Bioleaching uses microorganisms like bacteria and fungi to extract metals from ores and concentrates. It has been used for over 3000 years to extract copper. Modern commercial bioleaching uses three main methods - slope leaching, in-situ leaching, and heap leaching. Key factors that affect bioleaching include choice of bacteria, ore composition, temperature, acidity, aeration and solid-liquid ratio. Bioleaching is a simple, inexpensive and environmentally friendly alternative to smelting for extracting metals from low-grade ores.
•Introduction of bioremediation: Bioremediation refers to the process of using microorganisms to remove the environmental pollutants i.e. toxic wastes found in soil, water, air etc.
•In situ bioremediation:
It involves a direct approach for the microbial
degradation of xenobiotics at the sites of pollution
(soil, ground water).
•Types of in situ bioremediation:
Natural attenuation.
Engineered in situ bioremediation.
- Bioventing, biosparging, bioslurping,
phytoremediation.
•Ex situ bioremediation:
Waste or toxic pollutants can be collected from the polluted sites and bioremediation can be carried out at a designated place or site.
• Types of ex situ bioremediation
Land farming, windrow, biopiles, bioreactors.
•Microorganisms use in bioremediation:
A number of naturally occurring marine microbes
such as Pseudomonas sp. is capable of degrading oil and other hydrocarbons.
•Factors affecting bioremediation:
Nutrient availability, moisture content, pH, temperature, contaminant availability.
•References:
Satyanarayana U. Biotechnology. BOOKS AND ALLIED (P) Ltd.
Sharma P.D. Environmental Microbiology. RASTOGI PUBLICATIONS.
Gupta P.K. Biotechnology and Genomics. RASTOGI PUBLICATIONS.
Dubey R.C. A Textbook of Biotechnology. S Chand And Company Ltd.
Dubey R.C. A Textbook of Microbiology. S Chand And Company Ltd.
Willey/Sherwood/Woolverton. Prescott’s Microbiology. McGRAW-HILL INTERNATIONAL EDITION.
www.sciencedirect.com/bioremediation.
IntroductionDefinitionPescidesType of pesticidesFate of pesticides in environmentBiodegradation of pesticides in soil Criteria for biodegradation
Strategies for biodegradationDifferent approaches of biodegradationChemical reaction leading to biodegradationChanging the spectrum of toxicityExample of biodegradationAdvantageDisadvantage
“Bioleaching" or "bio-oxidation" employs the use of naturally occurring bacteria, harmless to both humans and the environment, to extract of metals from their ores.
Conversion of insoluble metal sulfides into water-soluble metal sulfates.
It is mainly used to recover certain metals from sulfide ores. This is much cleaner than the traditional leaching.
•Introduction of bioremediation: Bioremediation refers to the process of using microorganisms to remove the environmental pollutants i.e. toxic wastes found in soil, water, air etc.
•In situ bioremediation:
It involves a direct approach for the microbial
degradation of xenobiotics at the sites of pollution
(soil, ground water).
•Types of in situ bioremediation:
Natural attenuation.
Engineered in situ bioremediation.
- Bioventing, biosparging, bioslurping,
phytoremediation.
•Ex situ bioremediation:
Waste or toxic pollutants can be collected from the polluted sites and bioremediation can be carried out at a designated place or site.
• Types of ex situ bioremediation
Land farming, windrow, biopiles, bioreactors.
•Microorganisms use in bioremediation:
A number of naturally occurring marine microbes
such as Pseudomonas sp. is capable of degrading oil and other hydrocarbons.
•Factors affecting bioremediation:
Nutrient availability, moisture content, pH, temperature, contaminant availability.
•References:
Satyanarayana U. Biotechnology. BOOKS AND ALLIED (P) Ltd.
Sharma P.D. Environmental Microbiology. RASTOGI PUBLICATIONS.
Gupta P.K. Biotechnology and Genomics. RASTOGI PUBLICATIONS.
Dubey R.C. A Textbook of Biotechnology. S Chand And Company Ltd.
Dubey R.C. A Textbook of Microbiology. S Chand And Company Ltd.
Willey/Sherwood/Woolverton. Prescott’s Microbiology. McGRAW-HILL INTERNATIONAL EDITION.
www.sciencedirect.com/bioremediation.
IntroductionDefinitionPescidesType of pesticidesFate of pesticides in environmentBiodegradation of pesticides in soil Criteria for biodegradation
Strategies for biodegradationDifferent approaches of biodegradationChemical reaction leading to biodegradationChanging the spectrum of toxicityExample of biodegradationAdvantageDisadvantage
“Bioleaching" or "bio-oxidation" employs the use of naturally occurring bacteria, harmless to both humans and the environment, to extract of metals from their ores.
Conversion of insoluble metal sulfides into water-soluble metal sulfates.
It is mainly used to recover certain metals from sulfide ores. This is much cleaner than the traditional leaching.
Hydrocarbon are major constituents of crude oil and petroleum. They can be biodegraded by naturally-occurring microorganisms in freshwater and marine environments under a variety of aerobic and anaerobic conditions. The ability of microorganisms - bacteria, archaea, fungi, or algae - to break down hydrocarbons is the basis for natural and enhanced bioremediation. To promote biodegradation, amendments such as nitrogen and phosphorous fertilizer are often added to stimulate microbial growth and metabolism
This ppt contains all types of Microbial Bioremediation methods . Everyone can understand clearly . Explaining with neat pictures and animation . Useful for presentation about Microbes in bioremediation . At last it contains a small animated video which helps to get clear view .
Bioremediation of heavy metals pollution by Udaykumar Pankajkumar BhanushaliUdayBhanushali111
Mechanisms and techniques used for Bioremediation which includes phytoremediation, Bacterial & fungal bioremediation. Examples of heavy metal pollution
Lignocelluloses, the major component of biomass, makes up about half of the matter produced by photosynthesis. It consists of three types of polymers – cellulose, hemicellulose, and lignin – that are strongly intermeshed and chemically bonded by non-covalent forces and by covalent cross-linkages. A great variety of fungi and bacteria can fragment these macromolecules by using a battery of hydrolytic or oxidative enzymes. In native substrates, binding of the polymers hinders their biodegradation. Molecular genetics of cellulose-, hemicellulose- and lignin-degrading systems advanced considerably during the 1990s. Most of the enzymes have been cloned, sequenced, and expressed both in homologous and in heterologous hosts. Much is known about the structure, genomic organization, and regulation of the genes encoding these proteins.
Biological treatment is an important and integral part of any wastewater treatment plant that treats wastewater from either municipality or industry having soluble organic impurities or a mix of the two types of wastewater sources.
The four processes are: (1) Preliminary Treatment (2) Primary Treatment (3) Secondary or Biological Treatment and (4) Tertiary or Advanced Treatment
Hydrocarbon are major constituents of crude oil and petroleum. They can be biodegraded by naturally-occurring microorganisms in freshwater and marine environments under a variety of aerobic and anaerobic conditions. The ability of microorganisms - bacteria, archaea, fungi, or algae - to break down hydrocarbons is the basis for natural and enhanced bioremediation. To promote biodegradation, amendments such as nitrogen and phosphorous fertilizer are often added to stimulate microbial growth and metabolism
This ppt contains all types of Microbial Bioremediation methods . Everyone can understand clearly . Explaining with neat pictures and animation . Useful for presentation about Microbes in bioremediation . At last it contains a small animated video which helps to get clear view .
Bioremediation of heavy metals pollution by Udaykumar Pankajkumar BhanushaliUdayBhanushali111
Mechanisms and techniques used for Bioremediation which includes phytoremediation, Bacterial & fungal bioremediation. Examples of heavy metal pollution
Lignocelluloses, the major component of biomass, makes up about half of the matter produced by photosynthesis. It consists of three types of polymers – cellulose, hemicellulose, and lignin – that are strongly intermeshed and chemically bonded by non-covalent forces and by covalent cross-linkages. A great variety of fungi and bacteria can fragment these macromolecules by using a battery of hydrolytic or oxidative enzymes. In native substrates, binding of the polymers hinders their biodegradation. Molecular genetics of cellulose-, hemicellulose- and lignin-degrading systems advanced considerably during the 1990s. Most of the enzymes have been cloned, sequenced, and expressed both in homologous and in heterologous hosts. Much is known about the structure, genomic organization, and regulation of the genes encoding these proteins.
Biological treatment is an important and integral part of any wastewater treatment plant that treats wastewater from either municipality or industry having soluble organic impurities or a mix of the two types of wastewater sources.
The four processes are: (1) Preliminary Treatment (2) Primary Treatment (3) Secondary or Biological Treatment and (4) Tertiary or Advanced Treatment
Bioleaching or Metal Bioleaching or Biomining is a process in Mining and
Biohydrometallurgy (natural processes of interactions between microbes and minerals)
that extracts valuable metals from a low-grade ore with the help of microorganisms such as
Bacteria or Archaea.
• Bioleaching is an alternative to more traditional physical and chemical methods of mineral
processing.
• The application of Biomining processes predates by centuries the understanding of the role
of microorganisms in Metal extraction. However, the modern era of biomining began with
the discovery of the bacterium Thiobacillus ferrooxidans.
• Bioleaching techniques are often more effective than traditional mining applications
mechanism of bioleaching
types of bioleaching
advantages and disadvantages
These slides provide a great knowledge about biomining, its types and its steps. These slides also provide the concise information about future of biomining.
Bioleaching,
Microorganinsms used in bioleaching,
Direct bioleaching, indirect bioleaching , bioleaching of gold, bioleaching of copper, bioleaching of uranium, factor affecting bioleaching, advantage of bioleaching, disadvantages of bioleaching, bioleaching summary
ENRICHMENT OF ORES BY MICROORGANISMS- Bioaccumulation and biomineralizationSijo A
Microbial ore leaching (bioleaching) is the process of extracting metals from ores with the use of microorganisms. This method is used to recover many different precious metals like copper, lead, zinc, gold, silver, and nickel. Microorganisms are used because they can:
lower the production costs.
cause less environmental pollution in comparison to the traditional leaching methods.
very efficiently extract metals when their concentration in the ore is low.
Bioleaching, or microbial ore leaching, is a process used to extract metals from their ores using bacterial micro-organisms.
The bacteria feed on nutrients in the minerals, causing the metal to separate from its ore.
Bioleaching - Introduction, Microorganism used in bioleaching, Mechanism of bioleaching, Commercial processes of bioleaching, Factor affecting bioleaching, advantage & disadvantage
Mechanism of Zinc solubilization by Zinc Solubilizing bacteriasJaison M
M.Sc. Credit Seminar
One of the way to manage Zn deficiency is by using Bacteria which have potentiality of solubilization of insoluble forms of Zinc. Some mechanisms have been reported for solubilisation of zinc by bacteria which are acidolysis, extrusion of protons, mineralization of zinc fractions, production of zinc binding proteins and complexation by organic acids.
Microorganism used in bioleaching
History
Microorganisms
Mechanism
Types
Advantage & disadvantage
Reference
Bioleaching
Bioleaching is the simple and effective technology used for metal extraction from low grade ores and minerals concentrate by use of microorganisms
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...University of Maribor
Slides from:
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Track: Artificial Intelligence
https://www.etran.rs/2024/en/home-english/
2. Introduction
Bioleaching is the simple and effective technology for metal
extraction from low grade ores and mineral concentrate by
the use of micro organisms.
Commonly used microorganisms are:
Mesophiles
Moderately thermophilic bacteria
extremophiles
3. History
Copper recovery from mine waters in the Mediterranean area
3000 years ago.
The role of bacteria in bioleaching was shown in 1947.
In 1950´s copper dump leaching.
In 1960´s the first industrial copper heap leaching operation.
First industrial gold bioleaching plant in 1980´s
Nowadays about 40 plants in industrial use for copper, gold,
zinc, cobalt, uranium.
4. Mesophiles -(Acidithiobacillus ferrooxidans, Leptospirillum ferrooxidans
and species of Ferroplasma)
Moderately thermophilic bacteria-(Sulfobacillus and Acidithiobacillus
cladus)
Extremophiles- (Sulfolobus metallicus and Metallosphaera sedula.)
Fungi – Fungal strains - Aspergillus niger and Penicillium simplicissimum
Organisms involved can be
conveniently classified into:
6. Process of Bioleaching
• Biomining encompases two processes
• 1. Bioleaching : Solubilization of one or more
components of complex solid by contact with
liquid phase. Solubilization is mediated by
bacteria. Hence, Bacterial leaching or
Bioleaching.
• Metal of interest is extracted from respective
ores by bacterial action.
• 2. Biooxidation: Bacterial oxidation of reduced
Sulphur accompanying the metal.
7. Procedure
Bacteria perform the key reaction of regenerating the major ore
oxidizer, mostly ferric ion. This reaction takes place in the cell
membrane of bacteria.
In the first step, disulfide is spontaneously oxidized to
thiosulfate by ferric iron (Fe3+), which in turn is reduced to
give ferrous iron (Fe2+):
• FeS2+6 Fe3++3 H2O⟶7 Fe2++S2O3
2-+6 H+ spontaneous
In second step Microorganisms catalyze the oxidation of
ferrous iron and sulphur, to produce ferric iron and sulphuric
acid:
• Fe2+ + 1/4O2 + H+ ---> Fe3+ + 1/2 H2O
• S + 3/2O2 + H2O ---> H2SO4
8. Thiosulfate is also oxidized by bacteria to give
sulfate:
• S2O3
2- +2O2+H2O⟶2 SO4
2-+2 H+ (sulfur oxidizers)
The ferric iron produced in reaction (2) oxidized
more sulfide as in reaction (1), closing the cycle
and given the net reaction
• 2 FeS2+7O2+2 H2O⟶2 Fe2++4SO4
2+4H+
The net products of the reaction are soluble
ferrous sulfate and sulfuric acid.
9. Mechanism involves in bioleaching
Two processes are used in bioleaching:
Direct bioleaching
Indirect bioleaching
10. In direct bioleaching
In indirect method of bioleaching of minerals
bacteria produce strong oxidizing agent which
reacts with metals and extract them from the ores.
11. In direct bioleaching minerals which are
susceptible to oxidation undergoes direct
enzymatic attack by the microorganisms.
Direct bioleaching
12. REACTIONS INVOLVED
Generation of ferric ions in indirect bioleaching
4FeSO + O + 2H SO 2Fe (SO4) + 2H O.
Cu S + 2Fe (SO4) 2CuSO +2FeSO +S
Direct bioleaching invoves:
CuS +2O T. ferroxidans CuSO
14. Commercial process of bioleaching
Naturally occur bioleaching process is very slow.
For commercial extraction of metal by
bioleaching the process is optimized by
controlling the pH, temperature, humidity, o2 and
co2 concentrations.
These processes are:
Slope leaching
In-situ leaching
Heap leaching
15. Slope leaching
In slope leaching the ore is finely ground and kept in large pile in a slope
which is subjected to continuous sprinkling of aqueous solution of
microorganisms. The leach liquor collected at the bottom of the ore is
processed further for metal recovery.
In situ leaching
In in situ leaching ore is subjected to bioleaching in its natural occurrence,
aqueous solution of microorganisms is pumped through drilled passages
with in the ore. The leach liquid collected at the bottom of the ore used for
metal extraction.
Heap leaching
In heap leaching ore is arranged in heap and goes through the same
procedure as in slope leaching. The aqueous solution containing
microorganism works on the heap of ore and produces the leach liquor. The
leach liquor is used for metal recovery.
19. FACTORS EFFECTING BIOMINING:
Success of biomining and efficiency in recovery of minerals depends on various
factors some of which are discussed below.
(a) Choice of Bacteria - This is the most important factor that determines the
success of bioleaching. Suitable bacteria that can survive at high temperatures,
acid concentrations, high concentrations of heavy metals, remaining active
under such circumstances, are to be selected to ensure successful bioleaching.
(b) Crystal Lattice Energy - This determines the mechanical stability and
degree of solubility of the sulfides. The sulfide ores with lower crystal lattice
energy have higher solubility, hence, are easily extracted into solution by the
action of bacteria.
(c) Surface Area - Rate of oxidation by the bacteria depends on the particle
size of the ore. The rate increases with reduction in size of the ore and vice-
versa.
20. Cont…
(d)Ore Composition – Composition of ore such as concentration of
sulfides, amount of mineral present, and the extent of contamination, has
direct effect on the rate of bio-oxidation being selected. The rate of
biooxidation is reduced significantly if the temperature is above or below
the optimum temperature.
(e) Acidity - Biooxidation requires a pH of 2.5-3 for maximum results.
The rate of biooxidation decreases significantly if the pH is not in this
range since the activity of acidophilic bacteria is reduced.
(f) Temperature - The bacteria used in biomining are either mesophilic
or thermophilic. Optimum temperature is required for biooxidation to
proceed at a fast rate. Optimum temperature range for a given bacteria is
between 25-35° C depending on the type of ore
21. (g) Aeration - The bacteria used in biomining are aerobic thus require an
abundant supply of oxygen for survival and growth. Oxygen can be provided by
aerators and pipes. Mechanical agitation is also an effective method to provide
continuous air supply uniformly and also to mix the contents.
(h) Solid-liquid Ratio - The ratio of ore/sulfide to the leach solution (water +
acid solution + bacteria inoculum) should be maintained at optimum level to
ensure that biooxidation proceeds at maximum speed. The leach solution
containing leached minerals should be removed periodically and replaced with
new solution.
(i) Surfactants - Adding small amounts of surfactants like Tween 20 to the
leaching process increases the rate of biooxidation of minerals from sulfide
ores. The surfactants decrease the surface tension of the leach solution, thus,
wetting the ore and resulting in increased bacterial contact which ultimately
increases the rate of biooxidation.
22. Benefits of bioleaching
Simple
Inexpensive
Employed for collecting metals from waste and drainages
Use to extract refines and expensive metals which is not
possible by other chemical processes
no poisonous sulfur dioxide emissions as in smelters
no need for hi pressure or temperature
ideal for low-grade sulfide ores
Environment friendly process
23. Disadvantages
Time consuming
(takes about 6-24 months or longer)
Have a very low yield of mineral
Requires a large open area for treatment
May have no process control
High risk of contamination
Inconsistent yield because bacteria cannot
grow uniformly
24. The future of Bioleaching
Isolate new bacterial strains from extreme environments, such as mine-drainage
sites, hot springs, and waste sites, and use these to seed bioleaching processes.
Improve isolates by conventional mutation and selection or by genetic
engineering. One possibility would be to introduce arsenic resistance into some
bioleaching organisms, which could then be used in gold bioleaching.
Heterotrophic leaching is a solution for wastes and ores of high pH (5.5) where
many of the acidophiles would not grow. Fungi like Trichoderma horzianum
have been shown to solubilize MnO2, Fe O3, Zn, and calcium phosphate
minerals.
The population dynamics within the bioleaching dumps and the relative
importance of various organisms and mechanisms needs to be understood