## 3 Results
### Nitrogen and Phosphorus  
The V1 groups showed no statistically significant differences in effluent TN. S2 SER1 (35\({}^{\circ}\)C) and S2 SER2 (55 \({}^{\circ}\)C) effluent contained 0.263 \(\pm\) 0.029 gTN/dm\({}^{3}\) and 0.273 \(\pm\) 0.027 gTN/dm\({}^{3}\), respectively, meaning that 48.5 \(\pm\) 3.7% and 49.2 \(\pm\) 5.2% of nitrogen was removed, respectively (Table 5). Conventionally heated reactors (S1) showed similar performance, with TN in the effluent ranging from 0.283 \(\pm\) 0.033 gTN/dm\({}^{3}\) (SER1) to 0.291 \(\pm\) 0.029 gTN/dm\({}^{3}\) (SER2) (Table 5). Effluent TN was positively correlated with the OLR. At loadings of 2.0 gCOD/m\({}^{3}\)-d, TN levels in the effluent were 0.351 \(\pm\) 0.026 gTN/dm\({}^{3}\) in S1 SER1 and 0.343 \(\pm\) 0.016 gTN/dm\({}^{3}\) in S1 SER2, which translated to TN removal rates of 31.5 \(\pm\) 5.0% and 34.3 \(\pm\) 3.2% (Table 5). Similar levels were observed for S2 effluent, with removal rates between 31.7 \(\pm\) 4.7% (S2 SER1) and 39.6 \(\pm\) 9.5% (S2 SER2) (Table 5). Subsequent variants featured diminishing TN removal rates. In V4, TN levels were 0.404 \(\pm\) 0.032 gTN/dm\({}^{3}\) in S1 SER1 and 0.401 \(\pm\) 0.030 gTN/dm\({}^{3}\) in S2 SER2, meaning that 21.1 \(\pm\) 6.3% and 21.5 \(\pm\) 4.2% of TN was removed, respectively (Table 5). The levels in S2 ranged from 0.386 \(\pm\) 0.034 gTN/dm\({}^{3}\) to 0.0389 \(\pm\) 0.022 gTN/dm\({}^{3}\), with removal rates of 24.0 \(\pm\) 6.7% in SER1 and 24.6 \(\pm\) 5.9% in SER2 (Table 5). Nitrogen levels in the reactor effluent peaked in V5 and V6, falling within the narrow range of 0.419 \(\pm\) 0.013 gTN/dm\({}^{3}\) to 0.470 \(\pm\) 0.032 gTN/dm\({}^{3}\) (Table 5). Removal performance was significantly worse in the 5.0 gCOD/dm\({}^{3}\)-d and 6.0 gCOD/dm\({}^{3}\)-d vari  
Figure 5: Daily (**a**) and specific (**b**) biogas output across experimental variants. Figure 6: CH\({}_{4}\) percentage content (**a**) and specific yields (**b**) across experimental variants. ants compared to the lower loadings. The poorest removal rate, reaching 8.1 \(\pm\) 5.4%, was noted in S1 SER1V6. SER2 (55 \({}^{\circ}\)C) performed slightly better, ensuring TN removal rate at 11.3 \(\pm\) 6.3% (Table 5). Among the V1 groups, effluent TP was the lowest in S2. The effluent from this MW-heated series was found to contain 0.068 \(\pm\) 0.006 gTP/dm\({}^{3}\) (SER1/35 \({}^{\circ}\)C) and 0.067 \(\pm\) 0.007 gTP/dm\({}^{3}\) (SER2/55 \({}^{\circ}\)C) (Table 5). This translated to almost 40% TP removal, regardless of anaerobic digestion temperature. S1 reactors managed to remove 30.2 \(\pm\) 8.3% of TP in SER1 and 35.8 \(\pm\) 4.3% of TP in SER2 (Table 5). At OLR = 2.0 gCOD/m\({}^{3}\) (V2), the final levels were 0.082 \(\pm\) 0.004 gTP/dm\({}^{3}\) in S1 SER1 and 0.075 \(\pm\) 0.005 gTP/dm\({}^{3}\) in S1 SER2, translating to 28.3 \(\pm\) 3.6% and 34.5 \(\pm\) 4.1% removal, respectively (Table 5). Significantly lower TP values were observed for S2, i.e., 0.074 \(\pm\) 0.003 gTP/dm\({}^{3}\) in SER1 and 0.069 \(\pm\) 0.003 gTP/dm\({}^{3}\) in SER2 (Table 5). Changing the heating method and temperature did not produce any statistically significant differences in effluent TP across V3 and V4, with phosphorus levels consistently hovering around 0.090 gTP/dm\({}^{3}\). TP in the digester effluent peaked at the highest OLRs.