Surface functional groups on acid-activated nutshell carbons

摘要

Nutshells from agriculturally important nut crops(almond, black walnut,English walnut, macadamia nut and pecan) were converted to granular activated carbon using phosphoroc aicd activation in nitrogen or air. Surface functional groups (carbonyl, phenols, lactones,carboxyl) were quantified by titration with bases of different ionization potential. The degree of copper uptake was correlated with the presence of various functional groups on these carbohs. The results indicate that acid-activation strategies which provide the greatest contact of nutshells with air during carobonization and activation also have the greatest quantity of surface functional groups and the highest copper uptake. Also, the type of nutshell used for activated carbon production has litte effect on the types of surface functional groups producted and subsequent copper adsorption. This study demonstrates that a judicious choice of activation strategy for nutshell precursors can produce activaated carbons with numerous surface functional groups and high copper adsoption acitivity.