Commercial compost: low nitrate levels. Experiments in holding pattern.

After the < 5mg/L reading I got from an earlier test, I ran the reference test, which ran correctly. Not that that's much more than a sanity check.

I wondered if I might have the wrong thing in the bag.

A first-level Agromin support person gave me values of nitrate as 2-8.6 milligrams per kilo dry weight of EcoScraps compost mix. That's less than 1/1000 of what I expected! I asked for someone else to call me back. No call so far today.

Further data from EcoScraps directly shows 0.001% dry weight as nitrates. So a kilogram of dry compost (is there such a thing?) would still contain on the order of 10mg of nitrate... right along with the Agromin folks and my tests.

It would appear that this compost is not suitable for LaConte style recoveries.

I now have the name of someone else to contact who may have more  comprehensive information on the subject of compost nitrate composition. I will call him tomorrow.

Compost experiments 2 and 3 halted for now.

Nitrates from commercial compost 3

I bought more equipment. This is a weakness. I must resist. I have two scales and a nitrate/nitrite test kit. I am continuing the previous experiment while moving on with this one.

Considerations

• Leaching may extract more (or less) nitrate over time.
  Check at 1 and 24 hours.
• According to the literature, the evaporite is going to be a mix of [Na,K,Ca,Mg][CO3,NO2] with either the Ca or the CO3 at zero. Fe and Cl may be present as well.
  We will presume it is the CO3 species that is absent.
• Potassium carbonate has the highest molecular weight of the various components of potash: 138g/mol.
• Calcium Nitrate has the highest molecular weight of the various potential components of raw saltpeter: 236g/mol.
• Suppose we have N grams of a CaCO3 precipitate. To calculate the amount of potash required to provide that much carbonate, divide by the molar mass of CaCO3 (100g) and multiply by the molar mass of potassium carbonate (138g) for a net mass multiplier of 1.38.
  1.38 times the Mass(CaCO3) is the max Mass(potash) to be used.
• Suppose we have N grams of a Ca(NO3)2.4H2O evaporite. The mass divided by 236g is the number of moles of calcium nitrate. Calcium nitrate mixed 1:1 molar with potash results in 1 mole of calcium carbonate and 2 moles of alkaline nitrate. 138/236 =  0.58, thus:
  0.58 times the Mass(Ca(NO3)2) is the max Mass(potash) to be used.

Process

Part 1, 1 hour

1. Place 1kg of compost in a stainless pot
2. Add 2 liters of distilled water
   Checked: Total mass: 3kg 
3. Let stand for 1 hour
4. Filter (seive and paper towels, as above)
5. Measure 1 liter of fluid
6. Get mass of solution to estimate dissolved salts, and verify by checking weight of remainder of fluid and soil
   Liter: 1003g (about 3g, estimate 6g in 1kg of compost)
   Remainder: 1997g
7. Perform Nitrate test
   Nitrates: < 5mg/L (Well THAT sucks. Maybe it's wrong?)
8. Return the fluid to the mass
   

   Part 2, 24 hours

9. Let stand for 23 hours
10. Repeat mass measurements
    Liter:
    Remainder:
    
11. Test for nitrate
    Nitrates:
12. Was it worth waiting the 23 hours
    ?
    

    Part 3, Analysis

13. Extract all the solution
14. Filter the solution
15. Evaporate with minimal heat
16. Weigh evaporite
    Evaporite: 
17. Calculate the maximum potash required:
    0.58 * mass(evaporite):
18. Gather the potash
19. Dissolve the evaporite in a minimum of distilled water
20. Divide the solution into two halves (S1 and S2)
21. Divide the potash into two halves (P1 and P2)
22. Add one tenth of P1 to S1
23. Observe a precipitate (hopefully)
24. Add more of P1 to S1 very slowly until no more precipitate is formed
25. Weigh the dry remainder of P1
    Remainder:  
26. Dry and weigh the precipitate from S1
    S1 Precipitate: 
27. Recalculate the maximum potash required:
    1.38 * mass(precipitate): 
28. If this new "maximum potash" value is lower than the mass of P2, reduce the mass of P2 to the lower maximum.
29. Add  the (possibly reduced amount of) P2 to S2
    Hopefully this achieves a zero value for both calcium and carbonate, leaving only nitrates in the wake
30. Dry and weigh the precipitate from S2
    S2 Precipitate: 
31. Compare the masses of the precipitates. They should be equal.

P.S.
The pictures here are very low res because my regular digital camera has been lost, and I am taking stills with a videocamera instead. :P

Nitrates from commercial compost 2

Ala laConte, I try to get the nitrates to effloresce.

General Process

1. Place 2 gallons (compacted) of compost in a 5 gal painter's bucket
2. Add 1 gallon of distilled water
3. Let stand in warm dry conditions
4. Add more water
5. Repeat steps 3 and 4
6. Observe (or not) efflorescence

Actual process

24-Aug-2013: Steps 1-4 complete
27-Aug-2013: After three warm dry days, the compacted soil was still damp-verging-on-wet. I roughed the surface up to give more surface area for evaporation.

Nitrates from commercial compost 1

Process

1. Place 2 liters (uncompacted) of compost in a stainless steel vessel
2. Add 1 gallon of distilled water.
3. Wait an hour
4. Filter the solution through metal sieves until all the large particles were removed.
5. Pour it through paper towels (poor man's filter paper for large quantity jobs)

A not-very-clear solution remained. It looked a lot like a cross between tea and black coffee. The humus is composted from local waste vegetable material, presumably including things like coffee grounds, tea leaves, and tree bark, all of which could give a soluble brown tincture.

I elected to try and precipitate it out using a base (assuming tannic acid and its ilk were the colorants) so I tried chalk, then sodium hydroxide. Neither changed the color significantly.

Results

Given a dark and now contaminated sample, I tossed it down the drain.

Aerobic Vegetable Composting 1

After the disheartening math on nitrate production from liquid mammal waste, I decided to do a regular compost based on food scraps.  Whether this makes sense or not, I avoided garden clippings in this run because the measured goal is nitrate production. Any fertilizer remaining on the garden clippings would skew the results, showing a false success.

With that in mind, I am composting things that humans would eat, not simply vegetation. I expect I'll do a vegetation one as well, and perhaps both varieties supplemented with other materials, but for now I'm just taking the simple route.

Tools and Materials

Organic matter

I got the material from several local chain restaurants. I walked in, asked to speak with the manager, and asked if I could get a day's worth of produce scraps from their counter/prep area. Some did prep in the morning, and asked me to come back the next day. Others gathered their scraps all day and asked if I could come back later in the evening. Everyone was quite willing to help.

Here's what I ended up with:

• Lettuce
• Mix of lettuce & other vegetable matter
• Meat scraps

The Composter

I just used a rolling trash bin I bought at the hardware store. I cut holes in the sides to allow aeration. I considered buying a "real" composter with a horizontally mounted cylindrical drum and a crank on the side, but for my first run I figured something less sophisticated would do. The bottom of the bin was watertight, to prevent solubles from escaping during the composting process.

Process

The pile

Lettuce, cabbage, tomato, and other vegetable scraps have a C:N of about 12, so in order to get out to 20 or 25, I needed some carbon added. I bought a bale of straw from a local pet supply, weighed out Nkg and added it in in layers with the vegetable matter. This was a single-batch process. Everything was added at the same time.

The Weather

August in southern California is sunny, not particularly humid nor arid, and stayed in the 70s and 80s for the entire period.

Results

Catastrophic failure, experiment terminated early. Apparently there was too much animal protein in the mix. By day six the rotting smell was overwhelming and I terminated it. I shall fall back and consider other alternatives, certainly including no animal matter in the next incarnation.

Paper 1

I have only a couple days before I leave on my trip, and I wanted to get something else done before I left, so a quick attempt at paper seemed reasonable. This may seem more craft than chemistry, but filter paper is important later on, so I'm including it here.

Raw materials: Dry grass, Potash, Water
Tools: A boiling pot, heat, a screen 

So here's the dry grass. It's really dry. It's been sitting in a box for weeks or longer, waiting for a project to come along. Originally it was going to be compost carbon, then weaving material, but finally it has become paper pulp fiber.

1 meter stalks of dry California grass

Step 1: Remove the nodes

I am not really sure why this is necessary, but all the small-scale references insist on it. I expect that if you're doing large-scale crushing or boiling the nodes break down by themselves, but on this scale it's worth doing the pruning.

Break the grass up into lengths with no "inter-segment nodes". That basically means break off the little hard parts where branches or leaves come out. Here is a piece of grass with two nodes circled

Grass with nodes circled

And break out the nodes completely, leaving just the stem bit

Grass stems

I am very slow, so after 50 minutes, I had a single thick handful, which I deemed a half liter or so.

A handful (~500ml) of straight grass stems

Step 2: Prep the Alkali

50ml Potash

WARNING: Do not use aluminum containers when working with alkali. Hot alkali, under the right conditions, can burn right through aluminum. When combined with boiling water, flames, and caustic solutions, this can be bad. Use glass, ceramic, or stainless steel containers.

I made a solution of 50ml of loose potash in 1 gal of water.

Step 3: Boil

The handful above contains more than a little woody stem (not wanted) as well as dirt, dust, and other detritus we want to get rid of. Boiling in alkali will separate all of these things for us as well as preparing the fibers themselves. If we were going to bleach the paper, this is the point where we'd do it. I didn't have the materials, so I skipped that step and just did the boiling.

I had the stems in the alkali while it came to a boil. After about 30 minutes of boiling, the scent of the steam changed from grassy to distinctly sweet. I held it at a boil for 60 minutes total, replacing the water as it boiled away. After that hour I took it off the fire, poured off the alkali and replaced it with fresh water.

Step 4: Rinse and Crush

This is pretty straightforward. I'm trying to separate the fibers from the rest of the stuff without making them too short.  I used a round wood stick against a flat wood surface, and the stems split and mashed immediately. Even though the stems were still rigid, the fibers themselves were extremely pliable and soft. The integrity of the stems as a whole was entirely an artifact of their geometry as a tube. During the rolling, some individual fibers got caught on the rolling stick and wound themselves up along it providing a very nice yarn which could be removed with a fingernail. The average fiber length at this point was quite long: over 8 cm.

Step 4a: The plan changes

The length of the fibers and the fact that they weren't crosslinking (they were staying parallel) gave me pause. I took the stems out and they bent and flattened easily, but the individual fibers stayed attached to their bretheren on the stem until something else snagged them.

I decided to alter the experiment mid course: I cut maybe half of the fibers to a length of about 3 cm using a knife and reboiled them in plain water, hoping that this would separate them and let them entangle/mat/felt more.

Shorter fibers boiling

Still not convinced

I took handfuls of the fibers and crushed them between two rocks, hoping to see something that looked like paper. Either this is going to take much longer than I expected (multiple hours) or the fibers are way too long. Perhaps more research is in order.

Glycerin 1

I attempted to create glycerin today using some "suspect" lye (a brown powder produced from potash rather than a white one from the store) and some beef tallow.

I melted the tallow in a pot, and mixed in double that volume of water, in which I had dissolved a half mole of lye. A white fluffy-looking layer immediately formed on top of the mixture, which I suspected might be a soft soap. But when I tested it, it was still very greasy, and very alkaline.

I set the whole mixture aside and let it cool. This took a surprisingly long time. (I think the alkali was still doing its thing and generating heat) After a bit I put it in the fridge to accelerate the cooling. Later I returned to find no glycerin layer at all, and a strongly alkaline and greasy layer where I had expected to find soap. I mixed in enough vinegar to neutralize the mixture, and set it aside to settle again. Two hours later there were still only two layers, when I had been expecting three.

I suspect I either used an inappropriate amount of lye, or that the lye was contaminated.

Saltpeter 1 (human urine)

I gathered

• 4.4L of peat moss
• 4.4L of pumice pea-gravel
• 2L of urine
• 2L of water
• 2 ceramic garden boxes

I put a 50/50 mix of moss and pumice in each garden box
I poured 1L of urine into one of the boxes, and 1L of water into the other, and labelled them
Conditions are warm and dry outside

Day 1

Day 2:

• Both are "wet"
• Conditions remain warm and dry
• Turned the containers

Day 3:
Both are "damp".

• I added 1L of urine and 1L of water to the respective boxes
• This was a mistake. This was far more than the urine box could absorb, leaving a pool atop the moss
• I turned everything

Day 3

Day 5:

• Still small pool in urine box
• I removed 1/3 of the "water" moss/gravel mix and put it in the "urine" side
• Turned everything

Day 6-10

• Turned every other day or so

Day 12:

• Everything dry
• Added another liter to both containers

Day 13:

• Turned earth.
• It's obvious now why they called it 'black earth'... even when dry it's much darker than the watered soil

Day 16

• May have observed the "white crust/crystals" mentioned in some texts
• Almost completely dry, no odor whatsoever
• Added another (4th) liter of urine, making it very wet... not quite pooling.

Day 17:

• Turned earth, very very wet. Maybe need to switch to 5 day cycle?

Day 18:

• Ditto. Looks like we need to slow down delivery. 

Postmortem
It appears that the timing (20-ish days) was short but reasonable, that the aeration was reasonable, but the carbon content may have been too low, and the containers neither large nor sufficiently insulative enough to maintain the required temperatures for rapid decomposition. Future tries should:

1. Scale up the carbon content (sawdust, straw, etc)
2. Add all the urine at once
3. Make some concession to keeping the mass temperature high.