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1Stantec2Johns Hopkins University Bloomberg School of Public Health3Metro Wastewater Reclamation District, Denver, CO
2018 IUVA Americas Conference
Evaluation of the Inactivation of MS2
Bacteriophage and Murine Norovirus in
Secondary Wastewater Effluent by
Peracetic Acid-UV Combined Treatment
Joe Jacangelo, Ph.D., REHS1,2, Shi-Chi Weng2,
Nate Dunkin2, Kellogg Schwab1, Jim McQuarrie3 and
Kati Bell, Ph.D., P.E., BCEE1
Presentation outline
• Regulatory considerations
for wastewater disinfection
• Drivers for use of peracetic acid (PAA) in
wastewater disinfection
• Literature reports of UV+ PAA synergies
• Experimental protocols
• Results and conclusions
Regulatory criteria for wastewater disinfection
US EPA 2012 Recreational Water Quality Criteria
http://water.epa.gov/scitech/swguidance/standards/criteria/health/recreation/index.cfm
Targets in cfu/100mL E. coli (cfu/100ml) Enterococci (cfu/100ml) Enterovirus3 reduction (geomean)
Bathing water (continuous discharges)
80 (maximum)32
(maximum)1 log10 through disinfection
4.4 log10 by treatment and dilution
Shellfish (continuous discharges)
110 (maximum) No target 1 log10 through disinfection
Stormwater Site-specific target Site-specific target 1 log10 through disinfection
Table 3.2 UK Environment Agency target concentrations in disinfected discharge to shellfish and bathing waters 1,2
EPA Ambient WQ Criteria
• BEACH Act (CWA Section 304(a)(9)(B)) requires a 5-
year review of RWQC
– Review the latest science and determine if there is a
need to revise the RWQC
– Output: Report summarizing the findings of the review,
to be published late CY2017
– Inform whether revisions are necessary/appropriate
• Norovirus is responsible for large majority of viral GI
illnesses from recreational water (U.S. EPA, 2009)
• US EPA is utilizing norovirus epidemiology to support
QMRA in development of new AWQC
What might change?
Drivers for use of peracetic acid (PAA) for
wastewater disinfection
• Security, transportation, use use and
and safety of gas chlorine
• Disinfection byproducts
– Ambient WQ Criteria
– Ecotoxicity of byproducts
• Capital costs of converting to UV disinfection for
facilities with high peaking factors
• PAA costs and benefits
– Chemical costs are half that of 5 years ago
– Low capital costs, and simple to operate
– “Back up” or “supplemental” technology to UV
What is PAA?
• Antimicrobial agent/biocide
• EPA-registered & FDA-approved
– Beverage packaging sterilizing agent
– Red meat, poultry, fruit, vegetable wash
– Oil & gas applications
– Commercial disinfectant, laundry applications
– Wastewater disinfectant
Project objectives
• Assess the feasibility of using PAA,
UV and PAA+UV for use at the
Metro Wastewater Reclamation
District (Denver, CO) Hite WWTP
– Meet NPDES compliance
– Provide virus inactivation similar to, or better than current
chloramination practice, requiring three chemicals
• Determine costs of “successful” technologies (SROI)
UV254 irradiation via collimated
beam5-250 mJ/cm2
MS2 assay
MNV assay
Sample
collected as
N0
10 mL virus-
seeded
sample
Experimental protocol – UV CB
• Organisms – MS2 and MNV
• Matrices – Secondary effluent and phosphate buffer
Disinfectant
analysis
(immediately)
Sample quenched
with sodium thiosulfate
and/or catalase
1 mL of MNV and 1 mL MS2 virus stock
5 mL of disinfectant
stock solution
MS2 assay
MNV assay
Sample collected as N0
94 mL Secondary
Effluent)
*All experiments performed at
ambient conditions
Experimental protocol – PAA and NH2Cl
• Organisms – MS2 and MNV
• Matrices – Secondary effluent
and phosphate buffer
Synergies of PAA+UV from literature,
and operational experience
• Reduce algae growth on MPUV lamps
• Minimizes mineral precipitation
• Can increase UVT, reduce power
• Oxidizes floc bridging compounds
(EPS); making particle associated
organisms more susceptible to UV
• Low capital cost backup to UV,
particularly for systems requiring
process redundancy
• Reduces potential “UV reactivation”
Synergies of PAA+UV from literature
• Summary of findings– Mixed reports in literature
on synergy of UV and PAA
– Virus synergy may be less
than for bacteria
– Test conditions evaluated
o PAA doses 2–8 mg/L
o Contact time 10–30 min
o UV doses 10–300 mJ/cm2
o Range of organisms
• “NO synergy”– Chen et al., 2005
• “Synergy”– Koivunen et al., 2005
– Caretti and Lubello et al., 2003
– Bianchini et al., 2002
– Lubello et al., 2002
– Koivunen and Heinonen–
Tanski, 2005
– de Souza et al., 2015
s Temporal profiles for
reduction of viral
infectivity in secondary
effluent wastewater
(WW) and 0.01 M
phosphate buffer (PB)
for (a) MS2 by NH2Cl,
(b) MS2 by PAA, (c)
MNV by NH2Cl, and (d)
MNV by PAA.
Hollow symbols with
no shading or
crosses represent
viral concentrations
below the sensitivity
limit of the assay.
Dunkin et al., Environ. Sci
Technol. 2017, 51, 2972-2981.
Introduction
Dunkin et al., Environ. Sci Technol. 2017, 51, 2972-2981.
Kinetic models for PAA (and chloramines)
Delivered UV Dose (mJ/cm2)
0 50 100 150 200 250
Infe
ctivity R
eduction
(-
log(N
/N0))
0
1
2
3
4
5
6
MS2 in 0.01M PBS, pH 7
MS2 in 2nd
Effluent
MNV in 0.01M PBS, pH 7
MNV in 2nd
Effluent
Infectivity reduction of MS2/MNV by UV
30 min
120 min
-1.0
-0.5
0.0
0.5
1.0
1.5
PAA contact time (minutes)
30 min
120 min
30 min
120 min
0.01 M PBS pH 7
2nd
Effluent
30 min
120 min
PAA = 1.5 mg/L PAA = 10 mg/LPAA = 1.0 mg/LPAA = 0.5 mg/L
Infe
ctiv
ity R
ed
uct
ion
Diff
ere
nce
Be
twe
en
PA
A+
UV
Co
mb
ine
d
Tre
atm
en
t a
nd
Se
pa
rate
UV
an
d P
AA
Tre
atm
en
tSynergy of PAA+UV at UV dose of 20 mJ/cm2
PAA reactions reported in literature
Luukkonen and Pehkonen, CRITICAL REVIEWS IN ENVIRONMENTAL SCIENCE AND
TECHNOLOGY, 2017, VOL. 0, NO. 0, 1–39.
Reaction of salicylic acid and hydroxyl radical
Adapted from Peralta, E., Roa, G., Hernandez-Servin, J.A., Romero, R., Balderas, P., Natividad, R., 2014.
Hydroxyl Radicals quantification by UV spectrophotometry. Electrochimica Acta 129, 137-141.
Scavengers
Absorption spectra in phosphate buffer: PAA only , salicylic acid only, salicylic acid plus UV, and salicylic acid plus PAA and UV
Wavelength (nm)
250 260 270 280 290 300 310 320 330 340 350
Diffe
rence in a
bsorb
ance a
fter
UV
irr
adaitio
n
-0.4
-0.3
-0.2
-0.1
0.0
0.1
0.2
UV only in PBS
PAA+UV in PBS
PAA+UV in MWW
Difference in absorption spectra of salicylic acid after UV only at 500 mJ/cm2 in PBS, with 10 mg/L of PAA and UV in PBS, with 10 mg/L of PAA with UV in MWW
Summary and conclusions
• PAA-UV synergy was observed
• Secondary wastewater appears to scavenge radicals formed
PAA during-UV treatment
• Synergy for WW disinfection applications is small, there may
benefits of PAA with UV from an intermittent operations and
capital cost deferral perspective
• Additional research is needed:
– Characterize disinfection byproducts
– Develop a working “model” to provide process control and operational
optimization of the combined system
– Develop a mechanistic understanding of process
– Evaluate the potential for reuse applications, where PAA could be
substituted for chloramines
