Any thoughts on "biochar"?

[damitall]

Biochar - carbon produced from waste organic material and added to soil for "conditioning" or simply buried is claimed to be, not just carbon-neutral, but carbon-negative.

Read about it here (http://www.biochar-international.org/aboutbiochar.html)

What are the chances of its making a difference to the amount of carbon we are releasing to atmosphere? It looks OK on the face of it - plants etc taking carbon from the atmosphere, which carbon is then reduced to - well, to carbon, actually - then buried. If nowt else, it looks like a reasonable way to treat sewage.

Thoughts, anyone?

[BWE]

It doesn't show how it's chemically bound? That's kinda weird. I'll look again. Seems odd at first glance. Like there's more to the picture.

[ofro]

Sounds like it could be a spectrum of high-molecular weight polycyclic aromatics all the way to graphite. None of which would be readily digestible by micro-organisms.

[VoxRat]

I remember in the book, 1491, there was a lot of discussion of what they called (IIRC) terra preta. It was soil mixed with charcoal, and which is supposed to make it super-productive, which would amount to carbon-negative I guess.

[damitall]

Sounds like it could be a spectrum of high-molecular weight polycyclic aromatics all the way to graphite. None of which would be readily digestible by micro-organisms.

Yeah, I think that's the idea. The carbon stays in the soil, undigested/unutilised, but having (it's asserted) some beneficial effects whilst it's there. More growth of vegetation, more carbon fixed. The main thing is, it's not in the atmosphere.

Perhaps we should turn all human waste the world over into biochar, and bury it in vast dumps, whence future generations (having run out of coal/oil/gas), can dig it up and burn it :cool:

Better still, breed mutant cattle with pyrolysing rectums fuelled by their own methane, so they crap carbon direct. Wth training, they could project carboncrap projectiles into a neat heap in the corner of the field

[VoxRat]

terra preta (http://en.wikipedia.org/wiki/Terra_preta)

[damitall]

^^^ Thanks, VoxRat - a most interesting read.

No reason, then, for NOT turning all our poop to biochar - improve soils and generate a bit of electricity on the side.

There's an old landfill along the road a ways - it's currently yielding very significant amounts of methane, which is used for generating electricity. I wonder if, when the methane yields drop, it would be worth pyrolysing the remainder, using the resulting biochar to condition local soils (saving on petrochemical-derived fertilisers), and reopening the landfill site to start all over again. That particular area has a number of old claypits which could be used likewise, and from which there is little or no leaching of pollutants into surrounding soils - presumably because the clay is pretty impermeable

[ofro]

Good idea, but .... Much of the landfill's content is not carbon based. I guess that after the micro-organisms stopped generating methane, most of the charrable material is gone, with the exception of old tires and plastics. These remnants are mixed with scrap metals, batteries and other potentially toxic material that you don't want to put back into the soil.

[damitall]

Good idea, but .... Much of the landfill's content is not carbon based. I guess that after the micro-organisms stopped generating methane, most of the charrable material is gone, with the exception of old tires and plastics. These remnants are mixed with scrap metals, batteries and other potentially toxic material that you don't want to put back into the soil.

Well, they weren't too toxic to prevent the methanogens methanogenising. Sieve 'em out. Remember that a lot of the material will be, by then, the corpses of the methanogens - an eminently charrable microbial sludge.

Possibly :dunno:

[Ray Moscow]

The "biochar" idea makes some sense in priniciple, but it strikes me as a very labour (energy?) intensive thing in practice.

Processing unsorted garbage is going to be even more labour intensive.

Still, if someone can work out the details, it might be worth doing.

[Berthold]

An alternative* would be ways of farming that generate and sustain higher levels of soil organic matter than are now usual in agricultural soils.

ETA: *or additional action

[epepke]

The "biochar" idea makes some sense in priniciple, but it strikes me as a very labour (energy?) intensive thing in practice.

Processing unsorted garbage is going to be even more labour intensive.

Still, if someone can work out the details, it might be worth doing.

Process sewage, then.

I have a toilet for the organic waste that has passed through my body and a garbage disposal in the sink for that which hasn't. There isn't much organic that goes into the trash can, except for some cardboard. Most cardboard is disposed of separately anyway.

[Lugubert]

If nowt else, it looks like a reasonable way to treat sewage.
Sewage contains a lot that isn't what you want in your veggies.
I have a toilet for the organic waste that has passed through my body and a garbage disposal in the sink for that which hasn't.
You have to be to a certain extent savvy to process human waste in a safe way. If you know, it's great. If not, you constitute an environment hazard.

A "garbage disposal in the sink" might be convenient on the surface, but could be a too heavy burden on waste treatment plants. I use a garden compost in a sufficiently rodent safe drum. I know what goes in there, and get excellent soil for my rhubarb, berries and other eatables. Sewage yields compost that's often high on heavy metals and other stuff that shouldn't be consumed. Your dahlias might thrive, though.

[Febble]

George Monbiot had a big anti- article in the Guardian here:

http://www.guardian.co.uk/environment/2009/mar/24/george-monbiot-climate-change-biochar

And there were various comments afterwards:

http://browse.guardian.co.uk/search?search=biochar&sitesearch-radio=guardian&go-guardian=Search

including a response from James Lovelock:

http://www.guardian.co.uk/environment/2009/mar/24/biochar-earth-c02

[epepke]

You have to be to a certain extent savvy to process human waste in a safe way. If you know, it's great. If not, you constitute an environment hazard.

I wasn't planning on doing it myself.

A "garbage disposal in the sink" might be convenient on the surface, but could be a too heavy burden on waste treatment plants.

Strange idea. We've had them here since the 1950s. They're ubiquitous. I think I may have lived in one or two places without them, but not many. Has that not been tried where you live?

I use a garden compost in a sufficiently rodent safe drum. I know what goes in there, and get excellent soil for my rhubarb, berries and other eatables. Sewage yields compost that's often high on heavy metals and other stuff that shouldn't be consumed. Your dahlias might thrive, though.

We've also had lead-free sewage disposal around here for a long time. Most new construction for the past 20 years has been PVC, and the pipes in the ground are concrete. Where to the heavy metals come from? Grecian Formula 19?

[Berthold]

Modern municipal sewage sludge is essentially free of heavy metal contamination. At least, that is true of countries where laws for the separate collection of hazardous wastes have been passed and are enforced. Such sewage sludge is a good component for composts, or for processes for making topsoils out of assorted waste materials.

Your unmixed domestic feces, of course, contain no worse elements than you take in with your food. :D

Knowing about this is part of my job, by the way.

[VoxRat]

Knowing about this is part of my job, by the way.
It's a dirty job, but someone has to do it!

What, exactly, is that job? If I may ask.

[Ray Moscow]

Modern municipal sewage sludge is essentially free of heavy metal contamination. At least, that is true of countries where laws for the separate collection of hazardous wastes have been passed and are enforced. Such sewage sludge is a good component for composts, or for processes for making topsoils out of assorted waste materials.

Your unmixed domestic feces, of course, contain no worse elements than you take in with your food. :D

Knowing about this is part of my job, by the way.

The main problem with human sewage, of course, is the parasites that it can carry. You don't want this contaminating the food or water supply.

[Berthold]

What, exactly, is that job? If I may ask.
Analysis and ecological interpretation of various materials.

Soil science applied to agriculture and forestry, especially long-term improvement and sustainable optimization, is one of our activities. The principles could also be used to restore degraded natural habitats, but those green woo types inherently mistrust anything that's scientific. :bang:

The other main field is waste management, especially profitable use of wastes where possible.

Oh, by the way, have a look at my employer's homepage (http://www.oeko-datenservice.com/). It's a bit ancient, however.

[epepke]

The main problem with human sewage, of course, is the parasites that it can carry. You don't want this contaminating the food or water supply.

By the time it's been processed to the point that it's a homogenous mass of various carbon compounds, I think that they have probably not only died but been blown into millions of pieces.

[Barefoot Bree]

[slight derail] I've been interested in the concept of composting toilets for a while, but I'd like to know a hell of a lot more before investing in one. Can someone point me to some (preferably free and on the net) info on them? [/derail]