Evaluation of Passive Treatment Technologies for the Treatment of - - PowerPoint PPT Presentation

Evaluation of Passive Treatment Technologies for the Treatment of Septic Tank Septage Under Temperate Climate Conditions

Christine Gan, Geof Hall Pascale Champagne, Professor

Department of Civil Engineering Queen’s University Kingston, Ontario, Canada June 23-25, 2016

Waste Stabilization Ponds (WSPs) in North America

• Low operational cost
• No electrical energy

required

• Easy to implement and

maintain

• High reductions of solids,

BOD, pathogens, nutrients

• Possibility of effluent reuse

(irrigation, agriculture)

2

Need for WSP attenuation

3

4,0 4,5 5,0 5,5 6,0 6,5 7,0 1920 1940 1960 1980 2000 2020

Population (millions) Year

Rural Growth (Canada)

http://www.statcan.gc.ca/

1. Increases in rural growth 2. More stringent discharge guidelines: Wastewater Systems Effluent Regulations by the Government of Canada

More waste, less leniency!

Storring Septic

• Licensed wastewater treatment facility in

Tamworth, ON

• Passive, evaporative stabilization ponds
• Environmentally-friendly operation

4

Test three, low-energy technologies to insulate ponds:

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1) BioDome system 2) BioCord system 3) Zebra Mussels

(Dreissena polymorpha)

Improve treatment efficiency and robustness

• Optimal conditions for

proliferation, activity

• Increased aeration/surface

area, min. sunlight

• Increased cold-weather performance

BioDome system BioCord system

6

Biofilm technologies (fixed film submerged media)

• Optimal conditions for

proliferation, activity

• Increased aeration/surface area
• Fibers meant for attached growth
• naturalized, low-cost systems
• easily customizable
• able to be retrofit into any lagoon system

Zebra Mussels

• Known filtration capabilities (particulate removal)
• Suspended solids removal up to 1L/day per mussel (Effler et al., 1996)
• Ability to reduce other wastewater parameters not definitively known
• Invasive species
• Collected from Beaver Lake

7

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• Deploy best technology for full-scale testing and use
• Ability to handle greater amounts of septage by increasing

efficiency of wastewater parameter reductions

• Ability to recover from shock (i.e. due to unknown 3rd-party

materials in influent, system shutdown, etc.)

• Effective treatment with smallest energy and maintenance

requirements

• Safely accept excess septage with minimum carbon footprint
• Recommendation matrix for optimal efficiency
• Optimal aeration cycling, retention times, discharge periods

for cold and warm weather

Overall Project Objectives

11

16

Site and Experimental Setup Summer/fall 2015 (full operational cycle)

• TSS
• Ammonia/ammonium
• Nitrite, nitrate
• COD
• Orthophosphate
• pH/temp
• HRT/loading rates
• Dissolved oxygen (DO)
• Water temperature
• Sampling ~2-3x/week
• On/off cycling of aeration

and retention times

Summer/fall 2015 testing

(full operational season)

Overall average temperature = 17.7oC

• Compare overall

treatment efficiencies

• f each technology
• ver the course of a

typical WSP

• perational season
• Varied aeration cycles

for differing objectives and treatment targets

• Addition of control

tank (air stones only)

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10 20 30 40 50 60

5 10 15 20 25 30 35 40

10 20 30 40 50 60 70 80 90 100 110 120 130 140

Precipitation (mm) Temperature (°C)

Day Temperature/Precipitation Data May 22 – Oct 8th, 2015

Max Min Average Precipitation

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Day 1 (start of flow) = May 22

Testing/air cycling schedule Week HRT (days) Loading rates (kg CODm-3d-1) Air Cycling (on/off) Rationale

1-7 3-7 ~1 – 1.21 24h/0h

• Consistent aeration
• Allow biofilm to acclimatize and

reach steady-state

• Develop heterogeneous microbial

population

4-7

7-10 ~0.57 – 0.77 8-13 6-7 ~0.15 – 0.80 4d/3d

• Beginning to cycle aeration
• Long aerobic/anaerobic conditions
• Inducing nitrification/denitrification,

possible P uptake

14

0h/24h

15, 16 7-10 ~0.15 — 0.55 4h/4h

• Shorter on/off air cycles
• Looking for best regime (low energy,

high reductions)

17, 18 3-7 ~0.57 – 0.87 12h/12h 19, 20 24h/24h

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Day 1 (start of flow) = May 22

Testing/air cycling schedule Week HRT (days) Loading rates (kg CODm-3d-1) Air Cycling (on/off) Rationale

1-7 3-7 ~1 – 1.21 24h/0h

• Consistent aeration
• Allow biofilm to acclimatize and

reach steady-state

• Develop heterogeneous microbial

population

4-7

7-10 ~0.57 – 0.77

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Day 1 (start of flow) = May 22

Testing/air cycling schedule Week HRT (days) Loading rates (kg CODm-3d-1) Air Cycling (on/off) Rationale

8-13 6-7 ~0.15 – 0.80 4d/3d

• Beginning to cycle aeration
• Long aerobic/anaerobic conditions
• Inducing nitrification/denitrification,

possible P uptake

14

0h/24h

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Day 1 (start of flow) = May 22

Testing/air cycling schedule Week HRT (days) Loading rates (kg CODm-3d-1) Air Cycling (on/off) Rationale

15, 16 7-10 ~0.15 — 0.55 4h/4h

• Shorter on/off air cycles
• Looking for best regime (low energy,

high reductions)

17, 18 3-7 ~0.57 – 0.87 12h/12h 19, 20 24h/24h

*Zebra mussel tank decommissioned

20 40 60 80 100 120

50 100 150 200 250 300 350

10 20 30 40 50 60 70 80 90 100 110 120 130 140

Average volume of septage added/week (thousand litres)

Total ammonia concentration (mg/L) Time (days)

Influent BioDome BioCord Zebra Mussels Control Volume

4h/4h

12h/12h 24h/24h

4d/4d

Aeration

• ff

24h/0h

Results – Total ammonia (ammonia/ammonium) (pH range: 7-8.1)

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Results – Ammonia/ammonium

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Total Nitrogen Compositions

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Influent BioDome BioCord

24h/0h

4h/ 4h

4d/4d

12h/ 12h 24h/ 24h

24h/0h 4d/4d

4h/ 4h 12h/ 12h 24h/ 24h

24h/0h 4d/4d

4h/ 4h 12h/ 12h 24h/ 24h

Total Nitrogen Compositions

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Influent Zebra Mussels Control

24h/0h 4d/4d

4h/ 4h 12h/ 12h 24h/ 24h

24h/0h 4d/4d 24h/0h 4d/4d

4h/ 4h 12h/ 12h 24h/ 24h

Mean percent reductions of total nitrogen (from influent)

Timeframe (Weeks) Aeration cycling (on/off) BioDome (%) BioCord (%) Zebra Mussel (%) Control (%) 1-7 24h ON 23 ± 5 36 ± 10 14 ± 10 23 ± 11 8-13 4d/3d 42 ± 6 †55 ± 6 43 ± 7 14 ± 7 14 24h OFF 16 ± 8 40 ± 6 5 ± 10 18 ± 2 15/16 4h/4h 33 ± 21 42 ± 11 No data 21 ± 18 17/18 12h/12h 58 ± 6 78 ± 4 35 ± 7 19/20 24h/24h 12 ± 5 55 ± 6 7 ± 5 Overall average percent reductions 31 ± 4 47 ± 5 17 ± 5 20 ± 5

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• Blue highlighted cells = percent reductions from influent are significantly

higher (p<0.05) than the control

*Statistics performed using Kruskal-Wallis post-hoc analysis

20 40 60 80 100 5 10 15 20 25 30

10 20 30 40 50 60 70 80 90 100 110 120 130 140 Average volume of septage added/week (thousand litres)

Ortho-P concentration (mg/L)

Time (days)

Influent BioDome BioCord Zebra Mussels Control Volume

Results – Ortho-P

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• PAOs – phosphorus-accumulating organisms (aerobic)
• enriched by alternating aerobic/anaerobic
• Anaerobic phases—release P; aerobic—uptake P
• No significant reductions for any treatment/air cycling (vs. control)
• Overall, all treatments showed significantly lower P levels than influent (overall), with

lowest concentrations seen during weeks of 12/12h cycling

24h/24h

24h/0h 4h/4h 12h/12h 4h/4h

Results – Chemical Oxygen Demand (COD), Total suspended solids (TSS)

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• BioCord showed significant reductions (vs.

control) during all air cycling regimes

• BioDome: only period 2 (24h off)
• ZMs: only period 2 (24h off)
• Highest reductions overall seen during

12/12h, followed by 24h on

• BioCord showed significant reductions

(vs. control) during all air cycling regimes

• BioDome: only period 1 (24h on)
• ZMs: only period 2 (3d/4d)
• Highest reductions overall seen during

24h on, followed closely by 12/12h

20 40 60 80 100 120

100 200 300 400 500 600 700 800 10 20 30 40 50 60 70 80 90 100 110 120 130 140

Average volume of septage added/week (thousand litres)

TSS concentration (mg/L)

Time (days)

TSS reductions

12h/ 12h 4h/4h 12h/ 12h 24h/ 24h 24h/0h 4d/4d

24h/ 24h

20 40 60 80 100 50 100 150 200 250 300 350

10 20 30 40 50 60 70 80 90 100 110 120 130 140

Average volume of septage added/week (thousand litres) COD concentration (mg/L)

Time (days)

COD reductions

24h/0h 4d/4d

4h/4h

Dissolved Oxygen levels

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1 2 3 4 5 6 7 8 9 10 20 40 60 80 100 120 140

DO Concentration (mg/L)

Time (days)

BioDome BioCord Zebra Mussels Control

24h/0h 4h/4h 4d/4d 12h/12h 24h/24h

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Full-scale testing and implementation at Storring Septic – Current operational regime

31

Full-scale testing and implementation Split-pond operation

Regular septage

32

Full-scale testing and implementation Split-pond operation

3rd-party/excess materials

33

In the case of pond shock . . .

Regular septage

34

Full-scale implementation – alternative scenario

All septage All septage

Conclusions/Contributions to North America

35

• BioCord was most promising treatment for full-scale testing/implementation in

terms of performance and maintenance

• Results suggest that full-scale implementation would allow for Storring Septic (and

WSPs across North America) to:

• More efficiently treat and process septage; take in more/higher-strength

wastewater

• See better treatment during cold-weather conditions (longer treatment

season, less volume in holding tanks, faster start-up in spring)

• Increase ability to buffer against drastic fluctuations in volume and

wastewater strength; have quicker recovery times following system shutdown/variable DO concentrations

Conclusions (continued)

36

• Taking into account energy requirements and reduction efficiencies of all

parameters, the 12/12h cycling method can be implemented for full-scale testing

• Consistent (24h) consistent aeration during start-up periods and low

(<10oC) temperatures

• Reduced aeration (e.g. 6h/18h on/off cycling) may be a viable option, but

continued testing is required in full-scale

37

Thank you!

Special thanks to:

Christine Gan Geoffrey Hall Stanley Prunster Curtis Ireland Greg & Cheryl Storring Champagne Bioresource Group

WSP group:

Rami Maassarani Alan MacDougall Lei Liu Martin Schueder Shijian Ge

NSERC Engage NSERC Discovery

Meng Jin Gustavo Leite Roland Lee Michael Jessop Summer students: Danielle Trembley Max Madill Madeline Howell

Supplemental slides

pH fluctuations; summer/fall testing (May 22 – Oct 8, 2015)

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6 6,5 7 7,5 8 8,5 9 1 11 21 31 41 51 61 71 81 91 101 111 121 131

pH

Day

pH changes

BioDome BioCord Zebra Mussels Control

Mean percent reductions of Ammonia

Testing Period Timeframe Aeration Tank 1 BioDome Tank 2 BioCord Tank 3 Zebra Mussels Tank 4 Control 1 Weeks 1-7 (days 1-47) 24h ON 23 ± 3 †75 ± 7 15 ± 12 41 ± 11 2 Weeks 8-13 (days 47-82) 4d ON/ 3d OFF 44 ± 6 †70 ± 5 47 ± 7 31 ± 7 Week 14 (days 83-91) 24h OFF 15 ± 10 37 ± 7 10 ± 9 18 ± 1 3 Weeks 15/16 (days 105-113) 4h ON/ 4h OFF 38 ± 11 48 ± 7 18 ± 7 Weeks 17/18 (days 114-127) 12h ON/ 12h OFF 48 ± 11 †82 ± 4 19 ± 8 Weeks 19/20 (days 128-140) 24h ON/ 24h OFF 13 ± 7 †68 ± 10 11 ± 5 All Weeks 1-20 (days 1-140) 31 ± 3 †69 ± 4 26 ± 7 30 ± 5 40

Daphnia magna/Water Fleas

• Present in significant amounts in tank #2 (BioCord) during day 20 (Oct

23rd, mean temp of 10oC) after no flow/aeration for 3 days

• Number reduced significantly (none seen) by next sample collection (day 24)

Ambient avg mean temp, days 20-24: 11.1oC

• Microcrustaceans—filter feeders
• Algae (primarily

green/diatoms), bacteria, bits of detritus

• Used as indicators of toxicity
• Tolerant down to 0.1mg/L DO, 0oC
• 0.7mg/L ammonia limit (unionized)
• Presence often associated with

low pH levels (Hathaway and Stefan, 1992)

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Zebra Mussels – things to consider

• Poor oxygen regulators
• Populations still found as low as 0.1mg/L O2
• Only slight tolerance of salinity
• Optimal pH 7.4 – 8.0, populations found in pH range 6.6 – 8.0
• Filtration rates: up to 1L/day
• Optimal temperature (for filtration): 10-20oC
• Rates may be inhibited at T > 20oC
• Known uptake of suspended particles, waterborne pathogens

(Graczyk et al., 2005), pharmaceuticals and drugs (Binelli et al., 2014) in wastewater

• Nutrient uptake/cycling?

43

Zebra mussels: In-lab experimental results

2 4 6 8 10 12 14 16 18 20 0,5 1 1,5 2 2,5 3 1 2 3 4 5 6 7 8 9 10 11 12

Ammonia Concentration (mg/L) Concentration (mg/L) Day

Ortho-P COD TSS Ammonia

• Start (Day 1): July 6th
• Sampling 3x/week
• End (day 12): July 31st
• 5 adult-sized ZMs
• Used diluted (not

synthetic) wastewater from tank #3 (1:9 dilution)

• Aerated 10L tank
• Noticeable/steady

declines in

• rthophosphate, TSS

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• A fertilized egg results in a free-swimming

planktonic larva called a veliger

• Veligers are about the diameter of a

human hair and are so small you can’t see them without a microscope.

45

Zebra Mussels – Nutrient uptake/cycling

• In lake environments:
• Amounts of N and P accumulated in ZM bodies similar to amounts stored in

macrophytes (McLaughlan and Aldridge, 2013)

• Can retain N and P in tissue and minimal amounts in shells (Goedkoop et

al., 2011; McLaughlan and Aldridge, 2013)

• Can reduce P through biodeposition into lake sediment as faeces and

pseudofaeces (Reeders and Bij de Vaate, 1990)

• No change in levels of total dissolved nitrogen in lakes between the pre and

post-invasion period (Higgins and Vander Zanden, 2010)

• (Kirsch and Dzialowski, 2012): effects of ZMs on nutrient concentrations varied in

3 reservoir experiments

• In 2/3 experiments, ZMs increased dissolved P concentrations
• Zebra mussels excrete high amounts of phosphate, therefore creating a low N:P

ratio (Bykova et al., 2006)

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Zebra Mussels – Experimental Set-up

• Two small (~2L), aerated (air stones) tanks
• 10-15 zebra mussels per tank (same number in both)
• No recirculation
• TANK 1:
• Synthetic wastewater with known start concentrations of C, N, P + food

source/particulates

• monitor changes/reductions in wastewater parameters on a regular basis (2-

3x a week) indefinitely

• If no changes/post experiment: alter DO, temp, #ZMs, etc.
• TANK 2 (control):
• DI water + ZM food source
• Monitor changes in wastewater parameters on a regular basis (2-3x a

week, same as tank 1)

• After time period of no change/insignificant change: remove food source and

aeration

• Monitor changes in wastewater parameters due to ZM death

Challenges Testing schedule – 105 weeks, 3 testing periods

• Periodic system shutdown – no air/water flow due to lack of power
• Flow rate variation in between sampling
• DO, water temperature data not collected
• Frequency of data collection
• Missing BioCord data for day 20 due to presence of Daphnia

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Site and Experimental Setup

1,0 1,2 1,4 1,6 1,8 2,0 1920 1940 1960 1980 2000 2020

Population (millions) Year

Rural Growth (Ontario)

Storring Site – up close!

http://www.statcan.gc.ca/tables-tableaux/sum-som/l01/cst01/demo62a-eng.htm

• Treat domestic wastewater coming from surrounding municipalities
• Offering third-party sewage haulers access to their facility
• Problem: too much waste—may shock ponds!