Sewage Sludge Reuse for Reducing Environmental Risks and Development of Multi-Functional Products with a Novel Disposal Technology

A significant amount of the industrial waste is sludge, which must be reduced and directed to recycling. Many municipalities find it important to develop disposal options of sewage sludge as an alternative to landfill or incineration. Carbonization is a valid process for facilitating sludge handling and decreasing environmental risks, while it increases the recycling rate.The thermal characteristics of carbonized tablets made from sewage sludge as a biomass were analyzed with DSC (differential scanning calorimetry) and a calorimeter. The results show that the heating value , or the calorific power, of the tablets was approximately 10.5 to 15.9kJ/g and corresponded to nearly 39 to 59 % of that of charcoal. It was dependent on the heating temperature and time in carbonization. The other functions of the porous carbonized tablets as manure, water retention, and humidity control material were studied with vegetation monitoring and water retention test.