On 17/4/2003,
Gerald Cairnes posted:
I have just
responded to advice given at Auntie's Greenhouse Site;
http://www.abc.net.au/science/planetslayer/greenhouse_qa.htm
on the disposal
of household oil. There we are advised to collect it and have it taken
away by one or other authority for disposal. While there is some logic
in this, it is really a cop out for what should happen. These materials
are eminently compostable and should be disposed of at source and NOT
collected by some toxic waste system that takes it away mixes it with
kero then sells it for fuel oil.
We even have the
lunacy of mine sites being forced to send their waste back to the
metropolitan centres because of the same legislation. As if the
metropolitan areas need more pollution???? This legislation was
drafted by a collection of vacuous twits just like the ones who drafted
the legislation about refrigerators being degassed before being able to
be disposed of at tips. The cost and transport to and from a service
centre for many are just too high, more privatisation, so we now have
the bloody things appearing
along side road dumped at night and nobody wants to touch them. At some
point they will have to do something about this stupidity.
A couple of
years ago I tried to get the various State EPA's to wake up to the
issue of composting mineral oils as a sensible approach but only the
Qld Department took any interest, encouraged and referred me to
Caltex/Ampol who had something like 1200 tonnes of contaminated lead,
copper and zinc containing greases to dispose of. It was going to cost
them from memory something like $2M to have the stuff removed and I
suggested that they put up the $2M for a joint venture to commercialise
the technology
and if I could demonstrate to them that these materials were thoroughly
and easily compostable. The copper and zinc were of no consequence once
dispersed in compost the levels were below standard fertiliser levels.
The lead material could be subjected to a separate process,
confidential, that would immobilise the lead but still permit rapid
composting. In conjunction with another company we were ready to
move a 15 cubic metre composter on site and begin processing
immediately and the lot would have been processed under accelerated
composting conditions in an estimated 3-6 months with a useful by
product. Of course this would have required a fee of $40,000++ by the
National Registration Authority, excessive though it is but even that
is chicken feed in this particular exercise.
Well I did
demonstrate successful composting of their wastes but they chose to pay
the fee and have it removed, I wonder what actually happened to
it???? Of course this was their right to make such a decision but
it begs a lot of questions.
Most pollies and
government departments seem to exist simply to wield large sticks at
people and are incapable of actually doing anything positive or
practical, no wonder we are all so pissed off by governments generally.
We had the great QA rip off and Standards Australia got themselves into
difficulties trying to be entrepreneurs and many other get rich quick
examples and "setting the stage" for their wealthy mates to further
profit from. Now we have the spectacle of all governments in this
Country withdrawing
from this excessively costly bureaucratic scheme and doing their own QA
in house while the rest of us must continue to pay for the extortionate
fees and processes which are screwing local innovation. We have just
withdrawn 2 new Provisional Patent Applications because we do not wish
to waste any more time on these expensive processes and the info now will not see the
light of day!!!!!
I would like to
say a great deal more about this but I cannot at present do that,
however, I will have more to say later in the year. What happened to
the principal of "mutual obligation" we hear so much about from our
squeaking pollies??
Apologies to
those sincere bureaucrats whom I know are trying to do the right thing
but being shat on from a great height for their troubles. One has to
wonder at the quality of the technical advice being given to these
departments and the interference that affects their ability to take the
advice. More anon!
Sorry Bernie but
you need to do better than just parrot the government line on these
issues.
Toby
Fiander replied:
Here
is some of the oil item from ABC Q&A site. Some of the stuff
there is quite good. I have removed the quotes as being too
tiresome....
Q:
What's the best way to dispose of household oil? I keep telling my
flatmate not to flush it down the loo, but it'd be good to know an
alternative.
A:
If you chuck oil on the ground, hose it into the gutter or wash it down
the sink it'll end up in our waterways - and that's not good. Water and
the things that live in it weren't designed to cope with slicks of
extra virgin anything - it upsets the passage of gases and gets all
over birds' wings. Your best bet is to keep the oil you use in an old
takeaway container and find out what your local council/garbage
collection service offers. Then take your flatmate on a nice site tour
of the local sewage treatment plant.
[ends]
I
am not certain which treatment plant might be referred to here, but
assuming it is an inland treatment plant in Sydney or almost any NSW
country town, then flushing it down the loo, while not recommended, it
probably not such a bad thing to do with oil that does not solidify....
the local sewage authority will probably be displeased, but here is
roughly what happens at a typical sewage transport system and treatment
plant of a small to moderate sized town.
Firstly,
when the waste with the vegetable cooking oil in it flows along the
gravity sewer it will pick up a whole lot of stuff which is adhering to
the sides of the sewer. It will act like a solvent to some
extent. So it will not be the nice nearly pure oil that is being
discarded down the sink/toilet. When it gets to the pumping
station, it will be mixed with lots of water and there will a
certain amount of emulsification with the soap in the water.
During the pumping this will be a fairly thorough mixing of the oil and
the water waste.
When
the wastewater arrives under pressure at the sewage treatment works, it
will be a grey mess, probably considerably warmer than the ambient
temperature thanks to the hotwater systems and body temperature of the
water, and with some solid matter in small pieces. It could also
be a day old and lacking oxygen, but that is another story. In
any case, the sewage in it won't stay at a warm temperature for
long. Hitting the inlet works, grit removal chamber and coarse
screens at the head of the works will cool it down considerably, so
that a lot of the body grease and whatever else has been picked up on
the way will tend to solidify. In any case, the emulsification
will break to a certain extent. The resulting oily material will
float, be skimmed off at the Primary Sedimentation tank and be pumped
to a composting or digestion area. Solids that sink are also
removed to the same place periodically. It can be buried at the
local tip, if it licensed for this purpose. A lot of plants reuse
the solid waste for fertiliser. It often contains some heavy
metals which can limit its use, and spreading around fairly thinly is a
good idea anyway. These days, with the addition of alum for
phosphorus removal from the effluent, the sludge can contain too much
aluminium for reasonable application to ordinary fields, and so is
unsuitable for agricultural use - aluminium is toxic to many plants and
is increasingly available to then as the pH drops. Regardless,
the oil is disposed of without serious interference in the process.
The
liquid and the items of neutral buoyancy are then aerated by one means
or another so that bacteria grow. When they bacteria run out of food,
the process is stopped so that the spent bacteria can settle and the
decanted liquid is passed to another tank, where clarification
occurs. There is more skimming with weirs and settling (the
products of which go to the digester) and the liquid passes into a
lagoon to await discharge and probably chlorination. The
spent bacteria are also sent to the digester. As a result, almost
all the oil in the mix will go to the digester. The process is
actually quite efficient even in small plants. I have overdosed
small plants with oil and coarse silt and the processed effluent is
none the worse.
Within
limits, the digester, an anaerobic place of strong odours, eventually
adapts to whatever it is fed. The only issue is then what happens
to the digested sludge which has to be removed from the digester from
time to time. Mostly the oil is broken down to shorter
chains. The fatty acids in partially digested sludge are used in
a few plants to power the removal of nutrients.
So
adding oil to sewage is not all bad news, and it is not surprising the
ever-creative Gerald has an innovative process for doing it better and
more formally.
However,
if you live on the coast with an ocean outfall, then there is often
only rudimentary treatment prior to release. The oil flushed down
the toilet will probably be surfed a day or so later....
Gerald responded:
Thanks for your
learned insight to the workings of the sewage disposal systems and the
effects of oils there upon. Most people in this Country have access to
a back/front yard where a simple garden composter can reside and this
ubiquitous or nearly ubiquitous device will easily handle even mineral
oils, as you point out these systems will adapt what ever you put into
them, carefully of course.
There is no good
reason to unnecessarily load up the central services supplied by
government with stuff we can simply handle ourselves. Centralised
services should be limited to those things we cannot do effectively
ourselves. Wherever possible kill the muck at source and save the
community a heap of money. Of course there are those of us who cannot
or will not do this and some latitude is required for them.
Industrially killing the waste at source can translate into large
economic savings in many ways but it needs a change in management
thinking to achieve this. As you will have noticed I have given up on
the art of gentle persuasion, life is now far too short so it's" kick
'em in the shins" time until they wake up! So they don't appreciate
that sort of diplomacy, well tough get used to it the "winds of change
are upon us" and I never kick shins without offering an "olive branch"
in the form of an effective alternative. If they don't want to be
embarrassed they should get their collective acts together.
There is another
benefit too from doing it yourself and that is that the oils do not
become contaminated by heavy metals in the sewage system so they make
very good compost to be used safely at home. Of course strictly
speaking we should pay the National Registration Authority $40,000+ for
registration to do this, shouldn't we?? :-((
The biggest
problem with oils is the low surface area, low oxygen content and small
number of reactive sites available for the bugs to work on, just simply
very difficult to get at the reactive sites. Answer spread it out
thinly on vegetable matter add some super phosphate, lime and mix well
with air as in a tumbling composter and this oil will go very quickly
indeed. If need be, emulsify with sufficient soap first. There are
other valuable uses for the waste oil but that is confidential at
present.
Peter
Adderley asked:
How
do small worm farms handle used cooking oils?
The
worm farms I refer to are the multi-tiered variety a measuring about 40
x 60 cm.
My
immediate assumption would be that the worms would collectively scream
"YUCK!!".
Would
it be better to pour the oil into some sort of absorptive medium to
break it up before letting it loose on the worms?
If
so, what?
Was
there not a product some time ago that came in tetrapak (milk) cartons
specifically for recycling?
Does
it still exist?
Gerald Cairnes
replied:
You are right,
worms are fussy feeders but if the material is first partially
biodegraded even they will tuck into it. The main thing is that it is
absorbed onto a medium that will allow them to swallow and digest it
without gumming up their guts which are simply live composting systems
anyway. They don't like volatiles or industrial flavours though.
There are
companies offering microbial cultures for sale for this purpose, though
I have not used them and can't offer advice as to how effective they
are. I simply collect volunteers from my local environment then train
them, they are quite willing learners. The name Enertech comes to mind
but can't be sure of the spelling.
You really don't
need special cultures for household oils, all of the organisms you need
will be found on the surfaces of grass and garden clippings etc. just
give them the right conditions and they will double their numbers every
20 minutes or so and that makes for some impressive count rates. The
main thing you need to take care of is that there is plenty of oxygen
available otherwise they will revert to anaerobic processing and
produce lots of hydrogen sulfide and other nasties.
Peter
Adderley answered:
Thanks
Gerald, but I'm still not sure you've actually answered the question.
Do
I imply from your response that I should pour the oil over some grass
clippings and leave it for a day or so? This is fine but it's a bloody
nuisance. I only mow my lawn about twice a year and never rake it.
(strange that my neighbours always seem to suffer cutworms, drought,
etc whereas my lawn always seems to survive). I'm looking for a
relatively easy (read lazy) way of disposing of oils. If I am not
willing to make the effort, then those I wish to inspire won't either.
My worm farm survives, not through my diligent efforts but, because my
wife takes bags of discarded lettuce leaves home from the supermarket
(she's a kinder person than me). Just looking for ideas, as this is an
important issue, and as environmentally aware as I try to be I still
haven't heard of a sensible domestic means of disposing of used cooking
oils. Would also be great to supply those who wish to know, a
means of disposing of automotive oils in a domestic manner.
I
understand that the basics are the same, but oils ain't oils.
David Maddern
commented:
On the lofty
principal that one mans rubbish is another mans treasure
Oil is about the
highest energy stuff
How about take
it to the nearest vineyard or orchard and tell them about the anti
mildew properties of sprayed oil or add some ash water... lye to it (or
caustic soda) and turn the oil into soap, cake it up for people who
dont want to get into the army or take it to a mob of vintage machinery
buffs who can use it as diesel fuel
Or if you spray
it on the soil and lawn and the bacteria as previously mentioned will
love it, you can get a cascade of different bacteria catabolising
different by-products, it will act like but better than 'Charlie Carp'
(which has proteins as well; therefore not as energetic) Three times a
year should do it.. emulsify in 200x water
Make an oil lamp?
Gerald
Cairnes responded:
How
do manage to only cut the lawn only twice a year? We managed that for
nearly 20 but that was a drought, now we let the four legged auto
mowers do it for us.
The
worms wont like the oils in any significant concentration so you are
looking at a two stage process;
1.
a short composting period of degradation where the microorganisms will
make the oil more to the liking of the worms. Strange they will
demolish faeces but don't like anything that has industrial odours
about it, probably because they "know" it is toxic. It is the gut
organisms that do the digestion and while they may survive the process
the worms may not.
I
can't say that is what I do because every drop of oil gets used for
R&D around here, however what I would do assuming it is practical
for unit dwellers and I understand that for some it may not be so, is
to mix the oil with hardwood sawdust and lawn clippings. The sawdust
helps to "dry" out the gooey mess, make it manageable and allows better
air circulation within the mix. I specify hardwood sawdust as the
softwood resins are particularly resistant to biodegradation and take
much longer to process. I also suspect that the higher lignin content
of hardwood provides more protein like precursors with phenylalanine
like structures, this latter point is pure speculation on my part.
2.
Once the oil is suitably degraded the worms will love it. Maybe you
could have a two tier structure with a composting chamber above and the
worms below and the composting material falling into the worm section
as it matures.
I
really feel that if you are in a unit that this process should be a
joint one for all residents managed by the gardener who ever that may
be.
In
regard to mineral engine oils, I have had no difficulty getting
volunteer organisms to degrade this type of oil BUT it take more time
because there are fewer reaction sites with which to work and it is
mainly carbon chains so you need to supply some nitrogen and phosphate
etc. Given the right conditions even these can be biodegraded in as
little as 6 weeks.
The
synthetic oils are silicones and these do not degrade at all easily,
degradation times can be measured in years rather than weeks. However,
they ultimately do breakdown and of course plants do use silicon for
reinforcing leaves etc. The odd thing about silicone oils is that plain
silicones are poor lubricants when it comes to metal to metal contact
and they must be specially formulated to perform as well as standard
mineral oils. They can destroyed by heating to temperatures above 300
deg. C. and some much less. Ignoring the metallic and organic
contaminants they pick up during service they present a physical
environmental challenge rather than a chemical one, although the
solution will be a chemical one ultimately.
While
I believe the silicone oils do have merit they are more expensive in
manufacture and harder to dispose of satisfactorily. The best use for
these compounds is in a recycling system that can recover the sound
material for reuse thus reducing the environmental burden. I have yet
to try these oils with serious composting but it may be that we can
find some microorganisms that
will deal with the material satisfactorily at speed. If such organisms
do exist or can develop the skills their physiology will be
interesting, I don't think the ubiquitous yeasts will cut the mustard
on these compounds. Thanks to repetitive government interference I no
longer have or can afford the kind of laboratory resources I used to
have that would allow a more focused effort on this subject.
I
still favour the use of the easily disposable fatty acid derivative
oils and greases for most purposes with silicones used for special
purposes and there are a few of these where the load on the environment
should not be much of a burden. Silicone oils flushed down the loo in
volume I believe would cause Toby's colleagues in the sewage game to
rethink their strategies!
However
since the silicone oils and greases tend to be phenyl derivatives this
may provide more points of reactivity that the simpler silicones do not
have and this may be a saving grace. As it happens a client is engaged
in just this sort of activity and we may have information by the end of
the year but the budget is LEAN and MEAN unfortunately.
I
suspect I still have not solved your problem of composting in a unit
but this is the best I can do for the time being. I have reached that
stage in life where crawling under the car to change oil or anything
else for that matter is no longer an option so it would be for most
unit dwellers I imagine. My local service station supplies me with all
the nasty waste oils and degreasing solutions I need to work on.
Steve Van Z
posted:
Some 25 years
ago we heated our house with diesel fuel (untill we got sick and tired
of feeding our supplier with hundred dollar bills) We had a big spill
once when our supplier forgot to turn off the tap: Oil everywhere. I
thought that patch was poisened for a long time, but...... to my utter
surprise in a very short time all was well Unfortunately I can
not remember how long (or rather how short) it took, but I was very
pleasantly surprised - months i.s.o. years
Podargus
commented:
I
must be missing out on something here. Where does all this
household oil come from? I have a small amount of fat from
grilling meat that gets drizzled over the dogs' dry feed. But
oil, I have none that is not inside me, or still in the bottle.
Toby Fiander
noted:
Cooking oil
(edible oil) used for deep drying is generally discarded after a number
of uses. Cooks I have known in the
past -
fortunately I know none of them now - have had a lot of oil in cooking
for other dishes as well.
Fat drained from
cooking meat is more likely to be solid than liquid at room temperature.
The oil in
sewage is usually body grease and from washing up greasy utensils and
plates. As to whether this is edible oil, I leave this to the
reader....
The few items of
wooden kitchenware at our house get washed up in lots of detergent like
everything else, but we are not growing anything on them of which I
know.
Peter
Adderley responded:
Pretty
simple really. I deep fry things; the oil goes stale after a couple of
uses.
What
do I do with it afterwards? I don't want to throw it down the sink nor
chuck it into the garbage.
We're
not talking industrial quantities from my household, but I don't think
this issue has ever been adequately dealt with from either a simple
convenience point of view, or from a community waste disposal
perspective. Maybe I'm wrong. Just looking for answers to questions I
ask myself. I have channels for disseminating answers at a community
level and would like to pass on some enlightenment. Spraying oil on the
lawn or its clippings, obtaining hardwood sawdust or possibly launching
it into space, aiming
it toward a black hole.. are not really what I call convenience
solutions. Come on guys, I'm gettin' that ol' "white coat" feeling
again.
David Maddern
added:
Mate oils ain't
oils
You have lipids
in you, principally because they are high energy storage molecules
Boil you down
and you would yield liquidised fats (which is why wood is so good on
funeral pyres)
Chocolate is
solid till you eat it.. copha turns from solid to liquid in your
mouth.. fat to oil
