ENE107 Report (Group 6) Acid Mine Drainage & Antimicrobial Resistance PDF

9 October 2024 GROUP 6 ACID MINE DRAINAGE & ANTIMICROBIAL RESISTANCE Presented by: Christopher Conje, Shakira Farhana Derico, Jasper Jimeno, Dynah Faye Zumel  9 October 2024 01 Acid...

9 October 2024 GROUP 6 ACID MINE DRAINAGE & ANTIMICROBIAL RESISTANCE Presented by: Christopher Conje, Shakira Farhana Derico, Jasper Jimeno, Dynah Faye Zumel  9 October 2024 01 Acid Mine Drainage TOPICS FOR 02 Case Studies of AMD DISCUSSION 03 Antimicrobial Resistance Case Studies of Antimicrobial 04 Resistance Group 6  9 October 2024 WHAT IS AN ACID MINE DRAINAGE (AMD)? An environmental problem worldwide caused by surface mining operations. It leads to leaching of heavy metals into water sources. Bacterial and spontaneous oxidation of sulfide minerals is the major cause. Group 6  9 October 2024 SULFIDE MINERALS Sulfide minerals are a class of minerals that contain sulfur as a major component. Common sulfide minerals include:, Pyrite: FeS₂ (iron sulfide), Chalcopyrite: CuFeS₂ (copper iron sulfide), Galena: PbS (lead sulfide), Sphalerite: ZnS (zinc sulfide), Molybdenite: MoS₂ (molybdenum sulfide) Group 6  9 October 2024 HOW DO THESE SULFIDE MATERIALS CAUSE AMD? When these minerals are exposed to oxygen and water, they undergo oxidation, producing sulfuric acid and metal ions. The resulting acidic water can contaminate water sources, harm aquatic life, and degrade ecosystems. Certain bacteria can accelerate this process, further exacerbating the problem. Group 6 OXIDATION OF IRON SULFIDE The oxidation of FeS2 is a combination of chemically and bacterially catalyzed reactions. Two electron acceptors that participate in the process: O2 & Fe3+ OXIDATION OF IRON SULFIDE  OXIDATION OF IRON SULFIDE A slow chemical reaction with O2 begins.  OXIDATION OF IRON SULFIDE Initiator Reaction Leads to the oxidation of HS- to SO4 2- and the development of acidic conditions as Fe2+ is released.  OXIDATION OF IRON SULFIDE Bacterial Oxidation: Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans are bacteria that play a crucial role in acid mine drainage (AMD). Iron Oxidation: These bacteria oxidize ferrous iron (Fe2+) to ferric iron (Fe3+). Sulfide Oxidation: The ferric iron reacts with sulfide minerals, such as pyrite, to produce sulfuric acid (H2SO4). Propagation Cycle: This process creates a positive feedback loop, where the increased acidity from sulfuric acid leads to further oxidation of sulfide minerals, ACIDITHOBACILLUS FEROOXIDANS AND LEPTOSPIRILLUM FEROOXIDANS accelerating AMD. OXIDATION OF IRON SULFIDE  OXIDATION OF IRON SULFIDE Under natural conditions some of the Fe2+ generated by the bacteria leaches away and is subsequently carried by anoxic groundwater into surrounding streams. However, bacterial or spontaneous oxidation of Fe2+ then takes place in the aerated streams, and because O2 is present, the insoluble Fe(OH)3 is formed.  BIOREACTORS It is a closed container with adequate arrangement for aeration, agitation, temperature and pH control, and drain or overflow vent to remove the waste biomass of cultured microorganisms along with their products.  CHALLENGES OF USING BIOREACTORS Bioreactors for AMD treatment require careful management of environmental conditions to ensure optimal microbial activity and metal recovery. Fluctuations in pH, temperature, and nutrients can hinder efficiency.  LIMITATIONS OF USING BIOREACTORS Bioreactor scalability for AMD treatment is limited by factors like microbial interactions and site-specific needs. This can hinder their widespread use in mining due to the need for customized designs.  01 Wheal Jane Mine CASES OF 02 Summitville Mine ACID MINE 03 Bjørndalen Mine DRAINAGE 04 Lily Mine Nelson Tunnel/Commodore 05 Waste Rock Pile  15 January 2023 AMD CASES WHEAL JANE MINE SUMMITVILLE MINE BJØRNDALEN MINE LILY MINE NELSON TUNNEL  WHEAL JANE MINE England, United Kingdom Location The mine is primarily known for its gold and copper Overview extraction operations Water Treatment Systems, Mine Reclamation and Treatment Environmental Rehabilitation, Monitoring.  SUMMITVILLE MINE Colorado, USA Location Summitville was a large-scale gold mine in Colorado. The Overview mining process exposed sulfide minerals to oxygen, which, when mixed with water, created severe AMD problems. A bioreactor using microorganisms, particularly sulfate-reducing Treatment bacteria, was introduced to treat the acid-laden waters contaminated with metals such as copper and zinc  BJØRNDALEN MINE Vestfold, Norway Location This site was historically used for mining various metals. Post- Overview closure, the waste rock and exposed ores contributed to AMD. Passive bioreactors with organic materials were used to Treatment encourage sulfate-reducing bacteria to precipitate metals out of the AMD, effectively neutralizing the water.  LILY MINE Mpumalanga, South Africa Location This gold mine faced significant AMD issues due to the exposure Overview of sulfide-bearing rocks after mining activities. Bioreactors using microbial processes were deployed to Treatment neutralize the AMD and remove heavy metals like iron and manganese from the water  NELSON TUNNEL/COMMODORE WASTE ROCK PILE Colorado, USA Location The Nelson Tunnel was part of a historic silver mining operation in Overview Colorado, which led to severe AMD due to exposed sulfide minerals. A bioreactor and permeable reactive barrier system were installed to Treatment treat the AMD by leveraging sulfate-reducing bacteria to remove metals like zinc, cadmium, and lead​.  9 October 2024 CONCLUSION The treatment of Acid Mine Drainage (AMD) through biological methods, particularly the use of bioreactors with specialized microbial communities, has shown significant potential in effectively neutralizing acidity and recovering valuable metals, thereby mitigating environmental impacts and promoting sustainable mining practices. Group 6