Agricultural Research Service

March 7, 2000

The invention relates to activated carbons made from nutshells which are used to effectively remove metals present at toxic concentrations in water and wastewater. Nutshells, including almond and pecan shells, are high volume, low value agricultural wastes that have limited metals adsorption properties. An activated carbon from nutshells has been developed in which the capacity to adsorb metals was increased five to ten times over nutshells in their normal or non-carbonized state. These carbons also adsorbed two to three times more metals than commercial carbons evaluated under identical experimental conditions. The conversion of nutshells to value-added, activated carbons for metals remediation of contaminated water represents an excellent use of low value agricultural waste. Nut shellers can find a value-added outlet for a by-product that normally gives them little or no profit. Adsorbent users from small businesses to large companies will appreciate a product that is potentially lower in cost and higher in metals adsorption than activated carbons currently available. A preliminary cost estimate to manufacture nutshell carbons is about $0.85/pound. This manufacturing cost assumes conversion of 13 ton/day of shells to 3.5 ton/day of activated carbon. Carbon production in the United States is more than 300 million pounds per year, and is expected to grow more than 4 percent annually.

Wayne E. Marshall USDA, ARS, SRRC New Orleans, LA (504) 286-4356 / Fax: (504) 286-4356	Christopher Toles USDA, ARS, SRRC New Orleans, LA (504) 286-4207 / Fax: (504) 286-4367
Mitchell M. Johns Department of Food Science Center Baton Rouge, LA (504) 286-4223

environmental, prevention, remediation, pollution, crop components, carbons, water, nutshells, metals, wastewater

Activated Nutshell Carbons from Agricultural Waste

Technology Description:

The invention relates to activated carbons made from nutshells which are used to effectively remove metals present at toxic concentrations in water and wastewater. Nutshells, including almond and pecan shells, are high volume, low value agricultural wastes that have limited metals adsorption properties. An activated carbon from nutshells has been developed in which the capacity to adsorb metals was increased five to ten times over nutshells in their normal or non-carbonized state. These carbons also adsorbed two to three times more metals than commercial carbons evaluated under identical experimental conditions. The conversion of nutshells to value-added, activated carbons for metals remediation of contaminated water represents an excellent use of low value agricultural waste. Nut shellers can find a value-added outlet for a by-product that normally gives them little or no profit. Adsorbent users from small businesses to large companies will appreciate a product that is potentially lower in cost and higher in metals adsorption than activated carbons currently available. A preliminary cost estimate to manufacture nutshell carbons is about $0.85/pound. This manufacturing cost assumes conversion of 13 ton/day of shells to 3.5 ton/day of activated carbon. Carbon production in the United States is more than 300 million pounds per year, and is expected to grow more than 4 percent annually.

Reference:

Please refer to Patent Number 6,033,573, which issued on March 7, 2000.

Inventors:

Christopher Toles USDA, ARS, SRRC New Orleans, LA (504) 286-4207 / Fax: (504) 286-4367	Wayne E. Marshall USDA, ARS, SRRC New Orleans, LA (504) 286-4356 / Fax: (504) 286-4356
Mitchell M. Johns Department of Food Science Center Baton Rouge, LA (504) 286-4223