Farm Runoff? Sewage? These Bacteria Eat It Up.
by Jonathan Fahey, FORBES.COM, July 30, 2010
A type of bacteria discovered in brewery wastewater in the Netherlands 25 years ago amazed scientists. Here were bugs that created hydrazine, an extremely unstable compound, used as rocket fuel, that is poison to most living things.
The microbes didn’t use the hydrazine to launch themselves into orbit, but as an intermediate step in a larger process. These creatures, now called anammox bacteria, transform caustic and hazardous ammonium into dinitrogen, the harmless nitrogen gas that makes up 78% of the air we breathe.
Which is what makes them so attractive to people like Eric Lohan, who is the research manager for Worrell Water Technologies’ Living Machine division. Worrell’s Living Machines are water recycling systems that drastically reduce water use and can eliminate sewer discharge.
Systems like these are becoming more attractive as fresh water is becoming more scarce and expensive. A recent McKinsey & Co. report on water predicts that by 2030 the world will require 40% more water than what is available today. There are Living Machines installed in 20 locations, like in a recently constructed Port of Portland building.
These Living Machines recycle wastewater by filtering it through a system of bacteria and plants. When the water emerges, it is clean enough to be used for flushing toilets and watering yards, gardens and crops. (In fact, it’s cleaner even than that and could easily be made drinkable. But securing permits for this kind of system, installing monitoring equipment to make sure the water is always perfectly clean, and getting over public squeamishness isn’t worth it. After all, only 10% to 20% of the water we use is for things like drinking and cooking.)
Now Lohan is trying to incorporate anammox bacteria into Living Machines. Anammox bacteria transform ammonia to nitrogen in fewer steps than more common bacteria, and require much less oxygen, and therefore energy, to do so.
This, Lohan hopes, will allow the system to deal with more concentrated waste streams from big buildings and even operations like pig and dairy farms, which produce huge volumes of concentrated waste. Now, waste from these farms is often just pumped into nearby pits. They often overflow into rivers and streams during storms. Traditional treatment is so expensive that regulators can’t force farms to do much about it.
"We think that this treatment technology can hit the ball out of the park for [agricultural] waste," says Lohan. The system would be cheap, especially compared with a traditional system, and it would require very little energy.
Lohan cautions that the company has only been able to incorporate anammox bacteria in the lab. Over the next few months, though, the company hopes to install a pilot system at a dairy farm in Texas near the New Mexico border, where water is scarce. The water would be reused to irrigate crops. [Read rest of story]