your septic system on drugs -...
TRANSCRIPT
Your Septic System on Drugs
John R. Buchanan, Ph.D., P. E.Associate Professor
Department of Biosystems Engineering & Soil Science
University of Tennessee
You may not Like Them
• But we need these
guys
– bacteria and fungi
are the workhorses
of wastewater
treatment
– they prefer their
carbon source to be
non-toxic
They are Exposed to Everything
We Put Down the Drain
• The good news
– is that most waste
organic compounds
can be degraded by
the microbes
• in the septic tank
• in the soil
• The bad news
– there are plenty of
organic compounds
that will kill themhttp://www.medicinenet.com/bacterial_infections_101_pictures_
slideshow/article.htm
What Goes Down the Drain
• Nearly everything
– that goes in or on our bodies
– or is used around the house
• The list is way too long
– organic
– inorganic
– liquids
– solids
http://bearingdrift.com/wp-
content/uploads/money-down-the-drain.jpg
Everything comes out in the
Wash
• If compounds are on our
clothes, then they are in our
septic system
– detergents
– fire retardant chemicals in fabrics
– dyes
– pesticides
• farmers
• yard work
Wash your Hands before you Eat
• If compounds are on
your hands
– then they are in your
septic system
– antimicrobial hand
soaps
• Petroleum products
are toxins in septic
systems
Consumer Products
• Ingredients in shampoo
– 1% pyrithone zinc, ammonium
laureth sulfate, ammonium lauryl
sulfate, sodium lauroyl sarcosinate,
glycol distearate, sodium sulfate,
fragrance, dimethicone, DMDM
hydantoin, disodium phosphate,
sodium phosphate lauryl alcohol,
PEG-12, polyquaternium-10,
sodium chloride
• It goes down the drain
And, of course, Pharmaceuticals
• If we are on drugs
– so is our septic
system
http://www.dreamstime.com/stock-photos-medicine-bottles-pills-
image800963
A little goes a Long Ways
• Your speaker takes
– 10 mg of allergy medication
– I weigh 95,254,397 mg
– relative to my body weight
• that is 10 parts per million
A Even Smaller Dose
• Estrogen in oral contraceptives
– 0.02 mg dose
– assume a body mass of 63,502,931 mg
– relative to body weight
• that is 36 parts per billion
So It doesn’t take Much to make
a Difference
http://www.bluegranola.com/2010/04/13/drugs-kitty-litter-clean-water/
Residual Pharmaceuticals in the
Environment
• Diclofenac
– NSAID
– injected in sick
cows in India
– vultures eat the
dead cows
– vultures die
Our Focus is on Trace Organic
Compounds in Septic Systems
• Why “Trace Organic Compounds”
– relatively small mass compared to typical
waste organic compounds
– measured in micrograms per liter → µg/L
• 1 part in 1 billion parts → ppb
• 1 sheet of toilet paper in a roll that is 3,459
miles long
Other Names
• Compounds of
emerging concern
• Contaminates of
emerging concern
Secondary/Emerging Constituents Report, Southern California
Regional Brine-Concentrate Management Study, U.S. IBR, Oct 2009
The State of the Knowledge
• Is based on municipal
WWTPs
• We know that certain
trace organics survive
treatment
– discharged to surface
water
– discharge to land via
biosolidshttp://southbendin.gov/government/content/treatment-plant
In Municipal Wastewater Treatment
• Primary treatment
– liquid/solid separation
• Secondary treatment
– aerobic biodegradation
– anaerobic digestion
• Tertiary treatment
– disinfection and nutrient removal
• There are plenty of trace organics that can
survive this process
For Onsite Soil-Based Treatment
• Primary treatment
– septic tank
• Secondary treatment
– largely microbial-driven
• soil based aerobic treatment
• soil based pathogen reduction
• soil based nutrient conversion
• soil based sorption of ionic compounds
In the Big Picture
• Organisms have evolved to break down
typical organic waste compounds
– enzymes are produced that will pull apart
larger organic compounds
2 2 2aerobic
microorganismsOrganic Carbon + O Energy + CO + H O + Residue
2 2 2new aerobic
microorganisms+ O Energy + CO + H O + Residue
2 2 2new aerobic
microorganisms+ O Energy + CO + H O + Residue
Think about the Carbon Cycle
• The Sun is the driver
– Photosynthesis
• carbohydrates
– Assimilation
• forms complex organic
compounds
• proteins
• Life
– Respiration
• metabolized organic
carbon to carbon dioxide
http://www.stroudcenter.org/livablelandscape/climate_change.shtm
Life-Form Based Organic
Chemistry
• Many pharmaceuticals are plant-animal
based
– degrade fairly easily
– Aspirin, by-product of willow leaves
• Some plant-animal based compounds are
natural toxics - antibiotic
– are harder to degrade
– penicillin, by-product of some molds
When we Synthesize Organic
Compounds
• We create an organic compound that was
not created by a natural process
– and thus may be difficult to degrade by natural
processes
– a lot of energy goes into the process
• For example
– Some drugs are designed to survive the liver
– in some situations, the break-down product is
the active ingredient
Okay, so what’s going on in the
Septic System
• In relation to pharmaceuticals
– Science is just starting to think about it
• Why, because until recently,
– we could not measure on the ppb and ppt
level
– If your equipment can only measure in the
magnitude of ppm
• then we could not find the trace organics
So,
• For many of the pharmaceuticals
– we really do not know if we are doing a good
job of protection water resources
• We can identify some pharmaceuticals
– that are readily biodegradable
– that will bind with the soil
– but, remember that shampoo bottle
There can be Combined Effects
• Surfactants – surface active agents
– can facilitate the movement of some trace
organics through the soil profile
– Detergent is basically a surfactant
• holds onto soil particles
• keeps them suspended in the wash water
– some dissolved organic compounds that are in
wastewater can facilitate movement
For Example - Triclosan
• Forth National Report on Human Exposure
to Environmental Chemicals
• CDC (2003-2004)
– 2,517 people studied
– 75% had triclosan detected in their urine
• Did not suggest harm – it just suggested
that it was in their bodies
There are Beneficial uses for
Triclosan
• It is the recommended body wash for
MRSA patients
– Methicillin-resistant staphylococcus aureus
• Used as a preservative
– Incorporated into surgery scrubs
– Personal care products
– Prevent microbial-induced metal corrosion
• Used as a sanitizer
– Industrial cleaners
And, of Course
• It is in anti-microbial hand soaps
• This session is not about whether this is a
beneficial use
– There is not an overwhelming dataset that
suggests that our bodies are any cleaner
– Alcohol-based hand cleaners just as good
– Regular soap is just as good
– And our body is NOT suppose to be free of
bacteria
And so, the Question is……
• Transport
– Most movement occurs down the drain
• Sinks, tubs, and floor drains
• into septic and sewer systems
• Fate
– What happens to triclosan once it goes down
the drain
Narrowing the Question
• Will the soil prevent triclosan from entering
the groundwater?
Specific Question
• Can dissolved organic matter facilitate the
transport of triclosan through the soil?
Dissolved Organic Matter
• Dissolved
– passed through a filter
– typically 0.45 micron (0.45 x 10-6 meter)
• Organic Matter
– mixture of organic, poorly biodegradable
decomposition products of natural organic
matter
– poorly defined physical & chemical
characteristics
Facilitate the Transport
• Water is considered the universal solvent
– a hydrophilic substance (water loving) will
readily dissolve in water
– a hydrophobic substance (water fearing) will
not go into the dissolved phase
• oil is a “separate liquid phase” when sitting
on water
• A substance dissolved in water will move
with the water
Poorly Soluble
• Triclosan
– 10 mg of triclosan per liter of water is
maximum solubility
– compare to a very soluble organic compound
• sucrose (sugar) 2000 mg L-1
• Considered to be largely hydrophobic
– it will remain crystalized (solid phase in liquid)
– or partition to a surface
• Will triclosan binds to dissolved organic
matter
– then triclosan would have an synthetic
solubility in water
• an emulsion on a “micro” scale
– there would be less binding to soil solids as
the water moved through the soil profile
But,
Two Investigation Methods
• Batch Studies
– different concentrations of dissolved organic
matter
– different concentrations of triclosan
– mixed with soil until equilibrium forms
• Column Studies
– breakthrough curves
– change of triclosan concentration as water
moves through a column
Batch Method
• Three treatments using sand filter effluent
– No organic carbon
– Low organic carbon (TOC ~ 5 mg L-1)
– High organic carbon (TOC ~ 60 mg L-1)
• Six triclosan concentrations
– 0.5, 1, 2, 3, and 5 mg L-1
• Quartz sand
– 4 g sand in 40 mL spiked wastewater solution
– three replicates
Data Collection
0
2
4
6
8
10
12
14
16
0 1 2 3 4 5
TC
S S
orb
ed,
q (
mg K
g-1
)
TCS Solution Concentration, Ceq (mg L-1)
HOC
LOC
NOC
First Conclusion
• With NOC
– significantly more triclosan partitions to the
sand
• With LOC
– significantly less triclosan partitions to the
sand
• The HOC
– somewhere in between
– not the expected result
Column Studies
• In pure sand
– Many pore volumes
were passed through
the columns
– To determine a
breakthrough curve
– When all attachment
sites are occupied,
triclosan passes
through column
Column Data
0.0
0.2
0.4
0.6
0.8
1.0
0 2 4 6 8 10 12 14 16
Rel
ativ
e C
once
ntr
atio
n (
C/C
o)
Pore Volumes
LOC measured
LOC fitted
HOC measured
HOC fitted
NOC measured
NOC fitted
Br measured
Br Fitted
Second Conclusion
• With NOC
– it took 16 pore volumes before triclosan
concentration matched the initial concentration
• With LOC and HOC
– the triclosan came through with just 8 pore
volumes
Triclosan Binds to Soils
• Sand is a poor treatment media
– Silts and clays provide many more surface-
active sites
– Should prevent deep movement
• Typically septic systems are not installed
in pure sands
– There must be some minimum mixture of soil
textures
Implications
• However
– The sandier the soil, the less treatment
capacity is available in the soil
– In all soils, once attachment sites are
occupied, then triclosan can pass deeper into
the soil profile
• There should be additional degradation in
the soil
– But these processes are not well understood
Additional Research
• Colorado School of Mines (2012)
Compounds Well Removed (>80%)
Acetaminophen (Tylenol) NSAID
Atenolol Beta Blocker – blood pressure,
chest pain
Caffeine Stimulant
Cimetidine (Tagamet) Histamine H2 blocker – acid
blocker
Diphenhydramine (Benadryl) Antihistamine
Additional Research
• Colorado School of Mines (2012)
Compounds Moderately Removed (20 to 80%)
Diethyltoluamide (DEET) Insect Repellent
Hydrocodone Narcotic Cough Suppressant
Oxybenzone UV Blocker
Sulfamethoxazole Antibiotic
Tri (2 chloroisopropyl) phosphate TCPP
Flame Retardant
Trimethoprim Antibiotic
Additional Research
• Colorado School of Mines (2012)
Compounds Poorly Removed (<20%)
Atrazine Pesticide
Carbamazepine Anticonvulsant
Diazepam Anticonvulsant
Meprobamate Anticonvulsant
Primidone Anticonvulsant
Tris(2 chloroethyl) phosphate TCEP
Flame Retardant
Treatment of the Future
• Quaternary treatment for trace organics
– Add more energy to the system
• UV light
– even exposure to sunlight can degrade many
recalcitrant compounds
• Ozone
– very strong oxidizers
– breaks apart larger compounds
A Potential Management Tool
• Source separation
– pharmaceuticals and
their metabolites
tend to be excreted
in the urine
• If we separate
– what do we do with
the urine?
http://www.chekhovskalashnikov.com/human-waste-disposal/
“No-Mix” Toilet
• Men
– are you ready to sit
down?
– may have to get a
waterless urinal
• Dual plumbing
– urine storage
– solids and flush
water move on to
treatment
http://inhabitat.com/nomix-toilets-separate-waste-are-super-eco-friendly/
Medication Use and Septic Systems
• Modified from University of Minnesota
– Water Resources Center
• There are some possible solutions to deal
with medication use and septic systems.
– They start with simple techniques, but get
more sophisticated as the problem increases.
Medication Use and Septic
Systems
• Minimize the use of antibacterial soap,
cleaners and bleach
– as these products further stress the bacteria in
the system.
Medication Use and Septic
Systems
• Increased maintenance of your system
may be required
– if you are taking certain strong medications,
such as chemotherapy drugs. Your tank may
have to be pumped more often to remove
solids that are accumulating rapidly due to the
loss of beneficial bacteria.
Medication Use and Septic
Systems
• If your septic tank gets too toxic
– it may be necessary to use your tank as a
holding tank during a prescribed treatment.
• Fill the septic tank with clean water after
pumping
– to dilute the concentrations of the medicines at
the restart of the system.
Medication Use and Septic
Systems
• Certain design changes may be necessary
to protect your drain field.
– These changes could include adding an
effluent screen, which is placed on the outlet
of the septic tank to limit solids exiting the
tank.
– Adding additional septic tanks or a
pretreatment device are other possible design
changes
Medication Use and Septic
Systems
• What about non-residential sources
• assistant living centers & nursing homes
• veterinary clinics
– System design will need to account for more than
just hydraulic loading
• organic loading
– check the ratio of BOD to COD
Take Home Message
• As an industry, we need to keep educating
folks
– take extra medications to collection
– don’t pour pesticides down the drain
• The septic system and soil has a tremendous
potential to capture trace organics
– but it’s not bulletproof
– someday we may have to evaluate trace organics
in septage