29
views
0
recommends
+1 Recommend
1 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Preparation and application of Zero Valent Iron immobilized in Activated Carbon for removal of hexavalent Chromium from synthetic effluent Translated title: Preparação e aplicação de Ferro Valência Zero imobilizado em Carvão Ativado para a remoção de Cromo hexavalente de efluente sintético

      research-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Abstract Unlike organic contaminants, heavy metals are not biodegradable and tend to accumulate in living organisms; they are also recognized for being toxic or carcinogenic. The use of nanoparticles of zero-valent iron (nZVI) is reported as an alternative technique with high potential for in situ and ex situ remediation of contaminated matrices with this metal, mainly due to its large active surface area and significant adsorption capacity to consolidate into a simple and efficient method of treatment. In this study, ZVI particles were synthesized by the chemical reduction method using hydrated ferrous sulfate (FeSO4.7H2O) and sodium borohydride (NaBH4) with subsequent aggregation to powdered activated carbon (PAC), forming the adsorbent PAC-ZVI, which was characterized by the techniques of XRD and SEM, which revealed the integration of the catalyst to the activated carbon matrix. Finally, developed kinetic studies revealed that the adsorption kinetics was better adapted to a pseudo second order model, the isotherms were better represented by the Freundlich model and the thermodynamic results showed that the adsorption reaction occurred through a spontaneous process with endothermic interaction between Cr (VI) and PAC-ZVI with increase in the randomness of the system.

          Translated abstract

          RESUMO Diferentemente dos contaminantes orgânicos, os metais pesados não são biodegradáveis e tendem a se acumular nos organismos vivos e também são reconhecidos por serem tóxicos ou carcinogênicos. A utilização de nanopartículas de ferro zero valente (nFVZ) é relatada como uma técnica alternativa e de elevado potencial para remediação in situ e ex situ de matrizes contaminadas com este metal, principalmente devido à sua grande área superficial ativa e significativa capacidade de adsorção, podendo se consolidar em um método simples e eficiente de tratamento. Neste estudo foram sintetizadas partículas de Ferro Valencia Zero (FVZ) pelo método de redução química utilizando o sulfato ferroso hexa hidratado (FeSO4.7H2O) e Borohidreto de Sódio (NaBH4) com posterior agregação a partículas de carvão ativado em pó (PAC), formando o adsorvente PAC-FVZ, o qual foi caracterizado pelas técnicas de DRX e MEV, as quais revelaram a integração do catalisador à matriz de PAC. Finalmente, estudos cinéticos desenvolvidos revelaram que a cinética de adsorção se adaptou melhor a um modelo de pseudo segunda ordem, sendo que as isotermas foram melhor representadas pelo modelo de Freundlich e os resultados termodinâmicos demonstraram que a reação de adsorção ocorreu através de um processo espontâneo com interação endotérmica entre o Cr (VI) e o PAC-FVZ com aumento na aleatoriedade do sistema.

          Related collections

          Most cited references16

          • Record: found
          • Abstract: found
          • Article: not found

          Removal of chromium(VI) from wastewater by nanoscale zero-valent iron particles supported on multiwalled carbon nanotubes.

          For the first time, nanoscale zero-valent iron (nZVI)-multiwalled carbon nanotube (MWCNT) nanocomposites were adopted to remove Cr(VI) from wastewater. Such composites were prepared through depositing nZVI particles onto MWCNTs by in situ reduction of ferrous sulfate and then characterized by TEM, SEM and XRD. The results showed that nZVI particles could disperse on the surface or into the network of MWCNTs. Compared to bare nZVI or nZVI-activated carbon composites, the nZVI-MWCNT nanocomposites exhibited around 36% higher efficiency on Cr(VI) removal. The mass ratio of nZVI to MWCNTs was optimized at 1:2, at ionic strength of 0.05M NaCl. The reaction followed a pseudo first-order model under different initial Cr(VI) concentrations and pHs. Low pH and initial Cr(VI) concentration could increase both removal efficiency and rate constants. Anions, such as SO(4)(2-), NO(3)(-) and HCO(3)(-), exhibited negative effects on the removal of Cr(VI), while the effects of PO(4)(3-) and SiO(3)(2-) were insignificant. Overall, nZVI-MWCNT nanocomposites offer a promising alternative material for the removal of Cr(VI) ions from wastewater. Copyright © 2011 Elsevier Ltd. All rights reserved.
            Bookmark
            • Record: found
            • Abstract: not found
            • Article: not found

            Activated carbon impregnated by zero-valent iron nanoparticles (AC/nZVI) optimized for simultaneous adsorption and reduction of aqueous hexavalent chromium: Material characterizations and kinetic studies

              Bookmark
              • Record: found
              • Abstract: found
              • Article: found
              Is Open Access

              Enhanced chromium (VI) removal using activated carbon modified by zero valent iron and silver bimetallic nanoparticles

              Recently, adsorption process has been introduced as a favorable and effective technique for the removal of metal ions from aqueous solutions. In the present study, bimetallic nanoparticles consisting of zero valent iron and silver were loaded on the activated carbon powder for the preparation of a new adsorbent (PAC-Feo/Ag). The above adsorbent was characterized by using XRD, SEM and TEM techniqes. Experimental data were exploited for kinetic, equilibrium and thermodynamic evaluations related to the adsorption processes. The Cr(VI) adsorption process was found to be favorable at pH 3 and it reached equilibrium state within 60 min. The stirring rate did not have a significant effect on the adsorption efficiency. Furthermore, the monolayer adsorption capacity of Cr(VI) based on the Langmuir model was measured to be 100 mg/g. The experimental equilibrium data were fitted to the Freundlich adsorption and pseudo second-order models. According to the thermodynamic study, the adsorption process was spontaneous and endothermic in nature, indicating the adsorption capacity increases with increasing the temperature. The results also revealed that the synthesized composite can be potentially applied as a magnetic adsorbent to remove Cr(VI) contaminants from aqueous solutions.
                Bookmark

                Author and article information

                Contributors
                Role: ND
                Role: ND
                Role: ND
                Journal
                ambiagua
                Revista Ambiente & Água
                Rev. Ambient. Água
                Instituto de Pesquisas Ambientais em Bacias Hidrográficas (Taubaté, SP, Brazil )
                1980-993X
                2019
                : 14
                : 5
                : e2380
                Affiliations
                [1] Pato Branco Paraná orgnameUniversidade Tecnológica Federal do Paraná orgdiv1Programa de Pós-Graduação em Tecnologia de Processos Químicos e Bioquímicos orgdiv2Departamento Acadêmico de Química Brazil graz_araujo@ 123456hotmail.com
                Article
                S1980-993X2019000500304
                10.4136/ambi-agua.2380
                4808a748-df71-4643-8165-9c2f5593b403

                This work is licensed under a Creative Commons Attribution 4.0 International License.

                History
                : 02 July 2019
                : 15 February 2019
                Page count
                Figures: 0, Tables: 0, Equations: 0, References: 16, Pages: 0
                Product

                SciELO Brazil

                Categories
                Articles

                activated carbon,hexavalent chromium,zero valent iron.,carvão ativado,cromo hexavalente,ferro valência zero.

                Comments

                Comment on this article