## 3 Results and Discussion
Nevertheless, the environmental effect was not satisfied. It was also observed that the loss of chlorides in the environment depended on the time of culture. \begin{table}
\begin{tabular}{c c c|c c} \hline
**IUPAC PCB Name** & \multicolumn{2}{c|}{**SRB**} & \multicolumn{2}{c}{**DB**} \\ \hline  & **Concentration after** & & **Concentration after** & \\  & **Process [ppm]** & & **Process [ppm]** & **Degradation [\%]** \\ \hline
2,6-CB (10) & 198.4 & 46.12 & 209.10 & 43.21 \\
2,4,4\({}^{\prime}\)-CB (28) & 447.90 & 35.18 & 413.4 & 40.17 \\
2,2\({}^{\prime}\),5,5’-CB (52) & 96.90 & 21.71 & 102.50 & 17.21 \\
2,2\({}^{\prime}\),4,4\({}^{\prime}\),5,5’-CB (138) & 14.50 & 15.20 & 11.90 & 30.41 \\
2,2\({}^{\prime}\),3,4,4\({}^{\prime}\),5-CB (153) & 32.30 & 65.16 & 43.40 & 53.18 \\
2,2\({}^{\prime}\),3,4,4\({}^{\prime}\),5,5’-CB (180) & 39.90 & 70.29 & 32.00 & 76.17 \\ \hline \end{tabular}
\end{table} 
Table 3: The degradation of chosen PCB congeners. There was also a difference in the loss of chloride ions depending on the medium used. The amount of chloride loss in medium B, which was tap water, was lower than in medium A, which contained mineral salts. This difference is appreciable for the samples with a chloride concentration of 100 mg/dm\({}^{3}\). The chloride degradation level in the samples where the initial chloride concentrations were 200 mg/dm\({}^{3}\) and 300 mg/dm\({}^{3}\) can be described as imperceptible. A slight change was visible for the samples from week 3. The loss of chloride ions was more effective with the mineral medium A than in the samples containing water. A greater efficiency of chloride removal with the use of a commercial mixture in a medium with mineral salts may indicate good nutritional conditions, as well as more favourable conditions affecting the viability of microorganisms, which translates into a better and more effective degradation of compounds containing chlorine compounds in an aquatic environment. The effect of the chloride ion concentration changes suggested that they could be calculated by a linear function. The model is described with the equations presented in Table 5. The high value of the correlation coefficients R\({}^{2}\) (Table 5) confirmed the proper use of the linear functions in the model description. The final effect of the study resulted from the inclusion of chloride ions in the metabolic pathways of microorganisms. The chloride ions could be the electron donors, while the minerals included in the aquatic media were the electron acceptors. The redox reactions which appeared in the environment determined the microorganisms' opportunity to eliminate chlorides. It is also well known that chlorine and its ions are used as the components of disinfection products that stop the physiological functions of microorganisms. This is a reason for the low environmental effect of chlorides moving from the aquatic media. The commercial mixture of microorganisms BIOACTIV PH is intended for the degradation of compounds such as phenols, formalin, benzene, chloroethane, and chlorinated hydrocarbons. It is mainly used in the chemical, petrochemical, and cooking industries. \begin{table}
\begin{tabular}{c c c c c} \hline \multirow{2}{*}{**Medium**} & \multirow{2}{*}{**CI\({}^{-}\) [mg/dm\({}^{3}\)]**} & \multicolumn{4}{c}{**Chlorides Decrease [\%]**} \\ \cline{3-5}  & & **1 st Week** & **2 nd Week** & **3 rd Week** \\ \hline \multirow{3}{*}{A} & 100 & 4.88 & 10.98 & 15.85 \\  & 200 & 1.04 & 3.13 & 4.69 \\  & 300 & 0.67 & 1.68 & 2.17 \\ \hline \multirow{3}{*}{B} & 100 & 4.83 & 9.20 & 13.79 \\  & 200 & 1.03 & 2.05 & 2.56 \\ \cline{1-1}  & 300 & 1.01 & 1.68 & 2.36 \\ \hline \end{tabular}
\end{table} 
Table 4: The chloride ion movement during the process of biodegradation. Figure 1: The decrease in chloride ion concentration: (1) 100 mg/L; (2) 200 mg/L; (3) 300 mg/L after 21 days of cultivation by commercial mixture BIOACTIV PH. However, the presented study proved its opportunity to remove chloride compounds in an aquatic environment.