DEQ-CFW_00069923

Godreau, Jessica
From: Detlef Knappe <[e-mail]>
Sent: Tuesday, July 18, 2017 3:48 PM
To: Godreau, Jessica
Subject: Re: Gen X treatment
Carbon should work for GenX (but not the other ethers) for a limited time even when fed chlorinated water.
On 7/18/17 3:33 PM, Godreau, Jessica wrote:
Actually, one quick question right now.
if chlorine was fed in advance of the carbon, I assume the carbon would remove the chlorine and not
the GenX, rendering carbon ineffective in home applications.
Do you agree?
Jessica
Jessica C Godreau
Chief, Public Water Supply Section
Division of Water Resources
Department of Environmental Quality
919 707 9078 office
919 707 9100 main number
Jessica. God reau (a)ncd en r. aov
1634 Mail Service Center
Raleigh NC 27699-1634
512 N Salisbury St, Raleigh, NC 27604
!Email correspondence to and from this address is subject to the
North Carolina Public Records Law and maV be disclosed to third parties.
From: Detlef Knappe [mailto:[e-mail]
Sent: Monday, July 17, 2017 11:41 PM
To: Godreau, Jessica <[e-mail]>
Subject: Re: Gen X treatment
Hi Jessica,
The only available GenX treatment study is the one we published in ES&T Letters (attached). If
shows that GenX is less adsorbable on activated carbon than PFOA, but it is adsorbable. We
have additional data showing that GenX is about as adsorbable as C6 (perfluorohexanoic acid).
What is important to note is that shorter -chain ethers, that occurrec in Wilmington at
concentrations much higher than GenX were essentially non -adsorbable on activated carbon.
Currently, we do not have GAC breakthrough curves for GenX
DEQ-CFW 00069923

:Anion exchange resins can remove GenX - we have date that has not yet been published.
RO can effectively treat C4 (perfluorobutanoic acid), which is smaller than GenX. Therefore, RO
should be able to take out most GenX (and most likely the other ethers). The attached paper may
be useful.
Let me know if you have questions.
Best,
Detlef
On 7/17/17 2:20 PM, Godreau, Jessica wrote:
Detlef,
I'm being asked to speak to effective treatments for Gen X.
Can you point me to any studies or analysis of a treatment system that conclude a
treatment effectiveness for Gen X? I've heard you mention RO; is there anything in
writing that at least compared the size of the particle to the pore size that I could
reference? I thought that was what Cape Fear was studying in part. I saw an article
suggesting a report out this week. Are you the researcher?
Any assistance is greatly appreciated.
jq"sica
Jessica C Godreau
Chief, Public Water Supply Section
Division of Water Resources
Department of Environmental Quality
919 707 9078 office
919 707 9100 main number
Jessica. GodreauCcD-ncdenr.gov
1634 Mail Service Center
Raleigh NC 27699-1634
512 N Salisbury St, Raleigh, NC 27604
=mail correspondence to and from this address is subject to the
."Vorth Carolina Public Records Law and n7ay be disclosed to third r�arties.
Detlef Knappe
Professor
319-E Mann Hall
Department of Civil,
North Carolina State
Campus Box 7908
Construction, and Environmental Engineering
University
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Y
1 s
Raleigh, NC 27695-7908
Phone: [phone]
Fax: [phone]
E-mail: knaLDR"(ncsu_edu
Web page: http_//knappelab.wordpress__ncsu.edu
Detlef Knappe
Professor
319-E Mann Hall
Department of Civil, Construction, and Environmental Engineering
North Carolina State University
Campus Box 7908
Raleigh, NC 27695-7908
Phone: [phone]
Fax: [phone]
E-mail: [e-mail]
Web page: http://knappelab.wordpress.ncsu.edu/
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