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Table 1 Comparison of WWTP parameters at the different sample collection times a

From: Diversity and dynamics of Archaea in an activated sludge wastewater treatment plant

Parameterb, c, d May 03 - Aug 04e May 07f Dec 07g Comment
Temp b 15 ± 3 15 ± 1 11 ± 1 **  
SRT b 3 ± 1 3 ± 0 2 ± 0  
F/M b 0.008 ± 0.002 0.014 ± 0.004 ** 0.008 ± 0.002 Max value in May 2007
COD b 1058 ± 240 999 ± 194 1068 ±97±  
NO23-N b 48 ± 8 46 ± 9 42 ± 22 Min and max values in Dec 07
SSVI c 80 ± 15 54 79  
Effluent NSS c 23 ± 17 26 31  
  1. a The three periods were compared using the Kruskal-Wallis test. A statistically significant difference, p(same) < 0.05, is marked with asterisks (**). b Average values (± standard deviation) from all sample dates and the six days preceding the sample dates. c Data only from sample dates, not including the six preceding days. d The parameters are water temperature (Temp, °C), solids retention time (SRT, days), food to mass ratio (F/M, g/kg*s), COD going into the activated sludge tanks (COD, g/s), nitrite/nitrate levels going in to the activated sludge tanks (NO23-N, g/s), standardized sludge volume index (SSVI, ml/g) and effluent non-settleable solids (Effluent NSS, mg/l). e Samples collected during this period were used for T-RFLP analysis. f A sample collected during this period was used for T-RFLP and clone library analysis. g A sample collected during this period was used for FISH analysis.