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Three methods, (a) dessication, (b) gas extraction and (c) immiscible-liquid extraction, are described and evaluated for removing interstitial water from coarse-grained sediments for semi-quantitative and quantitative chemical analyses. The dessication method is useful for chlorinity or chlorosity determinations and (with a correction of 5%) gives results probably accurate to within about ± 2%. Extraction of interstitial water with gas of high relative humidity gives results which are correct to within an error of ±1.0%. The chlorosity of interstitial water extracted by forcing a highviscosity epoxy plasticizer (immiscible with water) through the sediment falls within about ±0.1% of the correct value. The immiscible-extraction method is therefore recommended for work requiring quantitative knowledge of interstitial water chemistry. [ABSTRACT FROM AUTHOR]

The effect on the growth of Gymnodinium breve of river waters and seawater samples collected in different seasons and locations was investigated with and without differential enrichments. Growth in natural seawater was most clearly enhanced by addition of EDTA-Fe, sulfide, N and P. The seasonal variation in growth-promoting properties of seawater and river water dominates variations due to differences in location. [ABSTRACT FROM AUTHOR]

Comparisons are made of pH and the concentrations of major ions in streamwater from Brownrigg Well (the source of Whelpside Ghyll) and from the River Duddon. pH in Brownrigg Well is usually >5.7, but the concentrations of sodium, potassium and possibly calcium are near to the minima required to support the amphipod Gammarus pulex. In contrast most insect taxa are not affected by low ionic concentrations. It is postulated that these had a wider distribution in mountain streams prior to the acidification of poorly buffered waters by acid rainfall resulting from large-scale combustion of fossil fuels. [ABSTRACT FROM AUTHOR]

Sodium and potassium in streamwater were measured over a period of 2 years, and concentrations of other major ions were occasionally monitored. The supply of sodium, potassium and calcium in rainfall was measured over a period of 1 year. A tentative budget is given for annual income and output of sodium, potassium and calcium in the Duddon catchment. Sodium and potassium concentrations in streamwater were independent of stream discharge; both ions displayed an annual cycle of high concentrations in winter and low concentrations in summer. The input of sodium was dependent on rainfall, wind direction and wind speed; 40% of the annual supply in rain was precipitated in the autumn. Sodium income in rainfall during the remaining 9 months of the year was insufficient to balance the output in streamwater. Annual income of potassium in rainfall was equal to annual output in streamwater. But potassium was retained on the catchment during spring and summer and was slowly released to the streams in autumn and winter. Only about 10% of the annual calcium output was derived from atmospheric sources. [ABSTRACT FROM AUTHOR]

Potentiometric or amperometric measurements with appropriate electrode systems are described, adapted to the rapid estimation of small changes of carbon dioxide or oxygen content in natural waters. Total carbon dioxide can be estimated from potentiometric (pH) titrations with six readings, with a graphical Gran transformation; in some instances three readings per sample are sufficient for the estimation of CO2 changes. The results can be used to calibrate the relationship between pH, alkalinity, and temperature, which is then available for the calculation of CO2 changes from pH changes. With examples, it is shown that deviations from the ‘theoretical’ behaviour of simple carbonate solutions are probably widespread in alkaline freshwaters. A semiempirical method of matching them by a postulated alkalinity component is outlined. The same factors are used to evaluate the buffer intensity (β) with respect to CO2 changes at constant alkalinity, so providing an additional method for calculating such changes. Graphs are derived from which the concentration of total carbon dioxide and the buffer intensity can be rapidly estimated. The use of pH-stat conditions to follow changes of carbon-dioxide by titrant consumption is also described, with examples involving photosynthesis by phytoplankton. Several procedures are given for estimating dissolved oxygen with the Winkler method followed by amperometric titration with a simple platinum-calomel combination electrode. No externally applied potential is required, and both forward and back titrations past the end-point can be followed by calculation of the latter from a few readings. Alternatively, titration to a small fixed electrode current (or derived potential) is a practicable method. The titration procedures can be adapted to macro- and micro-estimations, used with pH-meters as current detectors, and automated. [ABSTRACT FROM AUTHOR]

Weekly measurements of chemical composition were made at sixteen sampling points on the River Frome and its main tributaries from October 1970 until December 1971. At fourteen of these points stream discharge was measured. Water samples from each sampling point were analysed for alkalinity, calcium, magnesium, sodium, potassium, pH, conductivity, reactive phosphate and nitrate. Magnesium varied little in concentration; alkalinity and calcium concentrations decreased in time of flood. The highest concentration of sodium occurred after snow had melted from salted roads; otherwise it showed little variation. The highest values for nitrate nitrogen were at peak flows but otherwise it altered little. Phosphorus and potassium varied most and both showed a reduction between February and May. These results are part of a survey of the chemical composition of the waters of rivers in the south of England. This survey is aimed at providing a picture of the chemical environment of the rivers as a background for ecological work on the biota, and to investigate the factors influencing variations in chemical composition (Westlake et al., 1972). A preliminary paper (Casey, 1969) has described the flow and chemistry at one point (East Stoke) on the lower part of the river. The present paper is an attempt to discover the contribution each main source makes to the flow and chemistry of the whole river. [ABSTRACT FROM AUTHOR]

The application of paraquat (1.0 mg/l) to a fishing reservoir was successful in controlling the angiosperms, Potamogeton pectinatus and Myriophyllum spicatum, but a second application (0.6 mg/l) failed to control a replacement growth of the macrophytic alga, Chara globularis. Paraquat was quickly lost from the water after each application and was largely taken up by the sediments, never more than 6% of the initial dose being recorded from the macrophytes. Final analysis of the sediments indicated that about 36% of the total amount of paraquat applied to the reservoir was not recovered. Some changes in the chemistry of the water after the first application of paraquat were consistent with the death of the plants (e.g. alkalinity), but there was no evidence that the subsequent decay of the plants produced large increases in the concentrations of major nutrients in the water. Although there was no gross deoxygenation there were changes in the oxygen status of the water following the herbicide-induced death of the angiosperms. Estimates of the biomass and net productivity of the macrophytes were made. [ABSTRACT FROM AUTHOR]

The changes in the chemistry of the waters of a small river before and immediately after it has been dammed are reported here. Pre-impoundment investigations reveal the paucity of nutrient salts which became slightly more concentrated in the lentic environment created after the closure of the dam. Also, the fluctuations in the chemistry of the waters were influenced by a number of physical factors notably water level, current velocity and temperature. Deoxygenation of the usually oxygen-undersaturated river waters was not observed after the closure of the Asejire dam built across the River Oshun. [ABSTRACT FROM AUTHOR]

The article presents the physicochemistry of stratification in Abbot's Pool in Somerset, England. Since thermal stratification occurs regularly, the chemical content of the shallow water in pool was investigated. It was found that the distribution of nitrate, ammonia, inorganic phosphate and dissolved silica are not homogenous down the depth profile throughout 1967. During conditions of thermal stratification, these dissolved substances accumulate in the hypolimnion. In summer, content of nitrate decreases in the oxygen deficient deeper water while levels of ammonia, phosphate and silica were high during autumn. It is concluded that large amounts of dissolved substances are recycled in the pool and the chemical cycles in Abbot's Pool are more complex than its dimensions would suggest.

The article presents a study which examines the chemical composition of some bog waters from the Falkland Islands. The study found that the bog waters exhibit unusually high salt concentrations, owing to very heavy deposition of sea spray. The result also revealed that the acidity of bog waters appears due partly to exchange of metal cations in sea spray for hydrogen ions absorbed on the peat colloids and partly to oxidation of hydrogen sulphide generated by peat decomposition. Moreover, according to the study, the relatively large amounts of sea salt deposited on the peaty soils of the Falklands, together with the lightness of the rainfall, may perhaps be of some importance in maintaining their grass cover against degeneration and erosion.

The article presents an experiment on the ability of sphagnum to take in cations from dilute solutions corresponding to natural water. In the experiment, the quantities of calcium, magnesium and iron in water samples taken from a bog in the pine forest, together with their potential of hydrogen-ion concentration (pH) and electrical conductivity were checked. It revealed that the total concentration of the metallic ions calculated was substantially lower in the sample from the bog than from the stream. The conductivity of the bog water was more than double despite the smaller concentration of hydrogen ions.

An investigation of Lake Ösbysjön, a seepage lake situated 9 km north of Stockholm, was carried out during the years 1957–1961. Different aspects of the water chemistry are treated in relation to the capacity of organic production of the lake. The water temperature of the ice-free season largely follows the changes in the maximum of the air temperature. Respiratory processes are predominant in the lake. The yearly average degree of oxygen saturation was about 60%. During the winter the entire lake can be completely oxygen-free for some time. PO4-P is low in the lake and the total phosphorus is lower than in several Uppland lakes investigated by Lohammar (1938). The phosphate released during the periods of stratification from the sediment is rapidly taken up by the living organisms. NO3-N is low during the ice-free season. At the end of the winter stratification comparatively high values of NO3-N occur in the upper water layers. The variations in silica concentration are governed by several factors. In the bottom water silica and CO2 show a similarity in development with time. [ABSTRACT FROM AUTHOR]