Applications of carbon nanotubes in environmental issues: Controlling water pollution Chapter uri icon

abstract

  • Carbon nanotubes were synthesized for the first time in the 90%27s and since then these have been used in electrical and electronics devices. In recent years, scientists from all around the world have focused also on carbon nanotubes to control water pollution. Hence, water treatment and purification systems based on carbon nanotubes might emerge in the near future. This chapter describes the most outstanding results obtained for the removal of organic and inorganic pollutants present in aqueous solutions (cadmium, lead and phenol) with different types of carbon nanotubes, such as single wall carbon nanotubes (SWCNT), multiwall carbon nanotubes (MWCNT) and nitrogen-doped multiwall carbon nanotubes (N-MWCNT). The adsorption experiments were carried out with ideal solutions of single and binary compositions of the mentioned pollutants, at different conditions of pH and temperature. Results for single component solutions show that the pH and temperature of the system play an important role in the adsorption capacity of nanotubes. Also, these features can correlate the adsorption capacity when two or more species are in solution (competitive adsorption). On the other hand, the physical-chemical characterization of adsorbents allows knowing their properties as active sites, specific area, pore size distribution, etc., involved in the adsorption process. The analysis of these properties may describe possible adsorption mechanisms and kinetics as will be shown throughout the chapter. The results of this research have helped to suggest adsorption mechanisms and to elucidate the relevance of nitrogen atoms in the lattice of carbon nanotubes to adsorption capacity. In addition, results from adsorption kinetic studies are presented, in an effort to determine mass transfer coefficients, which are important to design industrial scale equipment. © 2013 Nova Science Publishers, Inc. All rights reserved.
  • Carbon nanotubes were synthesized for the first time in the 90's and since then these have been used in electrical and electronics devices. In recent years, scientists from all around the world have focused also on carbon nanotubes to control water pollution. Hence, water treatment and purification systems based on carbon nanotubes might emerge in the near future. This chapter describes the most outstanding results obtained for the removal of organic and inorganic pollutants present in aqueous solutions (cadmium, lead and phenol) with different types of carbon nanotubes, such as single wall carbon nanotubes (SWCNT), multiwall carbon nanotubes (MWCNT) and nitrogen-doped multiwall carbon nanotubes (N-MWCNT). The adsorption experiments were carried out with ideal solutions of single and binary compositions of the mentioned pollutants, at different conditions of pH and temperature. Results for single component solutions show that the pH and temperature of the system play an important role in the adsorption capacity of nanotubes. Also, these features can correlate the adsorption capacity when two or more species are in solution (competitive adsorption). On the other hand, the physical-chemical characterization of adsorbents allows knowing their properties as active sites, specific area, pore size distribution, etc., involved in the adsorption process. The analysis of these properties may describe possible adsorption mechanisms and kinetics as will be shown throughout the chapter. The results of this research have helped to suggest adsorption mechanisms and to elucidate the relevance of nitrogen atoms in the lattice of carbon nanotubes to adsorption capacity. In addition, results from adsorption kinetic studies are presented, in an effort to determine mass transfer coefficients, which are important to design industrial scale equipment. © 2013 Nova Science Publishers, Inc. All rights reserved.

publication date

  • 2013-01-01