The effects of three different influent strategies on the protein content of extracellular polymeric substances(EPS)were investigated to assess their impact on sludge retention capacity of the CANON process. R1was operated under conventional influent strategy as the control group, while R2 and R3 were subjected to different variable influent strategies. After 90 days of operation, the SVI values in R1, R2, and R3 were 62.93, 53.10, and 57.59mL/g respectively indicating that the variable influent strategies could improve sludge settleability. The PN/PS ratios were significantly higher in R2(8.21)and R3(7.61)compared to R1(5.56). Three-dimensional fluorescence analysis revealed that the proportion of aromatic proteins in TB-EPS was highest in R2(32.47%), much higher than in R1(11.58%)and R3(10.5%). This indicated that the variable influent strategy promoted the formation of aromatic proteins in TB-EPS, enhancing the hydrophobicity of the sludge and improving settleability. The specific anaerobic ammonium oxidation activity(SAA)increased to 4.03, 4.68 and 4.36mg N/(g VSS· h)in R1, R2, and R3, respectively. Notably, the SAA in R2 and R3 exceeded that of the seed sludge, indicating the successful formation of mature CANON granular sludge. Although microbial activity in R2 and R3 was initially inhibited by loading fluctuations during early operation, the microbial communities gradually adapted to environmental fluctuations and regained stable metabolic activity, successfully operating the CANON process on day 54 and day 51, respectively. Total nitrogen removal efficiencies reached approximately 72.54%, 70.14%, and 73.75% in R1, R2 and R3 by day 90, demonstrating effective nitrogen removal performance.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |