With the development of urbanization, municipal solid waste incineration fly ash (IFA) and municipal sewage sludge (MSS) increased annually, hindering the sustainable development. IFA, which had a high alkaline, salty ion, heavy metals (HMs) and dioxin, listed hazardous materials. Despite various water washing and thermal methods were used to meet the safety disposal, large amount of clean water or energy-consumption was needed, which was not sustainable. Due to high moisture content in MSS, which was helpful for chlorine removal in IFA, created an excellent environment to treat IFA and MSS simultaneously. In addition, high alkaline and ion strength promoted MSS dewatering.

Based on the principle of “waste treated waste”, the Group of Clean Energy Technology and Carbon Material (team of Pro.Wang Yin) in Institute of Urban Environment, Chinese Academy of Sciences selected IFA and MSS as target, hydrothermal as treatment methods, to treat them synergistically. Not only a high-efficiently MSS dehydration was achieved, also HMs immobilization and chlorine removal was realized meanwhile. In addition, the migration regulation of chlorine was investigated in detail in our work, providing a reference in application. The product obtained in the system become more safety, which was conducive to reuse.

The research was published in the Journal of Waste Management 2019, 100, 182 - 190 , and titled as “Research on synergistically hydrothermal treatment of municipal solid waste incineration fly ash and sewage sludge”. The first author is Chen Zhan and the corresponding author is Pro. Wang Yin. This research was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences, the China-Japanese Research Cooperative Program-China, etc.