Feasibility of dibromochloropropane (DBCP) and trichloroethylene (TCE) adsorption onto activated carbons made from nut shells of different almond varieties

Steam-activated carbons were made from shells from five different almond varieties (‘Nonpareil,’ ‘Padre,’ Tuono,’ ‘23-122,’ and ‘Y120-74′) and from a mix of almond types. The purpose of the work was to evaluate if the composition of shells had any effect on the performance of the final product. The shells contained the same level of cellulose, but differed in their lignin and hemicellulose composition. The yield of carbon from the shells ranged from 20% to 23.5%, indicating a loss of about 80% of initial mass. Regardless of the composition, the performance of the activated carbons made from the shells was very similar in a feasibility study. The carbons were found to have a capacity of 100–105 mg/g of carbon for the two contaminants tested (dibromochloropropane and trichloroethylene). The finding that the activated carbons performed equally well, regardless of source of almond shells, suggest that that carbons could be made from almonds shells with consistent quality.