title: 2,4-D adsorption to biochars: effect of preparation conditions on equilibrium adsorption capacity and comparison with commercial activated carbon literature data.
abstract: Batch isotherm experiments were conducted with chars to study adsorption of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). Chars generated from corncobs, bamboo and wood chips in a laboratory pyrolyzer at 400-700 °C were compared with traditional kiln charcoals collected from villages in S/SE Asia and with activated carbons (ACs). 2,4-D uptake by laboratory chars obtained from bamboo and wood chips after 14 h of pyrolysis at 700 °C, from wood chips after 96 h of pyrolysis at 600 °C, and one of the field-collected chars (basudha) was comparable to ACs. H:C and O:C ratios declined with pyrolysis temperature and duration while surface area increased to >500 m(2)/g. Increasing pyrolysis intensity by increasing temperature and/or duration of heating was found to positively influence adsorption capacity yield (mg(2,4-D/g(feedstock))) over the range of conditions studied. Economic analysis showed that high temperature chars can be a cost-effective alternative to ACs for water treatment applications.
authors.affiliation: Department of Civil, Environmental, & Architectural Engineering, University of Colorado-Boulder, 1111 Engineering Dr, ECOT 441, UCB 428, Boulder, CO 80309, USA. Electronic address: yeah.yeah.right.on@gmail.com.
authors.forename: J P
authors.initials: JP
authors.lastname: Kearns
authors.affiliation: Geosyntec, Raleigh, NC, USA.
authors.forename: L S
authors.initials: LS
authors.lastname: Wellborn
authors.affiliation: Department of Civil, Environmental, & Architectural Engineering, University of Colorado-Boulder, 1111 Engineering Dr, ECOT 441, UCB 428, Boulder, CO 80309, USA.
authors.forename: R S
authors.initials: RS
authors.lastname: Summers
authors.affiliation: Department of Civil, Construction, & Environmental Engineering, North Carolina State University, 2501 Stinson Dr, Campus Box 7908, Raleigh, NC 27695, USA.
authors.forename: D R U
authors.initials: DR
authors.lastname: Knappe
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000302:isolation & purification*; D000327:Adsorption; D002606:Charcoal / Q000737:chemistry* / Q000191:economics; D004602:Elements; D005240:Feasibility Studies; D006358:Hot Temperature; D007700:Kinetics; D010575:Pesticides / Q000302:isolation & purification
chemical_list: D004602:Elements; D010575:Pesticides; C540010:biochar; D002606:Charcoal; D015084:2,4-Dichlorophenoxyacetic Acid
keywords: Charcoal; Herbicide; Low-cost adsorbent; Pesticide; Water treatment