Tyler Ludens wrote:Could be tough if you want some plastic and the guys come along and eat it while you're still using it. So I hope the improved versions aren't just randomly let loose upon the world.
Alan Booker wrote:The scope of the plastic problem is a bit hard to wrap your head around. We definitely need to develop as many effective bioremediation techniques as we can, but I don't think we could ever keep up if we don't slow down on creating the problem in the first place.
I was at the Alabama Rivers Alliance conference weekend before last and one of the educators there did a presentation where she showed how to sample water for microplastic contamination. The number of microplastic particles carried by a single gallon of water from the Mobile Bay is a bit startling.
A few of the things she pointed out included:
* Microplastics are technically defined as any plastic particles smaller than 5 millimeters in diameter, but many of them are small enough that you need a microscope to see them.
* They are typically classified as either primary microplastics, which are plastic particles that are manufactured at that size, such as microbeads, and secondary microplastics, which as plastic particles formed from the physical breakdown of larger plastic items into smaller pieces.
* They end up being eaten by everything across the size scale from plankton to whales.
* In addition to being toxic themselves, these plastics also absorb hydrophobic chemicals such as pesticides, steriods, and BPA.
* There is now good evidence that these microplastics are bio-accumulating up the food chain to produce even higher impact on organisms higher on the trophic ladder, including us.
* A very common form of microplastic is the microfiber, a very common source of which is shedding from synthetic clothing such as fleece.
* Even many "bioplastics" break down very slowly. We haven't really perfected the idea of biodegradable plastics quite yet.
I have to agree with Wen that phasing out plastics is increasingly looking like a good idea.
Jennifer Richardson wrote: Are there labs you can just send this kind of stuff to? Cost?)
Chris Kott wrote:I think that if there are fungi and bacteria eating away microplastics at some point of the remediation process, then, while the breakdown might be largely mechanical, the addition of larger insects in earlier stages can't possibly hurt.
I would still want the insect feces, and the insect corpses themselves, tested to see whether they're breaking the plastics down into their constituent parts, or just making smaller pieces and sequestering it inside their bodies, just as I would want the end product tested before application anywhere. And the aforementioned suggestion that the remediated soil product resulting from this process should be kept to growing non-food items isn't without merit.
As to biological sequestration, that is also a possibility. I would be interested to know if the possibility of sinking sequestered plastics into active subduction zones would work as a method of long-term sequestration and conversion back to petroleum (not that more petroleum is the goal, but that putting that stuff back in the ground would be nice, as it was safe there for millions of years before we got here).
I also wonder, following that thought, if it is possible to find or create an inert substance that attracts microplastics to itself, or to other microplastics, causing them to gather together, like alum with waste water treatment. From there, the plastics could be strained from the oceans, or caused to get larger and heavier, and hopefully find their own way down into subduction zones, perhaps with a little human help.
I guess that might be georemediation, especially if the flocculant is a mineral.
Jennifer Richardson wrote:Plastics are such an enormous problem. If I could wave my magic wand (or release the all-plastic-eating microbe) and trade all plastics for none, I probably would, despite all genuinely beneficial and irreplaceable applications. I have been roaming the local beach, collecting (mostly plastic) trash lately, and it is depressing—not just how trashed the beach is, but that there’s no way to recycle most of it, and a lot of it I can’t even collect because it’s so degraded, it breaks into bits that end up in surf and sand. I know the water is plastic soup. I definitely advocate using less/none if possible, but I fall so depressingly short of this myself, and fail so hard in managing the trash that family members heedlessly bring into the household, that it feels kind of useless even talking about it, but I think it’s the only solution.
More generally for bioremediation, I think a lot about issues of diffusion vs concentration. The best case scenario is obviously if the harmful compounds can genuinely be changed into benign ones. But a lot of the time it’s just sequestration, and then moving the harmful stuff to somewhere more secure. Or possibly dispersing it until it’s at non-harmful concentrations. But we know that the food chain tends to reconcentrate it.
I think a lot about whether it’s better overall to speed up the biodegradation process (as with my styrofoam worms) even at the risk of potentially incorporating more microplastics or harmful compounds into the biosphere, or to keep the bad stuff sequestered, where maybe it will not introduce as much contamination to the biosphere, but will also not be subject to biological processes which could render it increasingly benign.
I also think that as humans it’s very easy to fool ourselves. When I used to burn trash (not recommended!), before I knew better, I would get a feeling of accomplishment as if I had cleaned stuff up and made the world a better, less polluted place, because I could not see the trash anymore and the beach or roadside or yard looked tidier. I think incinerators vs landfills are basically the same psychological phenomenon on an industrial scale, and invisible problems like dioxins get ignored. I worry that things like the superworms are in danger of being the same—the worm poop LOOKS better than big chunks of styrofoam, so it must BE better for the environment. I do think the research looks positive, but it is tempting to descend into handwaving and magical thinking on some bioremediation projects (on that note, if anyone knows concretely how to go about getting the worm waste tested, I would like to know. Are there labs you can just send this kind of stuff to? Cost?)
Tyler Ludens wrote:Got a reply from TAMU soil lab:
"Our laboratory does not test for these type of compounds, and we really do not have a good suggestion/reference to provide. This link might provide some insight to laboratories in your area to contact. I would suggest only looking at the "Solid and Chemicals" marked laboratories: https://www.tceq.texas.gov/assets/public/compliance/compliance_support/qa/txnelap_lab_list.pdf"