Timothy K. Tsukamoto, Ph.D. RCTS™ Overviews of Two Advanced AMD Treatment Technologies: Semi-passive Sulfate Reducing Bioreactors and the Rotating Cylinder Treatment System July 2008 Timothy K. Tsukamoto, Ph.D.

Semi-passive Bioreactors Timothy K. Tsukamoto, Ph. D Semi-passive Bioreactors Timothy K. Tsukamoto, Ph.D. (775) 321-8100 www.iwtechnologies.com

Options for Treatment Advantages Disadvantages Bioreactor and other passive systems Mostly Passive Requires space Lifetime limited Higher capital cost Caustic addition Semi-passive Easily implemented Higher chemical cost Increased sludge volume Adds sodium to water Lime precipitation Removes sulfate Decreases TDS Requires some O&M

Types of Bioreactors Passive Bioreactors -The carbon or energy source is part of the substrate. -Once the degradable carbon sources are depleted, treatment efficiency falls off. -Metals are precipitated within the matrix. -Plugging and short circuiting leads to decreased treatment efficiency. Semi-Passive Bioreactors -The carbon source is added to the influent water -The majority of the metals are precipitated outside of the bioreactor. -Flushing built into the matrix. -All three contribute to a longer lasting system Passive Bioreactors -The carbon or energy source is part of the substrate. -Once the degradable carbon sources are depleted, treatment efficiency falls off. -Metals are precipitated within the matrix. -Plugging and short circuiting leads to decreased treatment efficiency. Semi-Passive Bioreactors -The carbon source is added to the influent water -The majority of the metals are precipitated outside of the bioreactor. -Flushing built into the matrix. -All three contribute to a longer lasting system

Sulfate-reducing Activity Passive Bioreactors 0.3 moles per cubic meter per day limited to about 1 meter deep so 0.3 moles per square meter per day Semi-passive Bioreactor 0.56 moles per cubic meter per day can go much deeper So for Leviathan Bioreactor 3 meters deep 1.68 moles per square meter per day

Leviathan Mine Original Manure Substrate at the Leviathan Mine. -down-flow reactor approximately 3ft deep. -ineffective at treating AMD after 1 year. -the source of manure substrate for the column experiments that follow.

Leviathan Mine Six Weeks of Treatment One Year of Treatment 7-27-93   Six Weeks of Treatment One Year of Treatment 7-27-93 7-1-94 Influent Effluent pH 4.78 6.97 4.7 6.45 Temperature C 9.9 15.6 8.4 13.1 alkalinity - 1458.00 269 Al 41.0 <0.02 48 0.24 As 0.41 0.023 0.28 0.015 Fe 310 2.8 380 260 Ni 1.8 0.01 2.1 Sulfate 1690 1190 2070 1910

Leviathan Mine

Leviathan Mine Improved flow distribution Improved matrix Improved sludge capture

Leviathan Mine

Leviathan Mine

Leviathan Mine

Leviathan Mine Sodium Hydroxide And Ethanol Delivery Sodium Hydroxide Bioreactor 1 Bioreactor 2 Settling Pond 1 Settling Pond 2 Pretreatment Pond Oxidizing Aeration Trench Infiltration Pond

Leviathan Mine Pretreatment Pond Recycle Line Bypass Line Aspen seep Bioreactor 1 Bioreactor 2 Settling Pond 1 Settling Pond 2 Ethanol Delivery Oxidizing Aeration Trench Sodium Hydroxide Delivery Infiltration Pond

Leviathan Mine

Leviathan Mine

Leviathan Mine

Leviathan Mine pH 2.93 6.79 6.86 7.66 6-9 SO4 1530 1090 1080 1170 NA Constituent Aspen Seep Bioreactor 1 effluent Bioreactor 2 effluent Discharge Discharge objectives pH 2.93 6.79 6.86 7.66 6-9 SO4 1530 1090 1080 1170 NA Al 28 <0.5 4.0 Fe 99 0.16 0.13 0.04 2.0 Ni 0.50 0.15 0.05 0.1 0.84 Cu 0.62 0.02 0.01 0.026 Zn 0.73 0.06 0.21

Leviathan Mine

Leviathan Mine

Leviathan Mine

Leviathan Mine

Leviathan Mine

Nacimiento Mine

Constituents of Concern for Nacimiento well field. Nacimiento Mine Constituents of Concern for Nacimiento well field. Well ID Al Cd Cu Fe Pb Mn Ni Zn Sulfate pH MW-2 0.94 ND 2.54 63.3 0.0039 0.777 0.1 8.58 980 5.6 MW-5 0.41 0.065 1.63 0.0057 0.02 1.76 190 6.5 MW-6 1.38 0.79 13.8 0.0119 0.088 0.09 260 5.2 MW-9 3.73 0.74 10.4 0.005 0.304 0.06 3.02 450 3.6 MW-10 28.6 0.01 20.8 124 0.0267 1.53 0.18 13.1 1,960 3.2 MW-11 43.3 0.012 57.6 261 0.0913 2.73 0.25 20.5 1,760 2.7 MW-12 0.36 0.21 9.92 0.0019 11.3 0.17 1,730 6.9 MW-14 0.51 7.62 0.0085 3.27 0.12 860 7.5 MW-21 70.5 0.018 116 324 0.111 16.2 28.2 2,930 2.9 MW-32 0.08 1.61 0.0095 0.084 250 MW-33 9.03 157 159 0.0024 2.71 0.37 25.4 1,630 4.0 MW-35 0.65 0.028 O.41 1.36 3.77 0.146 0.03 2.57 30 6.2 MW-36 3.59 0.0017 0.343 750 7.2

Nacimiento Mine

The Rotating Cylinder Treatment System™ Timothy K. Tsukamoto, Ph. D The Rotating Cylinder Treatment System™ Timothy K. Tsukamoto, Ph.D. (775) 321-8100 www.iwtechnologies.com

CONFIDENTIALITY PROPRIETARY INFORMATION NOTICE All information delivered in this presentation relating to the Rotating Cylinder Treatment System (“RCTS”), US Patent No. 7,011,745 is patented technology proprietary to Ionic Water Technologies, Inc. The presentation’s content related to IWT’s technologies shall not be used for any purpose by any recipient or viewer hereof without the express written consent of Ionic Water Technologies, Inc.

RCTS CONCEPT Rotating perforated cylinders add oxygen from the atmosphere to the water Energy efficient 10 hp system treats up to 500 gpm Aggressive agitation optimal reagent efficiency Reduced lime costs Low maintenance rotor maintenance on most sites 2 to 3 times per year (takes 3 to 4 hours) Small footprint most units are mobile Effective Aeration and Oxidation Less Sludge produced Faster sludge settling

Chemistry and Stoicheometry For Hydrated Lime Ca(OH)2 + M 2+ M(OH)2 (s) + Ca 2+ Ca 2+ + SO4 2- CaSO4 Gypsum generally precipitates to ~ 2,000 mg/L For Sodium Hydroxide 2 NaOH + M 2+ M(OH)2 (s) + Na + Sodium remains soluble

Chemistry and Stoicheometry CaO=1 Na(OH)=1.43 Ca(CO)3=1.78 If 2000 mg/L acidity then need= 1120 mg/L of CaO and 1600 mg/L of NaOH and 920 mg/L will be Na

Lime Precipitation Add lime (CaO) or Ca(OH)2 to raise the pH Precipitate metals as hydroxides Precipitate sulfate as gypsum Requires oxygen addition if there is significant dissolved iron, manganese Oxygen addition is typically accomplished with large compressors and air diffusers and tanks Lime addition requires thorough mixing due to it’s low solubility and slow dissolution rate. Mixing is typically accomplished with large mixers inside reaction tanks Labor and energy demanding

Iron Hydroxide Solubility with Respect to pH pH vs Total Iron Solubility Diagram for Ferrous and Ferric Hydroxide Precipitation. Note the Minimum Solubility for Manganese Precipitation is Between pH 9 and 10. (Taken from USEPA 1983).

Improved Oxygen Addition Type of Aeration Pounds of O2 delivered per horsepower-hour Mechanical surface aeration 3.0-3.5 Submerged turbine aerators utilizing dual impeller turbines 2.5-3.0 RCTS 600 gallon four rotor 9.0 O2 = Qw x Fe x 7.14 x 10 -5 O2 = Theoretical O2 demand (lb O2/hr) Qw = Acid mine drainage flow rate (gal/min) Fe = Fe 2+ initial concentration (mg/L) U.S. Environmental Protection Agency (USEPA). 1983. Design Manual: Neutralization of Acid Mine Drainage. EPA-600/2-83-001.

Elizabeth Mine

K (sampled from unit and filtered immediately no settling ) Results from Startup Table 1. Results for samples taken at various pH with and without settling. All samples were taken at an influent flow rate of approximately 32 gpm. Sample ID Initial pH FeT Fe2+ Mn Al Cu Zn 24 hour pH Influent 6.13 710 715 A (24 hours settling) 11.35 0.46 0.24 0.50 0.03 0.00 0.35 10.56 B (24 hours settling) 10.29 0.05 0.02   9.12 C (24 hours settling) 9.64 0.38 0.14 0.40 0.01 9.23 D (24 hours settling) 9.45 0.28 8.90 E (24 hours settling) 9.08 0.06 8.42 F (24 hours settling) 8.06 1.18 0.07 3.00 7.85 G (24 hours settling) 7.52 1.44 2.30 7.34 H (24 hours settling) 6.83 3.22 0.08 7.80 6.66 I (24 hours settling) 6.08 84.50 10.65 8.00 5.42 J (24 hours settling) 5.60 54.00 4.42 K (sampled from unit and filtered immediately no settling ) 9.80 0.20 Pond 7-26 (not filtered) 7.51 0.36 0.26 1.80 Pond 7-27 (filtered) 0.04 0.70 Pond 7-28-08 (not filtered) 7.54 0.10

Iron and Manganese Oxidation

The Effect of pH on Oxidation Rates for Iron and Manganese The Effect of pH on Oxidation Rates for Iron and Manganese. All experiments were conducted at dissolved iron and manganese concentrations of less than 5 x 10-4 M. (a) oxygenation of Fe 2+ in bicarbonate solutions (b) oxygenation of Mn 2+ in bicarbonate solutions (c) oxidation of Mn 2+ in bicarbonate solutions (autocatalytic plot) (d) Effect of pH on oxidation rates (taken from Faust and Aly 1981)

Sunshine Mine Residence time in RCTS 1 to 2 minutes

LEVIATHAN MINE, NORTHERN CALIFORNIA ATLANTIC RICHFIELD SITE 2007

Comparison of RCTS with Conventional System Leviathan Mine Hydraulic Capacity (gallons) Average Flow Rate (gpm) System Residence Time (minutes) Influent pH Effluent Filter Bag DO mg/l Lime per Day Conventional Tank Reactor System 4000 30.38 131.67 4.73 7.88 8.12 4.22 398 Rotating Cylinder Treatment System 1600 * includes dosing tank 27.33 58.54 4.86 8.11 7.86 233

EMERGENCY TREATMENT AT THE LEVIATHAN MINE 2006 Plowed the road April 9 and let the road dry. Mobilized the lime on April 12 and 13 via 4 wheel drive equipment. Mobilized the entire treatment system on April 13 Started treating on April 14 and by 10 a.m April 15 the average pH of the pond was 8.4. Treated 24 hours/day with 2 man crew onsite an average of 4.6 hours/day Met USEPA directives Treated and actively discharged ~7.5 million gallons of water containing iron as high as 610 mg/L and aluminum as high as 490 mg/L. Removed ~ 180 m3 of sludge from the lined pond in 2 days

Comparison of RCTS with Conventional System Leviathan Mine

RCTS vs Conventional System Leviathan Mine Water Treated per ton of lime RCTS 150,000 gallons Conventional System 73,000 gallons

Empire Mine HCO3- + H+ H2O + CO2 Goals: To oxidize and precipitate the iron and co precipitate arsenic from solution. It was initially proposed that sodium hydroxide would be added to raise the pH from 6.6 approximately 8.0. The addition of base was not necessary (Degassing of carbon dioxide from the water) HCO3- + H+ H2O + CO2

Nevada Pit Lake

Nevada Pit Lake 6 Billion gallon pit lake pH~2.9 Utilize CaO fed through a silo Utilize the RCTS and IWT lime grinder to slake the lime and dissolve it Add CaO at ~ 2.8 lbs/ min and slake with ~ 2 to 10 gpm to obtain a slurry of 3.5% to 17.5% Mix with between 50 and 300 gpm of water in the RCTS unit (lime dissolves Completely) Reintroduce with the ~6,000 gpm of water feeding the pit lake It will take ~ 1,000,000 lbs of CaO to neutralize 1 B gallons 2.8 lbs/min ~ 120,000 lbs per month so we would neutralize ~ 1.5 B gallons per year

Cost Comparison = $0.11/1000 gallons neutralized

Sludge Settling Elizabeth Mine 5 minutes 10 minutes 15 minutes

Sludge Settling 1hour 2 hour 4 hours

Sludge Settling 7 hour 24 hour

Sludge Settling Grouse Creek Mine RCTS Settling vs Conventional System A B C D A B C D 1 Minute Settling 2 Minute Settling A= Conventional System with polymer and sulfide B= RCTS no polymer no sulfide C= RCTS with polymer no sulfide D= RCTS with polymer and sulfide

Sludge Settling A= Conventional System with polymer and sulfide A B C D A B C D 5 Minute Settling 20 Minute Settling A= Conventional System with polymer and sulfide B= RCTS no polymer no sulfide C= RCTS with polymer no sulfide D= RCTS with polymer and sulfide