## 4 Conclusions  
In conclusion, this research aimed to investigate the impact of wastewater irrigation on aromatic compounds in two varieties of capia peppers in the Kalecik District of Ankara. With the increase in the global population and an accompanying six-fold increase in global water demand over the past century, the sustainable management of water resources, particularly in agriculture, has become a critical concern. The research examined the crucial role of water in agriculture, particularly in Turkiye, the fourth largest producer of fresh vegetables worldwide. It analyzed the aromatic compounds of the capia pepper, a widely used vegetable in the food industry. It is worth noting that peppers, which belong to the Solanaceae family, are sensitive to soil and water conditions and therefore require careful irrigation practices. The research discusses the challenge of climate change and predicts that Turkiye will be one of the countries most affected by changes in water usage by 2070. The study investigates the potential of wastewater, specifically from the Kalecik Wastewater Treatment Plant, for sustainable agricultural practices. The research used a rigorous experimental design to investigate the effects of various irrigation waters, including primary and secondary treated wastewater and tap water, on the aromatic compounds of capia peppers. The results showed that using raw wastewater increased the Soluble Solid Content (SSC) levels, which affected the fruits' ripening time and harvest date. Wastewater irrigation had a statistically significant effect on the pH levels of both pepper varieties. Titratable acidity (TA) values varied among pepper varieties and irrigation water sources, providing insights into the impact of different water qualities on fruit acidity. Furthermore, the research found high total phenol values in plants irrigated with raw and treated waters, highlighting the correlation between wastewater irrigation and phenolic content. When the heavy metal data obtained from pepper fruits in our study were analyzed, WW1 resulted in the highest value of all heavy metals. This was followed by WW2 and MW, respectively. Therefore, it was determined that as the wastewater treatment level used as irrigation water decreases, the heavy metal content in the product increases. However, all heavy metal data obtained were below the permissible levels. Therefore, our study revealed that irrigation of capia-type peppers with wastewater is not objectionable regarding heavy metals. Wastewater must be analyzed before being used as irrigation water. The heavy metal content accumulated in the crop is directly related to the heavy metal content of the wastewater to be used as irrigation water. The research extended beyond conventional analyses by exploring the volatile aroma components through GC-MS, identifying 25 compounds, and highlighting variations in their levels based on pepper variety and irrigation water source. The research conducted an in-depth investigation into the effects of wastewater irrigation on the aromatic profile of capia peppers, revealing significant alterations in several key aroma components. Specifically, the study identified that para-dichlorbenzene, a compound known for its sharp and somewhat medicinal scent, exhibited noticeable changes under wastewater irrigation. Similarly, alpha-cubebene, which contributes a woody and spicy character to the peppers, showed a distinct shift in its concentration. The analysis also highlighted modifications in hexyl-hexanoate levels, a component that imparts a sweet and fruity aroma, enhancing the sensory appeal of capia peppers. Additionally, alpha-farnesene, which provides a green, citrus-like fragrance, was affected, suggesting an impact on the fresh and vibrant notes of the peppers. Limonene, another critical component recognized for its bright, lemony scent, experienced significant variations, potentially altering the overall aromatic balance.