Table 1.

Quantification of enterovirus eluted by eight techniques from 16 samples of different types of sludgea

Sample or parameterEnterovirus concna
Technique 1Technique 2Technique 3Technique 4Technique 5Technique 6Technique 7Technique 8
PCRCulturePCRCulturePCRCulturePCRCulturePCRCulturePCRCulturePCRCulturePCRCulture
Primary sludge (3–4% dry matter)
 Sludge 113,44020<400112,448<3172,800<367,2005054,7201057,600<3<400<3
 Sludge 224,9609543,680352115,200159254,400154384,000434230,400326144,00035249,600136
 Sludge 3292,8001,067100,80098418,2401,201230,400696336,0001,744115,2002,242201,600400172,800850
Activated sludge (0.4–0.6% dry matter)
 Sludge 4<4001318,160<352,800<3<400<352,80048<40010725,440<347,040<3
 Sludge 5<400<3576644,800<3<400<3<4006014,400278<400<3<400<3
 Sludge 6<400<3<400<36,240<3<400<3576<35,664<3480<35,664<3
Thickened sludge (1.6–2.3% dry matter)
 Sludge 78,6409<4004518,24011<40021<4001014,400<3<400<3<40023
 Sludge 8<400<3<4001548,000<323,040<31,440<314,40072<400<3<400<3
 Sludge 9<400<3<400<33,888<310,080<352,800<3<400<3<400<360,480<3
Digested sludge (24–33% dry matter)
 Sludge 10127,000<3219,000<3<400<3<400<3173,000132<400<38,64084<40090
 Sludge 11<400<374,900<3<400<3<400<354,10011115,0005<400<3121,000<3
 Sludge 12115,0006<400<3<400<3<400<369,100<386,400<3<400<3<4008
 Sludge 13121,000<369,100<363,400<374,900<363,400<3156,000<374,900<3<400<3
 Sludge 1463,400<3<400<3<400<380,600<3115,000<3<400<3<400<374,900<3
 Sludge 15104,000<3<400<3<400<3<4006<400<374,900657,600<3<400<3
 Sludge 16144,00036184,000<3<400<34,490<3<400<3<400<3<400<3<400<3
Statistical ranking
 Samples 1 to 9
  Sum Rank3040.525.55150.537443353.551.54552.53524.540.534
  Rankb 2516745287683143
 Samples 10 to 16
  Sum Rank43.53434.526.51926.529.530.534.536373427.529.526.535
  Rankb NCc NCNCNCNCNCNCNCNCNCNCNCNCNCNCNC
 Samples 1 to 16
  Sum Rank73.574.56077.569.563.573.563.58887.58286.562.5546769
  Rankb NC 5NC6NC2NC2NC8NC7NC1NC4
  • a RT-PCR results are expressed in numbers of copies per 10 g (dry weight) (lower limit of detection, 400 copies/10 g [dry weight]), and cell culture results are expressed in MPNCU per 10 g (dry weight) (lower limit of detection, 3 MPNCU/10 g [dry weight]).

  • b Ranks were assigned by assigning the higher value to the better technique.

  • c NC, not classified (the critical probability corresponding to Friedman's test was greater than 5%).