Figure 1.
![Nitrogen cycle in the environment [3]](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/64706f9983f1392090d697be/j_acee-2019-057_fig_001.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6AP2G7AKOUXAVR44%2F20251207%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20251207T083225Z&X-Amz-Expires=3600&X-Amz-Signature=b5ae12c1765e8cbd2a12c9ae0f312d5bdd44b13660b77c53cb2848f08038bfce&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Figure 2.
![Typical side stream deammonification (SD) application in a WWTP with activated sludge process [13]. SD: sidestream deammonification; RAS: return activated sludge; WAS: waste activated sludge](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/64706f9983f1392090d697be/j_acee-2019-057_fig_002.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6AP2G7AKOUXAVR44%2F20251207%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20251207T083225Z&X-Amz-Expires=3600&X-Amz-Signature=aefc11a97a8c2ef0f55c795686003ec4b0ab8efee4bd48d4c6c2addf687460d3&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Figure 3.
Figure 4.
![The principles of a DEMON® reactor activity [15]](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/64706f9983f1392090d697be/j_acee-2019-057_fig_004.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6AP2G7AKOUXAVR44%2F20251207%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20251207T083225Z&X-Amz-Expires=3600&X-Amz-Signature=22adc6eaa6be50424916c313a78fbafa3fe7fe42c81207a53a0ddbbbbde31532&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Comparison of N-NH4 + concentrations at the corresponding points of the technological cycle
| 2017 | 2018 | 2017 | 2018 | 2017 | 2018 | 2017 | 2018 | 2017 | 2018 | |
|---|---|---|---|---|---|---|---|---|---|---|
| Raw wastewater | Wastewater after sedimentation tank | Treated wastewater | Wastewater after sludge thickener | Effluent after centrifuge | ||||||
| Ammonium nitrogen [g N-NH4 +/m3] | ||||||||||
| January | 64.1 | 57.9 | 62.6 | 63.0 | 0.5 | 0.4 | 0.8 | 1.2 | 1006.0 | 1368.5 |
| February | 44.0 | 55.1 | 43.0 | 53.2 | 0.5 | 0.3 | 0.8 | 0.8 | 1079.5 | 1376.5 |
| March | 45.5 | 64.9 | 45.0 | 62.5 | 0.4 | 0.8 | 0.8 | 0.7 | 1153.0 | 1586.0 |
| April | 42.0 | 70.2 | 43.5 | 57.6 | 0.3 | 0.3 | 1.0 | 0.2 | 1189.5 | 1596.0 |
| May | 41.8 | 64.6 | 41.4 | 43.6 | 0.4 | 0.3 | 1.9 | 0.9 | 1093.0 | 1004.0 |
| June | 59.8 | 60.6 | 56.6 | 55.2 | 0.4 | 0.3 | 1.1 | 0.1 | 1187.5 | 988.0 |
| July | 59.4 | 62.7 | 46.7 | 58.3 | 0.3 | 0.5 | 1.8 | 1.2 | 1016.0 | 905.5 |
| August | 64.9 | 55.6 | 70.1 | 58.3 | 0.6 | 0.3 | 1.5 | 1.4 | 1013.0 | 937.0 |
| September | 54.5 | 68.1 | 41.5 | 60.8 | 0.2 | 0.3 | 0.9 | 0.3 | 1011.0 | 934.0 |
| October | 50.5 | 71.1 | 48.9 | 41.4 | 0.2 | 0.1 | 0.5 | 1.5 | 1054.5 | 910.0 |
| November | 55.8 | 69.9 | 48.5 | 70.1 | 0.4 | 0.0 | 1.2 | 0.2 | 1166.5 | 918.0 |
| December | 50.9 | 69.5 | 46.8 | 64.0 | 0.5 | 0.2 | 2.1 | 1.6 | 1306.5 | 602.0 |
| Average | 52.8 | 64.2 | 49.5 | 57.3 | 0.4 | 0.3 | 1.1 | 0.8 | 1106.3 | 1093.8 |
| Min. | 41.8 | 55.1 | 41.4 | 41.4 | 0.2 | 0.0 | 0.5 | 0.1 | 1006.0 | 602.0 |
| Max | 64.9 | 71.1 | 70.1 | 70.1 | 0.6 | 0.8 | 2.1 | 1.6 | 1306.5 | 1596.0 |
Efficiency of N-NH4 +removals
| 2017 | 2018 | 2017 | 2018 | 2017 | 2018 | 2017 | 2018 | 2017 | 2018 | |
|---|---|---|---|---|---|---|---|---|---|---|
| Raw wastewater | Effluent after centrifuge | Treated wastewater | % of N- NH4 + in total nitrogen | % of N- NH4 + reduction | ||||||
| Ammonium nitrogen [g N-NH4 +/d] | ||||||||||
| January | 1086.4 | 1159.5 | 206.7 | 265.3 | 8.1 | 8.3 | 19.0 | 22.9 | 99.3 | 99.3 |
| February | 861.7 | 986.7 | 218.5 | 246.5 | 8.8 | 6.0 | 25.4 | 24.9 | 98.9 | 99.4 |
| March | 1024.2 | 1156.2 | 230.3 | 279.9 | 8.7 | 13.9 | 22.5 | 24.2 | 99.2 | 98.8 |
| April | 1064.7 | 1294.4 | 190.2 | 349.5 | 6.2 | 4.7 | 17.9 | 27.0 | 99.4 | 99.6 |
| May | 956.7 | 1251.8 | 187.2 | 187.9 | 9.9 | 6.5 | 19.6 | 15.0 | 98.9 | 99.5 |
| June | 1172.6 | 1081.8 | 140.2 | 151.6 | 8.0 | 4.9 | 11.9 | 14.0 | 99.3 | 99.5 |
| July | 1104.9 | 1227.7 | 210.8 | 157.9 | 4.6 | 9.8 | 19.1 | 12.9 | 99.6 | 99.2 |
| August | 1175.7 | 928.1 | 230.5 | 183.3 | 9.9 | 4.2 | 19.6 | 19.8 | 99.2 | 99.5 |
| September | 1433.1 | 1275.1 | 226.3 | 161.1 | 5.7 | 4.8 | 15.8 | 12.6 | 99.6 | 99.6 |
| October | 1219.2 | 1264.6 | 232.7 | 173.1 | 5.4 | 1.4 | 19.1 | 13.7 | 99.6 | 99.9 |
| November | 1264.8 | 1208.8 | 204.8 | 176.2 | 9.7 | 0.3 | 16.2 | 14.6 | 99.2 | 99.9 |
| December | 1178.7 | 1433.2 | 226.6 | 97.2 | 10.6 | 4.9 | 19.2 | 6.8 | 99.1 | 99.7 |
| Average | 1128.6 | 1188.9 | 208.7 | 202.5 | 7.99 | 5.8 | 18.8 | 17.4 | 99.3 | 99.5 |
| Min. | 861.7 | 928.1 | 140.2 | 97.2 | 4.6 | 0.3 | 11.9 | 6.8 | 98.9 | 98.8 |
| Max | 1433.1 | 1433.2 | 232.7 | 349.3 | 10.6 | 13.9 | 25.4 | 27.0 | 99.6 | 99.9 |
Comparison of N-NH4 + loads at the corresponding points of the technological cycle
| 2017 | 2018 | 2017 | 2018 | 2017 | 2018 | 2017 | 2018 | 2017 | 2018 | |
|---|---|---|---|---|---|---|---|---|---|---|
| Raw wastewater | Wastewater after sedimentation tank | Treated wastewater | Wastewater after sludge thickener | Effluent after centrifuge | ||||||
| Ammonium nitrogen [g N-NH4 +/d] | ||||||||||
| January | 1086.4 | 1159.5 | 1060.1 | 1262.7 | 8.1 | 8.3 | 20.9 | 36.9 | 206.7 | 265.3 |
| February | 861.7 | 986.7 | 842.1 | 951.8 | 8.8 | 6.0 | 15.9 | 19.5 | 218.5 | 246.5 |
| March | 1024.2 | 1156.2 | 990.4 | 1113.4 | 8.7 | 13.9 | 16.4 | 21.5 | 230.3 | 279.9 |
| April | 1064.7 | 1294.4 | 1102.7 | 1062.1 | 6.2 | 4.7 | 22.0 | 4.6 | 190.2 | 349.5 |
| May | 956.7 | 1251.8 | 947.5 | 844.6 | 9.9 | 6.5 | 36.5 | 25.9 | 187.2 | 187.9 |
| June | 1172.6 | 1081.8 | 1109.9 | 986.2 | 8.0 | 4.9 | 19.5 | 3.0 | 140.2 | 151.6 |
| July | 1104.9 | 1227.7 | 867.8 | 1142.4 | 4.6 | 9.8 | 51.5 | 32.1 | 210.8 | 157.9 |
| August | 1175.7 | 928.1 | 1269.9 | 972.5 | 9.9 | 4.2 | 54.7 | 38.2 | 230.5 | 183.3 |
| September | 1433.1 | 1275.1 | 1089.9 | 1137.5 | 5.7 | 4.8 | 37.3 | 8.3 | 226.3 | 161.1 |
| October | 1219.2 | 1264.6 | 1180.6 | 738.8 | 5.4 | 1.4 | 18.9 | 50.7 | 232.7 | 173.1 |
| November | 1264.8 | 1208.8 | 1100.3 | 1211.4 | 9.8 | 0.3 | 47.9 | 5.1 | 204.8 | 176.2 |
| December | 1178.7 | 1433.2 | 1083.7 | 1319.7 | 10.6 | 4.9 | 86.4 | 25.7 | 226.6 | 97.19 |
| Average | 1128.6 | 1188.9 | 1053.6 | 1061.9 | 7.9 | 5.8 | 35.7 | 22.6 | 208.7 | 202.5 |
| Min. | 861.7 | 928.1 | 842.1 | 738.8 | 4.6 | 0.3 | 15.9 | 3.0 | 140.2 | 97.2 |
| Max | 1433.1 | 1433.2 | 1269.9 | 1319.7 | 10.6 | 13.9 | 86.4 | 50.7 | 232.7 | 349.5 |