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ARS Home » Southeast Area » New Orleans, Louisiana » Southern Regional Research Center » Commodity Utilization Research » Research » Publications at this Location » Publication #165007
Title: MUNICIPAL WASTEWATER AND PECAN SHELLS

Author
item BANSODE, RISHIPAL - LSU AG CENTER
item LOSSO, JACK - LSU AG CENTER
item Marshall, Wayne
item RAO, RAMU - LSU AG CENTER
item PORTIER, RALPH - LSU ENVIRON.STUDIES

Submitted to: Louisiana Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/4/2004
Publication Date: 4/8/2004
Citation: Bansode, R.R., Losso, J.N., Marshall, W.E., Rao, R.R., Portier, R.J. 2004. Municipal wastewater and pecan shells. Louisiana Agriculture. 47:24-25.

Interpretive Summary: Increased water demand in the face of an essentially fixed fresh water supply and increased pollution of existing supplies by inadequately treated waste discharge have been identified as problems in Louisiana. One solution to this problem would be to treat contaminated water such as municipal wastewater with a by-product of tree nut production in Louisiana, namely, pecan shells. This scenario would increase the value of the nut shells for the producer and clean up contaminated water in Louisiana's numerous municipalities. Scientists from the LSU AgCenter and the USDA-ARS, Southern Regional Research Center have demonstrated that pecan shells, converted to granular activated carbons, are effective in treating contaminated water such as municipal wastewater and can be manufactured at a competitive price of $1.20 to $1.40 per pound compared to a retail price of more than $2 per pound for some coal-based commercial carbons, which are widely used in water purification. Pecan shell-based carbons can offer Louisiana municipalities the choice of helping the state economy by using "home grown" products for wastewater cleanup.

Technical Abstract: Increased water demand in the face of an essentially fixed fresh water supply and increased pollution of existing supplies by inadequately treated waste discharge have been identified as problems in Louisiana. The purpose of this study was to determine the effectiveness of treating contaminated water such as municipal wastewater with a by-product of tree nut production in Louisiana, namely, pecan shells. Municipal wastewater is characterized by its physical attributes as well as its organic and inorganic contaminants. Physical attributes include color, odor and turbidity caused by dissolved or suspended solids. Organic contaminants include dissolved volatile organic compounds (VOCs), which include phenols, chlorobenzene, hydrocarbons and dissolved or undissolved non-volatile organic compounds designated as chemical oxygen demand (COD). Inorganic contaminants may include compounds of trace metals such as copper, zinc and lead. Production and processing of pecans in Louisiana is estimated to generate nearly 6 million pounds of shells annually. At present, pecan shells have found limited applications in landscape mulch. Most of the nutshells are discarded, creating a significant environmental problem. Scientists from the LSU AgCenter and the USDA-ARS, Southern Regional Research Center have demonstrated that pecan shells can be converted to granular activated carbons, which can be used to effectively treat contaminated water such as municipal wastewater and can be manufactured at a competitive price of $1.20 to $1.40 per pound compared to more than $2 per pound for some coal-based commercial carbons, which are widely used in water purification.