BIOSSORPTION OF HEAVY METALS ON GREEN COCONUT POWDER / BIOSSORÇÃO DE METAIS PESADOS UTILIZANDO PÓ DA CASCA DE COCO VERDE (COCOS NUCIFERA)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

Heavy metal pollution has become one of the most serious problems today, and the use of organic material biomass for the detoxification of industrial effluents for environmental protection offers a potential alternative to existing trea tment technologies. The aim of this work was determined the biosorption capacity of coconut fibers (Cocos nucifera) for different heavy metals. The effect of pH, initial concentration, size of particle and kinetics were studied. The characteristics of the surface of coconut fibers had been investigated using measurements of potential zeta and analyses with scanning electron microscope. The removal was found to be higher for cadmium, chromium (III) e chromium (VI) among the 6 metallic species studied (As, Cd, Cr (III), Cr (VI), Ni e Zn). The values of pH used were 7 for cadmium and chromium (III) and of 2 for chromium (VI). For cadmium, chromium (III) and chromium (VI), with an initial metal concentration lower than 100 mg/L, removal rates of 95%, 85% and 80% respectively had been observed. For cadmium and chromium (III), with an initial concentration lower than 1000 mg/L, removal rates of 80% and 85% respectively were found. The adsorption capacity of coconut fibers for heavy metals had been evaluated using Langmuir and Freundlich adsorption isotherms. The Langmuir´s model gave best results for cadmium and chromium (VI) and Freundlich´s model for chromium (III). The kinetics of the process was studied just for cadmium, because it presented the best removal rates. The kinetics study showed that the biosorption process followed a pseudo second order model. This suggests that coconut fibers represent a good option for biosorption process and can be used as an alternative to the classical technologies for effluent decontamination.

ASSUNTO(S)

cocos nucifera fluentes heavy metals biossorcao biosorbent cocos nucifera biosorption biossorvente wastewaters metais pesados

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