Avaliação da capacidade adsortiva de carvões ativados para a remoção de diuron e hexazinona. / ASSESSMENT OF ACTIVATED CARBON ADSORPTIVE CAPACITY FOR REMOVAL OF DIURON AND HEXAZINONE

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

The municipal district of Ribeirão Preto is located in the northeast region of the São Paulo State with a population of approximately 560.000 inhabitants (IBGE, 2005). In its economic base the agroindustry is considered as the main pole producing of sugar cane and alcohol of Brazil. In sugarcane culture they are applied several agricultural defensives among them the herbicides diuron and hexazinone. The city of Ribeirão Preto is 100% supplied for water underground come from of Water Bearing Guarani and is distributed by the department of water and Sewer of Ribeirão Preto (DAERP). As the municipal district presents areas of recharge of the water bearning guarani, there is possibility of appearing the substances, which can be affecting the quality of the water. In this context it is intended with the present work to study the adsorption capacity activated carbons in the liquid phase for removal of the herbicides diuron and hexazinone. The methodology used was involved the characterization of eight types of powdered activated carbons and five types granulate activated carbons that are produced in Brazil. Initially the carbons were characterized according to the real density, humidity percent, Ph, iodine numbers, index of methyleno blue ashes percent. Based on the best results of the characterizations, in the variation raw material and carbon type, there are 9 activated carbons were selected (4 powdered and 5 granulate). The chosen carbons were done studies through adsorption of the mixture of diuron and hexazinone by espectrophometric methods. In these studies were chosen two activated carbons, a granulate one and a powdered one for determination of isotherms through adsorption diuron and hexazinone by espectrophometric methods and gaseous chromatograph. The results of espectrophometric and gaseous chromatographic is showed that two activated carbons which were chosen possess a adsorptive capacity - Kf higher 350 (mg/g).(L/mg)1/n) and the affinity between adsorbate and adsorbent 1/n smaller than 0,21 for removal of the herbicide diuron, and for herbicide hexazinona a adsorptive capacity Kf approximately 124 (mg/g).(L/mg)1/n) and 1/n smaller than 0,24.

ASSUNTO(S)

herbicidas activated carbons diuron hexazinona carvão ativado adsorção conservacao de solo e agua adsorption pesticides diuron hexazinone

ACESSO AO ARTIGO

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