## 2 Materials and Methods  
* _Location and design of experiment_ The research conducted in 2023 in the Kalecik District of Ankara investigated the impact of wastewater on aromatic compounds in two different pepper varieties. Soil analysis was performed at the Ankara University Soil Science and Plant Nutrition Department Laboratory. Soil analysis results showed that the soil structure was clayey, slightly alkaline, non-saline, moderately rich in organic matter, and had a high lime content (Table 1). The experiment employed irrigation water from the Kalecik Wastewater Treatment Plant, which has a daily capacity of 2500 m\({}^{3}\). Table 2 presents the analysis results. Table 3 shows that the amount of Cd, Pb, Ni, Co, and Mn in the wastewater used in our study is below the limit values for use as irrigation water according to the Permissible limits by the Food and Agriculture Organization [43]. \(\bullet\) _Plant and water materials_  
The research utilized two varieties of capia pepper, _Capsicum annuum_ L. _cv. Capia cvs. Amfora_ and _cvs. Yalova Yaglik_. The pepper seedlings were planted with a row spacing \begin{table}
\begin{tabular}{c c c} \hline
**Depth (cm)** & **0–30** & **30–60** \\ \hline
**Texture** & Clay & Clay \\ \hline
**Sand (\%)** & 28.10817 & 24.07214 \\ \hline
**Silt (\%)** & 24.90601 & 22.94990 \\ \hline
**Clay (\%)** & 46.98581 & 49.97796 \\ \hline
**Clay + silt (\%)** & 71.89183 & 72.92786 \\ \hline
**OM (\%)** & 3.16 & 2.53 \\ \hline
**CaCO\({}_{3}\)** & 22.78 & 19.88 \\ \hline pH & 8.44 & 8.63 \\ \hline
**EC (dS m\({}^{-1}\))** & 0.397 & 0.439 \\ \hline \end{tabular}
\end{table} 
Table 1: Soil characteristics of the trial parcels (Kalecik, Ankara, Türkiye). \begin{table}
\begin{tabular}{c c c c c} \hline
**Wastewater (WW)** & & & **Municipal Water (MW)** & \\
**Analysis Parameters** & **WW1** & **WW2** & **Analysis Parameters** & **MW** \\ \hline
**pH** & 7.5 & 7.1 & Turbidity (NTU) & 0.30 \\ \hline Total hardness (CaCO\({}_{3}\)) (mg L\({}^{-1}\)) & 341.00 & 307.00 & Chlorine (mg L\({}^{-1}\)) & 0.20 \\ \hline Conductibility (EC) (25 \({}^{\circ}\)C, mS m\({}^{-1}\)) & 124.7 & 90.3 & Conductibility (EC) (25 \({}^{\circ}\)C, mS m\({}^{-1}\)) & 57.0 \\ \hline Total suspended solid matter (TSS) (mg L\({}^{-1}\)) & 451 & \textless{}10 & Ammonium (mg L\({}^{-1}\)) & \textless{}0.06 \\ \hline Total dissolved solids (TDS) (mg L\({}^{-1}\)) & 8119 & 9247 & Nitrite (mg L\({}^{-1}\)) & \textless{}0.006 \\ \hline K (mg L\({}^{-1}\)) & 13.2 & 13.1 & SO\({}_{4}\) (mg L\({}^{-1}\)) & 47.1 \\ \hline Na (mg L\({}^{-1}\)) & 108.0 & 111.00 & \\ \hline SO\({}_{4}\) (mg L\({}^{-1}\)) & 73.1 & 81.30 & \\ \hline Total N (T-N) (mg L\({}^{-1}\)) & 53.20 & 21.40 & \\ \hline Total P (T–P) (mg L\({}^{-1}\)) & 0.88 & 0.93 & \\ \hline \end{tabular}
\end{table} 
Table 2: Water utilized in the research conducted in Kalecik, Ankara, Türkiye. \begin{table}
\begin{tabular}{c c c c c c} \hline  & & & \multicolumn{4}{c}{**Heavy Metals**} \\ \hline
**Irrigation Water** & **Cd** & **Pb** & **Ni** & **Co** & **Mn** \\ \hline WW1 & 0.82 & 2.24 & 3.44 & 0.65 & 31.26 \\ \hline WW2 & 0.24 & 0.50 & 1.67 & 0.37 & 2.60 \\ \hline Threshold values, [40] & 10 & 5000 & 200 & 50 & 200 \\ \hline WW1, Physical treatments; WW2, Physical + biological treatment. & & & & \\ \end{tabular}
\end{table} 
Table 3: Heavy metal content of treated wastewater used in the study (mg L\({}^{-1}\)). of 35 cm and 35 cm between rows. The experiment had three replications in a randomized complete block design, considering edge effects. Fifteen plants were grown in each replication, and three different irrigation waters were applied:  
* Primary treated wastewater (physical treatment) (WW1). * Secondary treated wastewater (physical + biological treatment) (WW2) obtained from the Ankara Kalecik Wastewater Treatment Plant. * Tap water (MW). The research was conducted in a region influenced by a continental climate. Hot and dry conditions characterize summers, while winters are cold and rainy, resulting in a high demand for water during the summer months.