Climate Change: Time to get the muck out


This is kind of backward. States have banned phosphorus fertilizers for lawns, because the phosphorus runs off the landscape, into rivers and streams, and breeds algal blooms and muck. Ever visited a beach visited by muck? It’s not a vacation.

But here comes some new warnings: Climate change can cause more phosphorus to leach from the soil. I can see the conflicts now: People who want thicker lawns vs. people who want to relax in the sweet, sweet sugar sand.

The argument for phosphorus bans has been the need to keep beaches free of dead algae, and the fact that soil in places like Michigan already contains enough natural phosphorus to grow a decent lawn.

But climate change predictions include more heavy rainstorms, with soil being rewetted more frequently. Apparently, this rewetting means an increase in phosphorus that leaches from the soil and into our waterways.

And this is about more than the beach.

Algal blooms also affect water quality. You may have smelled one coming out of your faucet. It takes more chemicals to clean drinking water when algal blooms are present, and some algal blooms are toxic. They can make swimmers sick and kill your dog, for instance.

Which brings me to the thought of phosphorus removal technology, via wastewater treatment plants. How much removal is economical? And what about technologies to reduce phosphorus runoff, via wetland construction or other methods? Is this a growth industry under climate change scenarios?

The phosphorus leaching research was published in a journal called Biology and Fertility of Soils. It was conducted by scientists from North Wyke Research in the United Kingdom.

“These results suggest that changes in patterns of rainfall frequency and intensity predicted by climate change scenarios could significantly affect the quantities of P leached from soils,” according to an abstract.



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8 comments on “Climate Change: Time to get the muck out

That link to the to Professor Strom’s paper (www.water.rutgers.edu/Projects/trading/p-trt-lit-rev-2a.pdf) is pretty helpful at understanding how to address it from an academic perspective, but are there companies that have tried commercializing some of those technologies? My water exposure is pretty weak (at best), but I think it is a classic example of why you need government intervention.

Should it be Fertilizer companies that are forced to pay for these technologies/projects? Do we leave it to the commons (government?) Ironic how CleanTeh VC’s that might be about saving the world as long as it makes them rich would love this in concept, but commercializing is tough when it isn’t clear who the paying customer is… Most those successful VC’s don’t believe much in taxes (I’m generalizing… I know).

Rob, Steve, Sanj.. any comments?

“Is this a growth industry under climate change scenarios?”

I think it may be, but maybe the question should rather be “How do we avoid P in wastewater in the first place?”

Jke: Duly noted. But I was thinking of soils that have high levels of phosphorus naturally, or have been loaded up for years.

James McDougal

What about the technologies that harvest the algae (or “plant” and harvest the correct algae) and refine it into biofuels?

Seems like the perfect way to turn a waste stream into a profit stream.

@James- Great in theory, much tougher in practice. Check out how complicated it is by peaking Solazyme, Solix, Live Fuels and other Algal Biofuel companies. It requires more than any algae to make biofuels. They have to grow quickly and produce hydrocarbons – they typically only do this under stressed/unnatural situations.

Another approach is to reuse runoff water for irrigation – that’s harder than with treated wastewater though, due to unreliable flows.

Treatment plants with nutrient removal are for wastewater, AFAIK – it sounds like a difficult and expensive task to apply this to stormwater runoff.

I’d say the key responses are:

* source reduction, as jke suggested. It would be interesting to know how much of a problem natural P vs fertilizer P is, and how long it takes to stop being a problem. If it only persists for a year, then fancy high-tech solutions would sound like overkill.

* peak flow mitigation devices. Not sure of the proper term, but I mean basins that store water from storm events and let it out slowly. Most nutrients and pollutants are attached to particulates, so the settling time helps reduce the load of P and other components of the stormwater.

* resilient treatment units, that cope with greatly varying flow would work for less extreme cases. (A fixed media biofilm system is one option – I’m thinking of a “roughing filter”.) The problem is that stormwater is too extreme in variation. So that leaves one option that I’m aware of:

* natural treatment systems, perhaps a constructed wetland. See http://www.appropedia.org/Arcata_Marsh_overview for an example of one used in wastewater treatment. Try looking for examples that have been used for stormwater. This would need the peak flow mitigation devices to be used as well, partly to remove the bulk of the pollutants, and to slow down the flow.

Does that help?

There are several examples of ecological engineering designs to manage phosphorus particulary using algae as the wastewater treatment medium. Oswald published many papers in the United States on the subject in 1950’s!

Human perception of algae still lives in dark ages, of course contact with algae will make humans ill, just as contact with bacteria will do the same, depending on species. Algae are the good guys!, they produced oil millions of years ago, which was ‘cooked’ and gave to the world fuel for transport. They are one of the most effiecent carbon sinks in the world and biosequestrate 1.5 tonnes of carbon dioxide for every tonne of biomass produced. Finally, algae is pretty much the beginining of the food chain, without it we wouldnt be alive as it generates most of our oxygen needs. If the objective is sustainablility then we must start thinking outside the square, challenge perceptions and start to integrate again with our natural systems.

Anjing

Well done! Thanks for this valuable information! 🙂

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