Effects Of NMC On Aquatic Microorganisms

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As the dependence on lithium batteries increased with an elevated demand for clean energy, it became increasingly important to consider the effect of these batteries on the environment. Nickel manganese cobalt oxide (NMC) made up many of these batteries and could dissociate in aquatic environments. Prior experiments, such as Hang et. Al. 2016, reported detrimental effects of dissociated NMC on aquatic microorganisms.1 In the first part of this project, the objective was to explore and develop an effective method to measure nickel (Ni) and cobalt (Co) concentration spectrophotometrically. This step was crucial for the second part of the project, which was to quantitatively analyze the impacts of glucose on the dissolution of these metal ions. …show more content…
This matrix was built to support the dithizone method in which dithizone complexes with Ni and Co, so that these transition metals become visible in the absorbance reading. A buffer solution was made to maintain a neutral pH, using 16.925 g Na2HPO47H2O, and 15.6564 g NaH2PO42H2O in a 100-mL volumetric flask. The pH of this solution was 6.65. To form a dithizone complex with the metal ions, specifications were important to follow in the matrix. The Manzoori paper suggested the concentration of Triton-X to be 0.05%, so 1 mL of 0.5% was added to the final 10 mL matrix. Dr. Doolittle’s handout suggested that the optimal dithizone concentration was 50 μM in 10 mL, so 0.5 mL of 1μM dithizone was added to the matrix. 1 mL of solution was added to the matrix, along with 3 mL of water. In previous trials, 0.5 mL of buffer was added to solution (and water was added appropriately to get to 10 mL); however, this was later modified (see table below), as it was crucial to main a neutral pH to prevent the complexation between dithizone and …show more content…
Doolittle’s handout suggested 0.04 g of NMC per 200 mL of solution (or 200 mg/L). From the Hang paper’s findings on expected dissolution of ions over 72 hours, it was estimated that the combined dissolution of Ni and Co would be around 384μM (272μM for Ni and 112μM for Co) for 200 mg/L of NMC. The experimental data from Trial 1 were discarded due to error in the initial calibration curves. Jan Dolezal’s paper suggested that the sugar to NMC ratio varied between 0.5:1 and 2:1. However, in Trial 2, a wider range of ratios were chosen to explore the effect of small particles. A positive control was made with the expected Ni and Co concentrations and no NMC. For Trial 2 the vessels were made as seen

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