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Perfluorinated Chemicals in Municipal Wastewater Treatment

plants in Arizona

Caracterización de Residuos Sólidos y Aguas Residuales

INA 440

Valeria Ochoa-Herrera, Ph.D.

Primer Semestre 2015 - 2016

Septiembre 04, 2015

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Referencias

Ochoa-Herrera, V.; Field, J.A. and Sierra-Alvarez, R. ¨Determinación de la Persistencia de Compuestos Perfluorinados en Plantas de Tratamiento de Aguas Residuales Municipales mediante Métodos Analíticos basados en LC-MS/MS¨. Avances en Ciencias e Ingenierias, 2010, Vol. 2, Pags. A8-A1.

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Introduction

Perfluorinated chemicals (PFC): C-H bonds C-F bonds

PFOS

PFOA

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Uses

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Environmental concerns

Giesy et al. (2001) Environ. Sci. Tech. 35:1339

Houde et al. (2006) Environ. Sci. Tech. 40:3463

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DuPont settles cases in 2005

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PFCs in sewage sludge

•  In 2001, PFOS concentrations about 58 – 3120 ng/g in Alabama, Tennessee, Florida and Georgia (one order of magnitude > PFOA).

•  In 2005, PFCs levels ranging from 55 - 3370 ng/g in San Francisco Bay Area, California (high MW)

•  In 2006, PFCs concentrations of 62 – 990 ng/g in Kentucky (2-5 fold > PFOA).

3M US EPA Agency Docket AR 226-1030a; Higgins et al. (2005) Environ. Sci. Tech. 39:3946; Loganathan et al. (2006) Organoh. Comp. 68:2515

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•  PFCs partition into solids due to –  High bioaccumulation potential –  PFOS binds to serum albumin –  Bioaccumulation factor (BAF) increases with

perfluoroalkyl chain-length and through the food web.

•  PFCs in environment

–  Effluent discharges –  Land applications of industrial biosolids –  Fire fighting foams

PFCs adsorb to biosolids

WWTP’s are point sources of PFCs

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Objective

To conduct a preliminary evaluation of the significance of PFCs in discharges from municipal wastewater treatment plants in Arizona by

–  developing analytical methods for the detection and

quantification of PFCs in WWT sludge. –  assessing PFCs levels in sludge samples obtained

from Ina Road nd Roger Road WWTP.

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Motivation

•  No PFCs data in environmental samples nor in WWTPs in Arizona.

•  PFCs uses (semiconductor industry) will be useful to understand the role of WWTPs as sources of PFCs emissions.

•  Biosolids are used as soil fertilizer throughout the State.

•  Understanding the occurrence and fate of PFCs in Arizona’s WWTPs could be critical to protect water supplies/regulations.

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Analytical Methods

•  HPLC-suppressed conductivity ion chromatography

•  LC-MS/MS

•  Sludge extractions

•  Solid Phase Extraction (SPE)

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HPLC-suppressed conductivity IC

•  Acclaim Polar Advantage II, C18 reversed phase chromatography

•  Mobile phase –  20mM Boric acid (pH 8.0) –  95% Acetonitrile –  Linear gradient program

0 min: 75:25 v/v 13.2 min: 45:55 v/v

•  LOD: 0.5 – 1 mg/l PFOS

HPLC-IC DIONEX 3000

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C4 (299 g/mol)

C8 (413 g/mol)

C8 (499 g/mol)

Monitor PFOS on a routine basis!

HPLC-IC chromatogram of a solution 1:1:1 molar ratio of each PFC

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LC-MS/MS

•  MagicMS C18 reversed phase chromatography

•  Mobile phase –  10mM NH4OAc –  Methanol –  Linear gradient program

0 min: 95:5 v/v 35 min: 10:90 v/v

•  Selected Ion Monitoring (SIM) to improve detection limits –  Standard solutions - peak intensity ratios –  m/z window + 3 around selected m/z ion –  LOD: 50 µg/L

•  Tandem MS/MS to get structural information

Finnigan LCQ-HPLC/MS

http://www.chem.arizona.edu

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PFCs evaluated in this study

SO3H F

F

F F F F

F F F F F

F F

SO3H F

F

F F F F

F F F F F

F F

F F

F F

SO3H F

F

F F F F

F F F F F

F F

F F

F F

F F

F F

PFHXs

PFOS

PFDS

COOH F

F

F F F F

F F F F F

F F

F

F

COOH F

F

F F F F

F F F F F

F F

F F

F F

F

F

PFOA

PFDA

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LC-MS/MS •  Emerging pollutants

0

50

100

1 0 1 5 2 0 2 5 3 0

0

50

100

1 0 1 5 2 0 2 5 3 0

0

50

100

1 0 1 5 2 0 2 5 3 0

0

50

100

1 0 1 5 2 0 2 5 3 0

0

50

100

1 0 1 5 2 0 2 5 3 0

0

50

100

10 15 20 25 30

Time (min)

PFHXs (399)

PFOA (413)

PFOS (499)

PFDA (513)

PFDS (599)

Relat

ive A

bund

ance

LC-MS chromatogram of a mixed solution (5 mg/l of each PFC)

C6

C8

C8-SO3-

C10

C10-SO3-

All PFCs

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LC-MS/MS •  Emerging pollutants

Negative ESI/MS spectrum of a mixed solution (5 mg/l of each PFC)

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Sludge extractions

Vortex Sonication

Centrifugation

I

II

WASH

B) Washing

EXTRACT

III

C) Extraction

1)  Dry at 70C 2)  Air-dry for 1 day 3)  Homogenization (6 g sludge)

A) Preparation

Higgins et al. (2005) Environ. Sci. Tech. 39:3946

75 ml 1% Acetic Acid 20 ml 90:10 v/v

MeOH:1% Acetic Acid

Vortex Sonication

Centrifugation

I I

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Solid Phase Extraction

•  Critical step in preparing PFCs samples for analysis

•  Clean-up and preconcentrate

wash and extract

•  SPE cartridges (3ml, 500 mg ODS-C18, Agilent Technologies)

•  Vacuum manifold: multiple

samples

SPE set-up

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Solid Phase Extraction

C18 Cartridge 1) Cleaning 6 ml MeOH

2) Preconditioning 6 ml 1% Acetic acid soln

3) Loading Wash/extract at 1ml/min

4) Drying Centrifugation 20 min (4000 rpm)

5) Elution 4 ml MeOH

II III

EXTRACT WASH

PFCs

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Results

•  Anaerobically digested sludge (ADS) samples from Ina Rd and Roger Rd WWTPs were evaluated.

•  Two extractions were conducted –  0.1 g homogenized sludge-Ina Rd and Roger Rd WWTPs:

no PFCs (min 2g) –  6 g homogenized sludge-Ina Rd WWTP: PFOS

•  Wash and extract were analyzed in all cases

•  High-molecular weight PFCs (PFHXs, PFOA, PFOS, PFDA and PFDS) were analyzed by SIM

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Selected Ion Monitoring-Quantification

•  PFDS as internal standard (chemical characteristics affect ionization process)

•  Area= height x peak width at half-height

h

w

•  Response factor - ratio of areas of PFOS and PFDS in equimolar solution.

•  Sludge samples analyzed in triplicate

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SIM analysis of ADS sample from Ina Rd WWTP

Spiked with PFDS (0.5 mg/l)

MW PFOS

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Signal suppression effects?

•  PFOS was the only compound detected (77 + 5 ng/g dwt)

•  PFOS levels are comparable to other WWTPs in USA (55 -3200 ng/g dwt)

•  Are other PFCs also present? –  Instrumental limitations –  Matrix interferences and suppression effects

•  ESI MS/MS: intensity = analyte concentration & total ion concentration

•  Organic matter could result into suppression of analyte signal

•  LAS co-eluted with high-molecular weight PFCs.

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Conclusions

•  PFCs are under scrutiny due to their world-wide distribution, environmental persistence and bioaccumulation potential.

•  HPLC-IC and LC-MS/MS were developed to measure PFCs in environmental samples.

•  First report of PFCs in sewage sludge in Arizona. PFOS detected in Ina Rd WWTP at 77 + 5 ng/g dwt.

•  Other PFCs might be present and cannot be detected

due to matrix interferences.

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Acknowledgments

•  Dr. Reyes Sierra and Dr. Jim Field •  Dr. Arpad Somoyogi (MS Facility) •  Sandra Hernandez (Autonomous University of

Coahuila, Torreon, Mexico) •  Chandra Katri •  Field-Sierra group

Water Resources Research Center, UA Federal Grant # 01-HQ-GR-0113

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Acknowledgments