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Nickel power point for sig xi
- 1. The Physiological Effects of Nickel Chloride Hexahydrate on Aquatic Microbial Biofilm Presented by: Desiree’ Shaw Mentored by: Dr. Sally Entrekin Adam Musto Background at http://faculty.uca.edu/sentrekin/
- 2. Aquatic Microbial Biofilm • Complex communities of aquatic microorganisms http://www.ncbi.nlm.nih.gov/pmc/articles/PMC99016/ • Bacteria • Fungi • Important foundation of aquatic food web • Eaten by benthic macroinvertebrates ftp://ftp.wcc.nrcs.usda.gov/wntsc/strmRest/wshedCondition/EPTIndex.pdf • Ephemeroptera • Plecoptera • Trichoptera
- 4. Nickel • Common metal found in surface waters Office of Water, Regulations and Standards, Criteria and Standards Division. United States Environmental Protection Agency • Naturally found in Earth’s crust http://www.atsdr.cdc.gov/toxprofiles/tp15-c6.pdf • Released into the environment • Dust in windstorms • Eruption of volcanoes • Contamination of ground and surface water http://www.atsdr.cdc.gov/toxprofiles/tp15-c6.pdf • By-product of many industrial processes • Industrial waste enter environment through water cycle • Natural gas hydraulic fracturing drilling
- 5. Natural Gas Hydraulic Fracturing Drilling • Fayetteville Shale Gas Region • Highlighted portion • Scott Henderson Gulf Mountain Wildlife Management Area • Blue arrow http://www.searcychamber.com/economi c-development/fayetteville-shale
- 6. Question • This study attempted to • expand on existing data to explore the physiological effects of nickel on the aquatic microbial community (fungi and bacteria) as measured by respiration • identify the physiological response of the biofilm, which are a food source for the macroinvertebrates, in order to provide further understanding of the macroinvertebrate response to elevated metals
- 7. Hypothesis • It was hypothesized that: • aquatic microbial biofilms require trace amounts of nickel to enhance respiratory functions • as nickel concentrations increase, the microbial community would be adversely affected, and less oxygen would be consumed by the aquatic microbial biofilm
- 8. Sweet Gum Leaf Preparation • Cut 105 Sweet Gum (Liquidambar styraciflua) leaves into 2 cm by 2 cm squares • Leeched leaves in hot tap water for 12 hours
- 9. Culturing of Aquatic Biofilm • Incubated leaves in enriched water for 25 days at room temperature • Leaves placed in mesh bag in plastic tank for containment • Bubblier added to provide oxygen • Enriched water changed once per week • 1400 μg/L Nitrate • 140 μg/L Phosphorus • 2 liter of distilled water
- 10. Incubation of Leaves Leaves in incubation tank Leaves after incubation period after 25 days (visible dark spots are biofilm)
- 11. Nickel Classification Criteria • EPA established criteria http://water.epa.gov/scitech/swguidance/standards/criteria/current/index.cfm • Chronic • Acceptable • Actual nickel levels acquired from Scott Henderson Gulf Mountain Wildlife Management Area streams • Black Fork Stream • Clifty Stream • Sunny Side Stream
- 12. Nickel Criteria, Classification, and Concentrations Concentration of Classification Criteria Nickel (mg/L) Blank No nickel nor leaves 0.00 Control No nickel 0.00 EPA Chronic EPA assignment 0.05 Low Black Fork Stream 0.20 Medium Clifty Stream 0.70 EPA Acceptable Allowed value under EPA standards 1.10 High Sunny Side Stream 1.60 Elevated Comparison value 3.00
- 13. Nickel Solution • Formulate 3 mg Ni2+/L • Nickel source from nickel chloride hexahydrate (NiCl2*6H2O) • Ni2+ is 24.7% of the weight of NiCl2*6H2O (237.71 g/mol) • Mass needed is calculated • 0.003 g Ni2+ needed/0.247 percent Ni2+ in NiCl2*6H2O • 0.01214 g NiCl2*6H2O needed for this concentration • 0.0122 g of nickel chloride hexahydrate weighed out • Dissolved in 1 liter enriched water
- 14. Dilution of Nickel Concentrations Concentration Volume Nickel for Volume Nutrient water Classification of Nickel dilution into 500 mL for dilution to 500 mL (mg/L) solution (mL) solution (mL) Blank 0.00 0.00 500.00 Control 0.00 0.00 500.00 EPA Chronic 0.05 8.33 491.67 Low 0.20 33.33 466.67 Medium 0.70 116.67 383.33 EPA Acceptable 1.10 183.33 316.67 High 1.60 266.67 233.33 Extreme 3.00 500.00 0.00
- 15. Sample Preparation • Twenty-four sterile 50 mL centrifuge tubes • Fifteen incubated leaves per nickel classification • Eight 500 mL beakers
- 16. Dissolved Oxygen Data • Calibrated Dissolved Oxygen (DO) probe • Initial DO levels recorded • Incubated leaves with biofilm for 24 hours in nickel solution in the dark • Final DO levels recorded
- 17. Biofilm Weight Dry weight of incubated Ash weight of incubated leaves determined leaves determined
- 18. Change in Dissolved Oxygen 250.00 0.02 200.00 mg Ni/L Control % Saturation/ gram 150.00 EPA Chronic Low 0.00 1.10 Medium mg Ni/L mg Ni/L 1.60 100.00 EPA Acceptable 0.05 mg Ni/L 0.70 High mg Ni/L mg Ni/L Extreme 50.00 3.00 mg Ni/L 0.00 Nickel Concentrations Relationship of concentrations of nickel in terms of change in dissolved oxygen per gram ± Standard Error
- 19. Hypothesis Affirmed • Increased respiratory functions at 0.20 mg/L concentration of nickel solution • Trend indicated that as nickel concentrations increased, biofilm respiration decreased
- 20. Future Work • Repeat the experiment: • Add more replicates per sample • Use nickel as the cation for 2 solutions • Nickel Chloride • Nickel Nitrate
- 21. Acknowledgments • Dr. Sally Entrekin: Assistant Professor of Biology at the University of Central Arkansas (UCA) • Dr. Robert Mauldin: Chair of Chemistry Department at UCA • Dr. Patrick Desrochers: Professor of Chemistry at UCA • Adam Musto: Graduate Student in the Biology Department at UCA • Department of Biology at UCA • Department of Chemistry at UCA