Large amounts of sewage sludge are produced in treatment process of wastewater worldwide, causing many problems in disposal of sewage sludge. Because sewage sludge contains nitrogen, phosphorus and inorganic materials, some of them are used as fertilizer and some are just applied to land (i.e. landfill). While the toxic material and heavy metals in the sewage sludge can cause problems when it is applied to land. There are many advantages of carbonization of sewage sludge, because carbonization can reduce the volume of sewage sludge, eliminate odor, bacteria and organic toxic substance in it. However ash and heavy metal cannot be eliminated during carbonization, which could lead serious problem.

Flash Carbonization process, which can carbonize biomass and organic material in short period, is one of options to carbonize sewage sludge. We have successfully carbonized sewage sludge in 10-15 min by means of our Flash Carbonization lab-scale reactor. The ash and heavy metal content in the sewage sludge charcoals were analyzed and their behavior during Flash Carbonization process will be discussed in the presentation. Moreover applicability assessment of sewage sludge charcoal land application will be also presented.