Microporous and Mesoporous Materials
Microporous and Mesoporous Materials
4 years ago

Ammonium modified natural clinoptilolite to remove manganese, cobalt and nickel ions from wastewater: Favorable conditions to the modification and selectivity to the cations

Ammonium modified natural clinoptilolite to remove manganese, cobalt and nickel ions from wastewater: Favorable conditions to the modification and selectivity to the cations
The removal of manganese, cobalt and nickel from industrial ammoniacal wastewaters has been studied using natural Cuban clinoptilolite modified to ammonium form. Favorable conditions to obtain the ammonium-clinoptilolite form (NH4-CLI) were determined from detailed kinetic studies of NH4 + ion-exchange in the clinoptilolite (CLI). Obtained NH4-CLI was characterized by IR spectroscopy and X-ray diffraction. NH4-CLI was used to remove Mn2+, Co2+ and Ni2+ from mixed aqueous solutions. The thermodynamic study on ion-exchange equilibrium between NH4 + in solution and these metallic cations from metal-clinoptilolite forms was performed. Increasing the temperature promotes the NH4 + exchange, which is controlled by the intracrystalline diffusion of ions inside the clinoptilolite. However, the activation energy of this process is not very high. This provides a wide temperature interval for the NH4-CLI efficient production. NH4-CLI removes Co2+ and Mn2+ by ion-exchange selectively at room temperature, being poorly selective to Ni2+, producing a well ions separation. Increasing the temperature greatly enhances the NH4-CLI capacity to remove these metal cations, which is substantially higher to Ni2+. The obtained values for the free energy variation and equilibrium constant lead to outline that the selectivity order of the metal-clinoptilolite forms by NH4 + at room temperature is Mn-CLI > Co-CLI > Ni-CLI. Divergences in the behavior to these exchange processes are associated with difference in the interaction of cations with their ligands in solution as well as into zeolite framework, and accessibility at ion-exchange sites inside clinoptilolite.

Publisher URL: www.sciencedirect.com/science

DOI: S1387181117305061

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.