Treating Metals in Acid Mine Drainage Using Slow-Release Hydrogen Peroxide

3 Acknowledgements . 6 List of Tables.9 List of Figures.10 Chapter 1: Introduction.13 1.1 Formation of AMD.16 1.2 Advanced Oxidation Reactions.18 1.2.1 Fenton’s Reagent.19 1.3 Slow Release Systems.20 1.4 Study Site.22 1.5 Study Objectives.26 Chapter 2: Materials and Methods.28 2.1 Material.28 2.2 Field Measurements.28 2.3 Designing Slow Release Forms.29 2.4 Estimating Release Rate: Column Leaching Tests.30 2.4. 1 Determination of Hydrogen Peroxide Concentration . 32 2.4.2 Determination of Ferrous Iron Concentration . 33 2.5 Proof-of-Concept Ferrous Iron Removal Tests.35 2.6 Small-scale Field Application Test.35 Chapter 3: Results and Discussion.37 3.1 Study Site.37 8 3.1.1 Baseline Chemical Sampling.38 3.2 Characterizing Slow Release Systems.40 3.2.1 Slow Release Form Dimensions.40 3.2.2 Column Release Tests.41 3.2.3 Oxidant Release Efficiency / Recovery Rate.62 3.3 Proof-of-Concept Iron Removal Tests.64 3.4 Small-scale Field Application Test.67 Chapter 4: Conclusion.84 References.86 Appendix A: H2O2 fluxes from 6 SR-HP column tests over two weeks.90 Appendix B: Weight of sodium percarbonate (kg/day) necessary for a [Fe]/[H2O2] 2:1 for different Fe concentrations (mg L) and discharges (L s). 91 9 LIST OF TABLES Page Table 1-1. Redox potential of common oxidants . 18 Table 1-2. Historic water chemistry and discharge measurements at study site BH00690.26 Table 3-1. Historic discharge and chemical parameter measurements at BH00690 (http://watersheddata.com) . 38 Table 3-2. Aqueous chemistry data for BH006900 sampled on 6/10/2014.39 Table 3-3. Properties of slow-release forms made with sodium percarbonate and casting resin.40 Table 3-4. P-values from two-sided T-tests performed between first order decay constants between SR-HP 23-28.62 Table 3-5: Properties of SR-HP forms used in field removal demonstration.65 Table 3-6: Percentage of dissolved oxidant from SR-HP forms removed from field demonstration.69 Table 3-7: Discharge measured during the small-scale field demonstration at BH00690 and upstream and downstream measurements.69 10 LIST OF FIGURES Page Figure 1-1. Locations of the three Appalachian Basin coal regions (from USGS, 2002). 14 Figure 1-2. Slow release diffusion modeled in cross sectional view. (Lee and Schwartz, 2007a). 21 Figure 1-3. Location of study site BH00690 within the Monday Creek Watershed (adapted fromMonday Creek Reclamation Project). 23 Figure 1-4. Location of study site BH00690 in relation to Jobs New Pittsburg Rd and Brush Fork,and other AMD sampling points stored on NPS website (http://watersheddata.com). 24 Figure 1-5. Solubility of major and minor metals at different pHs (modified from Wei et al., 2005). 25 Figure 2-1: Release kinetics of SR-HP forms at 8 mL min -1 column test (adapted from Tong, 2013) . 31 Figure 2-2. Standard curve for Hydrogen Peroxide concentration determination.33 Figure 2-3. Standard curve for Ferrous Iron concentration determination.34 Figure 3-1: Small-scale field demonstration site, BH006900, located within the Monday Creek watershed. Baseline chemical sampling on June 10th, 2014.37 Figure 3-2a. H2O2 release profile from a 1.66 : 1 SR-1 form during a column leaching test using a 7 ml min-1 flow rate.42 Figure 3-2b. H2O2 release profile from a 2.5 : 1 SR-2 form during a column leaching test using a 7 ml min-1 flow rate.43 Figure 3-2c. H2O2 release profile from a 3.33 : 1 SR-3 form during a column leaching test using a 7 ml min-1 flow rate. 43 Figure 3-3a. H2O2 release profile from a 5 : 1 SR-4 form during a column leaching test using a 7 ml min-1 flow rate. 44 Figure 3-3b. H2O2 release profile from a 5 : 1 SR-5 form during a column leaching test using a 7 ml min-1 flow rate. 45 Figure 3-3c. H2O2 release profile from a 6 : 1 SR-6 form during a column leaching test using a 7 ml min-1 flow rate. 45 Figure 3-3d. H2O2 release profile from a 6 : 1 SR-7 form during a column leaching test using a 7 ml min-1 flow rate. 46 Figure 3-3e. H2O2 release profile from a 5 : 1 SR-8 form during a column leaching test using a 7 ml min-1 flow rate. 46 Figure 3-3f. H2O2 release profile from a 5 : 1 SR-9 form during a column leaching test using a 7 ml min-1 flow rate. 47 Figure 3-3g. H2O2 release profile from a 5 : 1 SR-10 form during a column leaching test using a 7 ml min-1 flow rate. 47 Figure 3-4a. H2O2 release profile from a 4.2 : 1 SR-11 form during a column leaching test using a 7 ml min-1 flow rate. 50 11 Figure 3-4b. H2O2 release profile from a 3.8 : 1 SR-12 form during a column leaching test using a 7 ml min-1 flow rate. 51 Figure 3-4c. H2O2 release profile from a 3.5 : 1 SR-13 form during a column leaching test using a 7 ml min-1 flow rate. 51 Figure 3-4d. H2O2 release profile from a 3.7 : 1 SR-14 form during a column leaching test using a 7 ml min-1 flow rate. 52 Figure 3-4e. H2O2 release profile from a 3.5 : 1 SR-15 form during a column leaching test using a 7 ml min-1 flow rate. 52 Figure 3-4f. H2O2 release profile from a 3.5 : 1 SR-16 form during a column leaching test using a 7 ml min-1 flow rate. 53 Figure 3-4g. H2O2 release profile from a 3.75 : 1 SR-17 form during a column leaching test using a 7 ml min-1 flow rate. 53 Figure 3-5a. H2O2 release profile from a 3.75 : 1 SR-18 form during a column leaching test using a 7 ml min-1 flow rate. 54 Figure 3-5b. H2O2 release profile from a 3.5 : 1 SR-19 form during a column leaching test using a 7 ml min-1 flow rate. 54 Figure 3-5c. H2O2 release profile from a 3.5 : 1 SR-20 form during a column leaching test using a 7 ml min-1 flow rate. 55 Figure 3-5d. H2O2 release profile from a 3.75 : 1 SR-21 form during a column leaching test using a 7 ml min-1 flow rate.