More carbon sink

Back in October last year, I was moved to intervene in the debate about plastic waste, suggesting that shoving the stuff down disused coal mines might not be such a bad idea.

I was prompted to revisit this matter by a short piece in yesterday's Guardian about microplastics in the soil, a piece which may have been lifted more or less verbatim from some science watch web site. In the past, when the Guardian has written something like this up, it was easy enough to find and download the something in question. But not on this occasion, and it took some fiddling around with search keys in both Bing and Google to turn up reference 2. Still firmly behind its paywall, £20 or so high. Then reference 3, also still firmly behind its paywall, rather higher.

Then I got to reference 4 and reference 5, both open access. Which I have taken a quick peek at, enough to learn that plastics in landfill are a problem. Landfill sites are not as inert as I might have thought and the rainwater which eventually leaches out of them - and it is hard to seal them off altogether - known as leachate - is apt to contain lots of unpleasant chemicals. But which can, in large part, be removed by water treatment works. Filtration beds and so forth.

Lots of other stuff out there and we can take some comfort from the fact that lots of people are beavering away at doing landfill better.

And thinking about it again, I dare say shoving the stuff down deep coal mines might avoid the leachate problem, but would probably be a lot more expensive that properly managed landfill.

So sadly, as ever, my magic bullet was not so magic after all.

Reference 1: https://psmv4.blogspot.com/2019/10/carbon-sink.html.

Reference 2: Microplastics negatively affect soil fauna but stimulate microbial activity: insights from a field-based microplastic addition experiment - Dunmei Lin, Guangrong Yang, Pengpeng Dou, Shenhua Qian, Liang Zhao, Yongchuan Yang and Nicolas Fanin – 2020. The end of the abstract: '... Our results highlight that taking into account the effects of microplastics at different trophic levels is important to elucidate the mechanisms underlying the ecological impacts of microplastic pollution on soil functioning'. Hmmm.

Reference 3: Municipal solid waste (MSW) landfill: A source of microplastics? - Evidence of microplastics in landfill leachate - Pinjing He, Liyao Chena, Liming Shao, Hua Zhang, Fan Lü - 2019. The end of the abstract: '... landfill isn't the final sink of plastics, but a potential source of microplastics'.

Reference 4: Microplastics in Landfill Leachates in the Nordic Countries - Martijn van Praagh, Cornelia Hartman and Emma Brandmyr - 2018. From the discussion: '... local treatment of landfill leachate is a potentially viable option to reduce the emission of microplastics from landfills to either WWTPs [waste water treatment plants] or surface water recipients...'.

Reference 5: https://en.wikipedia.org/wiki/Leachate. The source of the snap above: '400,000 gallon leachate processing / equalization or storage tanks at Seneca Landfill, Evans City, Pennsylvania'.