Chrisf1020

Chrisf1020 t1_j5yiyc2 wrote

Reply to comment by Girafferage in The world is (on average) 50% reliant on nonrenewable sources of phosphorus fertilizer to grow food. It won't go away this century, but prices will increase and ~3/4ths of reserves are controlled by one country by fartyburly

>It would be, except there isn't rain anywhere on the entire planet that doesn't already contain dangerous levels of it.

Just because it is already everywhere, doesn’t mean it is less dangerous/concerning than PPCP (though it obviously doesn’t mean the contrary, either. Need more research). Keep in mind that the bar for ‘dangerous’ has been lowered so significantly that all water on the planet is basically guaranteed to contain dangerous levels of PFAS at this point. One of your linked articles mentioned it, but last year the EPA also set new health advisories for the two most common PFAS (PFOA and PFOS) at unconscionably low levels: 0.004 ppt for PFOA and 0.02 ppt for PFOS. These values take into account lifetime exposure and bioaccumulation. The previous advisory was 70 ppt for both, so the new advisories are 17,500x and 3500x more strict, respectively. EPA considers these levels “near zero” and admits they are “below EPA’s ability to detect at this time,” meaning the safe level of consumption for those two chemicals is practically zero.

>Good on Maine though for actually trying to do something at least. We really need a system to remove them from the environment at this point, and maybe hold the companies that made these chemicals and knew about these negative effects accountable.

Thermal destruction seems to be the most promising at the moment. Carbon-Fluorine bonds are very hard to break. It requires temperatures around 1000 °C, so very energy intensive. Time and turbulence are also factors in destruction. Typical sewage sludge incinerators (most sludge is incinerated in my state) do not reach these temperatures, however.

>There haven't been a ton of study's on the pharmaceuticals in waste fertilizer from humans, but the ones that have checked the contents of different brands aren't optimistic. Dangerous levels of a multitude of drugs, some that women aren't even supposed to handle period.

I’d be interested to read those PPCP fertilizer studies if you have links. I work in the wastewater industry if that wasn’t already obvious, so I’m always trying to learn more.

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Chrisf1020 t1_j5y9c00 wrote

Reply to comment by Girafferage in The world is (on average) 50% reliant on nonrenewable sources of phosphorus fertilizer to grow food. It won't go away this century, but prices will increase and ~3/4ths of reserves are controlled by one country by fartyburly

Here is a link for struvite harvesting. The process is very energy intensive: https://www.sciencedirect.com/science/article/abs/pii/S0921344919303246

On the subject of biosolids reuse: Last year, Maine became the first state to ban the land application of biosolids —— not due to pharmaceuticals and personal care products (PPCP), on which little research has been done, but due to per- and poly-fluorinated alkyl substances (PFAS) a.k.a. “forever chemicals”. This should be your main concern regarding the reuse of biosolids for agriculture, as PFAS bioaccumulate in your body.

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