Open AccessExamination of the Effectiveness of Physical and Chemical Activation of Natural Bentonite for the Removal of Heavy Metal Ions from Aqueous Solutions
Author(s) -
Fawzi Banat,
Sameer AlAsheh,
Leena Abu-Aitah
Publication year - 2002
Publication title -
adsorption science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.682
H-Index - 36
eISSN - 2048-4038
pISSN - 0263-6174
DOI - 10.1260/026361702320360577
Subject(s) - bentonite , aqueous solution , chemistry , adsorption , metal ions in aqueous solution , metal , inorganic chemistry , nuclear chemistry , chemical engineering , organic chemistry , engineering
The ability of physically and chemically activated bentonite to adsorb copper and nickel ions from aqueous solutions was examined under various experimental conditions. Physically activated bentonite was obtained by thermal treatment of the initial material in an oven at 700°C (T-bentonite), while chemically activated bentonite was obtained in two ways, either by treatment of the initial material with sodium dodecyl sulphate (SDS) as an anionic surfactant to give SDS-bentonite or with aluminium hydroxypolycation as a pillaring agent to give Al-bentonite. Batch adsorption tests were undertaken to study the removal of Cu 2+ and Ni 2+ ions from aqueous solutions using the above-mentioned types of activated bentonite. The adsorption capacity of the bentonites towards both Cu 2+ and Ni 2+ ions followed the order: Al-bentonite > SDS-bentonite > T-bentonite > natural bentonite. The initial metal concentration, solution pH, temperature and salinity of the solution affected the adsorption capacity towards both metal ions. The uptake of Cu 2+ ions increased with an increase in temperature (25–45°C) as well as with an increase in the initial pH of the solution (3–5). The uptake of Cu 2+ and Ni 2+ ions decreased significantly with an increase in the NaCl and KCl concentrations present in the aqueous solution. Sulphuric acid of 0.1 M concentration was found to be an effective desorbent for bentonite laden with heavy metals.