A Bioassay to Assess Wastewater Toxicity to Aerobic Biological Treatment.

摘要

The objective was to develop a bioassay for wastewater toxicity that could be used at sewage treatment plants. Nitrobacter was used as the test organism due to the simplicity of quantifying substrate removal rates by measuring nitrite removal, a sensitivity for most toxicants greater than that of heterotrophic organisms,and a slow growth rate which enables the use of batch-fed tests. A method was developed for preserving the Nitrobacter organisms by freeze-drying. Substrate removal rates were measured for both freeze-dried and non-freeze-dried Nitrobacter in the presence of a heavy metal and an organic toxicant. Zinc and 2,4,5-trichlorophenol exhibited toxic effects to the Nitrobacter at concentrations comparable to those toxic to activated sludge.