Production of glass ceramics from sewage sludge

Abstract

Environmental problems are a worldwide concern. So recycling with a zero-emission objective is being pursued. For this purpose, a melting process whereby sludge was converted into slag has been developed and commercialized. However, as the glass material of conventional slag is inferior compared to natural stone, the use of slag as a substitute material has been limited. Therefore, glass ceramics technology was studied to produce crystallized glass from sewage sludge. The technology was researched and developed jointly with the Tokyo Metropolitan Government in pursuing the basic study and pilot plant studied from 1991 to 1995. As a result, we have successfully commercialized this technology to convert sewage sludge into a resource as stone-like products, followed successfully by a long pilot operation. Now the commercialized plant of 150 ton-cake/day was installed and has been producing stone products from sewage sludge since 1996. In this paper, we report the results of the latest pilot plant test, and the application study of stone products for recycling use as well. For long decades, we obtain building materials from mountains and forests then built up metropolis. Then the metropolis exhaust waste and surrounding environment is polluted. We are convinced that this technology may contribute to prevent such environmentally unbalanced cycle.

Glass-ceramics: Their production from wastes—A Review

“…Fly ash from the incineration of sewage sludge has been studied by Endo et al [168], Suzuki et al [169] and Park et al [170] regarding the production of glass and glass-ceramics to reduce the environmental impact of such waste. Endo et al [168] focused mainly on the feasibility of crystallising the glass obtained from melting of the fly ash.…”

“…Endo et al [168] focused mainly on the feasibility of crystallising the glass obtained from melting of the fly ash. The work was considered successful, where the slag was crystallised into 80% anorthite with properties meeting the requirement for construction and civil works materials.…”

Effect of SiO2 on Immobilization of Metals and Encapsulation of a Glass Network in Slag

“…Melting/vitrification has been developed as a proper technology in the further stabilization of ashes, radioactive waste, or sewage sludge. [3][4][5] This technology not only reduces the volume of waste and the mobility of metals but also destroys toxic substances such as polycyclic aromatic hydrocarbons (PAHs) or dioxins. 6 -9 The leaching of hazardous metals has been controlled by stringent regulations.…”

“…During vitrification, the chemical composition of the ternary system (silica [SiO 2 ]-alumina [Al 2 O 3 ]-lime [CaO]) is a major factor controlling the formation of the slag structure. 3,11 Among these constitutes, SiO 2 is of the greatest importance for the main constituents in a glass network when fly ash is vitrified. 12 Therefore, this study focused on the effect of SiO 2 addition on vitrification.…”

Study on the influence of additives in an industrial calcium fluoride and waterworks sludge co-melting system

“…This sludge-derived slag can be used in construction materials, including aggregate and paving. Following post-melting or sintering, the slag can also be formed into blocks and other crystal materials (Bijen, 1996;Endo et al, 1997;Okuno and Takahashi, 1997;Wiebusch and Seyfried, 1997).…”