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Treatment Options for Wastewaters Collected from On-Site Systems Gordon Balch Centre for Alternative Wastewater Treatment, Fleming College, Lindsay, Ontario Association of Sewage Industry Services (OASIS) Friday October 24 th , 2014, Lindsay, Ontario

Treatment Options for Wastewaters Collected from On-Site Systems

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Page 1: Treatment Options for Wastewaters Collected from On-Site Systems

Treatment Options for Wastewaters Collected from On-Site Systems

Gordon Balch Centre for Alternative Wastewater Treatment, Fleming

College, Lindsay,

Ontario Association of Sewage Industry Services (OASIS)Friday October 24th, 2014, Lindsay, Ontario

Page 2: Treatment Options for Wastewaters Collected from On-Site Systems

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Disposal Challenges• Regulatory oversight / requirements

increasing– post Walkerton– Ont. Environ Protection Act, Ont. Clean Water Act,

etc.

• Complexity of wastewater increasing– Pharmaceuticals and personal care products

• Increasing number of wastewater sources– Petroleum, agra-farms, aquaculture, etc.

• Treatment Costs Increasing

Page 3: Treatment Options for Wastewaters Collected from On-Site Systems

only 2.5% of global

water is drinkable

of this nearly ¾ is

locked away in ice and

snow

only a small fraction

if readily available for

human use

Global Perspective

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Page 4: Treatment Options for Wastewaters Collected from On-Site Systems

1st everything (1,385 km diameter)

2nd groundwater, fresh surface water (272.8 km diameter)

3rd fresh water in lakes and rivers (56.2 km diameter)

Source: Scientific American

Global Water Supply

Page 5: Treatment Options for Wastewaters Collected from On-Site Systems

Water use growing twice as fast as population growth

world’s 6 billion people are drawing from 54% of all water resources (rivers, lakes, aquifers)

Water Use Trends

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North AmericaWastewater Infrastructure Deficit

• Wastewater infrastructure deficit in 2 Provinces and 8 US states is $10 billion

• $90 billion needed in next 10 y (2007) to replace and upgrade Canada wide

Great Lakes Commission – 2007 report

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Aging municipal infrastructure

When Bigger Isn’t Better: Decentralized Wastewater Treatment Systems (Environ. Commission 2009)

• Small or rural communities in Ontario faced with: – Increasing population– Climate change– Stricter environmental regulations

• A call for decentralized systems

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Waste Generation from DWWTs

• 1980 USA census – 3.8 trillion L per year to vadose zone (US EPA 1987)

• 25-30% of households in USA are served by septic systems (Bremer & Harter 2012)

• 22% of Canadians utilize on-site systems (Richardson & Fulton 2009)

Septic system leachate represents the largest unregulated source of wastewater

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Increasing complexity of wastewaters

• Consumption of pharmaceuticals $16 million in Canada (2000)– double digit growth (nearly doubling 2000-2005) Morgan

2004 & 2005• Estrogen example (2007) Richardson & Fulton 2009

– dispensed 1,700 kg of synthetic estrogen compounds• 760 kg diverted to wastewater (½ to WWTPs; ½ to on-

site)– excreted 960 kg endogenous estrogen compounds

• ½ to WWTPs; ½ to on-site– WWTPs (75% degraded) ; on-site (zero degradation)– Mass of estrogens released via on-site equivalent to

release from WWTPs

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Impediment to Decentralized Systems

• DWWT have historically been poorly understood and managed

• Regulatory agencies need scientifically sound third party validation

• Need new more advanced systems to treat a greater complexity of wastewater matrices

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What Wastewater Disposal Options Exist?

• Options depend on source of wastewater and regulatory requirements

• Most treatment options are best suited for liquids with final disposal via absorption into ground

• Solids have fewer options at this time

• Primary focus of talk on treatment of liquids (all options to treat liquids need some form of solids separation)

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Liquid disposal options• Decentralized systems typically dispose of the

primary treated wastewater to soil absorption systems rather than release to surface waters

• There are several options for disposal to soils, including:– Sandfilters (open, buried, recirculating)– Spray and drip irrigation– Mounded systems– Evaporation systems

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Alternative Treatment Systems

Number of treatment options is increasing to accommodate• Complexity of waste stream• Volume of waste generation• Replacement of older technology found

to be inadequate• Mitigate environmental impacts

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Future Trends in Treatment

• New twist on old methods– Constructed

wetlands,– lagoon systems

• Biofilm Technologies– Fixed films

• Advanced Systems– ozonation

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Constructed Wetlands

Many different configuration

Designed for different wastes

Passive, low maintenance

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Hybridized Constructed Wetlands

• Growing trend towards combining different types of CWs

• Can treat complex wastewater• Large wastewater volumes

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Continuous Stirred Tank Reactor

Blue Frog™ (base unit) is an efficient mixer and passive aerator that provides up to 7 mm gallons per day flows and has the ability to layer the treated water

• helps to better mix lagoon systems

• Aids in sludge digestion

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Continuous Stirred Tank Reactor

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Hog Farm Location: Western Oklahoma

Farrowing operation with 6,600 sows Total of 14 feet of sludge was remediated in-situ over a one

year period

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BioCord Floating Islands (fixed film)

Absorbed by plants and biofilm

Nitrogen Gas to atmosphere

Phosphorus removal however is limited to what plants can accumulate during growth

Phosphorus

Nitrogen

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Waterloo Biofilter

There are different configuration depending on the wastewater constituents and desired treatment level

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Fixed Film Bioreactor- rotating contact reactor -

• Biofilm grown on several discs stacked in a row• Only half of disc rotates through effluent

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Fixed Film Bioreactor- rotating contact reactor -

Rotation ensure oxygenation for bacteria

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Moving Bed Biofilm Reactor

• High BOD, NH4+, NO2/NO3, potential to add a P removal media that is

regenerative• Relatively small foot print• Chamber 1: BOD Chamber 2: organic solids & N oxidation

Chamber 3: NO3 removal

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Advanced On-Site Treatment

• Ozone

• Pressure differentials

• Poly-filter

• Granulated activated carbon filter

• Nutrients (N & P)

• TSS

• BOD

• Pathogens

• PPCPs

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Results: Selected PPCPs (ppt)

Levonargestrel

Progesterone

Medroxyprogesterone

Aspartame

Diclofenac

Carbamazepine

Trimethoprim

Sulfamethoxazole

0 100 200 300 400 500 600 700 800 900 1000

Influent Effluent

n.d.

n.d.

n.d.

n.d.

n.d.

n.d.

n.d.

Concentration (ng L-1) Mean ± SD

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Summary

• Need is great• Expect greater demand for on-site

treatment• More research needed to increase

options for solids• Greater effort needed for verification

of emerging environmental technologies

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Questions

“You cannot get through a single day without having an impact on the world around you. What you do makes a difference, and you have to decide what kind of difference you want to make.” — Jane Goodall

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