Removal of toxic metals from wastewater by Brazilian natural scolecite

Bosco, Sandra Maria Dal; Jimenez, Ricardo Sarti; Carvalho, Wagner A.

doi:10.1016/j.jcis.2004.08.060

Cited by 125 publications

(74 citation statements)

References 30 publications

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“…Entre os metais menos retidos pelas zeólitas, vários autores vêm apontando o níquel (ZAMZOW et al 1990, OUKI & KAVANNAGH 1997, FAGHIHIAN et al 1999, BOSCO et al 2005, RÍOS et al 2008 e o cromo III (GENÇ-FUHRMAN 2007, SHINZATO et al inédito, OUKI & KAVANNAGH 1997, RÍOS et al 2008.…”

Section: Seletividade Iônicaunclassified

“…Muitos trabalhos têm verificado a grande eficiência desse tipo de tratamento na dessorção de chumbo da fase zeolítica, no entanto, o mesmo não tem sido observado com o crômio (III) (PANSINI et al 1991, BOSCO et al 2005. Acredita-se que esse fenômeno ocorra devido à forte influência da energia de adsorção do Cr 3+ na estrutura da zeólita, dificultando a sua troca com o Na + (SHINZATO et al inédito).…”

Section: Capacidade De Regeneração Das Zeólitasunclassified

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Remoção de metais pesados em solução por zeólitas naturais: revisão crítica

Shinzato

2007

Rev. Inst. Geol.

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RESUMONesta síntese são discutidos os resultados de trabalhos publicados nos últimos anos referentes à aplicação das zeólitas naturais na remoção de metais pesados em solução. A seqüência de seletividade iônica, bem como os parâmetros associados à eficiên-cia de adsorção e capacidade de troca catiônica (CTC), estão inteiramente relacionados à estrutura cristalina das zeólitas e às características químicas dos íons encontrados em solução. Cabe ressaltar que, algumas variáveis externas como temperatura, pH e concentração iônica inicial podem interferir no processo de remoção de metais, assim como na seqüência de seletividade iônica. De forma geral, íons com menor energia de hidratação possuem maior preferência pelos sítios de troca disponíveis nas estruturas das zeólitas. A eficiência de remoção de íons de maior energia de hidratação, por sua vez, pode ser controlada pela sua concentração na solução: quanto menor, melhor. Verifica-se, portanto, que as zeólitas naturais possuem grande potencial de aplicação em tratamentos de efluentes contaminados com metais pesados.Palavras-chave: zeólitas naturais, adsorção, troca iônica, metais pesados. ABSTRACTRecent work on the application of natural zeolites to the removal of heavy metals in solution is discussed. Ionic selectivity sequences of natural zeolites, as well as parameters associated with their efficiency of adsorption and ionic exchange, are closely related to their crystal structure and the chemical characteristics of the ions in solution. It is noteworthy that some external variables such as temperature, pH and initial ion concentration can interfere in the process of removal of heavy metals in solution, as well as in the sequence of ionic selectivity. In general, ions with low energy of hydration have greater preference for available charged exchange sites within the zeolite framework. The efficiency of removal of ions with higher energy of hydration, in turn, can be controlled by its solution concentration: the less concentrated the better. It is evident, therefore, that natural zeolites have a great potential in the treatment of effluents contaminated by heavy metals.

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Section: Seletividade Iônicaunclassified

Section: Capacidade De Regeneração Das Zeólitasunclassified

Remoção de metais pesados em solução por zeólitas naturais: revisão crítica

Shinzato

2007

Rev. Inst. Geol.

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“…The adsorption of metal species has been investigated using various alternative materials (Korn et al, 2004;Bosco et al, 2005;Soto et al, 2005), but little attention has been given to manganese removal from AMD solutions. Adsorption has proven to be a particularly interesting technique in hydrometallurgical applications.…”

Section: Introductionmentioning

confidence: 99%

Batch removal of manganese from acid mine drainage using bone char

Sicupira

Silva

Leão

et al. 2014

Braz. J. Chem. Eng.

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-The present study investigated batch kinetics and the batch equilibrium of manganese removal from acid mine drainage (AMD) using bone char as an adsorbent. Equilibrium tests revealed that the Langmuir-based maximum manganese uptake capacity was 22 mg g -1 for AMD effluents and 20 mg g -1 for laboratory solutions at a pH ranging from 5.5 to 5.7. The pseudo-second order model best described the manganese kinetics within bone char. Manganese removal was mainly influenced by the operating variables of the solid/liquid ratio and the pH of the aqueous phase. In fact, metal uptake was favored at nearly neutral pH values. The effect of particle size and temperature proved to be insignificant for the investigated operating range. This work also evaluated the mechanism for manganese removal using bone char. Results showed that intraparticle diffusion is the main rate-limiting step; however, additional contributions from boundary layer diffusion may well affect this removal when particles of smaller sizes are used. The final concentration of fluoride and other metals present in the AMD effluent was in agreement with the concentration limit set forth by Brazilian legislation. The present study demonstrated that bone char is a suitable material to be used for the removal of manganese from AMD effluents.

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“…Minerals of this group are quite commonly used in laboratory experiments for the removal of heavy metals from aqueous solutions, mainly in the ion-exchange process [10][11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%