The Ocean Cleanup immediately comes to mind. I very much doubt that they're even slightly "sustainable" in a financial sense, but their engineering and logistics efforts seem to be serious, and outcomes meaningful.
And I've seen various cottage industries in the developing world grow out of/highlighted by Precious Plastic - ones who provide perhaps 5-30 jobs in poor and polluted areas of the world. A warehouse, some crude but effective machinery for processing the waste.
I will mention. Ocean Cleanup has a 55 million Euro budget. Precious Plastic is being criticized for having squandered a 100k donation. That 550 times less.
Ocean Cleanup claims to have removed 21,000 metric tons of plastic in its existence.
If we assume linear growth in budget, that's $330M Euro / 21k ton = 15,000 Euro per ton of garbage.
About 10 million tons of plastic end up in the ocean each year, so over their history, they've cleaned up 0.2% of the annual input.
I can't really comment if any of that good or bad, but I thought numbers (even if squishy estimates) would be helpful to inform the discussion.
If I wanted to spend 100k on plastic recycling, I’d start a company with a viable business model. The most probable business model would be shaming big companies into paying me for green washing, so hiring great marketing talent would be top priority. Getting the first companies on board to fund further development would be second.
