During composting of bioplastic under aerobic conditions, there has to be an oxygen inlet. The microbes will use the oxygen to metabolize the bioplastic into carbon dioxide and water. What is the correct setup to estimate CO2 evolution during composting? How can we determine the amount of CO2 evolved? How to supply oxygen for the composting to be aerobic and then at the same time trap the carbon dioxide that is released? Like any kind of opening left for the incoming of oxygen will eventually lead to the escape carbon dioxide released during the process of composting.
Please guide.
Dear Disha Pamecha ,
You can perform a respirometry experiment. For this, you must set up two experiments. Assay 1: composting the bioplastic; Assay 2: respirometry. For this, you will need:
- Transparent glass jars (volume 1.5 to 5.0 L) with lid;
- 100 mL flask that can be positioned inside the glass jars;
- Sodium hydroxide (1N);
Barium chloride;
Chloridic acid (1N);
- 1% phenolphthalein.
For more information see:
Alef, K. Soil respiration. In: Alef, K., Nannipieri, P., 1995. Methods in Applied Soil Microbiology and Biochemistry. London: Academic Press, p.214-219.
There is solvita test of carbon dioxide which is used to track the composting process and identify when compost is stabilized based on carbon dioxide generation or burst. This might be useful for your studies.
Dear @Disha Pamecha.
To achieve your goal, you need to conduct an incubation experiment on your material. As I mentioned before, you must use respirometry. Set up the assay using 100 g of the material under study (for example, 100 g of the material that is in the compost pile), the control (another bottle containing the only bioplastic) and white (empty bottle containing a NaOH beaker). This type of trial generally lasts 28 to 35 days. And the CO2 readings captured in the NaOH are taken every 7 days. At the end of this period, you will have the courses of degradation of bioplastic and total daily or weekly CO2 evolved.
Please see:
https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0067353&type=printable
https://www.nature.com/articles/s41598-017-14803-0
https://www.tandfonline.com/doi/abs/10.1080/03601234.2019.1620043?journalCode=lesb20
This articles there is methodology detailed to respirometry assays.