title: Influence of mixture ratio and pH to solidification/stabilization process of hospital solid waste incineration ash in Portland cement.
abstract: Solidification/stabilization (S/S) is an established utilization technology to treat hazardous wastes. This research explored the influence of pH (3-12) on the immobilization of heavy metals present in five mixtures of hospital solid waste incinerator ash and Portland cement, following two different processes of waste solidification/stabilization (cement hydration and granulation). In general, cement hydration process resulted in more stable products than granulation process. A high ash content in the mixture with Portland cement (60wt%) resulted in the highest immobilization of Pb(2+) and Cu(2+), while a low ash content in the mixture (10wt%) resulted in the lowest leachability of Zn(2+). When ash and Portland cement was mixed in equal proportions (50wt%) the highest encapsulation was observed for Ni(2+), Cd(2+) and Cr(3+). Neutral and weak alkaline pH values within the range pH=7-8 resulted in the lowest leachability of the monitored heavy metals.
authors.affiliation: Lodz University of Technology, Institute of General Food Chemistry, ul. Stefanowskiego 4/10, 90-924 Lodz, Poland. Electronic address: elzbieta.sobiecka@p.lodz.pl.
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Sobiecka
authors.affiliation: Lodz University of Technology, Faculty of Process and Environmental Engineering, ul. Wolczanska 213, 90-924 Lodz, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Obraniak
authors.affiliation: The University of Edinburgh, Institute for Infrastructure and Environment, School of Engineering, Mayfield Road, Edinburgh EH9 3JL, United Kingdom.
authors.forename: Blanca
authors.initials: B
authors.lastname: Antizar-Ladislao
mesh_terms: D017610:Calcium Compounds / Q000737:chemistry; D060729:Coal Ash / Q000737:chemistry*; D003252:Construction Materials / Q000032:analysis*; D052918:Environmental Restoration and Remediation; D005782:Gels / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D017745:Incineration; D017744:Medical Waste Disposal; D019216:Metals, Heavy / Q000032:analysis / Q000737:chemistry; D017640:Silicates / Q000737:chemistry; D012996:Solutions / Q000737:chemistry; D013054:Spectrophotometry, Atomic; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry
chemical_list: D017610:Calcium Compounds; D060729:Coal Ash; D005782:Gels; D017744:Medical Waste Disposal; D019216:Metals, Heavy; D017640:Silicates; D012996:Solutions; D014874:Water Pollutants, Chemical; C031293:calcium silicate
keywords: Ash from hospital incinerator; Metal immobilization; Metal leachability; Physico-chemical waste utilization