My concept was that the entire organic portion of the municiple waste stream, in addition to the sanitary sewerage, would all be decomposing in this rather huge "digester" dome, and the production of methane would be encouraged so that it would produce enough to be commercially worthwhile. The ultimate goal would be to discover the mechanism that converts decomposing bio-matter into petroleum. The ultimate goal would be to do in just a few days what originally took a lot of years and quite a bit of pressure. The end result would be not only a sustainable source of fuel, but a way to dispose of our daily trash production.
Of course it all does sound "a bit utopian", perhaps, but the best part is that it should not infringe on people or limit personal freedoms, but rather provide enough enery without consuming resources.
William, that's a great idea, and it's already being implemented. Microbes for quickly digesting and biodegrading plastic have been recently discovered. Meanwhile, there are already industrial composting facilities connected to landfills that reduce the amount of methane gas, and some of them capture and reuse it in power production. Waste Management is one of the biggest:
One of my ideas many years ago was an enclosed system for "digesting" garbage and sewerage into dirt and methane. The only really new discovery needed was a bacteria that would work on more materials. My idea was that all of the mixing and decomposing would happen under a gastight inflatable dome type of structure that would keep all of the methane in so that it could be separated and collected. The big challenges are that it would take up lots of realestate, and that any maintenance would be a problem because of the explosive methane atmosphere. The logistics would get complicated because of the amount of land that it would take, which would locate it far from the cities, which is where all the garbage and sewerage are created.
William, I agree that not putting things like lead, or even metals, into trash would be ideal. Lead came into the discussion because we were talking about front end and back end aspects of the cradle-to-cradle concept. As Rob and I were discussing in the comment thread below, there's no infrastructure set up yet to prevent that from occurring, and it's a complex one, indeed, that needs to be created.
BTW, biodecomposing anything to produce methane gas is not usually considered the best option, unless it's done in controlled circumstances by industrial composting facilities that recapture the methane.
Not sure just how lead got into the discussion, but there certainly is a lot of absolute hysteria about getting rid of it in all products. The solution there is actually obvious, which is: don't put the trash in landfills. The immediate recycling of metals and plastics, and possibly glass, would leave a mix that could be bio-decomposed to produce methane gas. The recovery of resources and energy would be one good way to prevent a lot of things from getting into the ecosystem, and possibly turn a profit at the same time. Of course, the recycling of mixed plasitcs does present a real challenge unless there is a cheap and low energy way to break them into more basic molecules.
The other option is sorting the plastics intothe different types, but that is quite a challenge for some of the types.
Since lead is a known poison, and in very small quantities, it's definitely not a good idea to let it leach into the ecosystem anywhere it might get into human or animal food or water sources. That's why it's no longer allowed in paint, although it still exists in many older houses where kids get sickened by it, and many workers are exposed to it in workplaces. Verifying whether a product containing lead will leach that lead into the environment is something that should be determined by objective, third-party sources not the product's manufacturer, which is highly likely to be biased.
You're right that the issue of lead not leaching into the environment was not upheld. Most people think that putting lead into a product is a bad idea even if some manufacturers say it won't go into the environment.
I do have to hand it to the European Commission. When the group was challenged by IPC and others on some of the science during RoHS redo, the EC backed off on some items.
Rob, thanks for that--I know you've written a lot about green issues. That's a good point, that RoHS tried to address EOL issues a bit, although they were mostly aimed at the front end. But I'm not aware that any of those claims about wrong-headed EU science were ever upheld. Seems like that's always the initial response from manufacturers when told their products are unhealthy by a governing body, and they must change.
You're right. Very little has been done to regulate what happens EOL. the RoHS regulations address it a tad. The effort to get lead out of solder was ultimately an EOL issue, since the EU's concern was lead slipping into the environment after the product was discarded. While many have complained the EU got its science wrong on that issue, the goal was eliminating the lead on the EOL side.
Transfers the control of a large number of motion axes from one numerical control kernel to another within a CNC system, using multiple NCKs, and enables implement control schemes for virtually any type of machine tool.
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