Solidification/stabilization of ash from medical waste incineration into geopolymers.
In the present work, bottom and fly ash, generated from incinerated medical waste, was used as a raw material for the production of geopolymers. The stabilization (S/S) process studied in this paper has been evaluated by means of the leaching and mechanical properties of the S/S solids obtained. Hospital waste ash, sodium hydroxide, sodium silicate solution and metakaolin were mixed. Geopolymers were cured at 50°C for 24h. After a certain aging time of 7 and 28 days, the strength of the geopolymer specimens, the leachability of heavy metals and the mineralogical phase of the produced geopolymers were studied. The effects of the additions of fly ash and calcium compounds were also investigated. The results showed that hospital waste ash can be utilized as source material for the production of geopolymers. The addition of fly ash and calcium compounds considerably improves the strength of the geopolymer specimens (2-8 MPa). Finally, the solidified matrices indicated that geopolymerization process is able to reduce the amount of the heavy metals found in the leachate of the hospital waste ash.
Laboratory of Toxic and Hazardous Waste Management, Department of Environmental Engineering, Technical University of Crete, Chania P.C. 73100, Greece. Electronic address: ktzanakos@gmail.com.
Konstantinos
K
Tzanakos
Laboratory of Toxic and Hazardous Waste Management, Department of Environmental Engineering, Technical University of Crete, Chania P.C. 73100, Greece.
Aliki
A
Mimilidou
Division Bridges and Structural Technology/Section Tunnel and Foundation Engineering, Tunnel Operation, Civil Security, Federal Highway Research Institute (BASt), Bruederstraße 53, P.C. 51427 Bergisch Gladbach, Germany.
Kalliopi
K
Anastasiadou
Laboratory of Applied Mineralogy, Department of Mineral Resources Engineering, Technical University of Crete, Chania P.C. 73100, Greece.
Antonis
A
Stratakis
Laboratory of Toxic and Hazardous Waste Management, Department of Environmental Engineering, Technical University of Crete, Chania P.C. 73100, Greece.
Evangelos
E
Gidarakos
D017610:Calcium Compounds / Q000032:analysis; D060729:Coal Ash / Q000737:chemistry*; D017745:Incineration; D008506:Medical Waste / Q000032:analysis*; D019216:Metals, Heavy / Q000032:analysis; D011108:Polymers / Q000737:chemistry*
D017610:Calcium Compounds; D060729:Coal Ash; D008506:Medical Waste; D019216:Metals, Heavy; D011108:Polymers
Bottom ash; Compressive strength; Fly ash; Geopolymer; Heavy metal; Medical waste