Oxygen In Water Samples Research Articles

Heavy Metals and Organochlorine Pesticides in Water and Sediments of the Sefidrud River, South of Caspian Sea, Iran

ABSTRACT The Sefidrud River, which flows into the Caspian Sea after traversing the northern Iranian province of Guilan, is the principal river in the southern Caspian Sea. Its water is utilized for drinking, agriculture, and aquaculture, while industrial and agricultural wastewater is discharged into this valuable body of water. This study aimed to measure the concentration of two heavy metals, nickel and lead, and organochlorine toxins in the water and sediment of this river. Water samples were taken from the Sefidrud River at three stations in four seasons to measure the concentration of the above-mentioned two heavy metals organochlorine toxins as well as some physiochemical parameters of the water. Results showed that the annual mean water temperature, calcium, magnesium, electrical conductivity (EC), T.D.S, pH, and dissolved oxygen in water samples were 16.35°C, 77 mg/l, 28.41 mg/l, 1245.41 mS/m, 782.7, 8.01, and 7.91 mg/l. The mean annual concentration of nickel and lead was also 0.008 ± 0.001 and 0.001 ± 0 mg/l in water and 29.75 ± 1.19 and 313.4 ± 17.13 mg/l in sediments. The results also showed that the mean annual concentration of Pertilachlor was 0.40 ± 0.046 mg/l in water and 2.91 ± 0.476 mg/l in sediments, and the mean annual concentration of Saturn was 2.81 ± 0.47 mg/l in water and 0.39 ± 0.47 mg/l in sediments. Since the sediments of the Sefidrud River contain relatively high concentrations of heavy metals such as lead and nickel as well as organochlorine toxins, the river should be regarded as polluted; therefore, the discharge of pollutants and wastewater into this river should be properly managed.

Toward a common methodological framework for the sampling, extraction, and isotopic analysis of water in the Critical Zone to study vegetation water use

AbstractThe analysis of the stable isotopic composition of hydrogen and oxygen in water samples from soils and plants can help to identify sources of vegetation water uptake. This approach requires that the heterogeneous nature of plant and soil matrices is carefully accounted for during experimental design, sample collection, water extraction and analyses. The comparability and shortcomings of the different methods for extracting water and analyzing isotopic composition have been discussed in specialized literature. Yet, despite insightful comparisons of extraction methods and benchmarking methodologies of laboratories worldwide, the community still lacks a roadmap to guide sample collection, extraction, and isotopic analyses, and many practical issues for potential users remain unresolved: for example, which (soil or plant) water pool(s) does the extracted water represent? These constitute a hurdle for the implementation of the approach by newcomers. Here, we summarize discussions led in the framework of the COST Action WATSON (“WATer isotopeS in the critical zONe: from groundwater recharge to plant transpiration”—CA19120). We provide guidelines for (1) sampling soil and plant material for isotopic analysis, (2) methods for laboratory or in situ water extraction, and (3) measurements of isotopic composition. We highlight the importance of considering the process chain as a whole, from experimental design to isotopic analysis to minimize biased estimates of the relative contribution of different water sources to plant water uptake. We conclude by acknowledging some of the limitations of this methodology and advice on the collection of key environmental parameters prior to sample collection for isotopic analyses.This article is categorized under: Science of Water > Hydrological Processes Science of Water > Water and Environmental Change Science of Water > Water Extremes

IMPACTS OF DUMPSITE ON SOIL AND GROUNDWATER QUALITY: A CASE STUDY OF ERINFUN COMMUNITY, ADO EKITI, SOUTHWESTERN NIGERIA

Groundwater pollution has increased as a result of poor waste disposal practices in developing countries. The purpose of this study was to determine the levels of physicochemical parameters and heavy metal concentrations in order to investigate the impact of dumpsites on groundwater and soil quality in Erinfun community. Four (4) water samples were collected hand dug well and four (4) soil samples designated Ss1 to Ss4 were collected at distances of 10, 20, 30 and 40 m, respectively, away from the waste dumpsite. Physicochemical parameters and traces such as odour, colour, taste and temperature, as well as Biochemical Oxygen Demand, Chemical Oxygen Demand, Dissolve Oxygen, Total Dissolve Solid, pH, and chloride were measured in collected water samples. Collected soil samples were also analyzed for heavy metals such as Magnesium, Zinc, Iron, Chromium, and Lead. All the physical parameters of the water samples analysed were found not to be within the acceptable limit of World Health Organization and Nigerian Standard of Drinking Water Quality standards. The chemical constituents tested were within the acceptable limit of World Health Organization and Nigerian Standard of Drinking Water Quality except for the Biochemical Oxygen Demand, Chemical Oxygen Demand and Dissolve Oxygen of water samples 1 and 2, respectively. The concentration of trace metals in water sample test were within health limit except for Magnesium and Iron which has the highest concentrations in water sample 1 at 10 m away from dumpsite (61.00 mg/l and 0.46 mg/l). Consequently, open dumpsites are discouraged, and constructed standard landfills with appropriate monitoring guidelines are recommended.

Bacterial Diversity in a Dynamic and Extreme Sub-Arctic Watercourse (Pasvik River, Norwegian Arctic)

Microbial communities promptly respond to the environmental perturbations, especially in the Arctic and sub-Arctic systems that are highly impacted by climate change, and fluctuations in the diversity level of microbial assemblages could give insights on their expected response. 16S rRNA gene amplicon sequencing was applied to describe the bacterial community composition in water and sediment through the sub-Arctic Pasvik River. Our results showed that river water and sediment harbored distinct communities in terms of diversity and composition at genus level. The distribution of the bacterial communities was mainly affected by both salinity and temperature in sediment samples, and by oxygen in water samples. Glacial meltwaters and runoff waters from melting ice probably influenced the composition of the bacterial community at upper and middle river sites. Interestingly, marine-derived bacteria consistently accounted for a small proportion of the total sequences and were also more prominent in the inner part of the river. Results evidenced that particular conditions occurring at sampling sites (such as algal blooms, heavy metal contamination and anaerobiosis) may select species at local scale from a shared bacterial pool, thus favoring certain bacterial taxa. Conversely, the few phylotypes specifically detected in some sites are probably due to localized external inputs introducing allochthonous microbial groups.

Contribution of soil water at various depths to water consumption of rainfed winter wheat in the Loess tableland, China

Soil water and stem water were collected in jointing and heading stages of the rainfed winter wheat in the Changwu Loess tableland, and the stable isotopic compositions of hydrogen and oxygen in water samples were measured to analyze the contribution of soil water at various depths to water consumption of winter wheat. The results showed that the isotopes were enriched in soil and wheat stem water in comparison with that in precipitation. Under the condition of no dry layer in soil profile, the contributions to wheat water consumption in jointing and heading stages were 5.4% and 2.6% from soil water at 0-30 cm depth, 73.4% and 67.3% at 60-90 cm depth (the main water source for winter wheat), and 7.9% and 13.5% below 120 cm depth, respectively. With the wheat growth, the contribution of soil water below the depth of 90 cm increased. It was concluded that soil evaporation mainly consumed soil water in 0-30 cm depth and wheat transpiration mainly consumed soil water below 60 cm depth in the experimental period. In the production practice, it is necessary to increase rainwater storage ratio during the summer fallow period, and apply reasonable combination of nitrogen and phosphorus fertilizers in order to increase soil moisture before wheat sowing, promote the wheat root developing deep downwards and raise the deep soil water utilization ratio.

Tritium Concentration in River Water and Groundwater Collected in Rokkasho, Aomori, Japan

In order to study the effect of 3H released from the commercial spent nuclear fuel reprocessing plant on 3H concentration in the local fresh water environment, river water and well water samples were collected at seventeen and nine points, respectively, around the plant. Concentrations of 3H were measured in the samples collected during the period of the final testing using actual spent fuel in the plant. The stable isotope ratios of hydrogen and oxygen in water samples were also measured for a hydrological study around the plant area. Concentrations of 3H in the river water samples were in the background level, and their variation among sampling locations was small. Although well water samples also did not have significantly high 3H concentrations originating from the 3H released from the plant, the variation in 3H concentration among sampling locations was larger than that in the river water samples. Comparison of ΔD and Δ18O data with a local meteoric water line suggested that groundwater around the plant area is mainly recharged by precipitation in winter.

Pulsating potentiometric titration technique for assay of dissolved oxygen in water at trace level

A simple but high performance potentiometric titration technique using pulsating sensors has been developed for assay of dissolved oxygen (DO) in water samples down to 10.0 μg L −1 levels. The technique involves Winkler titration chemistry, commonly used for determination of dissolved oxygen in water at mg L −1 levels, with modification in methodology for accurate detection of end point even at 10.0 μg L −1 levels DO present in the sample. An indigenously built sampling cum pretreatment vessel has been deployed for collection and chemical fixing of dissolved oxygen in water samples from flowing water line without exposure to air. A potentiometric titration facility using pulsating sensors developed in-house is used to carry out titration. The power of the titration technique has been realised in estimation of very dilute solution of iodine equivalent to 10 μg L −1 O 2. Finally, several water samples containing dissolved oxygen from mg L −1 to μg L −1 levels were successfully analysed with excellent reproducibility using this new technique. The precision in measurement of DO in water at 10 μg L −1 O 2 level is 0.14 ( n = 5), RSD: 1.4%. Probably for the first time a potentiometric titration technique has been successfully deployed for assay of dissolved oxygen in water samples at 10 μg L −1 levels.

Application of capillary electrophoresis for the determination of dissolved gases in water samples: I. Determination of dissolved oxygen

The determination of dissolved oxygen in water samples was performed by capillary electrophoresis. This was based on the oxidation of pyrogallol in alkaline media by dissolved oxygen. The oxygen sample was injected into the capillary electrophoresis system consisting of phosphate buffer at pH 5.6 and 0.5 M pyrogallol. Electrophoretic mixing of sample and reagent was achieved during the electrophoretic run and the reaction product was monitored at 440 nm. The assay procedure was optimized with respect to the carrier electrolyte concentration and pH, pyrogallol concentration, sample pH, and modes of operation of the applied voltage. As little as 20 ppb of the dissolved oxygen could be determined by the proposed method within 10 min. The method was successfully applied for the determination of dissolved oxygen in river and drinking water.

Determination of Dissolved Oxygen in Water Samples Using Capillary Electrophoresis

Abstract Capillary electrophoresis was successfully applied for the determination of a gaseous analyte of interest i.e., dissolved oxygen in water samples, for the first time. Each analysis was performed within 5 min and as low as 50 ppb dissolved oxygen can be determined by this method. The proposed method was successfully applied for the analysis of river water. The method is versatile for analysis of miniaturized samples and studies of reaction kinetics.

Photometric determination of dissolved oxygen with iron(II) cacotheline oxalate blue

Iron (II)-cacotheline-oxalate blue solution is used as reductometric reagent for the estimation of dissolved oxygen. By titrating the blue complex solution photometrically, the dissolved oxygen in water samples can be accurately determined in the range of 2 to 8 mg/l. The stoichiometry of the reaction between dissolved oxygen and the blue complex was found to be 1:0.8 or 5:4. The applicability of this method to distilled water, river water and reservoir water was tested.

An improved desorber design for use in couloximetry

A new desorber design for use in the couloximetric determination of oxygen in water samples is described. In comparison with previous systems it significantly improves the efficiency of transfer of oxygen from sample to carrier gas and reduces the ingress of atmospheric oxygen through leaks. Lower and more stable baselines are now attainable, with levels of <0.5 μV being commonly produced. The enhanced stability of the baseline has decreased the lower limit of oxygen detection to around 0.13 pg of oxygen. The minimum sample size for analysis with a 1% error due to baseline fluctuation has also been reduced to around 1 μl for saturated seawater at 0°C.

Microdetermination of dissolved oxygen in water by a rapid spectrophotometric method

A spectrophotometric method utilizing the dye indigo carmine has been applied to the analysis of dissolved oxygen in water samples. Oxygen concentration has been determined by the decrease in absorbance at 410 mμ of reduced indigo carmine solutions oxidized by dissolved oxygen. A simple modification of the sample compartment of a Bausch and Lomb Spectronic 20 or 340 spectrophotometer allows rapid and accurate measurements to be made within 3 min. Dissolved oxygen in the ranges of 0 to 10% and 0 to 100% saturation can be analyzed without many of the interferences inherent in the standard Winkler method.

Mass Spectrometric Determination of Oxygen in Water Samples

Mass Spectrometric Determination of Oxygen in Water Samples