TITLE:
Removal of Chromium (VI) from Tannery Effluent Using Bio-Char of Phoenix reclinata Seeds
AUTHORS:
Joseph Katenta, Caroline Nakiguli, Paul Mukasa, Emmanuel Ntambi
KEYWORDS:
Phoenix reclinata, Chromium (VI), Tannery Effluent, Adsorption
JOURNAL NAME:
Green and Sustainable Chemistry,
Vol.10 No.3,
August
28,
2020
ABSTRACT: The potential of the Senegal date palm (Phoenix reclinata) seed bio-char to remove chromium (VI) ions from aqueous solutions by
adsorption was investigated. Adsorption experiments were performed on the
tannery effluent and standard aqueous solutions of chromium (VI) for varying
adsorbent doses, contact times, pH, temperatures, and interfering anionic ions
by batch mode. Phoenix reclinata seeds (PRS) bio-char was used in the investigation and the residual
chromium (VI) was determined using the atomic absorption spectrophotometer
(AAS). Results showed that the bio-char removed up to 86% of chromium (VI) ions
in the effluent at pH 2. The highest percentage adsorption registered was 97%
in an aqueous solution of chromium (VI) at pH 1 and this dropped to less than
10% at pH greater than 2. A general increase in adsorption with the increase in temperature was
observed but reduced when the temperature was raised beyond 60°C. The presence of interfering anions caused a reduction in the
adsorption of chromium (VI) ions. The adsorption process fitted both Langmuir
and Freundlich adsorption models and the maximum adsorption capacity, Qo, was 0.6593 mg/g. Thus, PRS bio-char can therefore be used by industries and institutions like secondary schools to treat
effluents that contain chromium (VI).