title: Atom-efficient route for converting incineration ashes into heavy metal sorbents.
abstract: Bottom ashes produced from municipal solid-waste incineration are suitable for sorbent synthesis because of their inherent composition, high alkalinity, metastable mineralogy, and residual heat. This work shows that bottom ashes can be atom-efficiently converted into valuable sorbents without the need for costly and hazardous chemicals. The ashes were hydrothermally treated in rotary autoclaves at autogenic pH conditions to promote the conversion of precursor mineral phases into zeolites and layered silicate hydrates. Two main mineral phases were formed: katoite and sodium aluminum phosphate silicate hydrate. These mineral alterations are accompanied by a tenfold increase in specific surface area and a twofold reduction in average particle size. Performance evaluation of the new sorbents for Cd(2+), Zn(2+), and Pb(2+) adsorption at pH5 indicates sorption capacities of 0.06, 0.08, and 0.22 mmol g(-1), respectively, which are similar to those of natural adsorbents and synthetic materials obtained from more demanding synthesis conditions.
authors: Department of Microbial and Molecular Systems, KU Leuven, Kasteelpark Arenberg 23, 3001 Heverlee (Belgium), Fax: (+32) 81-72-54-14.
authors: Yi Wai
authors: YW
authors: Chiang
authors: Rafael M
authors: RM
authors: Santos
authors: Kenneth
authors: K
authors: Vanduyfhuys
authors: Boudewijn
authors: B
authors: Meesschaert
authors: Johan A
authors: JA
authors: Martens
mesh_terms: D000327:Adsorption; D004785:Environmental Pollutants / Q000737:chemistry*; D017745:Incineration; D007220:Industrial Waste; D019216:Metals, Heavy / Q000737:chemistry*; D059027:Recycling
chemical_list: D004785:Environmental Pollutants; D007220:Industrial Waste; D019216:Metals, Heavy
keywords: green chemistry; hydrothermal synthesis; ion exchange; microporous materials; waste prevention