Resumo

BELLO-HUITLE, V.; ATENCO-FERNANDEZ, P.  e  REYES-MAZZOCO, R.. Adsorption studies of methylene blue and phenol onto pecan and castile nutshells prepared by chemical activation. Rev. Mex. Ing. Quím [online]. 2010, vol.9, n.3, pp.312-322. ISSN 1665-2738.

The use of agricultural wastes (AWs) as raw materials in the production of granular activated carbon (GAC) is an important topic worldwide. The abundance of pecan nutshells (PNs) and castile nutshells (CNs) provided the motivation for producing GAC from these materials. Phosphoric acid was used at several activation ratios (Rs), and the adsorption capacity of methylene blue (1MB) and phenol (PH) by thv products was measured. The highest GAC yields and the maximum adsorption capacities were obtained at R=2. Although the maximum MB adsorption capacity of GAC produced from CNs was relatively small, 170 mg g^-1; that of GAC produced from PNs was 400 mg g^-1, which is among; the highest reported. The SEM images of GAC from PNs reveled gin ordered arrangement of nearly straight and tubular macropores with abundant mesopores inside. The ball-pan hardness number of the PN GAC is 80, equal to the value reported for bituminous GAC. These characteristics make the GAC obtained from PNs suitable for packed tower applications.

Palavras-chave : agricultural waste; granular activated carbon; activation ratio; pyrolysis.