This article ( also sent as a newsletter) written by Narsi Santhanam provides useful insights on the importance of diatoms and some details about the Oilgae team ‘s visit to a company called Nualgi; This Indian-based company uses diatoms for bio remediation of waste water – Interesting stuff!!!
Here you go..
As you all might be knowing, diatoms are at the bottom of the aquatic food web. Thus, they comprise a critical component of the aquatic world.
But even more importantly, diatoms perform a very important service in decreasing atmospheric CO2 levels. Some studies estimate that the diatoms could be absorbing close to a quarter of the atmospheric CO2. And when they die, the diatoms sink to the bottom of the ocean, carrying and thus sequestering the CO2 along with them. In fact, it is owing to their sinking to the bottom that the diatom deaths are harmless, when compared to the the typical, harmful blooms of algae species such as blue green algae.
In short, diatoms are important, important guys.
The impetus for this article was provided by Mr M.V.Bhaskar, who assists a company by name Nualgi
( http://nualgi.blogspot.com/ ). Nualgi‘s idea is simple: They use diatoms to clean up wastewater, and these diatoms are consumed by zooplankton. These zooplankton are in turn consumed by fish.
So, the logic goes as follows:
Wastewater =& gt; Diatoms =& gt; Clean Water.
Diatoms =& gt; Zooplankton =& gt; Fish
The bottom line is, you start with a lake full of sewage water, and end up with a clean lake full of fish.
Sounds too good? Nualgi is making it happen in the city of Bangalore, India. The Nualgi team essentially provides an algal nutrient that results in a large diatom population, and the rest is taken care of by nature.
The Oilgae Team had the opportunity to visit them a few months back and the inventor of Nualgi (=nutrient + algae) Sampath Kumar took time off the entire day to show us around the lakes in which Nualgi was working its magic. You can see more on our visit from here – http://www.oilgae.com/blog/2009/10/nualgi-algae-nutrient-that-cleans.html .
Bhaskar in his mail to me a couple of days back, pointed out a few other advantages with diatoms being used for wastewater treatment:
* Diatoms grow very fast. They double in the matter of a few hours
* Diatoms give more oxygen than other algae, this is very significant since wastewater treatment requires more oxygen.
* Since diatoms are consumed by zooplankton and these by fish, there is no need to harvest them, this reduces the cost of using Diatoms for sewage treatment. Well, this might not be of huge interest to those keen on obtaining biofuels from algal biomass, though.
The diatoms thus are incredibly useful when they are alive, and as mentioned earlier, even in their deaths!
To me, it makes a lot of sense to explore the use diatoms for wastewater remediation. I would like to know if there are any others on this mailing who are using diatoms or have heard of companies using diatoms for wastewater treatment.
Speaking of diatoms, I came across another interesting piece on them, though not exactly in the context of wastewater treatment – but in the context of low-cost fishmeal. At the CleanTech Forum at San Francisco that ended recently, the company SBAE from Belgium demonstrated its efforts for using diatoms for producing low-cost, high nutrient fishmeal.
The company grows algae in simulated water streams, and uses a new way to harvest algae. It sticks mesh nets into the stream. Diatoms cling and grow on the nets. When it is time to harvest, the company pulls the nets out and harvests it. The net system lets the company circumvent one of the vexing problems of algae: separating the algae from the water. No centrifuges or evaporation systems are needed – you just hoist it out! Ha!
SBAE is targetting – not the biofuel market – but the less demanding market for fish meal for aquaculture. The company says it can produce fishmeal at half the costs of the current products. It does it by mixing the algae with the traditional, hig cost fish meal.
The diatoms continue their impressive march!
Adapted from the Oilgae Newsletter sent in the month of July.
Share and Enjoy