New 'Swiss Army knife' cleans up water pollution:
Phosphate pollution in rivers, lakes and other waterways has reached dangerous levels, causing algae blooms that starve fish and aquatic plants of oxygen. Meanwhile, farmers worldwide are coming to terms with a dwindling reserve of phosphate fertilizers that feed half the world's food supply.
Inspired by Chicago's many nearby bodies of water, a Northwestern University-led team has developed a way to repeatedly remove and reuse phosphate from polluted waters. The researchers liken the development to a "Swiss Army knife" for pollution remediation as they tailor their membrane to absorb and later release other pollutants.
[...] Phosphorus underpins both the world's food system and all life on earth. Every living organism on the planet requires it: phosphorous is in cell membranes, the scaffolding of DNA and in our skeleton. Though other key elements like oxygen and nitrogen can be found in the atmosphere, phosphorous has no analog. The small fraction of usable phosphorous comes from the Earth's crust, which takes thousands or even millions of years to weather away. And our mines are running out.
[...] Ecologists and engineers traditionally have developed tactics to address the mounting environmental and public health concerns around phosphate by eliminating phosphate from water sources. Only recently has the emphasis shifted away from removing to recovering phosphate.
[...] The team's Phosphate Elimination and Recovery Lightweight (PEARL) membrane is a porous, flexible substrate (such as a coated sponge, cloth or fibers) that selectively sequesters up to 99% of phosphate ions from polluted water. Coated with nanostructures that bind to phosphate, the PEARL membrane can be tuned by controlling the pH to either absorb or release nutrients to allow for phosphate recovery and reuse of the membrane for many cycles.
[...] The team has demonstrated that the sponge-based approach is effective on scales, ranging from milligrams to kilograms, suggesting promise in scaling even further.
Journal Reference:
Benjamin Shindel, Roberto dos Reis and Vikas Nandwana. "Phosphate Elimination and Recovery Lightweight (PEARL) Membrane: A Sustainable Environmental Remediation Approach," Proceedings of the National Academy of Science
(Score: 0) by Anonymous Coward on Thursday June 03 2021, @01:44AM (3 children)
So it's not like swiss army knife. At all.
(Score: -1, Flamebait) by Anonymous Coward on Thursday June 03 2021, @02:07AM (2 children)
Runaway submission. Understanding optional.
(Score: 0) by Anonymous Coward on Thursday June 03 2021, @05:22AM (1 child)
Runaway is not an editor. Lay off that dope. He contributes much more here than some of you SJW belgians.
(Score: 0) by Anonymous Coward on Thursday June 03 2021, @08:08AM
But what he contributes is on par with this one. All his Brietbarf/RT subs get shitcanned faster than aristarchus subs!
(Score: 1, Interesting) by Anonymous Coward on Thursday June 03 2021, @02:23AM (8 children)
So, you're going to be pumping a vast amount of water, from a place where it collects at low elevation, and through sponges, and then collect phosphorus compounds from those membranes, and then cycle them back uphill in the direction of farmers ...
Gotcha. And this will be expensive, in energy terms, in the same ballpark as Saudi Arabia's desalination plants. Probably a similar order of magnitude.
And we're going to power this how, exactly? Huge solar plants? Massive windfarms? Monumental nuclear power stations?
I'm not against the idea, don't get me wrong, and if we don't want agricultural productivity to crash and burn, something along these lines will have to be considered, but I foresee major technical, political and resource challenges to making it happen whatsoever, let alone globally.
(Score: 1, Interesting) by Anonymous Coward on Thursday June 03 2021, @02:35AM (4 children)
The Phosphorus compounds all drain off farm fields to get into larger bodies of water. Why not put these "sponges" at dam spillways along this path--keep the Phosphorus out of the large rivers & lakes all together?
(Score: 0) by Anonymous Coward on Thursday June 03 2021, @07:48AM (3 children)
Or prevent the drain off in the first place. But hey, fertilizer is cheap and keeping the soil healthy is hard/expensive. Let someone else deal with the pollution (which is basically what this is).
(Score: 1, Interesting) by Anonymous Coward on Thursday June 03 2021, @01:40PM (2 children)
It's not that simple. Many of the ways in which phosphorus is lost, if we're not simply talking about sediment (i.e. stripped soil) are soluble phosphorus compounds. So to stop it, we would have to have total water control at the boundaries of every field and orchard. Think rice paddies, but on a much larger scale and with much, much stricter water control.
And to make it worse, even if this were technically feasible (it's not) or utterly desirable from every other perspective (it's not) in many areas it would be outright illegal owing to water rights. In many states in the USA (and this situation is not unique) farmers don't actually own the rain that falls on their lands, and capturing more than the land naturally absorbs requires a right that they often do not have.
But sure, on a strictly technical level of theoretical chemistry, you're not entirely wrong.
(Score: 2) by DeathMonkey on Thursday June 03 2021, @06:37PM (1 child)
Every single business and construction site in the country already has to follow this rule already. All stormwater that flows off a site is effluent and emissions standards apply. The controls that are required if you go above those limits can get extreme for highly polluting business but they're also pretty damn reasonable for low impact businesses. Construction sites, for example, generally just need to put down pads and erosion control fabric to prevent sediment runoff.
This article basically just describes one of those absorbent pads but for phosphorus. So no they won't be pumping around a lot of water as alleged up-thread. These would be placed on property boundaries, likely, and would actually be a really easy control to install and use which is the whole point.
(Score: 0) by Anonymous Coward on Thursday June 03 2021, @07:50PM
Welp, I think that we've just found Bloomberg's agricultural consultant.
The USA's arable land amounts to about 4 * 10 ^ 9 acres, or roughly 1.5 * 10 ^ 9 hectares, if you prefer.
Even assuming everything is in 20 hectare plots of convenient shape (it's not) and water consistently leaves each plot along one edge (it doesn't) and they're all oblong (nope) with the effluent edge only 100m long (hah), all you need is to control water flow along 75 million kilometers.
That is EXACTLY LIKE every construction site and business in the world.
Except that it's not.
(Score: 0) by Anonymous Coward on Thursday June 03 2021, @01:45PM (1 child)
Its not like they are talking about moving the WATER back up hill, just the phosphates, this seems like a significantly smaller problem.
(Score: 0) by Anonymous Coward on Thursday June 03 2021, @04:00PM
It hardly matters.
The desalination plants are huge, energy-hungry beasts even if you close your eyes and pretend that none of the return pumping stations exist. You want to extract phosphates from runoff? You have to collect the runoff (pumping), and get the water post-treatment back to where it was going (pumping) and put it through your process (pumping) and extract it from your sponges again (pumping) and that completely ignores any post-processing that you're doing to the sponges to extract the phosphates for reuse.
What we're really proposing here is a shortcut to the phosphate cycle that we front-loaded by digging a bunch up and putting on our farm soils, but it's not really happening in the kind of way that is easy to control to any useful extent without damming and processing huge rivers on a scale that would make the Sierra Club shit their collective shorts. It would almost be easier to perform algal aquaculture and re-oxygenation of waters.
(Score: 2) by DeathMonkey on Thursday June 03 2021, @06:21PM
And how expensive is every single fish in the river dying from hypoxia?
The Mighty Buzzard, may he rest in peace, might even agree with me on this one!
(Score: 0) by Anonymous Coward on Thursday June 03 2021, @10:23AM
Phosphate pollution? St. Greta isn't lobbying against it, so it can't be all that bad.
(Score: 2) by Taxi Dudinous on Thursday June 03 2021, @02:06PM (4 children)
Ironic. Phosphate pollution is a big problem in both fresh and salt water all over the planet. And yet, there is a looming shortage on the supply end. No matter what we do, things will get ugly. There is a mass extinction of some sort coming. We may hold it off for a while, but I am pretty sure it is inevitable. How many will be culled? 2/3 of a population is not uncommon in other species. Our dependence on technology to supply water may mean we get hit harder than that. We may be able to minimize the deaths, but society will have to make some huge changes for that to work. Nature has some tough rules. We like to think they do not apply to us. Other species have dealt with those same basic rules for millennia. Our turn is coming.
(Score: 1, Interesting) by Anonymous Coward on Thursday June 03 2021, @04:17PM
Yup.
Actually, we have a few bottlenecks there.
Phosphates are one major one, but it applies to all elements of the basic NPK bulk nutrient sources. All of them require a lot of energy. Nitrogen collection is hugely energy hungry. Mining for phosphates, ditto. Potash (Potassium) comes from salts, which generally require some refinement to exclude undesirable salts (otherwise you're basically salting your fields) which means both mining and refinement.
Bottom line: when the oil reserves dry up at a given price, and the price rises to convert more mineral energy resources to reserves, the price of plant nutrients and thus the price of agricultural products will rise. We're eating oil, and when we run out we will return to pre-Borlaug levels of global population sustainability. Maybe three billion. If we're smart and lucky, maybe four.
Before some technocratic fanatic comes in to remind us all about how vertical urban aero/aquaponics will save us, not only does the requisite infrastructure require a lot of mining, the processes (ranging from pumping water around to ventilation and temperature control) are energy hungry as well. This makes it worse, not better. And even that's if you pretend that you can magically gather enough energy (including solar) to replace the required sunlight for plant growth in such a dense arrangement.
But hey, fusion will give us infinite energy. Unless it doesn't. And if it doesn't, a lot of the necessary deaths will happen by war, motivated by hunger. Good luck negotiating your way out of that hole.
(Score: 1) by khallow on Friday June 04 2021, @12:31PM (2 children)
As in we'd have to mine slightly more expensive phosphate sources. This is a non-problem.
(Score: 0) by Anonymous Coward on Saturday June 05 2021, @09:24PM (1 child)
Until and unless our masters agree to nuclear power, it'll actually be a vast problem as the price of energy continues to rise. Solar and Wind's viability is still dependent on magical energy storage systems that don't exist (yet, if ever), and big industrial systems like refineries and ventilation systems for mines aren't the sort of thing that you can shut down and shrug your shoulders about just because it's been cloudy and still.
Even if we more or less put that problem off and suck up the rising cost of mineral hydrocarbon fuels, that still implies a rise in the cost of food - which is already a major pressure source on the people. There's a reason that they like to avoid talking about food inflation when they complain about how low inflation is. Real household expenditure inflation dwarfs the official numbers - which turns out also to be a problem for people on incomes from Social Security and similar systems, because those payments are upped by (you guessed it!) the official inflation rate.
(Score: 1) by khallow on Sunday June 06 2021, @12:00AM
The price of energy isn't currently rising, let us note.