# Demonstration of Wastewater Recycling in a Slaughterhouse
## 4 Conclusions  
The recycling of SWW was demonstrated. At the end of the monitoring phase, steady-state operation was achieved, demonstrating the feasibility of transferring research results into practical applications. The system is capable of treating wastewater up to two quality levels, including drinking-water quality. In the process, 35% of the wastewater produced could be treated up to the standard for agricultural irrigation. A further 35% of the total wastewater could be purified to process-water quality, resulting in a significant reduction of 70% in wastewater discharge at the site. The energy consumption of the plant is high. However, even under non-optimal conditions, 4.1 kWh was required to produce 1 m\({}^{3}\) of irrigation water, and 5.2 kWh for 1 m\({}^{3}\) of process water. In the framework of this project, a wastewater recycling system was developed. The next step would involve scaling up the system. However, the legal feasibility of reusing slaughterhouse wastewater in different countries and its social acceptance remain open questions.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Process** & \
\begin{tabular}{c} **Electrical Energy** \\ **Consumption [kWh-m\({}^{-3}\)]** \\ \end{tabular} &
\begin{tabular}{c} **Theoretical Energy** \\ **Consumption [kWh-m\({}^{-3}\)]** \\ \end{tabular} \\ \hline Flotation & 0.3 & 0.03–0.3 [43; 44] \\ Membrane bioreactor & 3.8 & 0.4–4 [45; 46; 47; 48] \\ Reverse osmosis & 1.1 & 0.5–0.8 [49; 50] \\ \hline \hline \end{tabular}
\end{table}
Table 8: Energy consumption of each treatment process.  
**Author Contributions:** Conceptualization, S.-U.G. and M.P.; methodology, M.P.; validation, S.-U.G. and J.P.; formal analysis, S.-U.G. and J.P.; investigation, M.P.; data curation, M.P.; writing--original draft preparation, M.P.; writing--review and editing, M.P.; visualization, M.P.; supervision, S.-U.G.; project administration, S.-U.G.; funding acquisition, S.-U.G. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research was funded by the \"Bundesministerium fur Bildung und Forschung\" (BMBF) and \"The APC was funded by the Open-Access-Publikationsfonds of Universitatsbibliotheken TU Berlin und UUK Berlin\". The study was conducted as part of the SUSPIRE project funded by the \"Federal Ministry of Education and Research\" (BMBF) as part of the TUNGER 2+2 program.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** The raw data supporting the conclusions of this article will be made available by the authors on request.  
**Acknowledgments:** Our thanks go to the cooperating abattoir for the opportunity to operate the pilot plant on their premises. We would also like to thank Delta-Umwelt for the construction of the pilot plant. Thanks to the company Gebr. Becker GmbH for sponsoring a blower and to Rdolf Messner Umweltechnik AG for providing three of their aerator plates. Thanks to [PERSON] and [PERSON] for carrying out the necessary analyses. Further thanks go to [PERSON] and [PERSON] for the professional operation of the system during the monitoring period. We would also like to thank the CERTE team for carrying out the analyses in Tunisia. The authors acknowledge that AI tools, including DeepL (www.deepl.com, accessed on 5 February 2024) and OpenAI's language models, were utilized for grammatical corrections and language refinement. We acknowledge support by the Open Access Publication Fund of TU Berlin.  
**Conflicts of Interest:** The authors declare no conflicts of interest.