The progress in urbanization has led to increased municipal solid waste incineration fly ash (IFA) and municipal sewage sludge (MSS) every year, hampering sustainable development. IFA, which has salty ion, high alkalinity, heavy metals (HMs), and dioxin, is listed as a dangerous material.
Regardless of the numerous water washing and thermal approaches used to fulfil safe disposal, a large amount of energy and clean water is required, which is not sustainable.
The high moisture content of MSS makes it useful for removing chlorine from IFA, leading to a perfect environment to treat IFA and MSS concurrently. Furthermore, ion strength and high alkalinity of IFA boosted MSS dewatering.
Founded on the concept of “waste treated waste,” the Group of Clean Energy Technology and Carbon Material led by Prof. Wang Yin from the Institute of Urban Environment of the Chinese Academy of Sciences chose IFA and MSS as target, and hydrothermal as treatment technique, to treat them synergistically.
A highly efficient MSS dehydration, as well as chlorine removal and immobilization of HMs, was realized.
Furthermore, the migration regulation of chlorine was analyzed in-depth in the study, offering a reference in application. The product provided by the system is a lot safer and favorable for reuse.
The study titled “Research on synergistically hydrothermal treatment of municipal solid waste incineration fly ash and sewage sludge” was reported in the Journal of Waste Management.
The study was aided by the Strategic Priority Research Program of the Chinese Academy of Sciences, the China-Japanese Research Cooperative Program-China, etc.