# The Influence of Spent Portable Battery Waste on the Aquatic Environment
## 3 Results  
### Solution Analysis  
During the stagnation of the batteries in the solutions, superficial corrosion of the case occurred. No deep damage or destruction of the case was observed, regardless of the type of battery used or the immersion solution. According to the graph in Figure 1, it can be seen that the batteries immersed in the alkaline medium suffered the greatest mass losses: A3 (2.08%), B3 (1.59%), C3 (1.64%), followed by the acid solution and rainwater. The lowest mass losses were observed for batteries immersed in a pH 5.63 solution (rainwater). Here, the lowest loss was for battery C (0.29%). Battery A shows the highest mass loss in the case of all three pHs of the contact solutions. The highest value is recorded for battery A in the basic solution (2.08%), followed by battery A in the acidic solution (1.98%). \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{\
\begin{tabular}{c} **Heavy** \\ **Metals** \\ \end{tabular} } & \multirow{2}{*}{
\begin{tabular}{c} **Unit of** \\ **Measurement** \\ \end{tabular} } & \multicolumn{5}{c}{**Quality Classes *} \\ \cline{3-6}  & & **Class I** & **Class II** & **Class III** & **Class IV** & **Class V** \\ \hline Cu & \(\mu\)g L\({}^{-1}\) & 20 & 30 & 50 & 100 & \(>\)100 \\ \hline Pb & \(\mu\)g L\({}^{-1}\) & 5 & 10 & 25 & 50 & \(>\)50 \\ \hline Zn & \(\mu\)g L\({}^{-1}\) & 100 & 200 & 500 & 1000 & \(>\)1000 \\ \hline Ni & \(\mu\)g L\({}^{-1}\) & 10 & 25 & 50 & 100 & \(>\)100 \\ \hline Fe & mg L\({}^{-1}\) & 0.3 & 0.5 & 1 & 2 & \(>\)2 \\ \hline Mn & mg L\({}^{-1}\) & 0.05 & 0.1 & 0.3 & 1 & \(>\)1 \\ \hline Cd & \(\mu\)g L\({}^{-1}\) & 0.5 & 1 & 2 & 5 & \(>\)5 \\ \hline \hline \end{tabular}  
* Class I—very good; class II—good; class III—moderate; class IV—weak; class V—very bad.  
\end{table} 
Table 4: Classification of metals in quality classes according to Order no. 161/2006 [43]. 3.1.1. Chromatic Changes in Contact Solutions  
In the first week of the experiment, a slight yellowish coloration of the solutions was observed, especially in the acidic and alkaline ones. A greater accentuation of this color toward yellow-brown was found in batteries A and B immersed in the solution with pH 4 but also in those in the alkaline solution (pH 8.00), in which case the solution was almost brown. The light brown coloration also occurred for the solutions with pH = 4.00 in the immersed C batteries. The solutions with pH 4.00 and pH 8.00 started even in the second week to change their aspect into a yellow-light rust color. After 4 weeks, the solution with pH 5.63 started to color, too, into the same chromatic. In the last week of the experiment, the color of the solutions was more accentuated, especially in the containers with acid and alkaline solutions. Moderate staining was observed for those solutions with a pH of 5.63. The strongest colored solution was the alkaline one with B batteries. Exceptionally, the acidic solutions with immersed B batteries had no more accentuated coloration compared to the first part of the contact period, keeping their brown color. At the end of the period of battery contact with solutions, the acid and alkaline media were the most reactive with the surface of the immersed batteries, leading to the intense coloration of the solutions. The solution with pH 5.63 was yellow-brown for all three types of batteries, and in the case of C batteries, the color of the solution remained slightly yellowish. At the end of contact, the batteries showed visible changes in the surface layer, highlighting areas of corrosion, especially on the metal and inscriptions cover. During the test, this trend intensified the color; thus, at the end of the test, the acidic and alkaline solutions had a rusty color and the solution with pH 5.63 had a light brown aspect. It is possible that this coloring was also influenced by the initial colors on the batteries, which is why it is considered not relevant for the intended purpose.