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Гидрохимическая характеристика вод европейской Арк­тики в летний период 2021 г.

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The article presents the results of studies of the hydrochemical structure of waters in the European Arctic around Svalbard. The data used in the work were obtained from the 84th voyage of the R/V Akademik Mstislav Keldysh in July–August 2021. A total of five transects were considered west, north, and east of Svalbard (Spitsbergen). Concentrations of dissolved oxygen, silicon, phosphate phosphorus, nitrite nitrogen, nitrate nitrogen and ammonium nitrogen were determined. Marked differences in dissolved oxygen distribution were identified between waters of Atlantic and Arctic origin. Surface, intermediate and deep layers were selected throughout the entire water column. Concentrations of silicon, mineral phosphorus and nitrate nitrogen gradually increase with depth. Maximum concentrations of nitrite and ammonium nitrogen are observed in the intermediate layer. It is noted that despite significant differences in the depth of the transects, the main changes occur in the surface and intermediate layers. Nutrient depletion in surface waters was reported in August for the second consecutive year.

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  • Research Article
  • 10.26565/2410-7360-2016-44-24
Assessment of water quality in the river Lopan within the boundaries of Kharkiv region
  • Dec 17, 2016
  • V H Klymenko + 1 more

The actuality of this article is in the implementation of a systematic approach to the study of natural water quality of the river Lopan (within Kharkiv region).Assessment of water quality in the rivers has been studied by such scholars as O.O. Alexin, A.M. Gorev, V.M. Zhukynsky, F.F. Kirkov, A.M. Nikanorov, A.V. Ogievsky, O.P. Oksijuk, N.P. Puzyrevsky, V.D.Romanenko, V.K. Khilchevsky, A.P. Yatsyk, et al. But they all studied mainly large river basins, and we propose to investigate changes in the chemical composition of an average river that flows in the industrialized region.The research has been conducted on the methodology of environmental assessment of surface water quality according to the respective categories, in three blocks: salt, trophy-saprobiological, and the block of specific toxic action substances.The results of the research have shown that according to the salt block water in the river is saline; according to the trophy-saprobiological block water in the rivers is the most heavily polluted with phosphate phosphorus, which often leads to significant eutrophication of the reservoirs, nitrite and nitrate nitrogen, low water clarity; according to the block of specific substances – with phenols; according to the environmental index surface water quality of the river Lopan virtually did not change during 1980-2014, 2-3 grade (water is quite clean, slightly contaminated), but in recent years there has been no improvement in water quality of the river.In previous years industry was the main source of water pollution of the river Lopan, but in recent years it is municipal services, industrial enterprises and agriculture. The river Lopan was the most polluted in 1990, the least - in 2010. The biggest pollutants in the river Lopan were nitrite nitrogen, nitrate nitrogen, phosphorus and phosphate phenols.The actuality of this article is in the implementation of a systematic approach to the study of natural water quality of the river Lopan (within Kharkiv region).Assessment of water quality in the rivers has been studied by such scholars as O.O. Alexin, A.M. Gorev, V.M. Zhukynsky, F.F. Kirkov, A.M. Nikanorov, A.V. Ogievsky, O.P. Oksijuk, N.P. Puzyrevsky, V.D.Romanenko, V.K. Khilchevsky, A.P. Yatsyk, et al. But they all studied mainly large river basins, and we propose to investigate changes in the chemical composition of an average river that flows in the industrialized region. The research has been conducted on the methodology of environmental assessment of surface water quality according to the respective categories, in three blocks: salt, trophy-saprobiological, and the block of specific toxic action substances.The results of the research have shown that according to the salt block water in the river is saline; according to the trophy-saprobiological block water in the rivers is the most heavily polluted with phosphate phosphorus, which often leads to significant eutrophication of the reservoirs, nitrite and nitrate nitrogen, low water clarity; according to the block of specific substances – with phenols; according to the environmental index surface water quality of the river Lopan virtually did not change during 1980-2014, 2-3 grade (water is quite clean, slightly contaminated), but in recent years there has been no improvement in water quality of the river. In previous years industry was the main source of water pollution of the river Lopan, but in recent years it is municipal services, industrial enterprises and agriculture. The river Lopan was the most polluted in 1990, the least - in 2010. The biggest pollutants in the river Lopan were nitrite nitrogen, nitrate nitrogen, phosphorus and phosphate phenols.

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  • Research Article
  • Cite Count Icon 5
  • 10.32845/bsnau.vet.2020.1.6
Control of abiotic factors of pots of Sumy region
  • Jan 1, 1970
  • Bulletin of Sumy National Agrarian University. The series: Veterinary Medicine
  • Roman Petrov + 3 more

Control of abiotic factors of pots of Sumy region

  • Conference Article
  • 10.1109/icbbe.2011.5780729
Notice of Retraction: Spatial Discrepancy of Nitrate and Nitrite Pollution in the Jiantan River in the Three Gorges Reservoir Area
  • May 1, 2011
  • 2011 5th International Conference on Bioinformatics and Biomedical Engineering
  • Xiangchao Liu + 4 more

Retracted.

  • Research Article
  • Cite Count Icon 4
  • 10.18307/1998.sup51
A Model on a Physico-Biological Engineering Experiment for Purifying Water by using <i>Trapa natans var</i>. <i>bispinosa</i> in Wulihu Bay of Taihu Lake, China
  • Jan 1, 1998
  • Journal of Lake Sciences
  • Hu Weiping + 2 more

A model on a physico-biological engineering experiment for purifying water in Wulihu Bay of Lake Taihu by using Trapa natans var. bispinosa was constructed. The state variables in water in the physico-biological engineering were ammonium nitrogen (NH<sub>4</sub><sup>+</sup>-N); nitrate nitrogen (NO<sub>3</sub><sup>-</sup>-N); nitrite nitrogen (NO<sub>2</sub><sup>-</sup>-N); phosphate phosphorus (PO<sub>4</sub><sup>3-</sup>-P); dissolved oxygen (DO); nitrogen (N) and phosphorus (P) in detritus; biomass density, N and P in phytoplankton and in Trapa natans var. bispinosa, N and P in the substance adsorbed by the membrane of the engineering and the rootstocks of Trapa natans var. bispinosa. The state variables in bottom mud layer were PO<sub>4</sub><sup>3-</sup>-P in the core water,exchangeable P and N. The external forcing functions were solar radiation, water temperature, NH<sub>4</sub><sup>+</sup>-N; NO<sub>3</sub><sup>-</sup>-N; NO<sub>2</sub><sup>-</sup>-N; PO<sub>4</sub><sup>3-</sup>-P; N and P in detritus; DO; phytoplankton concentrations in inflow water and the retention time of the water in physico-biological engineering channel. The main physical, chemical and biological processes considered in the model were:growth of Trapa natans var. bispinosa and phytoplankton; oxidation of NH<sub>4</sub><sup>+</sup>-N and NO<sub>2</sub><sup>-</sup>-N, of detritus break down; N and P sorption by the enclosure cloth of the experimental engineering and by the rootstocks of Trapa natans var. bispinosa in water; reaeration of water; uptake of P, NH<sub>4</sub><sup>+</sup>-N, NO<sub>3</sub><sup>-</sup>-N by phytoplankton and <span style=text-decoration:underline>Trapa natans</span> var. <span style=text-decoration:underline>bispinosa</span>:mortality of the phytoplankton and <span style=text-decoration:underline>Trapa natans</span> var. <span style=text-decoration:underline>bispinosa</span>:settling of detritus; and nutrient release from sediment. Comparison of calculated results and observed results showed that the model was constructed reasonably for the experiment. The mechanism of purifying lake water in the experiment engineering was discussed by the use of the model.;A model on a physico-biological engineering experiment for purifying water in Wulihu Bay of Lake Taihu by using Trapa natans var. bispinosa was constructed. The state variables in water in the physico-biological engineering were ammonium nitrogen (NH<sub>4</sub><sup>+</sup>-N); nitrate nitrogen (NO<sub>3</sub><sup>-</sup>-N); nitrite nitrogen (NO<sub>2</sub><sup>-</sup>-N); phosphate phosphorus (PO<sub>4</sub><sup>3-</sup>-P); dissolved oxygen (DO); nitrogen (N) and phosphorus (P) in detritus; biomass density, N and P in phytoplankton and in Trapa natans var. bispinosa, N and P in the substance adsorbed by the membrane of the engineering and the rootstocks of Trapa natans var. bispinosa. The state variables in bottom mud layer were PO<sub>4</sub><sup>3-</sup>-P in the core water,exchangeable P and N. The external forcing functions were solar radiation, water temperature, NH<sub>4</sub><sup>+</sup>-N; NO<sub>3</sub><sup>-</sup>-N; NO<sub>2</sub><sup>-</sup>-N; PO<sub>4</sub><sup>3-</sup>-P; N and P in detritus; DO; phytoplankton concentrations in inflow water and the retention time of the water in physico-biological engineering channel. The main physical, chemical and biological processes considered in the model were:growth of Trapa natans var. bispinosa and phytoplankton; oxidation of NH<sub>4</sub><sup>+</sup>-N and NO<sub>2</sub><sup>-</sup>-N, of detritus break down; N and P sorption by the enclosure cloth of the experimental engineering and by the rootstocks of Trapa natans var. bispinosa in water; reaeration of water; uptake of P, NH<sub>4</sub><sup>+</sup>-N, NO<sub>3</sub><sup>-</sup>-N by phytoplankton and <span style=text-decoration:underline>Trapa natans</span> var. <span style=text-decoration:underline>bispinosa</span>:mortality of the phytoplankton and <span style=text-decoration:underline>Trapa natans</span> var. <span style=text-decoration:underline>bispinosa</span>:settling of detritus; and nutrient release from sediment. Comparison of calculated results and observed results showed that the model was constructed reasonably for the experiment. The mechanism of purifying lake water in the experiment engineering was discussed by the use of the model.

  • Research Article
  • Cite Count Icon 7
  • 10.31857/s0869-78092019342-51
Features of the water quality in small rivers of Khabarovsk in winter season
  • Jun 24, 2019
  • Геоэкология. Инженерная геология. Гидрогеология. Геокриология
  • V P Shesterkin + 2 more

The paper presents the results of studies of the water chemical composition in small rivers of Khabarovsk and its surroundings in the winter low water period in 2017-2018. A significant variation is shown in the concentrations of dissolved substances in river water due to large differences in the composition of underlying rocks, groundwater and wastewater, as well as water of worn-out water supply and sanitation systems. The hydrocarbonate-calcium composition of water, the lowest pH and mineralization values, the phosphate concentrations, as well as the dominance of sulfate ion over chloride and nitrate nitrogen’s dominance over ammonium in the river water in the protected areas were identified. The higher content of dissolved substances and the bicarbonate-calcium (sometimes magnesium) composition of water are typical for the rivers in the outskirts of the city, fed mainly by groundwater in alluvial deposits. Hydrocarbonate-sodium (rarely ammonium) composition of water, maximum concentrations of major ions, contamination with phosphates, ammonium nitrogen, petroleum products and surfactants, absence of nitrite and nitrate nitrogen in anaerobic conditions were noted in the river water at the outskirts of the city, which are fed by wastewater. The hydrocarbonate-calcium composition of water, a decrease in the elevated concentrations of major ions during the winter season, pollution with ammonium and nitrite nitrogen, phosphates and oil products of water in the rivers of the central part of the city fed by groundwater and water of worn-out water supply and water disposal systems were established.

  • Research Article
  • Cite Count Icon 10
  • 10.1007/bf00016627
Nitrogen and Phosphorus in a Stretch of the Guadalupe River, Texas, with Five Main-Stream Impoundments by
  • May 1, 1973
  • Hydrobiologia
  • Herbert H Hannan + 2 more

Nitrogen and phosphorus were studied in a 168-km stretch of the Guadalupe River that had five main-stream impoundments. Flow through the study area was controlled by releases from these five reservoirs and from Canyon Reservoir, a deep-storage reservoir, located 30 km upstream. Parameters measured monthly on a diel basis at 16 stations were nitrate nitrogen, nitrite nitrogen, ammonia nitrogen, Kjeldahl nitrogen, inorganic phosphate phosphorus, organic phosphate phosphorus, and total phosphate phosphorus. Inorganic nitrogen concentrations observed in this study were as high or higher than that previously reported for other bodies of water. Nitrate nitrogen entered the study area in relatively high concentrations from Comal Springs which was a major source of water for the Guadalupe River. Water from Canyon Reservoir, the other major source of water, was relatively low in nitrate nitrogen. The concentration of nitrate nitrogen was, therefore, dependent in part upon the portion of the total river flow originating from the two sources. Increased discharge from Canyon Reservoir and utilization by plants in areas of high chlorophyll a resulted in low nitrate-nitrogen levels. Retention of water in reservoirs reduced the concentration of nitrate nitrogen due to increased utilization by plants in areas of low flow. Nitrate nitrogen, in general, reached seasonal minima in summer and maxima in winter. Nitrite nitrogen showed considerable variation with no meaningful pattern except that higher concentrations occurred in association with high chlorophyll a and high Kjeldahl nitrogen, regions and periods of low river flow, and large phytoplankton populations. There was no increase in concentration of any form of nitrogen in the vicinity of sewage outfalls and no downstream accrual. Phosphorus levels in the study area were as high or higher than those reported in studies of other bodies of water. Sewage treatment plants at New Braunfels and Seguin, Texas, were major sources of phosphorus to the Guadelupe River. Total phosphate phosphorus was determined to be the most critical phosphate parameter in assessing eutrophication. Seasonally, it ranged from a winter high to a summer low. Concentrations were highest immediately below sewage outfalls and decreased as water progressed downstream. Inorganic-phosphate-phosphorus concentrations showed no clear seasonal trend but were clearly associated with sewage outfalls. Since large standing crops of phytoplankton were observed in areas of low inorganic phosphate phosphorus, it was not considered to limit photosynthesis. Total organic phosphate phosphorus varied seasonally, with high concentrations occurring during the spring and low concentrations in the fall. Total organic phosphate phosphorus showed no correlation with sewage outfalls, but was correlated to a degree with total Kjeldahl nitrogen and chlorophyll a. No consistent pattern of diel fluctuations was evident for any phosphorus or nitrogen compounds analyzed.

  • Research Article
  • Cite Count Icon 3
  • 10.2166/ws.2019.036
Experimental effect of medium ratio on removal efficiency of nitrate nitrogen in groundwater by zero-valent iron, activated carbon and zeolite
  • Feb 26, 2019
  • Water Supply
  • Sizhi Cao + 6 more

In this study, column experiments in the laboratory were set up to examine how the concentrations of nitrate nitrogen, nitrite nitrogen, and ammonia nitrogen changed when a nitrate-rich solution was passed through a medium comprising zero-valent iron, activated carbon, zeolite, and coarse sand. We varied the proportions of the components of the medium to determine how it influenced the nitrate removal and nitrogen fractions. Three different scenarios were used, with: (1) iron, activated carbon, and coarse sand at a ratio of 3:1:6; (2) iron, activated carbon, and zeolite at a ratio of 3:1:6; and (3) iron, activated carbon, and zeolite at a ratio of 3:3:4. The nitrate nitrogen concentration decreased from 25 mg/L to 2 mg/L in the first scenario. Removal was better when zeolite was added to the medium as most of the nitrate nitrogen broke down to ammonia nitrogen, with nitrite nitrogen as an intermediate product. The results of the tests showed that nitrate removal was best when the medium was iron, activated carbon, and zeolite, mixed at a ratio of 3:1:6. This study provides a scientific reference for in situ remediation of nitrate pollution in groundwater.

  • Research Article
  • 10.30970/vlubs.2021.85.05
Вплив кам'яновугільного попелу та гумату калію на вміст нітрогену і карбону в субстраті відвалу вуглепромисловості й органах Sorghum drummondii (Nees ex Steud.) Millsp. &amp; Chase
  • Feb 25, 2021
  • Visnyk of Lviv University. Biological series
  • S Beshley + 2 more

Researched ammonium, nitrite and nitrate nitrogen and organic carbon contents in gray-black unburned rock substrate from coal industry waste rock dump of Central Enrichment Factory (CEF) owned by PJSC “Lviv Coal Company” (Lviv Oblast, Ukraine) and total nitrogen and organic carbon contents in organs of Sorghum drummondii (Nees ex Steud.) Millsp. &amp; Chase under effect of coal fly ash from the Dobrotvir thermal power plant (Lviv Oblast, Ukraine) and potassium humate “ГКВ-45” (made by LLC “PARK”, Lviv Oblast, Ukraine). Found high content of organic carbon and ammonium nitrogen in waste rock dump substrate with contrast to low content of nitrite and nitrate nitrogen compare to re­latively optimal soil mixture of the standard. Detected low carbon and nitrogen contents in organs of S. drummondii which grew on the waste rock dump substrate, as well as a significantly increased carbon/nitrogen-ratio (in this research the ratio of organic carbon content to total nitrogen content) compare to plants of the standard. Addition of coal fly ash in waste rock dump substrate decreased ammonium nitrogen and organic carbon contents with contrast to nitrite and nitrate nitrogen increasing, as well as organic carbon and total nitrogen in roots, stalks and leaves of researched plants. Introduction of potassium humate increased nitrite and nitrate nitrogen contents in waste rock dump substrate, organic carbon and total nitrogen contents in organs of S. drummondii. Changing of both studied macronutrients contents in plants under the effect of ameliorants caused decreasing carbon/nitrogen-ratio to the direction of the standard values. Growing of S. drummondii grass for 95 days increased organic carbon content in all options of substrates except the rock with potassium humate addition and decreased ammonium, nitrite and nitrate nitrogen contents in all researched options of substrates without exceptions. Noted that combined effect of coal fly ash and potassium humate on carbon and nitrogen contents in waste rock dump substrate and organs of S. drummondii is stronger than just one of both above mentioned researched ameliorants.

  • Research Article
  • Cite Count Icon 12
  • 10.1080/00032719.2016.1238923
Determination of Total Nitrogen, Ammonia, and Nitrite in River Water by Near-infrared Spectroscopy and Chemometrics
  • Jun 29, 2017
  • Analytical Letters
  • Jian Huang + 5 more

ABSTRACTTotal nitrogen, ammonia nitrogen, and nitrite nitrogen were determined in river water during intermittent aeration by near-infrared spectroscopy with a back-propagation neural network. Near-infrared spectra were obtained for 138 samples. A total of 116 samples were used as the calibration set and the remainder as the test set. The spectral region was from 4000 to 12,500 cm−1. Principal component analysis was used as a preprocessing method of the near-infrared spectra to eliminate redundant information. The six principal components were extracted through principal component analysis. Back-propagation neural network models of total nitrogen, ammonia nitrogen, and nitrite nitrogen showed that the correlation coefficients were 0.9816, 0.9783, and 0.9562, respectively, with root-mean-square error of cross validation values of 0.04735, 0.03689, and 0.03766. The results of the back-propagation neural network models of total nitrogen, ammonia nitrogen, and nitrite nitrogen indicated that the correlation coefficients were 0.9752, 0.9690, and 0.9524, respectively, with root-mean-square errors of prediction equal to 0.05763, 0.04537, and 0.04157. This study showed that the described approach accurately determined total nitrogen, ammonia nitrogen, and nitrite nitrogen. The concentrations of total nitrogen, ammonia nitrogen, and nitrite nitrogen were 0.64–54.25, 0.57–45.04, and 0.05–31.40 mg · L−1 in river water, respectively.

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  • Cite Count Icon 1
  • 10.21303/2504-5695.2017.00356
IMPROVEMENT OF THE MODEL OF TRANSFORMATION OF NITROGEN-CONTAINING SUBSTANCES IN A WATER BODY FOR THE SOLUTION OF NATURE MANAGEMENT PROBLEM
  • May 31, 2017
  • EUREKA: Life Sciences
  • Oleg Proskurnin + 4 more

In the article is considered the one of aspects of nature management regulation – an account of successive transformation of pollutants in a water body, that come with waste waters of industrial, municipal and agricultural enterprises. It is necessary at the determination of permissible pollutants emission with waste waters that doesn’t allow the excess of the permissible level of substances content in the control point of a water body. This problem is considered on the example of successive transformation of nitrogen-containing substances in the following transformation order: organic nitrogen – ammonium nitrogen - nitrite nitrogen – nitrate nitrogen. The topicality of the modeling of nitrogen-containing substances is conditioned by their role in water ecosystems functioning. At that existent mathematical models of natural water quality formation that take into account substances transformation contain the large number of unknown parameters. So, the use of such models in problems of nature management regulation is problematic, because identification of model parameters is a separate very complicated scientific problem. And existent models with relatively small number of parameters don’t take into account the natural pollution of water bodies, caused by the life activity of organisms; substance losses in the transformational chain are also possible. The improved matrix mathematical model of nitrogen-containing substances transformation without the indicated shortcomings is offered.

  • Research Article
  • Cite Count Icon 5
  • 10.1002/clen.201300259
Fate of Nutrients in Secondary Treated Municipal Wastewater during Percolation through the Soil Media
  • Nov 26, 2013
  • CLEAN – Soil, Air, Water
  • Mesut Ak + 1 more

The fate of nutrients (phosphorous and nitrogen species) was investigated in secondary treated municipal wastewater (STMWW) during percolation through soil media by using an experimental set‐up that consists of multiple soil columns. The columns were packed with silt loam soil samples and were operated under two different wetting and drying cycles to represent the typical operational conditions in a soil aquifer treatment (SAT) system. Dissolved oxygen, oxidation–reduction potential, ammonium nitrogen, nitrite nitrogen, nitrate nitrogen, total nitrogen, and phosphate phosphorus concentrations were measured in samples collected from different sampling ports along the columns. Average removal values of 62.8, 67.1, and 97.1% were achieved over 75 cm of effective soil depth over 25 weeks of operation for ammonium nitrogen, total nitrogen and phosphate phosphorus, respectively. The removal performance of nutrients typically increased by soil depth and no decrease in removal performance was observed up to end of the study. Consequently, SAT system can be considered to be an effective and low cost advanced treatment method for polishing residual nutrients in a STMWW.

  • Single Report
  • Cite Count Icon 13
  • 10.3133/wri874004
Effects of runoff controls on the quantity and quality of urban runoff at two locations in Austin, Texas
  • Jan 1, 1987
  • Clarence T Welborn + 1 more

Rapid urban development in the Austin metropolitan area, Texas, is causing concern about increasing peak discharges from storm runoff and the degradation of the quality of water in receiving streams, lakes, and aquifers. In an attempt to decrease peak discharges and improve water quality, runoff controls are being required in some watersheds. This report summarizes the precipitation, streamflow, and water-quality data collected from September 1982 to September 1984 upstream and downstream from runoff controls at two locations, and presents the effects of these runoff controls on streamflow and the quality of runoff water. The two controls are a detention and filtering pond near Barton Creek Square Shopping Center, a large shopping center southwest of downtown Austin, and a grass-swale control in the Al ta Vista Planned Unit Development, a mul tipie-family housing area.

  • Research Article
  • Cite Count Icon 2
  • 10.15244/pjoes/92123
Using Near Infrared Spectroscopy to Quickly Analyze Different Nitrogens during the Shortcut Biological Removal of Nitrogen from a Polluted River
  • Mar 5, 2019
  • Polish Journal of Environmental Studies
  • Jian Huang + 8 more

During shortcut biological nitrogen removal in a polluted river, total nitrogen, ammonia nitrogen and nitrite nitrogen were quantified by near infrared spectroscopy and the synergy interval partial least squares (siPLS) algorithm. Spectral data of 138 water samples were obtained with a near infrared spectrometer. In addition, the real values of total nitrogen, ammonia nitrogen and nitrite nitrogen were measured with traditional chemical methods. SiPLS analysis models of total nitrogen, ammonia nitrogen and nitrite nitrogen were built through the siPLS algorithm based on spectral data and real values. The results obtained from the siPLS analysis model of total nitrogen revealed that, when the full spectra were divided into 19 intervals, the combination of the 7 th , 12 th and 19 th subintervals yielded the best model. The correction coefficient (R p ) is 0.9931, with the root mean squared error of calibration (RMSECV) being 1.7869. The results obtained from the siPLS analysis model of ammonia nitrogen indicated that, when the full spectra were divided into 16 intervals, the combination of the 1 st , 7 th , 15 th and 16 th subintervals yielded the best model. The R p is 0.9947 and the RMSECV is 1.3419. For nitrite nitrogen, the siPLS analysis model indicated that, when the full spectra were divided into 16 intervals, the combination of the 7th and the 11th subintervals yielded the best model. The R p and RMSECV was 0.9951 and 1.0518. These findings demonstrated that the proposed approach may effectively analyze the concentrations of total nitrogen, ammonia nitrogen and nitrite nitrogen during the treatment of a polluted river based on shortcut biological nitrogen removal. This approach,

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  • Cite Count Icon 9
  • 10.1155/2015/798397
Effect of Nitrite and Nitrate Concentrations on the Performance of AFB-MFC Enriched with High-Strength Synthetic Wastewater.
  • Oct 1, 2015
  • Biotechnology Research International
  • Jian-Sheng Huang + 7 more

In order to study the effect of nitrite and nitrate on the performance of microbial fuel cell, a system combining an anaerobic fluidized bed (AFB) and a microbial fuel cell (MFC) was employed for high-strength nitrogen-containing synthetic wastewater treatment. Before this study, the AFB-MFC had been used to treat high-strength organic wastewater for about one year in a continuous flow mode. The results showed that when the concentrations of nitrite nitrogen and nitrate nitrogen were increased from 1700 mg/L to 4045 mg/L and 545 mg/L to 1427 mg/L, respectively, the nitrite nitrogen and nitrate nitrogen removal efficiencies were both above 99%; the COD removal efficiency went up from 60.00% to 88.95%; the voltage was about 375 ± 15 mV while the power density was at 70 ± 5 mW/m2. However, when the concentrations of nitrite nitrogen and nitrate nitrogen were above 4045 mg/L and 1427 mg/L, respectively, the removal of nitrite nitrogen, nitrate nitrogen, COD, voltage, and power density were decreased to be 86%, 88%, 77%, 180 mV, and 17 mW/m2 when nitrite nitrogen and nitrate nitrogen were increased to 4265 mg/L and 1661 mg/L. In addition, the composition of biogas generated in the anode chamber was analyzed by a gas chromatograph. Nitrogen gas, methane, and carbon dioxide were obtained. The results indicated that denitrification happened in anode chamber.

  • Research Article
  • Cite Count Icon 3
  • 10.1080/00288330.1978.9515723
Groundwater quality along the eastern shores of Lake Taupo, 1975–76
  • Mar 1, 1978
  • New Zealand Journal of Marine and Freshwater Research
  • Peter H John + 2 more

To investigate the extent of spatial and temporal variation in groundwater quality along the eastern shores of Lake Taupo, New Zealand, data were collected from May 1975 to March 1976 from 14 boreholes sited to represent a variety of land use and human population density. Physical parameters investigated were water level, temperature, and electrical conductivity; the chemical constituents monitored were soluble reactive phosphorus, total dissolved phosphorus, nitrate and nitrite nitrogen (combined), ammonium nitrogen, total soluble iron, major cations and anions, and pH. The results show that groundwater quality can vary greatly over time and space. For example, spatial variation in mean soluble reactive phosphorus levels was 1–340 mg.m −3 , in mean nitrate and nitrite nitrogen (combined) 3–13 930 mg.m −3 , and in ammonium nitrogen from 5–633 mg.m −3 . The most extreme variation with time concerned nitrate nitrogen at a site in Taupo township, where the concentration dropped from 16 430 mg.m −3 in early June 1975 to 1170 mg.m −3 in March 1976. Sometimes temporal variation was relatively small: at Motutere nitrate nitrogen stayed within the range 131–202 mg.m −3 during the study period. Generally, a few infrequently monitored boreholes should not be relied on to describe variations in groundwater quality.

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