Dear Elvis Klaucans

You might have a look at:

Zakharova, L. Y., Pashirova, T. N., Doktorovova, S., Fernandes, A. R., Sanchez-Lopez, E., Silva, A. M., ... & Souto, E. B. (2019). Cationic surfactants: self-assembly, structure-activity correlation and their biological applications. International journal of molecular sciences, 20(22), 5534. Best regards.

All cationic surfactants kill bacteria. Therefore, biodegradation does not work well for all cationic surfactants. Other methods are needed. If all the same to discuss biodegradation, then it is necessary to present the mechanism of their interaction with the cell. At concentrations higher than CMC, surfactants totally destroy cell membranes. At low concentrations, surfactants penetrate cells and block the work of alcohol dehydrogenases. We have proved that the C9 cationic surfactant is equal in size to the length of the hydrophobic pocket of dehydrogenase and therefore their antimicrobial properties are an order of magnitude higher. Otherwise, their concentration for the destruction of bacteria is less.

https://www.researchgate.net/publication/299537375_Mirgorod_YuA_Mikhno_IL_Taran_VV_Test_of_bactericidal_activity_nonilizotiuronium_chloride_in_natural_conditions_Bulletin_of_the_Sumy1996_University1-13

Biodegradation occurs at low surfactant concentrations. Therefore, cationic surfactants with large anions, as in ionic liquids, can be biodegradable.

benzalkonium bromide is a cationic surfactant and phase transfer agent it is an active antimicrobial agent.