Biodegradable additives are additives that improve the biodegradation of the polymers by letting microorganisms to utilize the carbon within the polymer chain itself.
Biodegradable additives attract microorganisms to the polymer through quorum sensing after biofilm creation on the plastic product. Additives such as Bio degradable, antistatic, stabilizer and etc… usually can be used in masterbatch that use carrier resins such as polyethylene, polypropylene, polystyrene or polyethylene terephthalate.
Chemical equation of the process is:
C6H12O6 → 3CO2 + 3CH4
Definition of this process is as follows – most of the time, plastic is made up of hydrophobic polymers. Chains should be broken down into constituent parts for the energy potential to be used by microorganisms. These constituent parts, or monomers, are readily available to other bacteria. The process of breaking chains and dissolving the smaller molecules into solution is called hydrolysis. For that reason, hydrolysis of these high-molecular-weight polymeric components is the necessary first step in anaerobic biodegradation. Through hydrolysis, the complex organic molecules are broken down into simple sugars, amino acids, and fatty acids.
Acetate and hydrogen firstly was created , can be used directly by methanogens. Other molecules, such as volatile fatty acids (VFAs) with a chain length greater than that of acetate must first be catabolised into compounds that can be directly used by methanogens.
The biological process of acidogenesis results in further breakdown of the remaining components by acidogenic (fermentative) bacteria. Here, VFAs are made, along with ammonia, carbon dioxide, and hydrogen sulfide, as well as other by products. The process of acidogenesis is like to the way milk sours.
The third stage of anaerobic digestion is acetogenesis. Simple molecules created through the acidogenesis phase are more digested by Acetogens to produce largely acetic acid, as well as carbon dioxide and hydrogen.
The terminal stage of anaerobic biodegradation is the biological process of methanogenesis. Methanogens use the intermediate products of the preceding stages and convert them into methane, carbon dioxide, and water. These components make up the majority of the biogas emitted.
Methanogenesis is sensitive to both high and low PHs and happens between pH 6.5 and pH 8. The lasting amount, indigestible material the microbes is not able to use any dead bacterial remains constitute the digestate.