Biosorption is a cost effective method of metal removal from industrial waste wate.

1. What is biosorption?
Biosorption is a property of certain types of
inactive, dead, microbial biomass to bind and
concentrate heavy metals from even very
dilute aqueous solutions.
It is particularly the cell wall structure of
certain algae, fungi and bacteria which was
found responsible for this phenomenon
Opposite to biosorption is metabolically
driven active bioaccumulation by living cells.

2. Advantages
The major advantages of biosorption
over conventional treatment methods
include:
 Low cost;
 High efficiency;
 Minimisation of chemical and
biological sludge;
 No additional nutrient
requirement;
 Regeneration of biosorbent;
and
 Possibility of metal recovery.

3. Mechanism
The complex structure of microorganisms implies that there are many
ways for the metal to be taken up by the microbial cell. The biosorption
mechanisms are various and are not fully understood. They may be
classified according to various criteria.
According to the dependence on the cell's metabolism, biosorption
mechanisms can be divided into:
1. Metabolism dependent and
2. Non -metabolism dependent.
According to the location where the metal removed from solution is
found, biosorption can be classified as:
1. Extra cellular accumulation/ precipitation
2. Cell surface sorption/ precipitation and
3. Intracellular accumulation.

4. Factors affecting Biosorption
 Temperature seems not to influence the biosorption performances
in the range of 20-35 0C.
 Since biosorption is determined by equilibrium it is largely
influenced by pH,the concentration of biomass and the interaction
between different metallic ion.
 Biomass concentration in solution seems to influence the specific
uptake: for lower values of biomass concentrations there is an
increase in the specific uptake.
 Biosorption is mainly used to treat wastewater where more than
one type of metal ions would be present; the removal of one metal
ion may be influenced by the presence of other metal ions. For
example: Uranium uptake by biomass of bacteria, fungi and yeasts
was not affected by the presence of manganese, cobalt, copper,
cadmium, mercury and lead in solution .

5. Biosorbents
 Bacteria
 Fungi (Aspergillus niger)
(Saccharomyces- yeasts)
 Algae (red and green)
 Seaweed (Sargassum)
Fig. Sargassum -seaweed

6. Biosorption of Pb2+ Streptomyces
pilosus cell

7. Pseudomonas aeruginosa

8. Metal capacities by biomass

9. Environmental Uses
Environmentally
friendly filtering
techniques.
Rigorous filtering of
harmful pollutants
created by
industrial process
and all around
human activity.

10. Biosorption In Industry
 Removal can be
accomplished with
biosorption techniques.
 It is alternative to using
man-made ion
exchange resin,which
cost ten times more
then biosorbents.

11. Common Uses
Uses of biosorption is seen inactivated carbon
filters.
They can filter air and water by allowing
contaminants to bind to their incredibly
porous and high surfaces structure.

12. Desorption
Desorption is important for the regeneration
of the sorbent for its more effective reused.
The desorption process should:
yield the metals in a concentrated form;
restore the biosorbent to close to the original
condition for effective reuse with
undiminished metal uptake and
no physical changes or damage to the
biosorbent.

13. Lead biosorption by Mangifera sp
Data in Table 1 reveals the biosorption of Pb2+ by Mangifera sp. biomass as a
function of initial concentration of blank solutions. Uptake capacity increases to 24.4
mgg-1 and removal of Pb2+ from solution is more at low initial concentration, that is,
maximum 92.003% at 26.01 mgl-1 concentration.
Pb2+concent Ci Cf Ci-Cf q %
ration (mgL-1) (mgL-1) (mgg-1 Removal
25 26.01 2.08 23.93 4.786 92.00308
50 48.07 6.65 41.42 8.284 86.16601
75 76.32 12.53 63.79 12.758 83.58229
100 102.21 13.71 88.5 17.7 86.58644
125 122.14 22.16 99.98 19.996 81.85689
150 147.41 25.41 122 24.4 82.76236

14. Linearized adsorption isotherm for Pb2+ on Mangifera sp. biosorbent.
A. Langmuir isotherm; B. Freundlich isotherm.