"Nanocomposites and nanomaterials"

Preparation and characterization of activated carbons obtained from the waste materials impregnated with phosphoric acid (V)

Zięzio M.1, Charmas B.1, Jedynak K.2
1Department of Chromatographic Methods, Faculty of Chemistry, Maria Curie -Sklodowska University. Maria Curie-Sklodowska Sq. 3, 20-031 Lublin, Poland. 
E-mail: madziula32.22@gmail.com
2Department of Physical Chemistry, Institute of Chemistry, Jan Kochanowski University, Swietokrzyska 15G, 25-406 Kielce, Poland.

Nowadays significant amounts of wastes, mainly of organic origin are produced. For this reason scientists pay more and more attention to searching for possibilities of their recycling and/or reuse. One of the many waste management alternatives is their reconversion into energy in pyrolysis or fermentation processes. Recently many researchers have used agricultural wastes as precursors for the production of activated carbon, due to their low cost and widespread availability. Active carbons are porous materials characterized by a very well developed specific surface area owing to which they are used in the separation, adsorption and purification processes.
The aim of the studies was optimization of the conditions for the pyrolysis process and the activation of starting materials. Spent coffee was used as a precursor for the preparation of effective carbon adsorbents. The activating agent was phosphoric acid (V) at the different impregnation ratios (0.5, 1, 1.5, 2). The pyrolysis process was conducted in various temperature ranges. The obtained materials were characterized by the nitrogen adsorption/desorption isotherms and thermal analysis.
On the basis of the research it was found that solid coffee wastes are an appropriate starting material for the preparation of activated carbons. It has been shown that the materials with good structural properties can be obtained during slow pyrolysis using a relatively high degree of impregnation with phosphoric acid (V). The obtained materials were characterized by significant surfaces with a well developed pore structure which makes them good potential adsorbents for water treatment.