Mid-Term-Bioleaching-Presentation-2015

Bioleaching

Justin Rangasawmy & Kusum BasnetENGI33126 – Tech. Report 2

Topics of discussion

Definition of bioleaching

Different methods of used in experiment: Acid leaching vs. Bioleaching

Purpose and general overview

Problems and solutions

Quality Control Method

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What is Metal-leaching?

Extraction of metal from ore using non traditional methods

Metallic ores contain metal sulphides.

Leaching converts metal sulfide to a metal forms which can be solubilized and filtered. 𝐅𝐞𝐒𝟐+𝟑 .𝟓𝐎𝟐+𝐇𝟐𝐎 𝑭𝒆𝟐+¿+𝟐𝑯+¿+𝟐𝑺𝑶 𝟒

𝟐−¿ ¿

Types of Leaching:

Bioleaching

Acid Leaching

Industrial Leaching

What is Bioleaching?

Definition: Bioleaching is a method of metal extraction of ore with the usage of microorganisms.

Examples: Bacteria:

Paenibacillus Polymyxa Fungi :

Aspergillus nigerPenicillium simplicissimum

What is Acid Leaching

Definition: Acid leaching is a wet method of metal extraction where ore is treated with acid and agitated for efficiency.

Goal is to oxidize the original metal form to a water soluble form.

The Purpose

In Bioleaching: Grow bacteria, Paenibacillus

Polymyxa, to extract a variety of metals from Olivine ore.

Comparative experiment – leached metals using bioleaching will be compared to acid leach.

The Purpose

In Acid-leaching: Usage of Lactic and Hydrochloric

acid to extract a variety of metals from olivine ore.

Comparative experiment of Acid-leaching of Olivine ore from various locations: Spain, Italy and Norway

The Purpose

Bioleaching and Acid-leaching: Metals extracted will be analyzed for

mass amounts using ICP-OES analysis.

Experiment Overview

Streak the plates with revived bacteria.

Leave plates in incubator for growth.

Bacteria Growth

Experiment Overview

Mature bacteria colonies were introduced to liquid broth sample along with pulverized ore.

Experiment Overview

Left to leach for 2 – weeks in incubator

Unknown Replicates

Experiment Overview

The Bioleaching sample triplicates were centrifuged.

Unknown Replicates

Experiment Overview

Live bacteria were killed off using the autoclave.

Experiment Overview

Acid leaching was also done on the ore for comparison of results.

Both Lactic Acid and Hydrochloric Acid were used in leaching process.

Left for 1 week on shaker table and later centrifuged.

Acid Comparison

Experiment Overview

5 standards were made for calibration of the instrument.

24 samples were made up for acid leaching.

3 unknown replicates were made from bioleaching process.

Acid-Leaching Samples

Experiment Overview

Standards, samples and unknowns were analyzed.

Problems and Solutions

Problems 1 : Fungi Aspergillus Niger

Originally, fungi, Aspergillus Niger was proposed

Aspergillus Niger: Important organism in biotechnology

Used in enzyme production A promising Nickel leaching micro-

organism

Problems: Fungi Aspergillus Niger

Problem? A. Niger contains toxic spores than can

be airborne

Can make people with weak immune systems become very sick may even result in death

Can cause a lung disease called Aspergillosis

Problems: Fungi Aspergillus Niger

Solution? Bacteria, Paenibacillus Polymyxa was

used

Seemed safer alternative.

Soil bacteria

Contributes in nitrogen fixation

Problem 2 : Contamination

Contamination of agar plate While incubating agar

plates it was discovered that different colonies of micro-organisms where growing along

Paenibacillus Polymyxa

Description: Rod shaped Gram positive Colorless

Paenibacillus Polymyxa

Problem: Contamination

Problem: Contamination

Blank Agar Test

Problem: Contamination

Blank Broth comparison

Problem: Contamination

Source? Shared micro-lab Fridge Sponge plug Desk Surface

Problem: Contamination

Solution? New agar solution was prepared Autoclaved equipment Use of biosafety cabinet Used UV light to disinfect surface

Problem: Contamination

Bio-safety Cabinate

Kusum working in biosafety cabinet

Quality Control

Methods to Check for viability

Bacteria when received were freeze dry

Growth and viability of bacteria was important

Temperature control and PH testing were done

Methods to Check for viability

pH strips were used for pH testing

What’s Next

Experimental Results

Waste/Disposal

Equipment Used (Shaker Table, Incubator, Bio-Safety Cabinet

etc.)

Case Study on Bioleaching – Current Research Projects.

Paenibacillus Polymyxa Overview

THANK YOU

Questions????