Heart Disease Prediction using machine learning.pptx
Bioremediation ppt
1. Presentation date: 18th January, 2018
BIOREMEDIATION OF HEAVY
METALS
Presentation by
Kumuda J.
2. CONTENTS
Introduction
Mobility of metal contaminants
Mechanisms for metal remediation
Immobilization
Mobilization
Bioremediation of Mercury-Case study
Advantages and Disadvantages
Conclusion
4. 2. Mobility of metal contaminants
Chemical and physical
properties affect the mobility
of metals in soils and
groundwater
Under acidic conditions metal-
cations are mobile while anions
tend to transform to oxide
minerals.
When a microorganism oxidizes
or reduces species, this reaction
causes metals to precipitate.
Mercury is an example of a
metal that can be precipitated.
5. 3. Mechanisms for Metal
Remediation
Isolation Immobilization
Mobilization
Physical
separation
Extraction
6. 3.1.Immobilization
Reduce the mobility of contaminants by
altering the physical or chemical
characteristics of the contaminant.
In situ treatment is below the ground
Ex-situ waste is excavated or pumped
above the ground for treatment
7. 3.1.1. Solidification and Stabilization
Achieved by mixing the contaminated material with appropriate amounts of stabilizer
material and water
Ex situ requires excavation, transport, and disposal of
hazardous
material.
Deep stabilization/solidification up to 50 ft can be
achieved by using gauged augers (up to 3 ft in diameter
each) that can treat 150-400 cubic yards per day
Cement-based binders
and stabilizers are used
when implementing the
solidification &
stabilization technique.
9. 3.2.1.Mechanisms of Mobilization
Autotrophic
leaching-
Acidophilic bacteria
obtain energy from
the oxidation of the
ferrous iron or
reduced sulfate
compounds, causes
solubilization of
metals.
Heterotrophic
Leaching-
Microorganisms
acidify their
environment by
proton efflux
leading to the
acidification
resulting in the
release of free metal
cations.
Methylation-
methyl groups that
are enzymatically
transferred to a
metal, forming a
number of different
metalloids.
Redox
transformation
-allow
microorganisms to
mobilize metals and
organometallic
compounds by
reduction and
oxidation processes.
10. 4.1. Characteristics of Mercury metal
State:
metallic
Color:
Silver-
white
Form:
Cationic
Dissolves
metals such as
gold and silver
to
form amalgams
4.Bioremediation of Mercury
12. 4.3. Bioremediation Process
Methyl mercury and Mercuric Chloride
Toxic forms of mercury
Pseudomonas putida
It involves the reduction of Hg2+ to volatile Hg0 by the inducible
enzyme mercuric ion reductase coded by the merA gene..
13. 4.4.Removal of Mercury from chemical
wastewater by Microorganism(Wagner-
Dobler, Von Canstein, Li, Timmis, and Deckwer, 2000)
• Pseudomonas putida
• Inoculated48hrs at 300 C in Liq Medium
• Transferred 150liter fermentation vessel 3L of Liq
media.
• Fermentation Fed-batch 4 days at 350 C.
Bacteria
• Analyzed using Automated instruments from Mercury
Instruments(Karlsfeld,Germany).
• Reduction of Hg(II) to Hg(0) was seen.
Mercury
concentrations
• Mercury-resistant bacteria and wastewater was added to
the bioreactor.
• Initial Hg outflow concn = 900μg/L, After 3 hrs = 306
μg/L.
• Full mercury Removal achieved after inoculation.
Bioreactor
14. 4.5. Conclusion
Mercury Resistant Bacteria enzymatically
reduced Hg(II) to Hg(0).
7 Strains of pseudomonas were used
Chloralkali electrolysis water having 3-10
mg/L Hg conc.was fed.
Within 10hrs Hg retention efficiency of
97% was obtained
Bioreactor outflow concn.was 50μg of
Hg/L, which fulfills the discharge limit for
industrial wastes.
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15. 7. Advantages
Bioremediation a natural process
Residues for the treatment are usually harmless products
Bioremediation is useful for the complete destruction of a wide variety of
contaminants
Carried out on site, often without causing a major disruption of normal
activities
Less expensive than other technologies that are used for clean-up of
hazardous waste.
16. 8. Disadvantages
Bioremediation is limited to those compounds that are biodegradable
Highly specific
Difficult to extrapolate from bench and pilot-scale studies to full-scale field
operations
Takes longer than other treatment options
Regulatory uncertainty remains regarding acceptable performance criteria
for bioremediation.
17. 9. Conclusion
Bioremediation, a process whereby natural degradation rates are
accelerated through simulation of indigenous microorganisms is an
effective ecological and economical reclamation alternative.
A beneficial addition to chemical and physical methods of managing
wastes and environmental pollutants – offers a saving of 60 to 90% over
landfills disposal costs.