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Richard Jack, Ph.D. Manager, Global Market Development

Anions and Metals Analysis for Waters Impacted by Hydraulic Fracturing

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Hydraulic Fracturing (Fracking) Controversy

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Hundreds of Known Chemicals in Fracking Solutions • Hundreds of chemicals in fracking solutions • 50,000 mg/L salt (10–20x sea water) • The EPA has narrowed the list of compounds down to less than 20. • The EPA is in the process of developing analytical methods for these target compounds.

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Pennsylvania Regulations for Wastewater from Fracking

• In lieu of the trace analysis described in Subsection b, the chemical analysis of wastewater produced from the drilling, completion and production of a Marcellus Shale or other shale gas well must include the following:

• Additional constituents that are expected or known to be present in the wastewater.

*Note: All metals reported as total.

Acidity Alkalinity (Total as CaCO3) Aluminum Ammonia Nitrogen Arsenic Barium Benzene Beryllium Biochemical Oxygen Boron Bromide Cadmium Calcium Chemical Oxygen Demand Chlorides Chromium Cobalt Copper

Ethylene Glycol Gross Alpha Gross Beta Hardness (Total as CaCO3) Iron – Dissolved Iron – Total Lead Lithium Magnesium Manganese MBAS (Surfactants) Mercury Molybdenum Nickel Nitrite-Nitrate Nitrogen Oil & Grease

pH Phenolics (Total) Radium 226 Radium 228 Selenium Silver Sodium Specific Conductance Strontium Sulfates Thorium Toluene Total Dissolved Solids Total Kjeldahl Nitrogen Total Suspended Solids Uranium Zinc

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Monitoring Environmental Impact

• Public concern poses a challenge to environmental laboratories. • Some contaminants do not have approved EPA analytical methods.

• Matrix issue—hypersaline fracking waters can affect analysis of certain compounds.

• Robust analytical methods needed to assess environmental impact from fracking processes.

• Following speakers will discuss inorganic analysis methods for anions and metals.

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Thermo Scientific Dionex Ion Chromatography (IC) Systems for Anion and Cation Analysis

Dionex ICS-5000

Dionex ICS-900

Starter Line IC System

Compact Design Chem. Suppression

DCR Mode

Premier Modular RFIC System

Capillary HPIC Modular Flexible

Single or Dual Channel Eluent Generation Proportioned and RFIC Gradients

Multiple Detectors Multiple Thermal Zones

Dionex ICS-1600

Dionex ICS-1100

Standard Integrated RFIC

System Compact Design

Electr. Suppression LCD Front Panel Column Heater

Integrated Sample Prep Eluent Regeneration

Dionex ICS-2100

Superior Integrated

RFIC System Compact Design

Eluent Generation RFIC Gradient

Electr. Suppression LCD Front Panel Column Heater

Integrated Sample Prep

Basic Integrated RFIC System

Compact Design Electr. Suppression

Integrated Sample Prep Eluent Regeneration

Dionex ICS-4000

Capillary High-Pressure Integrated RFIC System

Capillary HPIC™

Eluent Generation RFIC Gradient

Multiple Detectors, Including

Electrochemical (ED) and Charge (QD)

Reagent-Free™ IC (RFIC™) Systems

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Thermo Scientific Dionex IonPac Anion-Exchange Columns

Column Formats Primary Application

Dionex IonPac™ AS19

0.4 × 250 mm 2 × 250 mm 4 × 250 mm

Recommended hydroxide-selective column for inorganic anions and oxyhalides, e.g., trace bromate in drinking water

Dionex IonPac AS18

0.4 × 250 mm 2 × 250 mm 4 × 250 mm

High capacity hydroxide-selective column for the analysis of common inorganic anions

Dionex IonPac AS18-Fast

0.4 × 150 mm 2 × 150 mm 4 × 150 mm

Hydroxide-selective column for fast analysis of common inorganic anions

Dionex IonPac AS23

2 × 250 mm 4 × 250 mm

Recommended carbonate-based column for inorganic anions and oxyhalides, e.g., trace bromate in drinking water (better solution for Dionex IonPac AS9-HC users)

Dionex IonPac AS22

2 × 250 mm 4 × 250 mm

Recommended carbonate-based column for fast analysis of common inorganic anions (better solution for Dionex IonPac AS14, AS14A and AS4A users)

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Comparison of Hydroxide and Carbonate Eluent for Separation of Common Anions

• Both eluents show excellent anion separation.

• Trace anions are well resolved. • Hydroxide does not show the water dip.

Column/Eluent: A) Dionex IonPac AS19 using hydroxide eluent B) Dionex IonPac AS23 using carb/bicarb eluent Detection: Suppressed conductivity A B Peaks 1. Fluoride µg/L 2. Chlorite 8.8 11.3 3. Bromate 4.7 5.1 4. Chloride 5. Nitrite 6. Chlorate 13.5 9.5 7. Bromide 8. Nitrate 9. Carbonate 10. Sulfate 11. Phosphate

0 . 2

0 . 5

µ S

1

2 3

A

0 5 1 0 1 5 2 0 2 5 3 0 – 0 . 1

0 . 7

µ S

1

2 3

B 4

5 6 7

9

8

4

5 6

7 8 9

1 1 1 0

1 0 1 1

Minutes

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AA, ICP and ICP-MS—Speed and Detection Limit

Detection Limit

Speed

Flame AA

Furnace AA

ICP-MS

ICP-OES

300s for 10 element

Single Element Technique

20 mins for 10 element

Single Element Technique

60s for 10 elements

Rugged Multielement Technique

120s for 10 elements

Sensitive Multielement Technique

Higher Cost < 1ppt DL

Ppm DL

> 1ppb DL

> 100ppt DL

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Complete Inorganic Elemental Analysis

H

Li

Fr Ra

Sc

Ac

Zr

Hf

Nb

Ta

Tc

Re

Ru

Os

Rh

Ir Hg

In

Tl

Ge

Sb

Bi

S

Te

Po

Cl

F

At

He

Ar

Ne

Kr

Xe

Rn

Pa Pu Am Cm Bk Cf Es Fm Md No Lw Np

Not measurable

ICP-MS

Unstable elements

AA/ICP/ICP-MS ICP/ICP-MS

IC

Na

K

Rb

Cs

Be

Mg

Ca

Sr

Ba

Y

La

Ti V Cr

Mo

W

Mn Fe Co Ni

Pd

Pt

Cu

Ag

Au

Zn

Cd

Al

Ga

Sn

Pb

B C O N

Br

I

Si P

As Se

Ce Pr

Th

Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu

U

IC is also used for additional anions, such as oxyhalides, SO4 and NO3.

Anion Analysis of Water Associated with Unconventional Natural Gas Extraction John F. Stolz, Ph.D, Duquesne University, Pittsburgh, PA

What is Marcellus Shale?

www.getmoneyenergy.com/wp-content/uploads/2010/01/shale-gas-basins-in-usa.jpg

Horizontal Drilling and Fracking

http://app1.kuhf.org/userfiles/hydraullic_fracturing_natural_gas.gif

Produced Water High Total Dissolved Solids (60–250,000 mg/L)

Chloride, bromide, strontium, barium

Gaudlip et al., 2008. SPE 119898

The System Thermo Scientific Dionex ICS-1100 with:

DS6 Heated Conductivity Cell

AS-DV Autosampler

Thermo Scientific Dionex DAD-3000 UltiMate 3000 Diode Array

Detector (UV-vis)

Thermo Scientific Dionex OnGuard II M Cartridge

Thermo Scientific Dionex IonPac AS-22 Anion Exchange

Column

Running Conditions Eluent: 4.6 mM sodium carbonate/ 1.4 mM sodium bicarbonate Flow Rate: 0.25 ml/min Samples: Filtered 0.22 um (PES filter0) Run Time: 20 min Conductivity Range: 0–1500 uS/cm UV-vis: 195 nm (ch 1), 200 nm (ch 2), 205 nm (ch 3), 215 (ch 4)

Standards (Retention Time): Bromide (6.887 min)

Floride (3.377 min)

Chloride (4.847 min)

Nitrate (7.654 min)

Nitrite (6.201 min)

Phosphate (10.534 min)

Sulfate (11.781 min)

Arsenate (19.05 min)

Arsenite (4.357 min)

Monomethylarsonic acid (9.967 min)

Dimethylarsonic acid (2.623 min)

Five-Point Calibration Curves: a: 0.5, 1, 2.5, 5, 10 ppm Bromide, Floride, Chloride b: 2.5, 10, 25, 50, 100 ppm Nitrate, Nitrite, Phosphate, Sulfate c: 10, 50, 100, 250, 500 uM Arsenate, Arsenite, Monomethylarsonic acid, Dimethylarsonic acid

Table 1: Anion data for impoundment water, coal mine effluent, and freshwater stream water Field Sample Field Sample Field Sample Field Sample Field Sample

Impoundment

Water Impoundment

Water Coal Mine

Effluent Freshwater

Stream Freshwater

Stream

Unit Sample #1 Sample #2 Sample #3 Fonner Run Bates Run Conductivity uS cm-3 102,864 61,477 6,400 387 476

pH 5.38 5.67 7.53 7.91 7.67 Sulfate mg/L 8.64 10.21 3,826 25.07 24.46 Nitrate mg/L ND ND 1.81 0.11 0.58

Bromide mg/L 255 226 14.25 ND ND Chloride mg/L 30,683 27,700 1,241 1.29 6.00 Arsenic ug/L BDL BDL BDL BDL BDL

ND - not detected BDL - below detection limit

J.L. Eastham, 2012

Conclusions The Dionex ICS-1100, equipped with the DS6 Heated Conductivity Cell provides a rapid means for separation and detection of anions (e.g., Cl, Br) commonly found in flowback and produced water associated with unconventional shale gas extraction.

Produced water from Marcellus Shale is higher in chloride and bromide but lower in sulfate, and can be distinguished from coal wastewater and natural streams.

The addition of the Dionex DAD-3000 UltiMate™ 3000 Diode Array Detector in tandem with the Conductivity Cell allowed for the detection of additional anions, e.g., As(III), and arsenic speciation.

Hydraulic Fracturing Flowback Water Analysis by ICP-OES and ICP-MS

Joelle Streczywilk Senior Group Leader Geochemical Testing

Outline

The importance of trace analysis of flowback water Sample preparation Choosing an analysis technique Analysis using the Thermo Scientific iCAP 6500

Duo View ICP Spectrometer Minimizing physical interferences Managing spectral interferences Summary

Importance of Flowback Water Trace Analysis

Gas exploration and development is growing quickly and analysis techniques should evolve with the Marcellus industry.

Flowback water is the main source of wastewater from Marcellus shale gas drilling.

Flowback water can be treated and reused or treated and discharged.

Metals analysis is essential for many reasons: – Ensures that treatment processes are functioning properly. – Meets discharge or storage requirements. – Assesses the hazards that could be related to a spill or leak.

Sample Preparation

EPA Method 200.2 is adequate for most flowback samples.

Use 1% nitric and 0.5% hydrochloric acid digestion (a nitric only digestion may be preferred if analysis will be conducted by ICP-MS).

Reduce sample to approximately 20% of original volume at 85 °C.

Cover sample with watch glass and reflux for 30 minutes.

Fill to original volume with DI water.

Sample Preparation

Flowback waters can be saturated with salts and precipitation may occur.

Precipitation will lead to inaccurate results for both major and trace element analysis.

Avoid crystallization by diluting the sample prior to digestion.

Analysis Techniques

ICP-OES and ICP-MS Governed by the elements of interest, detection

limits required and the makeup of the sample The constituents and permitting needs of flowback

water vary greatly so analysis techniques should be sample specific.

Flowback Water Analysis by ICP-MS

Uranium analysis should be conducted on the ICP-MS because uranium is a heavy isotope with a simple spectrum and a slight interference from 206Pb16O2 (ICP-OES: weak signal and severe interference).

Many other analytes of interest may be analyzed on the ICP-MS with caution due to interferences and high total dissolved solids (TDS). The use of reaction or collision cells can minimize or resolve many interference issues.

ICP-MS Spectral Interferences

Isobaric overlaps: some isotopes occur at the same mass number. – Choose and monitor alternate isotopes. – Correction equation

Polyatomic overlaps: dimers, oxides, hydrides, etc. – Dynamic or empirical correction equations (may not be

accurate depending on the intensity of the interference)

ICP-MS Physical and Matrix Interference

High TDS (some flowback waters are over 10% TDS) – Viscosity—consistent aerosol formation is desired – Plasma loading—reduces ions generated by the plasma – Instrument drift—clogs cones

Minimized by internal standards, robust plasma conditions, keeping dissolved solids below 0.5% – Dilutions: introduce error, raise practical quantitation limit

(PQL), detector life

Flowback Water Analysis by ICP-OES

Most analytes of interest in flowback water can be analyzed accurately with ICP-OES.

iCAP™ 6500 Duo View ICP Spectrometer has the advantage of viewing the plasma both axially and radially. – Enables the analysis of trace metals at low and high

concentrations simultaneously

ICP-OES Line Selection

Line sensitivity – Is based on detection limit required. – Avoid lines that require complex spectral correction

algorithms. – Select a radial or an axial view of the plasma. – Line switching is available for analyte measurements that

are found at both high and low concentrations (extends linear range).

Flowback Example on iCAP 6500

• Diluted prior to digestion

• ^ and * on Barium and Strontium: peak saturation

• ChkFail: check table limit (Ba, Sr, Ca, Li, Mg and Na)

• Sodium defaulted to the low line (linearity and interfering element corrections [IECs])

• RSDs less than 3% for all analytes above the MDL

Minimizing Physical Interferences

Avoidance: dilute if possible High solids nebulizer to minimize “salting out”

effects (Noordermer v-groove) Humidify argon stream Intelligent rinse Use of internal standard

Internal Standard Compensation

Plasma loading from flowback waters – Readings are generally suppressed

Calibration Blank Cts/S

Flowback Sample Cts/S

Internal Standard Recovery

Low axial Sc 4122 3486 85%

High radial Sc 19812 17357 88%

High axial Sc 405400 313240 77%

Flowback Water and Calibration Blank Comparison

Low axial Sc 227 Low axial Se 196

Managing Spectral Interferences

Background interference – Routine and relatively easy to deal with

Direct spectral overlap – Avoidance

Use different line(s)

– Complete a full spectral interference study Trace metals should be studied at a concentration of at least

1000 µg/mL of interferant

Interfering Element Corrections

IECs may be calculated, but should be checked after every calibration. – Use multiple check solutions.

IECs must not be used if the interferer concentration is above the linear range.

IECs should be calculated quarterly and with each nebulizer or torch change.

Spectral Interferences

Spectral tables can be helpful but not depended on.

A matrix study is also important for flowback water sample analysis.

Conduct fullframe analyses of all views in use (high radial, low axial, and high axial).

Low Axial View of a Flowback Sample with Blank Subtraction

Fullframe of 1000 µg/mL Strontium

Summary

The complex matrices of flowback waters make accurate trace analysis difficult.

ICP-OES analysis is more conducive to multi-element determinations for both high and most low analyte concentrations.

ICP-MS is required only for uranium, however it can be used to determine most other elements as well.

Avoidance is the key with both techniques. If avoidance is impossible, caution must be used in

every determination.