Assiut university researches
Hydrogen production from acid hydrolyzed
molasses by the hydrogen overproducing
Escherichia coli strain HD701 and subsequent
use of the waste bacterial biomass for
biosorption of Cd(II) and Zn(II)
Fatthy Mohamed Morsy
Abstract:
This study was devoted to investigate production of hydrogen
gas from acid hydrolyzed molasses by Escherichia coli
HD701 and to explore the possible use of the waste bacterial
biomass in biosorption technology. In variable substrate
concentration experiments (1, 2.5, 5, 10 and 15 g L 1), the
highest cumulative hydrogen gas (570 ml H2 L 1) and
formation rate (19 ml H2 h 1 L 1) were obtained from 10 g
L 1 reducing sugars. However, the highest yield (132 ml H2
g 1 reducing sugars) was obtained at a moderate hydrogen
formation rate (11 ml H2 h 1 L 1) from 2.5 g L 1 reducing
sugars. Subsequent to H2 production, the waste E. coli
biomass was collected and its biosorption efficiency for Cd2þ
and Zn2þ was investigated. The biosorption kinetics of both
heavy metals fitted well with the pseudo second-order kinetic
model. Based on the Langmuir biosorption isotherm, the
maximum biosorption capacities (qmax) of E. coli waste
biomass for Cd2þ and Zn2þ were 162.1 and 137.9 (mg/g),
respectively. These qmax values are higher than those of
many other previously studied biosorbents and were around
three times more than that of aerobically grown E. coli. The
FTIR spectra showed an appearance of strong peaks for the
amine groups and an increase in the intensity of many other
functional groups in the waste biomass of E. coli after
hydrogen production in comparison to that of aerobically
grown E. coli which explain the higher biosorption capacity for
Cd2þ or Zn2þ by the waste biomass of E. coli after hydrogen
production. These results indicate that E. coli waste biomass
after hydrogen production can be efficiently used in
biosorption technology. Interlinking such biotechnologies is
potentially possible in future applications to reduce the cost of
the biosorption technology and duplicate the benefits of
biological H2 production technology.
Key words:
Hydrogen production Biosorption Cd2þ Heavy metals Zn2þ
Waste Escherichia coli biomass a b s t r a c t This
Published in:
international journal of Hydrogen Energy ,Vol. 36,PP.1438114390