## 5 Conclusions  
Bacterial protein toxins are secreted by foodborne pathogens and represent a significant threat to public health. These toxins can be present in various environments, such as food matrices or water, even after the microorganism has been destroyed after thermal or other processes. Moreover, they are large biomolecules that remain stable to chemical inactivation and are generally resistant to extreme conditions, such as low pH, freezing, and drying. All proteins form in aqueous solution ions, positively and negatively charged, which are carried by ionizable groups in the amino acid residues. The theoretical model presented in this study describes the removal of four specific bacterial toxins from water by drifting after the application of an electric field. Here, it should be mentioned that two basic assumptions were made: (a) the spherical shape of the toxins and (b) the solution contains only toxins in a low concentration. In this theoretical analysis, the solution is considered as containing only toxins in a low concentration in order to study the behavior of charged protein toxins under the influence of an electric field. The analysis evaluates whether there is primary evidence of drift based on this hypothesis (there are only toxins present) because there is also a possibility that no drift is observed due to their relatively large size. The outcome of the analysis revealed that not only can drift be observed, but also that almost complete purification of toxins can be achieved, even in the application of very low voltages. More specifically, the results presented in this study are very encouraging for the application of the above method as a future tool for the removal from aqueous solutions of bacterial toxins, such as the three _Staphylococcus aureus_ toxins, which have a total positive charge, and the Stx2 toxin of a STEC strain of _Escherichia coli_, which has a total negative charge and is much larger than the other three since it is an AB\({}_{5}\) hexamer. For a duct width of 1 cm or less and for low applied potentials (0.1-0.4 V), a reduction up to 99% in the concentration of toxins was achieved in the main volume of the solution (which is the major part of the duct width) for target concentration \(56\times 10^{-9}\)\({}^{\text{mol}/\text{m}^{3}}\). Therefore, acceptable toxin concentrations can be achieved from solutions a hundred times more contaminated, and this makes the method applicable to pre-purified solutions and for small-scale water decontamination. In practice, of course, usually, the contaminated water may also contain other impurities, some of which are in ionic form (which create resistivity). Consequently, they will also be affected by the electric field and will move accordingly, some of them faster than the toxins, polarizing the electrodes [16; 17; 18] and preventing the drift of toxins. For this reason, purification of the contaminated water with other methods should have preceded in order to remove most of the pollutants. According to the theoretical analysis, the method can provide a solution to the removal of toxins from already purified solutions which have low concentrations of toxins but remain capable of causing harm to health and which cannot be removed by primary treatment. Due to the very encouraging results, a future study analyzing the drift of toxins in the presence of other ionic pollutants and with the application of higher voltages would contribute further to the development of an effective model.