## 3 Results  
### Infrared Spectroscopy Analysis  
The infrared spectra of the feedstock samples are reported in Figure 1, and their assignments are summarized in Table 2. \begin{table}
\begin{tabular}{c c} \hline \hline
**Wavenumber (cm\({}^{-1}\))** & **Band Assignments** \\ \hline
3700–3000 & H-OH groups of alcohols, phenols, and organicacids, as well as N–H \\  & groups of amides and amines \\
3000–2850 & C–H stretching in aliphatic structures \\  & C=C stretching in aromatics, \\
1650–1630 & C=O stretching in amides (I), \\  & C=O Stretching in ketone and quinone groups \\
1400 & C–H stretching in aliphatic structures \\  & Amide III, alphaticalcohols, or acids, C–O and O–H deformation of \\
1121 & carboxylic groups of carbohydrates, C–O stretch of arylethers, esters, \\  & and organo-sulphur compounds \\  & C–H vibration, \\
1060 & OH deformation in carboxyls, \\  & C–O of ethers on an aromatic ring \\  & N–H amides II \\  & \textless{}1000 & Vibrations of aromaticethers, polysaccharides (C–H vibration) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Assignments of the main vibrations of the infrared spectra. Figure 1: _Cont._Infrared spectroscopy was used in order to identify the functional groups present in the feedstock used. The common predominant peaks observed at 3400 cm\({}^{-1}\) indicate the hydrogen vibrations of alcoholic O-H, marking the presence of phenols, aromatic, polysaccharides, and saturated aliphatic species in all feedstock used [26]. Aliphatic methylene groups (C-H) were also detected between 2941 and 2892 cm\({}^{-1}\) in textile waste and paper and cardboard waste. The shoulder at 1631 cm\({}^{-1}\) in textile waste and in paper and cardboard waste indicates the formation of ketones, aldehydes, and carboxylic acid derivatives owing to the C=O stretching vibrations. Aromatic components in all feedstocks used were further detected via the peaks at 1400 cm\({  
1120 and 1111 cm\({}^{-1}\), respectively, for green waste and for paper and cardboard waste are attributed to the stretching of polysaccharide [27]. The peak at 1060 cm\({}^{-1}\) in textile waste characterizes primary alcohols, polysaccharides, aromatic ethers, and esters. C-H vibration was detected via the peak at 783 cm\({}^{-1}\), ascribed to aromatic ethers and polysaccharides [28]. Changes in Total Organic Carbon and Total Nitrogen Concentrations and the C/N Ratio during the Composting Process  
The initial value of total organic carbon (TOC) ranged between 32.64 \(\pm\) 1.50% and 43.96 \(\pm\) 0.90% (Table 3). During the composting, the amount of total organic carbon decreased to 22.23 \(\pm\) 0.92%, 23.57 \(\pm\) 1.39%, and 23.53 \(\pm\) 2.39% for mixes A, B, and C, respectively (Table 3). At the same time, the amount of total nitrogen increased to reach values at the end of treatment of 1.37 \(\pm\) 0.07%, 1.39 \(\pm\) 0.06%, and 1.10 \(\pm\) 0.14% for the mixtures A, B, and C, respectively (Table 3). Due to the nitrogen concentration increase and the decrease in organic carbon during composting, a decrease in the C/N ratio was observed. From the first weeks onward, a sharp decrease in the C/N ratio was observed: from 32.56 to 20.87, from 39.15 to 25.04, and from 58.29 to 30.42, respectively, for mixes A, B, and C (Table 3), reflecting sustained decomposition of organic matter. Consequently, it was found at the end of the treatment that the C/N ratios were 16.30, 16.96, and 21.39 for mixes A, B, and C, respectively, which proved that the compost was reaching the stage of maturity.