I want to make a research about the effect of CO2 supply on the microalgae growth. While I googling about CO2 supply I found that we can use a NaHCO3 to supply CO2 on the water. Is this make sense? And then, how can I calculate the amount of chemical compound (NaHCO3, or something) into the amount of CO2 on the water?
Yes, using NaHCO3 make it sense for your purpose. Just add the bicarboante needed and contro pH so as to achieve the corresponding CO2 concentration from the bicarbonate dissosiation constant. It is easier if you use an automatic pH-control system to set a fixed pH value.
Darwin Darwin
visit any online site for biotope or planted tank accessories and check out the vast array of CO2 cylinders equipped with solenoid based autoregulators and pH meter. You can control and monitor the addition of CO2 for a very large volume of liquid. This set up is a must in growing many not so called truly submerged aquatic flora underwater with effective and visible oxygen bubble eggression via photosynthesis. NaHCO3 addition is cheap but to maintain a large bulk of microalgal culture under relatively contamination free condition the addition of purified carbon dioxide is a must.
Regards,
Dr. Abhishek Mukherjee
Be aware of the need for constant mass balancing which is difficult when adding solids or liquids to aqueous systems. Also, the pH range to obtain the desired CO2 concentration from the NaHCO3 may not be correct for the cultured organism(s). Therefore, gas addition is preferable in my experience. Using gas has the benefits but also comes at the price of other equipment and of course the safety issues associated with compressed gas use.
Jose Pedro Canavate thanks alot.
Abhishek Mukherjee yeah, there are a lot of researchers said that NaHCO3 addition could reduce the cost of CO2 supply system, so I tought that instead of using purified CO2, I can just using NaHCO3 as inorganic carbon source.
Ali A. Al-Homaidan I want to reduce the cost so I prevent using CO2 cylinders..
Ned Murphy yep, I want to avoid to use compressed gas
Darwin Darwin When using sodium bicarbonate be aware of the stability fields of HCO3 vs CO2 which are controlled by pH. And make sure the microalgae are compatible with the pH range you are going to work in. Then practice managing the ecosystem.
Good luck.
Ned Murphy thank you. So, it means that we have to control the pH within the range that microalgae can survive?
Yes. Patience will be a good tool. And some reading to make sure the environment you will make is the environment you are going to want, or at least the environment your culture will want.