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DRP #5: Waste Disposal

Home Forums Archive Distributed Research Projects DRP #5: Waste Disposal

This topic contains 14 replies, has 12 voices, and was last updated by Profile photo of Jeff-Chan Jeff-Chan 5 years, 3 months ago.

Viewing 15 posts - 1 through 15 (of 15 total)
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    Profile photo of Wayne-Gramlich

    What are our options for disposing of waste? What do existing boats do with their waste stream? Over the side? Store in containers and dispose in the next port? Incenerate? Can we be more innovative? Use it to grow food? We are interested in solutions from small to large.

    Profile photo of livefreeortry

    As far as organic waste is concerned, anaerobic digestion of human and food waste is a reliable, scalable and cheap option for individual seasteads, producing biogas (methane and CO2) and fertilizer: http://www.arti-india.org/content/view/45/52/ , http://www.sulabhinternational.org/st/community_toilet_linked_biogas_pant.php , http://www.communitycompost.org/news/Community%20Biogas%20Gell.doc The waste is incubated with methanogenic bacteria in the absence of oxygen, and may require some stirring and heating. The reduced organic carbon is converted into CH4 and CO2, while nitrogen, sulphur, phosphorus and other minerals are retained in liquid/solid form, and may be recycled, a far better option compared to dumping into the ocean IMO.

    The biogas is commonly used for cooking or electricity generation, while the fertilizer may be re-used for hydroponic applications on a seastead. Thus minerals and nitrogen can be placed in a closed loop onboard, while carbon is in an open loop with the atmosphere, minimizing the impact of the seastead on its surroundings.

    Profile photo of Thorizan

    That about sums up my thoughts on the subject as well.

    Did we just finish one of these DRPs in record time?

    Profile photo of acehigh

    well, you could use the waste to increase the size of the seastead like this guy http://ecoble.com/2007/11/18/250000-bottles-amazing-recycled-mexican-island-paradise/

    Profile photo of Jesrad

    Organic waste can be cheaply composted and reused for food production, with proper care. Inorganic waste, however, might require high temperature incineration (quite energy-hungry) ? I personnally favor
    plasma torch vitrification for turning waste into bricks, but it may be inaccessible to seasteaders because of high capital and power costs.

    Profile photo of Thorizan

    I forgot about that guy… the first time I saw this, I thought we was friggin’ nuts. But the longer I stay on these boards, the smarter he gets. Oh, he’s still nuts, but he’s no longer an idiot about it.

    Profile photo of

    For organic human waste, I always liked the LectraSan. (Raritaneng.com) We had one installed on our Hunter 42′ and I loved it. Very environmentally friendly. It doesn’t allow for the compost option, but I on a Seastead, we will be surrounded by fish which have been used as fertilizer for ages. My only concerns with anaerobic are the relatively confined space and the timeframe.

    Metals, glass, and paper could be recycled and reused. You could have a small workshop for it and probably use the furnace for both metal and glass.

    Profile photo of Jimius

    I suppose the less stuff you bring with you on the seastead that will eventually become trash, the less trash you will have to deal with. So minimizing packing needs for all kind of (essential) goods will make the problem of wast disposal more managable. Bottles and other containers for (food)stuff or liquids van be easily re-used once cleaned.

    I think we might take a good hint from ecological housing which have closed loop sewage systems where (clean) “white” water is used to drink, to shower with and do the dishes. This water is then “gray”. This gray water is used for flushing the toilet and watering the plants in the greenhouse, where the soil filters out all the contaminents. The toilet water is “black” water and gets put in a solar septic tank.

    And the trash that we really can’t do anything with, we can always buy disposal services from land-based companies.

    Profile photo of libertariandoc

    Solve the energy budget problem, and all other problems just about go away: Thermal depolymerization.


    I won’t be wronged. I won’t be insulted. I won’t be laid a-hand on. I don’t do these things to other people, and I require the same from them.

    Profile photo of Thorizan

    That, or a Plasma Converter.


    There is no fate but what we make for ourselves. Each to his fate.

    Profile photo of tomohern

    I avoid almost all plastic on my boat by purchasing most of my food in bulk and when on sailing trips I keep everything in reusable containers. I pre-cook meals before my trip and also use reusable containers. On a seastead level, most food will either be grown and stored, or bought in huge bulk amounts. Rice and grains, root vegetables, dried goods, etc can all be kept in large containers in “root cellar” like rooms. I don’t imagine that a seastead will have large amounts of packaging plastic that needs to be disposed of as we can’t order tons of stuff off of amazon.com.

    A semi-sufficient seastead will probably have small scale metal casting facilities to fabricate small tools, parts, etc. Any metal collected can be sorted and melted down for later use.

    All organic material can be composted. Methane and heat can be collected and the left over material would be important for putting back into soil beds. At home I compost a lot of my human waste following the method described in the Humanure Handbook (linked above).

    The only material I can imagine would be a problem would be broken equipment (computers, radios, etc) that can’t easily be broken down into component parts.

    Any other ideas on what someone would bring aboard a seastead that we would need to dispose of?

    Profile photo of Michael-Hawkins

    Polystyrene plastics can be recycled without much trouble. This includes insulation, tupperware and most everything in between. It’s either avoiding plastics, or being smart about the kind you bring.

    tomohern wrote:

    A semi-sufficient seastead will probably have small scale metal casting facilities to fabricate small tools, parts, etc. Any metal collected can be sorted and melted down for later use.

    I hope by the time things get going, stereolithography and 3D-printing will have advanced to the level (and cost) to make metal obsolete for all but the most -subjected to stress- parts and bits.

    Profile photo of tomohern

    Michael wrote:

    I hope by the time things get going, stereo lithography and 3D-printing will have advanced to the level (and cost) to make metal obsolete for all but the most -subjected to stress- parts and bits.

    In my experience, when you are at sea, everything falls under the category of “most -subjected to stress”. The ability to cast and machine metal to produce bolts, cleats, gears will be important if you plan on spending a significant time without coming back to shore. I don’t foresee seasteads being held together with plastic and having spare parts for anything beyond the most critical pieces would be overwhelming. And spares can only get one so far and keep us afloat for so long. CNC machines that work in wood and plastic can be used on metal too so there can be some overlap in workshop tools. It may not be the first thing that gets included but I would think it would be very handy to have.

    My small metal casting equipment can fit in a few square feet of space (not including my lathe).

    Profile photo of jcrawford

    I think some metalworking and casting facilities will be vital. Basic equipment for these purposes is constantly getting smaller and less expensive, although you still need money and space for the equipment to fabricate with some flexibility. The continuing development of CNC machinery and software would reduce the need for manual skill on the part of the operator, too, making metal fabrication a little more 3-easy-steps.

    I’ve been captain of a competition robotics team for two years now. Our shop facility is about 5000 sq ft, but I think you could easily fit all the equipment we actually use in to a space 6′ by 50′ or so, if you put the machines in a row. You also need 2-phase 240vac power to that. Most of our machinery is 50+ years old, though, and newer equipment tends to be smaller for the same work area. With that equipment we fabricate everything from aluminum chassis to custom brackets of all sorts, we exceed what you’d need for a seastead, I’d think. We buy all of our stock materials from an industrial supplier, but we tend to make everything from a pretty small set of stock types.

    Profile photo of Jeff-Chan

    libertariandoc wrote:
    Solve the energy budget problem, and all other problems just about go away: Thermal depolymerization.

    Thermal depolymerization takes some energy to operate (the “thermal” part), but could possibly be at least partially self-energizing using an organic feedstock. Also there are lots of different ways to get heat.

    But your first point is the most important one. Most of these issues boil down to energy; having enough, using it efficiently, etc.

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