Showing papers in "Water Research in 1970"

TL;DR: It is now possible to predict toxicity of mixtures of two or more pollutants on the basis of chemical measurements, and chemical autopsy methods seem promising, more so than histopathological approaches, which suffer from practical difficulties in field situations.

TL;DR: The literature on the microbiological changes involving inorganic nitrogen has been extensively surveyed and the known essential characteristics of the identifiable processes have been listed under the appropriate headings as discussed by the authors, where the nutritional and other requirements of the organisms involved have been described in some detail, as have methods for inhibiting the processes.

TL;DR: The aim of this review is to summarize the literature on Cladophora growing in freshwaters, especially those situations where nutrient enrichment by man has led to the presence of conspicuous and sometimes troublesome growths.

TL;DR: An improved phenol-hypochlorite method for determining ammonia in water using nitroprusside as catalyst has been investigated in this paper, and the method is simple and sufficiently sensitive for low-level analyses.

TL;DR: Evidence was found which suggested that the species structure of the protozoa population in activated sludge was in some way associated with the quality of effluent delivered, and a method was devised which enables the assessment of the average effluent quality delivered from a knowledge of the species present in the sludge.

TL;DR: No real evidence was found to suggest that any particular component of industrial effluents had, by itself, any harmful effects upon the protozoan populations of activated-sludge plants.

TL;DR: Bluegills were exposed to seven malathion concentrations in a diluter-regulated, flowing-water test system and the similarity of the two pairs indicates that an “application factor,” consisting of the maximum acceptable toxicant concentration divided by the short-term test value, for one species exposed to a toxicant might be useful in estimating long-term safe concentrations of this substance to other species from short- term test results only.

TL;DR: In this paper, the stability of First Sister Lake, Michigan has been studied and it was shown that salt entering the lake increased the density of the water in the lower lake strata.

TL;DR: An automated method to determine ammonia-nitrogen over a wide concentration range was developed in this paper, which did not require changes in manifold and sensitivity was altered by changes in the reagents.

TL;DR: In this paper, a method for the determination of pentachlorophenol (PCP) in tissues and natural waters is described, where PCP is extracted from the acidified sample with n-hexane and then re-extracted into a borax solution.

TL;DR: A comprehensive description of the physical factors involved in the dispersal of conservative pollutants in the Great Lakes, based mainly on experimental data obtained in Lakes Huron and Erie over 7 years, is given in this paper.

TL;DR: In this paper, the effect of temperature on oxygen transfer by diffused-air aeration is presented, and the results are analyzed statistically and summarized in the form of a mathematical expression.

TL;DR: In this article, the effects of changes in phenol, hypochlorite and catalyst concentrations on the indophenol blue reaction to determine ammonia-nitrogen, using acetone and sodium nitroprusside as catalysts.

TL;DR: In this paper, a method for recovering small amounts of virus from very large volumes of water was described, where the virus was recovered by adsorbing the virus onto thin layers of an insoluble polyelectrolyte (a crosslinked copolymer of isobutylene maleic anhydride), with subsequent concentration into small volumes of eluent for assay purposes.

TL;DR: Three invertebrate species were submitted to acute (96 hr) followed by chronic (6 week) detergent exposures, thus enabling more than one generation cycle to be tested under toxicant stress.

TL;DR: In this article, the authors used the buccal cavity technique to measure the threshold concentration level at which effluents produce respiration abnormalities in fish, and the elapsed time requirement for this assay is the same as for an acute bioassay.

TL;DR: A review of the present state of knowledge concerning environmental contamination by organochlorine compounds indicates that the chlorinated biphenyls may be one of the more widespread contaminants as discussed by the authors.

TL;DR: The TCID 50 (50 per cent tissue culture infective dose) method was found to be superior to the PFU (plaque forming unit) method for the detection and evaluation of viruses in sewage.

TL;DR: In this paper, a simplified diffusion calculation of oxygen transfer within the probe provides a reasonable basis for describing instrument response and the inherent lag in a measurement of transient oxygen concentration is described.

TL;DR: The effects of varying concentrations of known environmental variables around marine domestic outfall sewers were studied on four species of polychaetous annelids which have been employed as indicators of varying degrees of marine pollution as discussed by the authors.

TL;DR: The most susceptible phase of these crustacean life cycles was the first instar during molting, while adults were most tolerant, and 0.525 to 0.70 mg cresol l −1 would be considered the upper limit in avoiding acute toxicity to benthic amphipod and isopod crustaceans.

TL;DR: In this paper, field studies made to determine the acute, lethal toxicity of some polluted river waters and an estuary water to rainbow trout, brown trout, roach, and dace are described.

TL;DR: In this article, the authors describe the relation between mineral content and the general taste quality of water and the implications of these results for establishing standards limiting mineral content in domestic water were discussed.

TL;DR: In this article, the effect of pH and ionic strength on the efficiency of recovery of mg l −3 organic solute from synthetic laboratory solutions and various tap waters has been determined by single-stage freeze concentration at −12°C with varying degrees of mixing.

TL;DR: In this article, a method for the direct determination of short-chain fatty acids in aqueous solution by gas-liquid chromatography was presented, where a flame ionization detector and glass columns packed with Chromosorb 101 (a polystyrene-divinylbenzene resin developed by Johns-Manville), coated with 3 per cent F.A.P., were used.

TL;DR: A mathematical model of the thermal decomposition process is identified by the variables COD and weight of solid matter, soluble non-evaporative matter and soluble evaporative matter in the sludge.

TL;DR: In this paper, a number of characteristics have been determined of water arthrobacters isolated from a dairy waste activated sludge, which give an indication as to the place of this group of bacteria amongst the other arthroprobacters, isolated from different sources such as soil and cheese.