Comparison of bioluminescence and nitrification inhibition methods for assessing toxicity to municipal activated sludge.
The aim of this study was to compare two alternative toxicity assessment methods to determine wastewater toxicity and predict treatment plant process upsets. The toxicity of two synthetic organic compounds (triclosan and 4-n-nonylphenol), which are commonly detected in municipal wastewater, and municipal and industrial wastewaters with different heavy metals content were evaluated by the nitrification inhibition assay and bioluminescence toxicity test. Comparison between both assays confirmed that Vibrio fischeri is generally more sensitive than autotrophic bacteria, and, if not calibrated, the bioluminescence method tends to overestimate toxic effects on activated sludge biomass. The nitrification inhibition assay appears to predict plant process upsets more accurately. Both methods showed a significant toxicity decrease through treatment that could be partially attributed to the significant heavy metals removal obtained by primary and secondary treatment. A good correlation for the two assays was obtained, as indicated by a high correlation coefficient (r2 = 0.80).
Mamais
Daniel
D
Department of Water Resources, Hydraulic and Maritime Engineering, Faculty of Civil Engineering, National Technical University of Athens, Greece. mamais@central.ntua.gr
Noutsopoulos
Constantinos
C
Stasinakis
Athanasios S
AS
Kouris
Nikolaos
N
Andreadakis
Andreas D
AD
D048908:Aliivibrio fischeri / Q000187:drug effects*; D018533:Biomass; D049449:Luminescence; D009573:Nitrites / Q000737:chemistry*; D010636:Phenols / Q000633:toxicity; D012722:Sewage; D014260:Triclosan / Q000633:toxicity
D009573:Nitrites; D010636:Phenols; D012722:Sewage; D014260:Triclosan; C041594:4-nonylphenol