Virus removal by integrated membrane systems for water reuse applications

Walter Betancourt, Christina Morrison, Bianca Chaves, Andrea Achilli, Charles Gerba

Rotavirus Norovirus Adenovirus Astrovirus Reovirus

Human immunodeficiency virusInfluenza virus

RhabdovirusPhoto credit:ICTV

Percentage of sewage virome contigs with homologues in the Viral

RefSeq database

Composition of viral types in sewage Aw et al. 2016

Rosario et al. 2009Composition of viral types in reclaimed water

Rusinol and Girones 2017

Major waterborne viral pathogens

Excretion characteristics of major waterborne viral pathogens

Rusinol and Girones 2017; Betancourt and Shulman, 2017; Gerba and Betancourt, 2018

Sewage

104 - 109 GC/L 105 MPN/L

104 - 109 GC/L

106 - 107 GC/L

104 - 106 GC/L

105 - 106 GC/L 102 – 104 PFU/L/103 MPN/L

105 - 107 GC/L (no reports in the US)

104 GC/L (no reports in the US)

104 - 109 GC/L

102 - 107 GC/L

107 - 108 GC/L

104 - 107 GC/L

Viral load in the inlet of two full-scale wastewater reclamation facilities in Arizona

serving ~1,000,000 customers

Plant A

Plant B

Schmitz et al. 2016

Morrison et al. unpublished

Co

nce

ntr

atio

n G

C/L

Schmitz et al. 2016

Virus reduction by wastewater treatment process consisting on primary sedimentation, dissolved air flotation (DAF), four

parallel five-stage Bardenpho, disc filtration, chlorination

Virus removal at full-scale advanced wastewater treatment processes

Comparative sizes of viruses and bacteria

Approximate pore size ranges of different types of membranes, compared todimensions of some components separated by membrane processes

Membrane Processes in Biotechnology and Pharmaceutics. DOI: 10.1016/B978-0-444-56334-7.00001-0

20 nm

Virus removal by integrated membrane systems for water reuse projects/applications

Feed water

Secondary effluent

filtered secondary effluent

MF-UF Reverse

OsmosisUV/AOP Chlorination

Log Removal

Credit: 0

Log Removal

Credit: 2.0

Log Removal

Credit: 6.0Log Removal

Credit: 6.0

Pressure Driven Membrane Technologies

• Low Pressure vs. High Pressure Membranes

• Reverse Osmosis (RO)

• Virus rejection widely studied in low pressure membranes, very few studies on RO• > 5 LRV in laboratory & pilot studies

• No full scale studies examining naturally occurring viruses

• Evaluate occurrence of indigenous wastewater viruses in integrated membrane systems at pilot and full scale operations

• Determine LRVs of indigenous wastewater viruses by MF-UF and RO processes

• Establish adequate methodologies and QA/QC plan for evaluation of virus removal by integrated membrane systems

Objectives

Sites

Preliminary Primary Secondary Tertiary Advanced

Plant A Screening /

Grit removal

Dissolved

Air Flotation

Modified 5-

Stage

Bardenpho,

Clarification

Disc Filtration,

Chlorination,

Dechlorination

Pilot Scale

Integrated

Ultrafiltration /

Reverse

Osmosis

process

Plant B Coarse

Screen

Clarification Activated

Sludge,

Clarification

Cloth Disc

Filtration

Ozonation,

Chloramination,

Ultrafiltration,

Reverse

Osmosis, UV

Sites

Preliminary Primary Secondary Tertiary Advanced

Plant A Screening /

Grit removal

Dissolved

Air Flotation

Modified 5-

Stage

Bardenpho,

Clarification

Disc Filtration,

Chlorination,

Dechlorination

Pilot Scale

Integrated

Ultrafiltration /

Reverse

Osmosis

process

Plant B Coarse

Screen

Clarification Activated

Sludge,

Clarification

Cloth Disc

Filtration

Ozonation,

Chloramination,

Ultrafiltration,

Reverse

Osmosis, UV

Operated at UA WEST

Center, Andrea Achilli Lab

Group

Sites

Preliminary Primary Secondary Tertiary Advanced

Plant A Screening /

Grit removal

Dissolved

Air Flotation

Modified 5-

Stage

Bardenpho,

Clarification

Disc Filtration,

Chlorination,

Dechlorination

Pilot Scale

Integrated

Ultrafiltration /

Reverse

Osmosis

process

Plant B Coarse

Screen

Clarification Activated

Sludge,

Clarification

Cloth Disc

Filtration

Ozonation,

Chloramination,

Ultrafiltration,

Reverse

Osmosis, UV

RO (Pilot Scale): ~14,000 GPD

RO (Full Scale): ~5-10 MGD

Research Approach

NanoCeram Filtration

Average Log Concentration Values in RO Permeate

= Less than (value

based on sample LOD)0/52/5

2/5

2/5

0/3

0/3

0/3

1/3

(N=5) (N=3)

Average Log Reduction Values: WEST RO Pilot

= Greater than (value

based on sample LOD)

Average Log Reduction Values: Plant B

• Low recovery of virus from feed, despite presence in

permeate• Requires QA/QC and Synoptic sampling

• Evaluate virus removal capabilities of full-scale integrated membranesystems• Select the most appropriate viruses to evaluate membrane integrity and

therefore water safety for potable reuse projects• Establish adequate methodologies and QA/QC plan for evaluation of virus

removal by integrated membrane systems*

Future work