Is ceramsite the last straw for sewage sludge disposal: a review of sewage sludge disposal by producing ceramsite in China

With the rapid development of urbanization, the amount of urban sewage treatment is increasing. Waste activated sludge (WAS) is a by-product of sewage treatment, and its output is increasing year by year. How to properly handle WAS is related to the sustainable development of the sewage treatment industry. The production of ceramsite from WAS is an effective way to realize the utilization of sludge. This paper comprehensively describes the use of WAS as raw material, adding clay, cement, glass powder, shale, coal gangue, river sediment, pulverized fly ash and other auxiliary materials (AM) to produce sintered sewage sludge ceramsite and non-sintered sludge ceramsite. This paper analyzes the advantages and disadvantages of the process of making ceramsite from WAS. The research points out the development prospect of ceramsite from WAS.