Evaluation of full scale thermal solidification processes implemented in Tokyo lightweight aggregate, slag and brick

Tokyo has an experience in operation of full-scale thermal solidification processes for around 10 years. They include artificial lightweight aggregates, slag, brick, and sludge fuel (dried by Carver Greenfield process). Many efforts were concentrated on improving the processes for the years. As a result, the thermal solidification of sewage sludge is no more academic research subject, but is a standardized engineering process. Any of them are able to be locally implemented depending on specific requests. Among them, the brick seems to be the best choice from the viewpoint of economy. On the other hand, a potential alternative is that the sewage sludge could be served as raw material for Portland cement manufacturing process.