Quantitative Passive DiffusiveQuantitative Passive ... 7/McAlary AWMA...Quantitative Passive DiffusiveQuantitative Passive Diffusive--Adsorptive Sampling Techniques for ... • Introduction

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  • Quantitative Passive DiffusiveQuantitative Passive Diffusive--Adsorptive Sampling Techniques for Adsorptive Sampling Techniques for

    Vapor Intrusion AssessmentVapor Intrusion AssessmentVapor Intrusion AssessmentVapor Intrusion Assessment

    ESTCP Project 08 30ESTCP Project 08-30

    T M Al H G lt T G ki S S th thT. McAlary, H. Groenevelt, T. Gorecki, S. Seethapathy, D. Crump, P.Sacco, H. Hayes, M. Tuday, B.

    Schumacher, J. Nocerino, P. Johnson

    AWMA Specialty Conference Vapor Intrusion 2010

    September 30, 2010Chi IL


    Chicago, IL

  • Outline Challenges with conventional sampling

    Introduction to quantitative passive sampling

    Comparative Studies Comparative Studies ESTCP Project 08-30 NAVY SPAWAR Projectj

    Summary of Findings to date


  • Challenges withgConventional Sampling


  • Summa Canister and TO-15

    Complex procedure, requires special training ($)

    Must be cleaned and certified ($)

    Bulky ($) to ship and handleBulky ($) to ship and handle

    Maximum ~24 hour samples

    Costly: $200 to $300/sample, depending on reporting limit

    Not useful for analytes heavier than naphthalene (poor recovery)


  • 55

  • Automatic Thermal Desorption Tubes / TO-17

    Typically customized for each application high level of training required

    Allows longer than 24-hour samples, but the pump must run reliably throughout the sampling periodsampling period

    Capable of a larger list of analytes


  • Introduction to Quantitative QPassive Sampling


  • Quantitative Passive Sampling Expose a sampler for a known time Ship to laboratory for analysis of adsorbed mass Calculate concentration

    M C0 = concentration of analyte in air (g/m3)

    tkMC 10

    M = mass of analyte collected by the sorbent (pg)

    k-1 = uptake rate (mL/min)

    Uptake rate is unique to each sampler/analyte pair

    tk t = sampling time (min) Uptake rate is unique to each sampler/analyte pair

    Usually requires expensive controlled experiments Some passive samplers dont control uptake qualitative!


  • Benefits of Passive Sampling Simple (minimal training)

    L i Less expensive Low reporting limits with no premium cost

    Ti i ht d t ti Time-weighted average concentration(up to a week or a month if needed)

    S ll t hi di t t d l Smaller easy to ship, discrete to deploy Long history of use in Industrial Hygiene

    Oth b fit i t h l Other benefits unique to each sampler


  • ESTCP Study TeamOrganization Name RoleGeosyntec Consultants, Inc.Guelph (Canada)

    Todd McAlaryHester Groenevelt

    Overall project direction &reporting

    US EPA Labs, Las Vegas (NV) Brian SchumacherJohn Nocerino (D)

    Experimental Design &Statistics

    Arizona State University (AZ) Paul Johnson Practicality for Vapor IntrusionSitesSites

    University of Waterloo(Canada)

    Tadeusz GoreckiSuresh Seethapathy

    PDMS Membrane Sampler

    Cranfield University (UK) Derrick Crump ATD Passive and Active Samplers

    Fondazione Salvatore Maugeri(Italy)

    Paolo Sacco Radiello Samplers

    Columbia Analytical Services(CA)

    Michael TudayKu-Jih Chen

    High Conc. Laboratory TestingUltra II samplers & canisters(CA) Ku-Jih Chen Ultra II samplers & canisters

    Air Toxics Limited (CA) Heidi HayesStephen Disher

    Low Conc. Laboratory TestingATD Passive and Active Samplers

    International Team incl ding the labs most familiar ith each of the samplers


    International Team, including the labs most familiar with each of the samplers

  • Four Different Passive Samplers

    Waterloo Membrane S l TM

    Automated Thermal Desorption (ATD) T bSampler TM

    (1-D permeation across a

    b CS


    (1-D diffusion through air, thermal desorption)

    membrane, CS2extraction or thermal desorption)


    SKC Ultra II

    (Badge sampler,

    (Radial uptake through porous cylinder, thermal desorption or( g p1-D uptake

    through porous plate, thermal desorption)

    desorption or solvent extraction)


    p )

  • Desorption Methods

    Thermal desorptionThermal desorptionThermal desorptionThermal desorption



    Solvent desorptionSolvent desorption


    Thermal desorption

  • Sorbent Media SelectionSorbent Description Sampling Properties

    Anasorb 747 Beaded active carbon

    High capacity for VOCs, solvent desorption

    Tenax TA Porous polymer Low capacity, medium to high boiling compounds, thermal

    60/80 mesh

    g pdesorption

    Non porous high capacity forCarbopack B

    60/80 mesh graphitized

    carbon black

    Non-porous, high capacity for VOCs, thermal desorption


    There are many, many more sorbents available

  • Laboratory Analyte List


    Selected to span a range of compounds of interest for vapor intrusion studies


    Selected to span a range of compounds of interest for vapor intrusion studiesChlorinated ethenes, ethanes, methanes, and VOCs of differing solubility and sorptive properties

  • Low Concentration Tests:To Mimic Indoor and Outdoor Air ConditionsTo Mimic Indoor and Outdoor Air Conditions

    Concentration : 1, 50 and 100 ppbvTemperature: 22, 25, 28 CTemperature: 22, 25, 28 CHumidity: 30, 60 and 90% RHFace velocity: 0.01, 0.2 and 0.4 m/sExposure time: 1 4 and 7 days

    High Concentration Tests:

    Exposure time: 1, 4 and 7 days

    High Concentration Tests:To Mimic Soil Gas Conditions

    C t ti 1 10 d 100Concentration : 1, 10 and 100 ppmvTemperature: ambientHumidity: 90-100%Face velocity: very low (5x10-5 m/s)


    Face velocity: very low (5x10 5 m/s)Exposure time: 30 minutes

  • Exposure Chamber Conditioned gas enters at

    bottom and flows past lsamplers

    Samplers rotate on a carousel to control facecarousel to control face velocity

    Baffles help to minimize t b lturbulence

    All surfaces passivated to minimize adsorptionminimize adsorption


  • Exposure Chamber (contd)Off th h lf All fOff the shelf glassware, modified by glass blower

    All surfaces passivated


    Surrounded by tube of circulating fluid and insulated for temperature controlcontrol


  • 1818

  • Inter-Laboratory TestingSecondary #ofSamplersto

    SamplerType HomeLaboratory Laboratories EachLaboratory

    W t l M b Ai T i LtdWaterlooMembraneSampler UniversityofWaterloo



    ATD Tubes with Tenax TA Air Toxics Ltd

    ColumbiaAnalyticalServices 2ATDTubeswithTenaxTA AirToxicsLtd Services 2


    ATDTubeswithb k Air Toxics Ltd

    ColumbiaAnalyticalServices 2CarboPackB AirToxicsLtd 2


    SKCUltra ColumbiaAnalyticalServicesAirToxicsLtd


    Radiello FondazioneSalvatoreMaugeri

    ColumbiaAnalyticalServices 2

    Air Toxics Ltd



  • Interlab Test Youden Plot

    (blank contamination)


    Most results show good agreement between labsMEK was problematic

  • ANOVA TestingSet the five factors at their midpoints, and run test multiple times

    to determine variance from experimental procedures

    Factor Units Center Value

    Concentration ppb 50

    Temperature C 20Temperature C 20

    Gas Flow Velocity m/s 0.2

    Sampling Duration days 4

    Relative Humidity % 60


    e at ve u d ty % 60

  • Fractional Factorial TestingA series of experiments strategically changing the 5 key factors



    Face Velocity

    Sample Time



  • Chamber Test Results to DateChamber Test Results to Date


  • Chamber Test Results to DateChamber Test Results to Date

    (l bi )(low bias)


  • Chamber Test Results to DateChamber Test Results to Date



    (Calculated Uptake Rate)


  • Chamber Test Results to DateChamber Test Results to Date

    (high bias)




  • Chamber Test Results to DateChamber Test Results to Date


  • Field Testing (SPAWAR/NESDI)Comparative sampling of indoor air, outdoor air, and soil vapor

    Indoor Air:

    ATD Tubes3M OVM 3500RadielloSKC Ult IISKC Ultra IIWaterloo Membrane


    6-day Summas


    3 Replicates


    Acknowledgements to Ignacio Rivera and Bart Chadwick of SPAWAR for Support


  • Indoor Air (3 Locations in Triplicate)Indoor Air (3 Locations in Triplicate)Indoor Air AverageTrichloroethene


    10Indoor Air - AverageTrichloroethene

    SummaWMS3M OVM

    (Anasorb 747)(Activated carbon wafer)




    ATDRadielloSKC Ultra

    Each bar is an average of the three

    (Chromosorb 106)(Activated charcoal)

    (Chromosorb 106)



    n (

    g/m Each bar is an average of the three

    samples collected at that location






    IA-1 IA-2 IA-3 Average


    Sample Location


    The low bias for SKC is believed to be due to sorbent selection (Chromosorb 106 worked well for ATD, but SKC has 20X higher uptake rate)TCE was the dominant compound

  • SubSub--Slab SamplingSlab SamplingTwo types:

    1) Fully passive (drop and cork for 24 hours)

    2) Semi-passive(drop and purge

    ith PID f 10with PID for 1


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