[avadodin]

There are techniques both at origin and downstream.

I have not reviewed every method but, even if they are energy intensive, they probably beat blasting a carburetor and dumping the compounds.

[undersuit]

I mentioned removing the excess nutrients from the water because removing them "works a small fraction of the time, it is awful to wildlife and it is an eyesore." not to mention the energy requirements which you think shouldn't include wind.