## 3 Results and Discussion  
### Thermal Behaviour of the Composting Sets  
The study of the temperature development during the composting process allows us to verify the evolution of the biological processes that enhance the reduction of pathogens in the compost [27]. Figure 3 shows the evolution of temperatures in the four processes studied. It can be observed that, in the initial phases of the process, temperatures higher than 60 \({}^{\circ}\)C were reached in practically all the composting sets in the first 2-3 process days. Similarly, during the first days of the process and until the maximum filling of the composter was reached (about 80% of composter capacity) (until process day 70, 60, and 52 for sets 2, 3, and 4, respectively), the temperature remained in thermophilic values (\(\leq\)40 \({}^{\circ}\)C) in all cases, except for set 1, which showed a higher variability in the thermal profile. [PERSON] et al. [28] also reported a rapid increase in the temperature in the first few days during the composting of food waste. However, throughout the processes, several drastic drops and rises in the temperature values of the composting sets were observed (Figure 3). The high temperatures reached in the processes diminished water content in the mixtures due to evaporation losses, reducing the microbial activity in the composting mass, with this being reflected in a temperature decrease. With water incorporation, the temperature increased due to the recovery of the process (blue points in Figure 3). Moreover, the transfer of the mass to the corresponding module (yellow lines in Figure 3) also implied a temperature increase, due to the homogenization and aeration of the mixture. The maximum temperatures observed in the composting sets were 73, 79, 78, and 77 \({}^{\circ}\)C for sets 1 to 4, respectively, with these values being higher than the optimal temperature range that ensures sanitization in the composting mass [27]. These temperatures were higher than those recorded in previous studies using similar wastes [1, 29] and were in line with those obtained by [PERSON] et al. [27] in a composting experiment using kitchen waste and [PERSON] et al. [30] in a study of composting of vegetable food waste with garden waste. In addition, the duration of the bio-oxidative phase of the composting sets was very long, lasting more than 130 days in all the sets, except for set 4, whose bio-oxidative stage lasted 89 days, probably due to this module managing the least amount of biowaste (674 kg, Table 4). However, the duration of the bio-oxidative phase, even in set 4, was similar to that observed by [PERSON] et al. [21] in a study with compost made from organic fraction collected separately from municipal waste mixed with urban pruning waste. Extended periods of thermophilic temperatures indicate a good evolution of the composting process [29]. In contrast, the duration of the bio-oxidative phase is significantly longer than that described in studies where the mixtures are inoculated with microorganisms [28]. Thus, all the four composing sets fulfilled the European Union requirements for the temporary duration of certain temperatures with the aim of ensuring compost sanitization [31] and maximum pathogen reduction [30]. \begin{table}
\begin{tabular}{l c c c c c c c c c} \hline \hline
**Samples** & **pH** & **EC** & **OM** & **TN** & **TOC** & **TOC/TN** & **Na** & **K** & **P** \\  & **dS\(\mathbf{=}\)1** & **dS\(\mathbf{=}\)1** & **(**s3**) & **(**s4**) & **(**s5**)** & **(**s6**)** & **(**s6**)** & **(**s6**)** & **(**s6**)** \\ \hline \hline \multicolumn{10}{c}{Set 1: 78\%-FVI + 21.5\%-CVI} \\ \hline M1 & 6.72 \(\pm\) 0.0 & 4.758 \(\pm\) 0.05 & 02.04 \(\pm\) 0.7 & 2.49 \(\pm\) 0.03 & 45.53 \(\pm\) 0.59  
In addition, the degree of exothermicity was assessed using the cumulative quadratic exothermicity index (EXI\({}^{2}\)) [32], which indicates the intensity of the bio-oxidative phase (Figure 3).