1. Innovative Strategies for Removing Emerging Contaminants for Indirect Potable Water Reuse - Oak Bluffs, MA Case Study
Marc Drainville, PE BCEE LEED AP | GHD
Chandra Mysore, Ph.D., PE, BCEE | GHD
Anastasia Rudenko, EIT | GHD
Rhodes Copithorn, PE, BCEE | GHD

2. Outline Background Emerging contaminants
Plant data and current performance
Technologies considered
Characterization & bench-scale testing
Current status

3. Background

4. Plant location Oak Bluffs, Massachusetts (Martha’s Vineyard)
Population 3,713 (US census data)

5. Wastewater treatment facility
SBRs with primary clarifier, effluent filters, and UV
Seasonal flows
Wastewater: municipal and hospital flow
Discharge to Ocean Park

6. Project need New disposal area
Purchased new property adjacent to existing WWTF
Requirements released March, 2009 include limitations for total organic carbon (TOC)
3.0 mg/L for discharge within a Zone II drinking water protection area and >2-year travel time to source
1.0 mg/L for discharge within a Zone II area and <2-year travel time to source
1.0 mg/L for discharge within a Zone II area without soil aquifer treatment
TOC limit is a daily limit (24 hour composite sample)

8. Emerging contaminants

9. Emerging contaminants
31 million organic and inorganic substances documented
14 million commercially available
< 250,000 inventoried or regulated
Domestic, industrial & agricultural compounds:
Pharmaceuticals: prescription & non-prescription
Personal care products
Industrial & commercial products (detergents & metabolites, plasticizers, flame retardants, pesticides)
Potential Health Effects
EDCs
Carcinogens
Developmental toxicants

10. Health effects of CEC
Concentrations are very small – but what are the potential effects?
Chemical Group
Common Uses
Reproductive Health Concerns
Alkyl phenols and related chemicals
Industrial and institutional cleaning sector (including domestic cleaning)
Textile and leather processing
Personal care products (PCPs)
Pesticide Production
Hormone mimicking activities
Reduced male fertility, testicular size, sperm quality
Phtalates
Plasticizers in PVC and special polymer applications
Gelling agents
Solvents and fixatives in cosmetics and other PCPs
Testicular toxicity
Reduced anogenital distance, cleft phallus, hypospadias and undescended testes in immature males
Reduced male and female fertility
Fetal toxicity (possibly leading to death or malformations)
Bromated flame retardants
As flame retardants in industrial and electrical appliances, vehicles, lighting, wiring as well as textiles, furnishing and insulating materials such as polystyrene
Estrogen mimicking
Birth defects in rodents documented
Impacts on nervous system and behavioral development
Organotin Compounds
PVC UV stabilizers
Argochemicals and biocides
Antifoulants
Catalysts
Inhibition of steroid hormone production
Adverse impact on in-utero development of fetus including abnormalities in genital development in male fetuses
Bisphenol-A and its derivatives
Production of polycarbonate plastic used in products like baby bottles, CDs, motorcycle windshields, etc.
Production of epoxy resin used in things like food packaging
Estrogenic activity
Altered male reproductive organs
Early puberty induction
Reduced breast feeding
Artificial Musks
Fragrance mixtures for detergents, fabric conditioners, cleaning agents, air fresheners, and other household products
Cosmetic products such as soaps, shampoos, and perfumes
Anti-estrogenic activity
Source: Virginia Department of Environmental Quality

11. Why TOC?
TOC as a surrogate for many contaminants of emerging concern (CEC)
Studies have shown that Pharmaceuticals & Personal Care Products (PPCPs) adsorb on to particulates of organic carbon, hence removal of TOC provides for removal of PPCPs.

12. Plant data and current performance

13. Plant data Design Flow = 370,000 gpd Design Peak Flow = 1.3 mgd
Current status: ~ 40% design flow

14. Historical TOC data

15. Water Quality Parameter
Water quality data
Water Quality Parameter
Unit
Influent
Effluent pH SU
6.6
7.16
Alkalinity
mg/L
190 90
Ammonia (unionized) 26
2.7
Total Nitrogen 45
5.3
Total Phosphorous
6.7
4.8
CBOD5
200 3
COD
550 55
TSS 94
UV Absorbance
(1/cm)
0.41
0.22
TOC 81 12
DOC 11

16. Technologies considered

17. Technologies to achieve less than 3.0 mg/L (post-tertiary)
Membrane filtration
Nanofiltration, reverse osmosis, ultrafiltration
Ion exchange
Adsorption (GAC)
Advanced Oxidation Processes (AOPs)
Coagulation and filtration

18. Process alternatives

19. Process alternatives

20. Membranes Requires pretreatment to minimize fouling
May require post-treatment for water chemistry stabilization
Concentrate disposal required (high salinity RO concentrate)
Excellent TOC and CEC removal

21. Ion exchange
Continuous process with magnetized anionic exchange resin designed for dissolved organic carbon (DOC) removal
DOC exchanged with chloride ions on the MIEX resin surface, resin has to be regenerated
Brine disposal required
Potential for good DOC and CEC removal

22. Adsorption Granular Activated Carbon (GAC)
TOC adsorbed in a downflow or upflow contactor
Requires pre-treatment and disposal / regeneration of spent GAC once breakthrough occurs
Good TOC and CEC removal
Treated Wastewater Effluent
GAC
Contactor

23. Treated Wastewater Effluent
Advanced oxidation
Oxidation by hydroxyl radicals
Typically used as polishing step following membrane filtration
Good CEC destruction, but mineralization to CO2 cost-prohibitive
Hydrogen Peroxide
Treated Wastewater Effluent
UV Reactor

24. Treated Wastewater Effluent
Pre-treatment
Alter physical / chemical properties of suspended particles to increase agglomeration (create larger flocs)
Chemical coagulants include aluminum sulfate (alum), ferric chloride, and ferric or ferrous sulfate
Coagulant
Sedimentation Basin
Treated Wastewater Effluent
Rapid Mix
Flocculation
Filters
BASIN

25. Challenges at Oak Bluff
Requirement for a high level of treatment
Need to achieve levels below 3 mg/L (desire to be as low as 1 mg/L)
A hospital contributes in the order of 10% of the flow to the plant
Small user base with median income (year round population) at or below state median
Piloting likely needed to determine optimum process
Limited options for waste stream disposal

26. Initial approach Phase I
Focus on technologies (pre-treatment) that could reduce TOC in economic ways
Focus on low cost means to determine an ultimate treatment solution (wastewater characterization, bench testing etc.)

27. Characterization & bench-scale testing

28. Phase I Wastewater characterization
Organic matter characterized at the University of Massachusetts
XAD-8/XAD-4 Resins and HPSEC
Bench-Scale testing

29. Influent organic matter characterization

30. Influent organic matter characterization

31. Phase I Bench-scale testing ACTICARB by Kruger MIEX by Orica
Ferrate by Ferrate treatment technologies
Testing by GHD

32. Bench-scale testing of ACTICARB
Alter physical / chemical properties of suspended particles to increase agglomeration (create larger flocs)
Best coagulant was ferric sulfate
50 mg/L dose, no PAC:- 47% removal of TOC
50 mg/L dose, 30 mg/L PAC:- 59% removal of TOC

33. Bench-testing with MIEX
Jar testing with MIEX alone
Jar testing with coagulation alone
MIEX + coagulation
Best coagulant was ferric sulfate
Coagulation alone provided 53%
Removal by MIEX alone was marginal.
Improved removal by 5%
WWTP
MIEX Resin with Ferric Sulfate Coagulation
MIEX Treatment Rate (BV)
600 Bed Volumes
Ferric sulphate (mg/L) - 30 40 50
DOC (mg/L)
12.3
5.30
5.20
5.11
DOC Removal (%) 57 58
UVA254(cm-1)
0.218
0.084
0.081
0.098
UVA254Remocal (%) 61 63 55
True Color (CU) 56 8 5 6 pH
8.40
6.37
5.79
3.82
Total Alkalinity (mg/L CaCO3)
100
Calcium Hardness (mg/L CaCO3) 80
Total Hardness (mg/L CaCO3)
Settled Turbidity (NTU)
10.8
1.34
2.25
0.84

34. Bench-testing with ferrate
Ferrate (iron six) acts as an oxidant, coagulant, and as a disinfectant.
Research is being conducted to understand ferrate effects on emerging contaminants

35. Bench-testing by GHD
Conducted jar testing with ferric sulfate and cationic polymer
Best dose was 50 mg/L coagulant with 0.5 mg/L polymer
Resulted in TOC reduction of 45-50%

36. Phase I findings
A Ferrate dose of 2-4 ppm resulted in 56-65% removal of TOC
For the other three jar tests, ferric sulfate performed the best in terms of TOC removal
For a ferric sulfate dose (45-50 mg/L), a TOC reduction of 45%-53% is possible

37. Phase I findings (cont’d)
Pilot would be needed to confirm results
Investigate cause of wide range of TOC
Focus on Pilot-Studies to confirm findings
Pilot-studies will be conducted with:
GAC
Ferrate - test Ferrate at various application points
Based on the outcome of the pilot-study, recommend a full-scale tertiary treatment technology to Town

38. Process flow diagram of pilot

39. Current status

40. Next steps
Costs of highly complex treatment process were determined to be in excess of $5 million and these were found to be unaffordable for the town at the time
Town requested research into “regulatory” alternatives
Worked with the state DEP for one year and met unofficial alternative requirements for safe distance from drinking water well (for TOC limit only)
Met with Town Water Department to make case about safe distance
Have received unofficial approval from both DEP and Town Water Department to pursue a modified permit
Currently in permit application process and hope to have a modified permit by spring of 2014
If the modified permit fails, the Town will pursue the TOC treatment