title: Encapsulation of lead from hazardous CRT glass wastes using biopolymer cross-linked concrete systems.
abstract: Discarded computer monitors and television sets are identified as hazardous materials due to the high content of lead in their cathode ray tubes (CRTs). Over 98% of lead is found in CRT glass. More than 75% of obsolete electronics including TV and CRT monitors are in storage because appropriate e-waste management and remediation technologies are insufficient. Already an e-waste tsunami is starting to roll across the US and the whole world. Thus, a new technology was developed as an alternative to current disposal methods; this method uses a concrete composite crosslinked with minute amounts of biopolymers and a crosslinking agent. Commercially available microbial biopolymers of xanthan gum and guar gum were used to encapsulate CRT wastes, reducing Pb leachability as measured by standard USEPA methods. In this investigation, the synergistic effect of the crosslinking reaction was observed through blending two different biopolymers or adding a crosslinking agent in biopolymer solution. This CRT-biopolymer-concrete (CBC) composite showed higher compressive strength than the standard concrete and a considerable decrease in lead leachability.
authors.affiliation: Sonny Astani Department of Civil and Environmental Engineering, Viterbi School of Engineering, University of Southern California, KAP 210, 3620 South Vermont Avenue, Los Angeles, CA 90089, USA.
authors.forename: Daeik
authors.initials: D
authors.lastname: Kim
authors.forename: Michael
authors.initials: M
authors.lastname: Quinlan
authors.forename: Teh Fu
authors.initials: TF
authors.lastname: Yen
mesh_terms: D001704:Biopolymers / Q000737:chemistry*; D001888:Boric Acids / Q000737:chemistry; D003252:Construction Materials / Q000032:analysis*; D003626:Data Display; D004581:Electronics; D004787:Environmental Pollution / Q000517:prevention & control; D005685:Galactans / Q000737:chemistry; D005898:Glass; D015386:Hazardous Substances / Q000032:analysis; D007854:Lead / Q000737:chemistry*; D008351:Mannans / Q000737:chemistry; D015394:Molecular Structure; D053149:Plant Gums / Q000737:chemistry; D011135:Polysaccharides, Bacterial / Q000737:chemistry; D012037:Refuse Disposal / Q000379:methods*
chemical_list: D001704:Biopolymers; D001888:Boric Acids; D005685:Galactans; D015386:Hazardous Substances; D008351:Mannans; D053149:Plant Gums; D011135:Polysaccharides, Bacterial; D007854:Lead; C007894:guar gum; C032688:boric acid; C002563:xanthan gum