterability of digested sludge and VS removal. In this mixing ratio the effect of semi-batch operation of aerobic stabilization on stabilization efficiency was determined by wasting and feeding of sludge. As result of VS removal efficiency and dewaterability of sludge, the best aerobic stabilization conditions were determined as 20 days of sludge retention time for sewage sludge including %25 percent of primary sedimentation sludge.