Abstract:
ABSTRACT
Background: In the 21st century, the rapid industrialization leads to excessive release
of heavy metals such as Cr (VI) in to the environment. An exposure to chromium (VI)
can causes kidney and liver damage, depressed immune defense systems, and a
variety of cancers. Most treatment technologies are also highly expensive and
impractical in developing nations. So the better way is to treat and remove Cr (VI)
using locally available and low cost adsorbent.
Objective: This study aims to determine and optimize removal efficiency of locally
available and low cost Teff husk activated carbon for removal of Cr (VI) from an
aqueous solution.
Method: The laboratory based study was conducted on the optimization of Cr (VI)
removal efficiency of Teff husk activated carbon from aqueous solution. Teff husk
activated carbon was developed and characterized its nature. The batch adsorption
was conducted to examine the effect of pH, initial concentration of Cr (VI), adsorbent
dose, and contact time. Central composite design was used to examine the effect of
interaction of process parameters and to optimize the process using Design Expert
version 7.0 software. ANOVA and log transformed second order polynomial
regression model were fitted to analyze the effect of process parameters.
Results: The maximum removal efficiency of Teff husk activated carbon (95.597%)
was achieved at pH 1.92, initial concentration of 87.83mg/L, adsorbent dose of
20.22g/L and contact time of 2.07Hrs. The adsorption of Cr (VI) on the THAC was also
found to be best fitted with pseudo second order kinetics (R2=0.9986) and Langmuir
isotherm model (R2=0.999) of the adsorption process.
Conclusion: Teff husk activated carbon can be used as an efficient adsorbent for
removal chromium (VI) removal from contaminated water. Column adsorption also
needs to be studied in future.
Key words: Batch Adsorption, Chromium (VI), Teff Husk Activated Carbon,
Central composite Design
