## 3 Results and Discussion
### Environmental Feasibility  
It is necessary to consider factors that may limit the applicability of certain processes, such as the availability and characteristics of the terrain, as well as environmental and climatic aspects. These analyses will make it possible to guarantee that the proposed photocatalytic system is viable from a sustainable and safe point of view for the environment where it will be implemented [83]. The application of magnetite-based photocatalysts to treat persistent wastewater is very promising for safeguarding environmental integrity [84]. The BF-5 proposed in this study is distinguished by its magnetic properties, high photocatalytic activity against pollutants in the wine and pisco industry, and its narrow band gap that allows it to be activated with solar irradiation and biocompatibility. According to what [PERSON] et al. [85] suggest, one key advantage of Fe\({}_{3}\)O\({}_{4}\)-based photocatalysts is their ease of recovery, significantly reducing the generation of secondary pollutants during treatment processes. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Description** & **Cost \({}^{*}\) (USD/h)** & **Cost \({}^{*}\) (USD/h)** \\  & **Solvothermal** & **Hydrothermal** \\ \hline A photocatalytic system with a solar CPC reactor, & & \\ includes a hydraulic pump (USD 6807 \({}^{\text{a}}\), service life & 0.218 & 0.218 \\
15 years) & & \\ High gradient magnetic separator, operates 1 h/day & & \\ (USD 68.98, service life 15 years) & & \\ Wastewater feeding system, considering hydraulic & & \\ passage pump and PVC pipes & (USD 96.26, service life—5 years) & 0.009 & 0.009 \\ Energy cost (step pumps and CPC system) & 0.004 & 0.004 \\ Labor \({}^{\text{b}}\), considers system operation and & & \\ maintenance. & 2.900 & 2.900 \\ Raw material \({}^{\text{c}}\) & 13.044 & 1.100 \\ \hline Total (USD/hour) & 16.178 & 4.234 \\ \hline \hline \end{tabular} \({}^{*}\): Calculation based on the estimated cost for 8 h/day, 5 days/week, and 52 weeks/year. a: Chilean peso to US dollar conversion (accessed on 23 August 2024). b: Cost estimation based on the labor rate of technical operators, Chile 2024. c: Estimation of the cost of materials for synthesizing BiOI/Fe\({}_{3}\)O\({}_{4}\). Based on the price of quotations for 2024 in Chilean companies.  
\end{table} 
Table 3: Costs associated with BiOI/Fe\({}_{3}\)O\({}_{4}\) pilot scaling for use in wastewater remediation from a small Pisco industry. It is considered to operate 0.04 m\({}^{3}\) of LIW in the system from 12 to 3 p.m. (180 min), where the greatest solar irradiance is concentrated. In this study, the integration of solar energy was evaluated by the availability of solar irradiation in Pisco Endemico throughout the year (Figure 14) and the classification of the photocatalyst as a substance, so that its use does not represent an environmental or health risk according to domestic and international legislation [86], essential information for the viability of projects seeking environmental sustainability. The light that actually reaches ground level depends on different parameters, such as weather conditions, latitude, and time of day. At the study site, located in the north of Chile, the solar exposure has the highest solar energy potential in the world [87], mainly between 12 and 3 pm (GTM -4). The CPC reactor (Figure 13) will be installed on a platform inclined at 30\({}^{\circ}\), at the latitude of the Coquimbo region, forming an acceptance angle of 90\({}^{\circ}\) to capture incident solar irradiance on the reactor surface for maximum efficiency. The main advantage of CPC is the ability to concentrate both the direct and a large part of the diffuse radiation that impinges on the acceptance angle (\(\theta\)) [88]. Regarding the dangerousness of the substances used in the synthesis of BF-5, bismuth (Bi) is an element of great interest in the synthesis of advanced photocatalysts due to its semiconductor properties, photocatalytic activity under visible light, and the fact it is biocompatible and non-toxic at low concentrations [89].