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Evaluation of Two Commercial Microbial Inocula as Seed in a 5‐Day Biochemical Oxygen Demand Test
Author(s) -
Paixão S.M.,
BaetaHall L.,
Anselmo A.M.
Publication year - 2000
Publication title -
water environment research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.356
H-Index - 73
eISSN - 1554-7531
pISSN - 1061-4303
DOI - 10.2175/106143000x137491
Subject(s) - biochemical oxygen demand , effluent , dilution , activated sludge , chemical oxygen demand , chemistry , correlation coefficient , food science , wastewater , mathematics , environmental engineering , environmental science , statistics , physics , thermodynamics
The use of two commercial microbial inocula (Bi–Chem and Biolen M112) as reference organisms for the 5‐day biochemical oxygen demand (BOD 5 ) test was studied using both dilution and manometric methods with the standard glucose–glutamic acid solution. A comparative study was carried out performing this test for several real effluent samples with the two commercial inocula and with a treatment plant inoculum. The microbiological characterization of these inocula was performed with the API identification system (bioMérieux S.A., France). The results obtained for the BOD 5 of the standard solution are within the range for activated sludge as found in the standards of the cited methods (mean values obtained were BOD 5 = 199.4 mg/L O 2 [variation coefficient, VC = 4.52%] and BOD 5 = 176.8 mg/L O 2 [VC = 4.66%] for the Bi–Chem inoculum and BOD 5 = 209.8 mg/L O 2 [VC = 7.35%] and BOD 5 = 228.6 mg/L O 2 [VC = 9.37%] for the Biolen M112 inoculum, with the dilution and manometric methods, respectively). Moreover, Pearson rank correlation analysis for the real effluent samples indicates that correlations between the BOD 5 values for the two commercial inocula and for the treatment plant inoculum were highly significant to 95% confidence ( r 2 = 0.922 to 1.00, p < 0.05).