title: Chemically modified maize cobs waste with enhanced adsorption properties upon methyl orange and arsenic.
abstract: The surface chemistry of maize naturasorbent was altered in this work by the modifying agents: phosphoric acid and different amines (triethanolamine, diethylenetriamine and 1,4-diaminobutane). Removal of methyl orange (25 mg l(-1)) was <50% by maize corn cobs modified by phosphorylation and higher by the quaternized samples: 68% with the 1,4-diaminobutane and 73% with the diethylenetriamine modificators. Adsorption of arsenite by the samples modified with phosphoric acid/ammonia was 11 microg g(-1), which corresponds to 98% removal from a 550 microg As l(-1) solution for an adsorbent dose of 50 mg ml(-1). The samples modified by phosphoric acid/urea removed 0.4 microg g(-1) arsenate from a 300 mug As l(-1) solution. Adsorption of methyl orange, arsenite and arsenate was superior by the chemically modified maize cobs judged against the initial naturasorbent. For comparison, removal by the commercial anion exchanger was 100% for methyl orange, 45% (5 microg g(-1)) for arsenite and 99% (5 microg g(-1)) for arsenate.
authors.affiliation: Universidad Autónoma de Puebla, Instituto de Ciencias, Centro de Química, Apdo. Postal J-55, Puebla 72571, Pue, Mexico. melizald@siu.buap.mx
authors.forename: María P
authors.initials: MP
authors.lastname: Elizalde-González
authors.forename: J
authors.initials: J
authors.lastname: Mattusch
authors.forename: R
authors.initials: R
authors.lastname: Wennrich
mesh_terms: D000327:Adsorption; D001149:Arsenates / Q000302:isolation & purification*; D001391:Azo Compounds / Q000302:isolation & purification*; D001673:Biodegradation, Environmental; D004602:Elements; D006863:Hydrogen-Ion Concentration; D014866:Waste Products; D003313:Zea mays / Q000378:metabolism*
chemical_list: D001149:Arsenates; D001391:Azo Compounds; D004602:Elements; D014866:Waste Products; C100258:methyl orange; C025657:arsenic acid