Specific Alkalinity Research Articles

TOXICITY OF TOTAL DISSOLVED SOLIDS ASSOCIATED WITH TWO MINE EFFLUENTS TO CHIRONOMID LARVAE AND EARLY LIFESTAGES OF RAINBOW TROUT

Assessment of total dissolved solids (TDS) represents an integrated measure of the concentrations of common ions (e.g., sodium, potassium, calcium, magnesium, chloride, sulfate, and bicarbonate) in freshwaters. Toxicity related to these ions is due to the specific combination and concentration of ions and is not predictable from TDS concentrations. Short-term chronic toxicity tests were conducted with larval chironomids and trout (eggs and swim-up fry) to assess their TDS tolerance relative to effluents from two Alaskan mines. Both effluents are characterized by high TDS content but differ with respect to concentrations of specific ions and alkalinity. The toxicity tests were conducted with synthetic effluents formulated to match the ionic composition of each mine discharge. No toxicity was observed at 2,000 mg of TDS/L with embryos or developing fry, but chironomids exhibited effects above 1,100 mg of TDS/L. These tests, together with information on the health of field populations (fish and benthic invertebrates), are appropriate and relevant for determining site-specific whole effluent TDS concentrations.

Mixing in the region of the midrift islands of the Gulf of California: effect on surface pCO2

Surface seawater carbon dioxide partial pressure (pCO2) and the CO2 flux through the air-sea interface in the region of the midrift islands of the Gulf of California were estimated. We used surface temperature (ºC), salinity and pH data collected during summer 1990, and we assumed a constant specific alkalinity value. Mixing by tide-related phenomena is particularly strong in this region of the gulf, and our objective was to compare the effect of post-spring tides with that of post-neap tides. Carbon dioxide was either near equilibrium or flowing from the water to the atmosphere, even with post-neap tides. Surface cooling, and larger pCO2 and CO2 flux were detected with post-spring tides. relative to post-neap tides (<4 mM m–2 d–1 with post-neap tides. up to 23 mM m–2 d–1 with post-spring tides). There is a fortnightly modulation of the CO2 system in the surface waters of this region due to the spring-neap tide sequence. Tidal mixing is a “physical pump” that carries CO2 efficiently from intermediate depths (500 m) to the atmosphere in this region of the gulf.

Distribution of Alkalinity, Ph, Salinity and Carbon Dioxide Components in the Coastal Waters of Alexandria

The ara studied is located between El-Dikheila Harbour in Elmex Bay and Mandara, at longitude 29° 47′ and 30° East and latitude 31° 17′ North. the aim of the work is to look at carbon dioxide components in this areA and the effect of waste water discharged on their concentrations. Surface and bottom water samples were collected from 12 stations during January, April, August and November, 1995. Total alkalinity, salinity, temperature and pH were measured. Carbonate alkalinity, total alkalinity, partial pressure and dissolved carbon dioxide, carbonate and bicarbonate ions were calculated, since the studied area includes two differetn sources of pollution. It wAs found conventient to refer El-Mex Bay as region “A” which contains stations from I to VI and the area located between Kayet Bey outfall and Mandara which contains stations from VII to XII as region “B”. When specific alkalinity is used As A tracer for El-Umum drain water it is observed that the drain water could reach Sidi Bishr area especially in August and November, while in January and April drain water did not reach this area.

Concentrations of chlorinated organic compounds in biota and bed sediment in streams of the San Joaquin Valley, California.

Samples of resident biota and bed sediments were collected in 1992 from 18 sites on or near the floor of the San Joaquin Valley, California, for analysis of 33 organochlorine compounds. The sites were divided into five groups on the basis of physiographic region and land use. Ten compounds were detected in tissue, and 15 compounds were detected in bed sediment. The most frequently detected compound in both media was p,p'-DDE. Concentrations of SigmaDDT (sum of o,p'- and p, p' forms of DDD, DDE, and DDT) were statistically different among groups of sites for both tissue and sediment (Kruskal-Wallis, p < 0.05). Concentrations in both media were highest in streams draining the west side of the valley. Concentrations of SigmaDDT in tissue were significantly correlated with specific conductance, pH, and total alkalinity (p < 0.05), which are indicators of the proportion of irrigation return flows in stream discharge. Concentrations in sediment on a dry-weight basis were not correlated with these water-quality parameters, but total organic carbon (TOC) normalized concentrations were significantly correlated with specific conductance and pH (p < 0.05). Regressions of the concentration of SigmaDDT in tissue, as a function of SigmaDDT in bed sediment, were significant and explained up to 76% of the variance in the data. The concentration of SigmaDDT in sediment may be related to mechanisms of soil transport to surface water with bioavailability of compounds related to the concentration of TOC in sediment. The results of this study did not indicate any clear advantage to using either bed sediment or tissues in studies of organochlorine chemicals in the environment. Some guidelines for protection of fish and wildlife were exceeded. Concentrations of organochlorine chemicals in biota, and perhaps sediment, have declined from concentrations measured in the 1970s and 1980s, but remain high compared to other regions of the United States.

Chemical Classification and Trophic Characteristics of Texas Reservoirs

ABSTRACT Texas reservoirs were classified into three groups by cluster analysis based upon the following properties of their surface waters: specific conductance, alkalinity, calcium, sulfate, pH, chloride, and sodium (listed in descending order of importance as discriminators). The three groups of reservoirs had a distinct geographic distribution corresponding to a strong east-west gradient of increasing aridity and differences in surface geology. Chemical characteristics of the western reservoirs were most influenced by the dissolution of evaporites formed in the geological past and current arid conditions (median specific conductance = 1817 μS cm−1; median alkalinity = 120 mg CaCO3 L−1). Sulfate and chloride accounted for 87% of the major anions (in equivalent charge concentrations). The second group of reservoirs, located in a wide band through central Texas, were dominated by weathering of limestone bedrock and calcareous soils (median specific conductance = 518 μS cm−1; median alkalinity = 133 mg Ca...

Alkalinity and total carbonate in the Arabian Sea. Carbonate depletion in the Red Sea and Persian Gulf

An estimation of the annual decrease in alkalinity ( A t) in the Persian Gulf was calculated to be 0.326 × 10 12 mol/yr and in the Red Sea 1.65 × 10 12 mol/yr. Together this amounts to a loss of carbon as calcium carbonate of 12 Mton/yr which is about 5% of the annual river input of carbon as hydrogen carbonate. The perturbation of the global CO 2 system is small, but the effect on the alkalinity of the northwest Indian Ocean should not be neglected. The depth profile of the specific alkalinity ( A t/ S) in the Arabian Sea shows an increase below 600 m which is partly ascribed to the dissolution of calcium carbonate and partly due to the sinking of cold water with high values of A t/ S. The depth profile of A t - C t shows low values below the euphotic zone due to decomposition of organic carbon. Station 2359 at 17° 52′N and 60°46′E from the Atlantis II Cruise 93-17 in February 1977 was selected to show the relationships between the total inorganic carbon (C t) and the concentrations of phosphate and nitrate+nitrite. The slope of 15 fits the phosphate data except in deep water where dissolution of carbonate may produce high values of C t. The slope of 105:15 for C:N does not fit the data and shows a loss of nitrogen due to denitrification. In the depth range 215–285 m the nitrogen loss was 45.5%.

Alkalinity and carbon budgets in the Mediterranean Sea

Alkalinity and salinity are linearly correlated in the waters of the most western part of the Mediterranean Sea. Nevertheless, the specific alkalinity of the saltier Mediterranean waters is higher than that of the less saline water of Atlantic origin. This may be explained by alkalinity input from rivers and the Black Sea. In the hypothesis of a steady state, the relationship between alkalinity and salinity permits calculation of the net flux of alkalinity between the Mediterranean Sea and the Atlantic Ocean, provided the water budget of the Mediterranean is known. The sources (rivers and the Black Sea) and sinks (seafloor) of alkalinity in the Mediterranean balance the net alkalinity transport into the Atlantic, if the water deficit of the Mediterranean is 2.2×1012 m3 yr−1 or 88 cm yr−1 per unit area. The budget of carbon in the Mediterranean Sea is more difficult to assess as the sources and sinks are numerous and not well‐documented. There is particularly a lack of data on the seasonal variations in the inorganic and organic carbon concentrations in the region of the strait of Gibraltar and on the partial pressure of CO2 in surface water of the Mediterranean Sea. It appears nevertheless that there is an important flux of inorganic carbon from the Mediterranean to the Atlantic due to the supply of carbon by the rivers and the Black Sea and to the transformation of 40% of the organic carbon entering the Mediterranean in inorganic carbon. Moreover, the Mediterranean is likely a sink for the atmospheric carbon.

Physicochemical Patterns within a Hyporheic Zone of a Northern Michigan River, with Comments on Surface Water Patterns

Interstitial temperature and chemistry were examined longitudinally and with depth in a hyporheic zone beneath a riffle–pool sequence of a third-order, sand-bottom river in northern Michigan (USA). Longitudinal and depth patterns were compared with surface and groundwater chemistries at the site and with surface chemistry over a 10-km length of the river. Interstitial water was more characteristic of surface water at the upstream end of the hyporheic zone and of groundwater at the downstream end. Hyporheic longitudinal and depth patterns occurred for temperature, chloride, silica, soluble reactive phosphorus, and winter dissolved oxygen. Dissolved organic carbon decreased with depth, but not with longitudinal distance downstream within the hyporheic zone. Hyporheic nitrate and ammonium patterns were variable, but concentrations generally increased downstream. Hyporheic specific conductance and alkalinity decreased with distance downstream, but not with depth. Gradients for temperature, chloride, silica, nitrate, and phosphate over the 10-km surface water reach were similar to those observed within the single hyporheic zone. Hyporheic chemistry patterns were consistent with models of underflow through porous substrata implying ground water/surface water interaction. Importance of the hyporheic zone should not be overlooked in solute transport or stream nutrient budgets.

Trends in Nutrients, Major Ions and Physical Water Quality Parameters in the Niagara River During the 1977–87 Period

Abstract This paper presents the seasonal and annual variations of the physical parameters, nutrients and major ions in the Niagara River for a period of eleven years, 1977–87. The discharge during this period was found to be steadily increasing and as a consequence the specific conductance was decreasing due to the higher dilution effect, as well as the lower concentrations of chloride and sodium. High concentrations of total phosphorus during the winter months corresponded with high turbidity. In addition, a steady decrease in total phosphorus concentrations was observed until 1984, while during the rest of the period concentrations were increasing. Nitrate nitrogen concentrations were found to be steadily increasing during the entire period except for 1987. Seasonal cycles of specific conductance, calcium, alkalinity, magnesium, and sulphate all showed decreases in April, May and June, during the high discharge period. Both chloride and sodium concentrations have decreased substantially during the 1977–85 period, the result of upstream industrial input decreases, but concentrations since then have levelled out.

Alkalinity in the south-eastern United States continental shelf waters

The distributions of salinity, alkalinity and specific alkalinity, and the relationship between alkalinity and salinity in the south-eastern United States continental shelf waters, commonly known as the South Atlantic Bight, in April, 1985 indicate that the primary mixing process is between Gulf Stream water and shelf water. However, in the inner shelf the influence of the Cape Fear/Pee Dee Rivers and the Savannah River were also detectable. The influence of the outflows from the other rivers, which also drain into this Bight, was not as clearly evident. In the outer shelf, and over the shelf break, the presence of the altered (Gulf Stream) continental edge water was found. The mixture of shelf and Gulf Stream waters was characterized by a specific alkalinity of about 6·6 × 10 −2 meq l −1 ‰ −1. While the river waters were characterized by significantly lower salinity and specific alkalinity, the altered (Gulf Stream) continental edge water had only slightly lower salinity but a significantly lower specific alkalinity relative to the shelf water. The intrusion of offshore water over the shelf break onto the outer and middle shelves as a result of the meandering of the Gulf Stream has been recognized as one of the major contributors to the exchange of water between the shelf and the Gulf Stream. The distributions of specific alkalinity and salinity in the middle and outer shelves were consistent with the occurrence of such a process. Alkalinity/specific alkalinity may be a potentially useful complementary tracer for studying mixing processes in coastal areas where seawater mixes with outflows from multiple rivers.

Controls on Carbonate Mineral Accumulation in Bahamian Basins and Adjacent Atlantic Ocean Sediments

ABSTRACT Carbonate mineralogical studies of surface Bahamian periplatform ooze, containing pelagic calcite as well as bank-derived aragonite and magnesian calcite, were coupled with studies of the carbonate chemistry of the waters overlying these sediments. The presence of metastable aragonite and magnesian calcite in the periplatform ooze presents a unique opportunity to assess the relation between the extent of carbonate saturation in the water column and the disappearance of metastable carbonate minerals in an area of the North Atlantic Ocean where intermediate and deep waters are saturated with respect to calcite. Aragonite is present in the fine fraction of the surface sediment to a water depth of 4,800 m, but decreases sharply below 4,000 m. This is also the depth limit of the occurrence of pteropod tests and fragments in the coarse fraction of the sediment. The aragonite compensation depth should be (by extrapolation) between 5,000 and 5,200 m. The saturation depth with respect to aragonite was estimated to be located between 3,800 and 4,500 m. This corresponds fairly well with the depth of a sharp decrease of the fine aragonite as well as the depth of pteropod disappearance. Magnesian calcite in the fine fraction of the sediment decreases irregularly with depth and disappears between 3,700 and 4,000 m. The calculated saturation depth with respect to magnesian calcite (13 mole % MgCO3) is between 900 and 1,500 m. At this depth a significant drop in the concentration of magnesian calcite occurs. This decrease of magnesian calcite from 25 to 15 percent could be caused by both dissolution and the increasing distance of deeper waters from the banks. However, the higher values of specific alkalinity of the waters ranging between 750 and 2,000 m, when compared with the alkalinity values of the Sargasso Sea at the same latitude, are interpreted to be indicative that some dissolution of magnesian calcite occurs in the Bahamian basins at these water dept s. Our results show depressed levels, by 500 m or more, of the aragonite saturation depth in the water column as well as of the depth of aragonite disappearance in the surface sediment, when compared with open ocean studies in the Northwest Atlantic. In addition, our results indicate that fine magnesian calcite (12 to 13 mole % MgCO3) disappears 1,200 to 1,500 m above the extrapolated disappearance depth of aragonite. This observation is consistent with results for experimental studies, showing that aragonite is more stable in seawater than a magnesian calcite of 12 to 13 mole % MgCO3.

Water Quality Effects of Excavation and Diversion

Water quality data collected from Yellow Creek in northeast Mississippi before and during construction of the Divide Cut of the Tennessee‐Tombigbee Waterway provide information regarding the water quality effects of stream channelization and large‐scale construction projects. Simple graphical and statistical procedures for detecting changes in stream water quality are demonstrated. Data analysis was hindered by missing data, inconsistencies in the list of variables monitored, and changes in sampling frequency. Observed water quality changes were evidently due to increased inputs of sediment and reduced shade. Statistically significant changes in variances and means were observed for most grab‐sample variables. Mean values of specific conductance, turbidity, color, COD, and total alkalinity, hardness, ammonia, phosphorus, sulfate, iron, lead, and manganese were 50–100% greater during construction than before construction. Estimated average daily loadings of total metals, nutrients, and dissolved solids wer...

Chemical oceanography of the Persian Gulf

Measurements of basic hydrographic properties, nutrient elements, alkalinity and total carbon dioxide were made in the Persian Gulf in February and March 1977, on R.V. Atlantis II Cruise 93. The results show clearly the penetration into the Gulf of surface Indian Ocean water, initially of 36.5% salinity which is carried northwards along the Iranian Coast, gradually increasing in salinity to more than 40%. The inflowing surface water is high in phosphate (1.0-0.5 μmoles kg −1) due to upwelling induced by the north-east monsoon. However, nitrate levels are at, or below, the detection limit and nitrogenous nutrients appear to be limiting. The seawater carbonate system is greatly perturbed by the precipitation of large quantities of calcium carbonate. The alkalinity-salinity relationship shows that the greatest carbonate loss occurs in the shallow waters of the Trucial Coast, where up to 125 μmoles kg −1 of CaCO 3 have been lost from the water. Dense, saline low specific alkalinity water formed in the shallows appears to migrate down slope to augment the outflowing waters in the deeper part of the Gulf. The outflow of the Tigris, Euphrates and Karun rivers to the north provides an intense, but low capacity signal, of low salinity, high specific alkalinity, waters. Large amounts of CO 2 are also fixed by photosynthetic processes. The classical Mediterranean type of circulation is plainly revealed. The residence time of water within the Persian Gulf is approximately 2.5 yr.

Seasonal effects of temperature and salinity on the partial pressure of CO2 in seawater

The exchange of CO2 between the atmosphere and the sea is of major importance to our understanding of the climatic consequences of anthropogenic CO2. Because the solubility of CO2 and the dissociation of carbonic acid in seawater are modulated by temperature and salinity, the detection of long-term changes in the oceanic carbonate system, first requires that the comparatively large short-term variations in the partial pressure of CO2 should be characterized. We present here the first direct observations of seasonal variations in the partial pressure of CO2 in the subtropical gyres of the North and South Pacific Ocean. These variations compare well with the variations predicted from observed changes in temperature and salinity using empirical equations which do not require the determination of alkalinity or total inorganic carbon, and the agreement is improved by the inclusion of air–sea exchange in the model calculations. Thus we predict that specific alkalinity within the two gyres remains extremely constant, which is confirmed by carbonate equilibrium calculations based on our measurements of total inorganic carbon.

Changes of chemical composition of water in two fish farming ponds with air-breathing teleosts

Changes of chemical composition of water due to growth kinetics ofAnabas testudineus and stocking of broods of different species of air-breathing teleosts were studied in two fish ponds at Kalyani Fish Farm over a period of one year. The results indicated significant differences in the mean values of temperature, bicarbonate alkalinity, hardness, specific conductivity, and phosphate content of water as well as organic carbon of the mud samples in the two ponds. The growth curve ofAnabas was not distinctly linked with the variations of pH, free CO2 and dissolved oxygen but was inversely related to the variations of specific conductivity, bicarbonate alkalinity and phosphate content of water. Also, there was a direct functional relationship between nitrite level and growth increment in individual fish.

The carbonate system in the western Mediterranean sea

Measurements of the pH and total alkalinity have been made on waters collected in the western Mediterranean Sea. These results have been used to examine the elements of the carbonate system, HCO 3 −, CO 3 2−, CO 2, ΣCO 2, P CO 2 , and specific alkalinity. The saturation of Mediterranean Gibraltar is supersaturated with respect to calcium carbonate. Our results for the saturation state (Ω) for Mediterranean waters are in good agreement with the results of Alekin ( Geochemistry, 206, 239–242, 1972) and those calculated from the GEOSECS (Geochemical Ocean Sections) test station in the eastern Mediterranean. The saturation state of calcite and aragonite in deep Mediterranean waters in higher than that of deep North Atlantic waters.

Specific conductance and alkalinity determinations in dilute natural waters

Specific conductance and alkalinity determinations in dilute natural waters

Physical and chemical features of a vernal temporary pond in Western Canada

Temporal changes in physical and chemical features of a vernal temporary pond in western Canada are described for the 7-week duration of the pond. Average water loss through evaporation was 3 m3/day. Daily temperature ranges of 11 and 12° were frequent. Specific conductance, hardness and bicarbonate alkalinity increased progressively in proportion to the decrease in pond volume. Increase in chlorides was much less than predicted from evaporative concentration. Sulphates increased rapidly during the filling phase but then decreased steadily during the remaining weeks. The decline is attributed to uptake by meadow vegetation. Other biologically important ions examined exhibited no distinct patterns. The relative importance of evaporation, capillary ‘creep’ and biological uptake processes is discussed.

Sedimentary Reflection of Depositional Environment in the Bardawil Lagoon, Northern Sinai

ABSTRACT Bardawil lagoon is a body of water about 600 km2, it is about 80 km long and its maximal width is approximately 18 km. The lagoon is separated from the Mediterranean by a sand barrier. Waters and sediments of the lagoon were analysed. The decrease in specific alkalinity of the waters with increasing distance from the inlets and with increasing chlorosity suggest that authigenetic carbonates are precipitating at present from the lagoon waters. The predominant type of sediment is sand, covering all the nearshore and nearbar areas; clayey sand covers the deepest and the most distant parts from the inlets, which connect the lagoon with the Mediterranean. The western-arm sediments, composed of sand containing marine diatoms and pelecypods, show that the region was under marine conditions throughout the period represented by the column of sediments studied. In the main lagoon a change from marine condition, represented by sand and marine shells found in the deeper portions of the cores to lagoonal evaporitic ones in the upper sediments (gypsum and clayey sediments present), is clearly demonstrated. At the present the salinities of the lagoon waters do not permit the precipitation of gypsum. This shows a restoration of the connection between the lagoon and the Mediterranean leading to the dilution of the highly saline lagoon waters and hence to the cessation of precipitation of gypsum. The relative abundance of the sand, the spatial distribution of gypsum and marine and lagoonal diatoms suggest that the sedimentary column studied was formed under marine to lagoonal conditions and that no streams entered the lagoon during this period. The sediments were brought to the lagoon from the Mediterranean. The Nile branches (including the Pelusiac) brought the sediments to the Gulf of El Tina in the Mediterranean and long shore west-east currents brought the sediments to the lagoon.

The major anions in Lake Maryût waters

Determinations for sulphate, bromide content and the alkalinity of Lake Maryut water were carried out at six stations during the four seasons of 1966. The sulphate chlorinity ratio increases with the decrease of chlorinity. It has an average of 0.2649 which is higher than the ratio of 0.1395 for sea water and lower than the ratio for river waters. Regional variations in the SO4/Cl ratio are attributed to the effect of drainage water which have a high sulphate content. The average bromine chlorinity ratio 0.00360 is compared with 0.00348 for sea water. The seasonal and regional variation of the Br/Cl ratio is less significant than the SO4/Cl ratio. The specific alkalinity decreases with the increase of chlorinity. The average specific alkalinity for the lake water is 3.20 which is higher than that for sea water, (0.126), and lower than that for river waters.