Environmental bio-remediation of various heavy metal by the process biosorption, with help of living or dead bacteria, algae and fungi.

1. COURSE WORK SEMINAR ON
BIOSORPTION OF HEAVY METALS BY VARIOUS ORGANISMS
(BACTERIA, ALGAE AND FUNGI)
Presented by
Swayam Prakash Nanda
Regd No:1981002011
Environmental Science
Department of chemistry

2. Contents
• Introduction
• Objective
• Biosorption
• Mechanism
• Factors affecting Biosorption
• Organisms for biosorption
• Advantages and disadvantages
• Conclusion
• References

3. Heavy Metals Source Threshold
limit value
(mg/m3)
Arsenic Pesticides 0.5
Cadmium Welding 0.2
Lead Paint 0.2
Manganese Fuel addition 5
Chromium Mines 1
Zinc Refineries 5
Copper Mining,
chemical
industry
1

4. Removal
Technology
Extraction
Chemical
precipitation
Others
Ion
exchange
Limitation
• Tedious
• Time consuming
• Expensive.
Biosorption
A solution for eliminating the
tedious heavy metal removing
process
SO AN ALTERNATIVE METHOD
IS NECESSARY

5. Objective
 Conventional methods for the removal of metal ions such as chemical precipitation and membrane
filtration are extremely expensive.
 efficient at low concentrations of metal
 Biosorption and bioaccumulation are eco-friendly alternatives.
 natural materials like microbial biomass, agro-wastes, and industrial by-products have been suggested as
potential biosorbents for heavy metal removal.

6. Biosorption
 Biosorption can be defined as a simple metabolically passive physicochemical process involved in the binding of metals ions
(biosorbate) to the surface of the biosorbent which is of biological origin.
 Biological removal includes the use of microorganisms, plant-derived materials, agriculture or industrial wastes, biopolymers,
and so on.
 Microorganisms (live and dead) and other industrial and agriculture byproducts can be used as biosorbents for the process of
biosorption.
 Biosorption can remove contaminants even in dilute concentrations and has special relevance with respect to heavy metal
removal owing to toxicity at ppb levels. Biosorption
Sorbent Sorbate

7.  The metal biosorption process involves a two-step process.
 In the first step metal ions are adsorbed to the cell surface by interactions between metals and functional groups
displayed on the cell surface.
 In second step due to active biosorption metals penetrates into the cell wall.
Continued…..
biosorption is a metabolically passive process, it does not require energy, and the amount of contaminants a sorbent can
remove is dependent on kinetic equilibrium and the composition of the sorbents cellular surface. Contaminants are
adsorbed onto the cellular structure.
Bioaccumulation is an active metabolic process driven by energy from a living organism and requires respiration.
Both bioaccumulation and biosorption occur naturally in all living organisms however, in a controlled experiment conducted
on living and dead strains of bacillus sphaericus it was found that the biosorption of chromium ions was 13–20% higher in
dead cells than living cells.
In terms of environmental remediation, biosorption is preferable to bioaccumulation because it occurs at a faster rate and
can produce higher concentrations. Since metals are bound onto the cellular surface, biosorption is a reversible process
whereas bioaccumulation is only partially reversible.

8. Mechanism

9. Types of mechanism
Biosorption mechanism
Metabolism dependant Non metabolism dependant
Transport across cell
membrane
Precipitation
Physical
adsorption
Ion exchange complexion

10. Types of mechanism
Biosorption mechanism
Intracellular Accumulation
Cell surface
accumulation/precipitation
Extracellular
accumulation/precipitation
Transport across cell
membrane
complexion
Physical
adsorption
Precipitation
Transport across cell membrane is common to both type of mechanisms intracellular and metabolism
dependent.

11. Factors affecting Biosorption
 Effect of pH
 increase in pH from 1 to 4 increased the biosorption of Cr (VI) from wastewaters by Saccharomyces
cerevisiae biomass.
 biosorption of Cr by pretreated Aspergillus niger the optimum pH was found to be 3.
 increase in pH from 2.0 to 4.5 increased the biosorption of Cd by Rhizopus cohnii biomass.
 Effect of temperature
 25 to 40°C is the optimum temperature for biosorption.
 Initial metal concentration
 The biosorption capacity of the biosorbent increases initially with the increase in metal ion concentration and
then reaches a saturation value.
 Effect of biosorbent dose
 Effect of contact time
 Effect of agitation speed: The optimum speed of agitation for the biosorption of Cd and Zn by Aspergillus
niger was found to be 120 rpm.

12. Algae as Biosorbents
 Because of their large surface
area and high binding affinity
they have been reported to
effectively remove metals from
waste water.
 High uptake capacities, similar
to commercial ion-exchange
resins and their availability is
nearly unlimited amounts from
the ocean
Algae Optimum pH
range
Adsorbed metals
Laminaria
japonica
4.3-6.5 Cd2+, Cu2+, Ni2+
and Zn2+.
Chlamydomonas
reinhardtii
6 Copper and lead
Oedogonium sp. 5 Cu, Co, Cr, Fe,
Hg, Ni, Zn, and
U.
Ulothrix
cylindricum
6 As(III)
Parvathy et al.2016

13. Fungi as Biosorbents
Economical and constant supply
source of biomass to remove metal
ions from waste water
• Can easily grow in substantial
amounts using unsophiscated
fermentation techniques
• Can also easily grow using
inexpensive growth media
Fungi pH range Metal
Adsorbed
Fungalia trogii 6 Hg2+, Cd2+ and
Zn2+
Trametes
Versicolor
6 Cu2+, Pb and
Zn2+,
Rhizopuscohnii 4.5 - 6.5 Cadmium
Parvathy et al.2016

14. Bacteria as Biosorbents
The bacterial cell wall is the first
effective compartment for adsorbing
heavy metal particles because it
contains many anionic functional
groups, capable of binding to heavy
metals, such as peptidoglycan,
teichoic acids, phospholipids and
lipopolysaccharides
Bacteria pH range Metals
adsorbed
Tsukamurella
paurometabola
6 Cd2+ and
Zn2+
Thermophilic
bacteria
2.3 strontium
Bacillus sp. 9 cadmium
and
nickel
Geobacillus toebii 3-6 Cd2+,
Cu2+,
Ni2+, Zn2+
and Mn2+
Parvathy et al.2016

15. Algae
Chlorella vulgaris removes Cd(II) with an efficiency at 96.8% (dead) and 95.2(alive)
Bacteria
Bacillus subtilis was most efficient in Zn removal with an efficiency 99.2(dead) and 96.3(alive)
Fungus
Phanerochaete chrysosporium removes 64.25 % Cr and 57% Ni

16. Advantages
• Very rapid and takes place between a few minutes to a few hours.
• A wider range of operating conditions such as pH, temperature and metal concentration is possible.
• No aseptic conditions are required.
• Low operating cost
• High efficiency
• Minimisation of chemical and/or biological sludge.
• No additional nutrient requirement.
• Regeneration of biosorbent.
• Possibility of metal recovery.

17. Disadvantages
• Early saturation
• Potential for biological process improvement is
limited
• Re-generation of biosorbent materials

18. • A useful and effective alternative against the conventional system
• From studies it is inferred that the microbial cells retain the activity in an optimum pH range and depend on
other factors like concentration of metal ion and biomass. This will help in identifying the suitable
biosorbent for biosorption process.
• Even though this is a cumbersome task, engineers are actively working to develop a biosorption
optimization by modelling
• More research on recombinant organism should be done for better result in biosorption.
Conclusion

19. Referances
Sri Lakshmi Ramya Krishna Kanamarlapudi, Vinay Kumar Chintalpudi and Sudhamani Muddada 2018 Application of
Biosorption for Removal of Heavy Metals from Wastewater, Biosorption.
F Veglio, Removal of Metal Ions by Biosorption.
R. Flouty, G. Estephane / Journal of Environmental Management 111 (2012) 106e114.
M. Akbari et al. / Journal of Environmental Chemical Engineering (2014)
R. Black et al. / Journal of Environmental Chemical Engineering 2 (2014) 1663–1671 effluent.
Heavy metal biosorption by white rot fungi, by Ulkii Yetis.
Biosorption of uranium and heavy metals using some local fungi isolated from phosphatic fertilizers, by Amany