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ARS Home » Pacific West Area » Corvallis, Oregon » Forage Seed and Cereal Research » Research » Publications at this Location » Publication #159764

Title: USE OF HOP (HUMULUS LUPULUS) AGRICULTURAL BY-PRODUCTS FOR THE REDUCTION OF AQUEOUS LEAD(II) ENVIRONMENTAL HEALTH HAZARDS

Author
item GARDEA-TORRESDEY, JORGE
item HEJAZI, MICHAEL
item TIEMANN, K
item PARSONS, J
item DUARTE-GARDEA, M
item Henning, John

Submitted to: Journal of Hazardous Materials
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/2/2001
Publication Date: 6/30/2002
Citation: GARDEA-TORRESDEY, J., HEJAZI, M., TIEMANN, K., PARSONS, J.G., DUARTE-GARDEA, M., HENNING, J.A. USE OF HOP (HUMULUS LUPULUS) AGRICULTURAL BY-PRODUCTS FOR THE REDUCTION OF AQUEOUS LEAD(II) ENVIRONMENTAL HEALTH HAZARDS. JOURNAL OF HAZARDOUS MATERIALS. 2002. V.95.P.112.

Interpretive Summary: Hop (Humulus lupulus) by-products were investigated for their potential use in the removal of heavy lead (II) ions from contaminated water solutions. Results showed a pH dependent binding trend with optimum binding occurring around pH 5.0 and a rapid adsorption of lead ions. The amount of Lead (II) ions bound per gram of tissue was approximately 75 mg. Exposing the metal laden tissue to 0.5M sodium citrate desorbed almost all of the bound lead ions. Further experiments were performed with silica-immobilized hop tissues to determine the binding ability and mode of action under flow conditions. Results indicate that carboxyl side-chain chemical compounds are involved in binding lead ions from water solution. These findings demonstrate hop agricultural waste products as viable alternatives for removal and recovery of aqueous lead (II) ions from contaminated waters.

Technical Abstract: Hop (Humulus lupulus) by-products were investigated for their potential use in the removal of heavy lead (II) ions from contaminated aqueous solutions. Results showed a pH dependent binding trend (pH 2-6) with optimum binding occurring around pH 5.0. Time dependency experiments showed rapid adsorption of lead ions within the first 5-min. Binding capacity experiments demonstrated that 74.2-mg lead were bound per gram of leaf biomass. Similar overall capacity was seen for leaves and stems. Desorption of 99% of the bound lead ions was achieved by exposing the metal laden biomass to 0.5M sodium citrate. Further experiments were performed with silica-immobilized hop tissues to determine the binding ability and mode of action under flow conditions. Results indicate that carboxyl ligands are involved in binding lead ions from aqueous solution. These findings demonstrate hop agricultural waste products as viable alternatives for removal/recovery of aqueous lead (II) ions from contaminated waters.