Showing papers in "Water Research in 1968"

TL;DR: In this article, the toxicity of mixtures of the common industrial pollutants ammonia, phenol, zinc, copper, cadmium, lead, nickel, and hydrogen cyanide is estimated.

TL;DR: In this paper, fathead minnows (Pimephales promelas, Rafinesque) were exposed to copper sulfate for 11 months to find the fraction or percentage of the median tolerance limit that does not affect growth and reproduction under prolonged, continuous exposure.

TL;DR: In this paper, the sources of phosphorus to flowing waters are reviewed on the basis of point of origin and quantities, and the rate constant of assimilation can be estimated, which occurs in both autotrophic and saprophytic ecosystems.

TL;DR: Using tissue culture criteria it is concluded that one-tenth of the 96 hr TLm is a demonstrably safer concentration for determining maximum permissible concentrations than is the calculated biologically safe concentration.

TL;DR: The toxicity of soft alkyl benzene sulphonate (ABS) to rainbow trout which had been chronically exposed (100 days) to water containing 0·8 mg Zn/l was compared with its toxicity to untreated control fish.

TL;DR: Rainbow trout (Salmo gairdnerii Richardson) showed strong avoidance reactions to sub-lethal concentrations of zinc sulphate as mentioned in this paper, with threshold avoidance level 5.6 μg/l of zinc added to laboratory water.

TL;DR: Some pathological changes found in rainbow trout poisoned by phenol concentrations near the 48-hour median lethal concentration are described in this article, where the authors show that fish killed within a few hours revealed at autopsy gross changes which included inflammation and necrosis of the pharynx and gills, internal haemorrhages, with blood in the body cavity and swelling of the spleen.

TL;DR: A comparison of coliform data with salmonellae data gathered in stream surveys throughout the United States shows little apparent correlation between levels of total or fecal coliform and the isolation of Salmonella.

TL;DR: Although there are divergent views on the likelihood that water is an important route in the transmission of viruses, there is general agreement that water could be important as a vehicle of disease transmission.

TL;DR: In this paper, the authors measured the electrophoretic mobility of activated sludge particles and found that the average mobility was directly proportional to the sludge volume index, which in turn was a logarithmic function of the ratio of ammonia-nitrogen to soluble phosphate in the liquors.

TL;DR: The use of algae ponds for removing nitrogen and phosphorus by assimilation from secondary sewage effluent suffers from the disadvantage of inefficient light utilization by the dense algal cultures required and from the practical problem of economically removing the algae from suspension as mentioned in this paper.

TL;DR: In this article, it was shown that sewage effluents contribute only a small proportion of the total flow of nitrogen, silicon, chloride, and sulphate in this river whereas the bulk of the phosphorus could be accounted for in terms of that discharged in effluent.

TL;DR: Biological and chemical analyses were carried out on several digesters operated on laboratory, pilot and full-scale, revealing different stages of adaptation of a raw sewage digester adapted to a synthetic substrate.

TL;DR: In this article, randomized duplicate continuous flow bioassays were made to determine the effect of three dissolved oxygen concentrations on subacute zinc toxicity to bluegills, and the 20-day median tolerance limits (TL m ) at various oxygen concentrations were significantly different at the 95 per cent level of confidence.

TL;DR: A comparison of the bacterial flora of a dairy waste activated sludge developing from the initial to the optimal stage in an oxidation ditch and in a laboratory apparatus, showed a close similarity between both systems, so that the latter may be used for representative experiments as mentioned in this paper.

TL;DR: The two groups containing fly populations showed increased efficiencies within 2 months of inoculation, with the larvae successfully controlling the film accumulations, and the filter group containing worms achieved similar high treatment efficiences, but not until 5 months after inoculation.

TL;DR: Adult lobsters in sea water are more resistant to neutralized bleached kraft pulp mill effluent than lobster larvae or salmon parr, and this agrees in general with work on other salmonid fish.

TL;DR: This review is intended to summarize the literature pertaining to the taxonomy, morphology, cytology and nutrition of members of the bacterial genus Sphaerotilus and present limited unpublished data of the author.

TL;DR: A large number of significant correlations was found between the different characteristics of the ecosystem and some of these correlations are discussed, as well as the advantages of such an approach to the study of ecosystems in general.

TL;DR: Evidence is shown that the dehydrogenase activity method is without significant modification, also applicable to the study of anaerobic treatment systems like the one used for these experiments, Nevertheless it is recommended to ensure that TF formation is biochemical by testing for factors characteristic for enzyme kinetics, such as was done in the work reported in this paper.

TL;DR: This method differed from conventional methods used for the enumeration and isolation of sulphate-reducing bacteria in the anaerobic digestion of raw sewage sludge in that anaerobiosis was achieved by the use of media with a low redox potential in stoppered bottles containing oxygen-free gas atmospheres.

TL;DR: In this paper, the authors describe the inhibition of chlorophyll synthesis and the destruction of Chlorella pyrenoldosa due to the presence of selected organic compounds, and show that chlorophil reduction seems to be a function of the substituted groups and their relative positions.

TL;DR: In this paper, the authors studied the role of Sphaerotilus and Arthrobacter-like bacteria in the mechanism of bulking of a dairy waste activated sludge.

TL;DR: In this paper, the diurnal variation of concentration of sugars and volatile fatty acids in fresh and settled sewage at three sites was determined, and no simple relation was found between BOD loading and the ability of a sludge to remove sugars, but in general the higher the "sugar loading" the greater the activity of the sludge.

TL;DR: Bleached kraft mill effluent seems to contain at least two different toxic mechanisms or materials which affect aquatic animals, and a waste treatment process which reduces toxicity of BKME for one species may not protect other species.