Thesis (MSc) - Cyprus International University. Institute of Graduate Studies and Research Bioengineering Department

Includes bibliography (sheets 41-47)

ABSTRACT
Precipitation, evaporation, electroplating, ion exchange, membrane processes, and
other techniques have all been developed to remove harmful metal ions from
wastewaters. However, the non-renewable materials utilized, the high cost, and the
production of hazardous sludge make these conventional technologies expensive.
Therefore, biosorption which refers to the process of desired chemicals being removed
or bound from an aqueous solution by biological material is both a biotechnological
breakthrough and a highly efficient method for removing heavy metals. It
demonstrates a common method for utilizing affordable alternative biological
materials for the intended function. Because of their inexpensive cost, wide
availability, rapid adsorption and desorption kinetics, and high surface to volume ratio,
microorganisms more specifically, bacteria, algae, yeasts, and fungi have attracted
increasing interest as biosorbents for heavy metals and other contaminants removal.
Biosorption tests with Cr (VI) as a contaminant were conducted using easily available,
inexpensive, and effective living biomass of Bacillus subtilis by varying pollutant
concentration under favorable parameters. After that, the data were analyzed and
showed that Bacillus subtilis living cells are highly efficient in absorption of Cr (VI).
Models for the Langmuir-1, Freundlich, and Elovich isotherms were used to interpret
the experimental results. were Freundlich was discovered to be best fit for the
biosorption with coefficient of regression (R2
) value of 0.994. The desorption
efficiency was analyzed to be 90.05% which show how possible the biosorbent can be
regenerated for other biotechnological processes.
Keywords: Bacillus subtilis, Biosorbents, Biosorption, Desorption, Elovich,
Freundlich, Langmuir-1.