Uronema nigricans
[ref. ID; 6011]
Test system
Acute toxicity (24-hr LC50)
Strains
From the aeration tank of activated sludge works designated for the treatment of domestic wastes in the district of Reggio Emilia, northern Italy.
Toxicants
Hydrated cadmium chloride, hydrated copper chloride, zinc chloride, mercury chloride.
Test design
Costar tissue culture plates with 24 wells were employed. Two replicates of 12 organisms each were run of each test concentration.
Evaluations
LC50 using the probit method.
[ref. ID; 6092]
Test system
Indirect effects of Chlorinated Wastewater on bacteriovorous ciliate growth
Test design
- Laboratory test: 26 degrees C, triplicate.
Food: chlorinated Escherichia coli (ATCC strain 25922), irradiated E. coli (ATCC strain 25922), live Pseudomonas sp. (strain 244), and irradiated Pseudomonas sp. (strain 244).
- Field test (only bacterial suviving):
Sampling station of Chlorinated wastewater: The Moores Creek Sewage Treatment Plant in Charlottesville, VA, USA (40 m upstream of the effluent source, 20 m downstream, 60 m downstream, and in a chlorine contact basin).
Measurements
- Laboratory test: Direct cell counts using light microscopy.
- Field test: Acridine orange direct count method using epifluorescent Zeiss microscope and cytochrome activity.
Evaluation
- Laboratory test: F-test was performed using slopes of exponential growth portions of growth curves, followed by a sequential variant of the Q test (Snedecor & Cochran, 1967) for least significant differences.
- Field test: One-way analysis of variance (ANOVA) and the Q method.