## 3 Results
### Material Flow Analysis
Water content is critical in this step since it adds excess weight if not adjusted correctly in the previous process, leading to discarding compostable materials as residue. The fact that the exiting material is collected by its size and gravimetric properties and not its chemical characteristics is advantageous. It provides optimal mechanical characteristics on the collected materials, although it does not prevent the infiltration of unwanted dissolved chemicals such as heavy metals. The collected materials have TS (75.03%), vs. (75.4) of TS, and 19.3% TS carbon of biogenic origin. The rejected material of the process consists of bulky and non-compostable materials. The same principle is followed for the transfer coefficients of the refinery process, and the above assumptions allow experimentation with variations of composition with the same system, providing a handy tool for further research. The material that continues to the final composting/maturation stage has a homogenous texture; the origin fractions are hard to recognize, only some paper-like remains, and some wood fraction with particle size lower than 10 mm are notable. The total vs. is high (69%). The material is accounted as concentrated biodegradable fraction, which justifies the intense composting stage, followed by a prolonged maturation state (composting windows). It must be stated that open-window composting can be challenging owing to variable weather conditions that advance or delay the composting process. Intensive mechanical mixing and constant window temperature monitoring which occurs once a week during this process minimize the number of anaerobic pockets in the composting mass. However, it is reasonable to assume that an inevitable release of CH\({}_{4}\) occurs. Hence, adopting the lowest emissions values, 0.8-2.5% of degraded C is released as CH\({}_{4}\), which seems reasonable [11]. Concerning nitrogen-based GHG, [60] stated that there is no production of N\({}_{2}\)O during the thermophilic phase since autotrophic nitrifier activity ceases above 40 \({}^{\circ}\)C. Since the maturation phase is considered a continuation of the primary composting process, GHG production is only scarce at the final stages of the process. For this reason, 0.1-0.7% of degrading N is accounted to transform to N\({}_{2}\)O. Mixing and water addition \begin{table}
\begin{tabular}{l l} \hline \hline
**Fraction** & **Transfer Coefficients (\%)** \\ \hline Biowaste & 45 \\ Paper & 60 \\ Cardboard & 100 \\ Green waste & 5 \\ Soft plastic (PE) & 2 \\ Hard plastic (PP) & 1 \\ Non-recyclable plastic & 1 \\ Other materials & 0 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Refinery process transfer coefficients total mass (%\(w/w\)) for open window composting and maturation. ensure a partially controlled maturation elongating to six or nine months until the desired physicochemical characteristics are reached. The quality of MSW compost is dependent on many parameters, including the composting facility design, feedstock source and proportions used, composting procedure, and duration of maturation [61]. The maturation typically requires minor active management. It is a crucial final stage that facilitates the conversion of potentially toxic NH\({}_{4}\) to NO\({}_{3}\), allows the loss of phytotoxic volatile compounds, and stabilizes the microbial community. At this state, mesophilic fungi and actinomycetes colonize the compost, which is thought to be responsible for the breakdown and transformation of humic substances and lignin. Although, maturation is a vital stage frequently given insufficient time, or is even missed out altogether, to save space and increase the throughput of composting plants. In this case study, the corresponding sub-process can be chronically adjusted depending on the aiming physicochemical characteristics of the final product. The average decomposition rate is calculated to be 75% of the total volatile solids of the initial material.