Nitrate Ion Concentration Research Articles

Quality of Water in the Road Drainage Systems in the Warsaw Agglomeration, Poland

Water from road drainage systems shed into ditches and infiltration reservoirs may pose a hazard to the natural environment due to the possibility of being introduced into groundwater and surface water. The paper presents the results of chemical analyses of samples collected from selected points of the Warsaw agglomeration road drainage system. The samples were tested for the content of the following parameters: pH, EC (multimeter-electrode), Cl− (Mohr method), SO42−, PO43−, NH4+, NO3−, TOC, COD (UV-VIS), Cu, Zn, Ni, and Pb (ASA). The analysed points differed significantly in the variability of the tested parameters in the measurement period. The highest values of EC and Cl− were noted in three tested points, in which the EC content exceeded the permissible values for the second class of water quality. The contents of sulphates in all but one point were within the range for water of very good quality. Water pH was slightly alkaline. Low concentrations of nitrogen forms, nitrate and ammonium ions were observed. The concentrations of Ni, Pb and Zn did not exceed the boundary values for industrial sewage shed into the water or ground. The concentration of Cu exceeded the permissible concentrations determined in the Regulation of the Minister of the Environment almost three times.

Preparation and Characterization of Chitosan-Humic Acid-Zerovalent Iron Nanocomposite for Nitrate Reduction in Water

A new zerovalent iron chitosan-humic acid nanocomposite was prepared and tested for nitrate ion reduction in water. Humic acid was used for intramolecular cross-linking of the chitosan linear chains to increase the active sites on the chitosan biopolymer and then further used as a stabilizer to synthesize zerovalent iron nanoparticles by the reduction of iron (II) chloride with sodium borohydride. Characterization of the products was carried out using infrared spectroscopy, scanning electron microscope, energy dispersive X-ray, and X-ray diffractometer. Batch experiments were conducted for the reduction of nitrate in water using different concentrations of the products in different concentrations of nitrate ion and at different contact time. The adsorption equilibrium data for the nitrate solution gave a favorable adsorption according to the Langmuir equation. Varying the nanocomposite-to-nitrate ion ratio generally led to faster nitrate reduction, with the pseudofirst-order rate constant for the adsorption increasing with increase in nanocomposite-to-nitrate ion ratio. Nitrate removal efficiency of zerovalent iron chitosan-humic acid nanocomposite was further confirmed using real water samples obtained from drainage waste and river with an initial nitrate concentration of 18.00±0.01 and 12.00±0.12 ppm, respectively. The reduction of nitrate in water using the nanocomposite was concluded to be highly effective.

Arsenic toxicity to Chlorella pyrenoidosa and its phycoremediation

Provision of clean drinking water remains a global requirement, so for arsenic-affected areas where various physico-chemical methods are used. These methods require regeneration of media requiring non-stop arsenic checking and it requires skilled operation. Otherwise arsenic contaminated water has to be discarded into the environment. This study examined the probability of using living microalgae Chlorella pyrenoidosa for phycoremediation of arsenic contaminated water (either As(III) or As(V). DO and pH cycles in presence of arsenic (either As(III) or As(V)) ions in the culture did not significantly differ from the control (pure media) indicating that the algae were still growing and photosynthesizing in presence of arsenic ions. As(V) was more noxious than As(III), particularly at pH7.0, but it was opposite at pH9.0. Phycoremediation efficiency of As(V) at pH9.0 by algal cells was greater than that As(III). Monod model has been employed for demonstrating growth kinetics of microalgae in pure media containing various concentrations of nitrate ions. Maximum specific growth rate and saturation constant have been found to be 0.146 d−1 and 8.29E–4g/L, respectively. With the increase in concentration of phosphate in growth medium the growth of microalgae increased. Media with 1.0g/L NaCl indicated the highest algal growth. Addition of NaHCO3 (1g/L) resulted in higher maximum biomass concentration.

Solvent extraction of Ce(III) from nitric acid medium using binary mixture of PC 88A and Cyanex 921

The extraction behaviour of Ce(III) from dilute nitric acid medium using a binary mixture of PC 88A and Cyanex 921 has been investigated. Several process parameters such as contact time, concentration of nitric acid, nitrate ion, extractant, diluents and Ce(III) concentration in aqueous feed, organic to aqueous phase volume ratio and temperature were varied to observe the influence on the extraction and to optimize operating conditions. Experimental results demonstrated that extraction of 0.001mol/L Ce(III) from 0.001mol/L HNO3 was 96.6% with mixture of 0.7mol/L PC 88A and 0.1mol/L Cyanex 921. The extraction mechanism was established by applying method of slope analysis. Thermodynamic parameters were calculated from temperature variation studies. The loaded Ce(III) was effectively stripped using 0.6mol/L HCl or 1.2mol/L H2SO4. Extraction data were analysed using regression method.

Toxicity and bioremediation of As(III) and As(V) in the green microalgae Botryococcus braunii: A laboratory study

ABSTRACTWorldwide threats of fuel shortages in the near future and climate change because of greenhouse gas emissions are posing severe challenges and therefore it is vital to search for sustainable ways of preventing the consequences. The dual use of microalgae for phycoremediation and biomass production for sustainable biofuel production is a viable choice. Phycoremediation of As(III) and As(V) ions using microalgae was investigated in a two-staged batch reactor. Accumulation and toxicity of inorganic arsenic forms (As(III) and As(V)) to green microalgae Botryococcus braunii depend on environmental factors. Dissolved oxygen and pH cycles did not significantly differ due to the absence or presence of arsenic (either As(III) or As(V)) ions in the culture. Monod model was utilized for representing the growth kinetics of microalgae in pure media containing various concentrations of nitrate ions. Maximum specific growth rate and saturation constant were found to be 0.14788 d−1 and 0.00105 g/L, respectively. With the increase in concentration of phosphate in growth medium, the growth of microalgae increased. Media with NaCl (1.0 g/L) and NaHCO3 (1 g/L) resulted in higher maximum biomass concentration. Effect of coexisting ions on phycoremediation of As(III) and As(V) ions using microalgae was studied.

Nitric Acid Leaching of Copper-Zinc Sulfide Middlings

Nitride leaching of copper-zinc sulfide middlings that are difficult to concentrate is studied with the aim of clarifying and supplementing results obtained previously. It is shown that organization of two-stage countercurrent leaching makes it possible to reduce the concentration of nitrate ions within leaching solution, to increase the degree of nitric acid regeneration, and to increase copper and zinc concentration in solution and precious metals in the residue.

POLYVINYLPYRROLIDONE AS A NEW FLUORESCENT SENSOR FOR NITRATE ION

Polymeric materials are widely applied in many areas, such as drug delivery', biomedical device', electrochemical' and fluorescence As for the fluorescence sensor, the most investigated polymeric material is the conjugated one. In this study, non-conjugated polyvinylpyrrolidone (PVP) is investigated for the first time as the potential polymeric material to sense nitrate ions by fluorescence spectroscopy. Since the toxic nitrate ions (NO,) leads to environmental pollution if present in high concentration, the unsatisfied detection limit and narrow linear detection range ofexisting nitrate ion sensor urges researchers to develop a better nitrate sensor'. Therefore, a good fluorescent sensor needs to be developed to overcome this problem. In this study, the PVP was diluted into various concentrations (3-10%) and used to sense the nitrate ions with different concentrations (10-4_10-1 M), based on the fluorescence spectroscopy quenching. PVP showed two excitation peaks at 285 and 330 nm due to the presence of C~ and N-C, respectively. As shown in Fignre 1, the two excitation peaks gave one strong emission at around 408 nm, which was used as the monitored wavelength for the sensing performance. It was found that the emission intensity increased proportionally with the concentration of the PVP. In order to investigate the sensing capability of the functional fluorescent groups, the quenching tests were carried out at excitation wavelength of 285 and 330 nm, At both excitation wavelengths, linear relationship was observed between the nitrate ions concentrations and the relative emission intensity. The quenching constants at excitation wavelength of 285 nm were much higher than those at 330 nm. This result indicated that C=O site was more favorable to sense NO, ions than the N-C site. The PVP 7% gave the highest quenching constant; the K,vvalue was 9.89 M 1 and 2.45 M 1 for excitation at 285 and 330 nm, respectively. The sensing capability was evaluated in the presence of interference ions (SOl-, HCO,-, OIr, and CI) It was observed that the interference ions interacted strongly with the C~, but weakly with the N-C. Therefore, in the presence of the interference ions, the PVP would be a potential fluorescent sensor when it is excited at 330 nm.

Groundwater contamination sourced from the main cemetery of Tabriz, Iran

ABSTRACTSitting on porous and highly permeable volcanic tuffs, the main cemetery of Tabriz (Vadi-e Rahmat) poses a high potential risk to groundwater quality. To investigate the potential pollution, groundwater was sampled in the fall of 2011 and spring of 2012 around the cemetery and analyzed for major physicochemical and microbial parameters by standard methods. The results indicated relatively high concentrations of calcium, magnesium, sulfate, nitrate, and fluoride ions and microbial colonies in the aquifer samples; nitrate:sodium and chloride:sodium ratios as well as good correlation between nitrate and fluoride concentrations confirmed the source of contamination to be the cemetery. These releases from the cemetery have also contaminated local qanats, traditional Iranian horizontal channels that are used for irrigation and drinking water. The main factors that increase the risk of groundwater pollution from the cemetery are the relatively shallow groundwater table, the relatively high permeability of the aquifer, and the high rate of burials.

Effect of salting-out agents on nitric acid distribution between liquid and vapor in the course of evaporation of nitric acid radioactive waste

The database on the influence of concentrations of salting-out agents with different cation valence (Li+, Na+, K+, Cs+, NH4+, Mg2+, Ca2+, Cu2+, Zn2+, Al3+, Fe3+, La3+, Pu4+, UO22+ nitrates) and of H2SO4 on the HNO3 distribution between liquid and vapor at atmospheric pressure was verified and expanded by performing equilibrium evaporation experiments in an evaporator without reflux with circulation of the bottoms. This equilibrium can be described by the equation \(\log {\kern 1pt} {\alpha _H} = - 2.35 + 2\log \;{X_{\Sigma N{O_3}}}\) (where \({X_{\Sigma N{O_3}}}\) is the total concentration of nitrate ions in aqueous solution), taking into account partial binding of water due to hydration of the salting-out agent and apparent hydrolysis of polyvalent cations, and also incomplete dissociation of sulfuric acid. The suggested model is valid at \({X_{\Sigma N{O_3}}}\) from 3 to 16 M (azeotrope); at \({X_{\Sigma N{O_3}}}{\text{ < }}\;3\), Raoult’s law is observed (αH = const), which is confirmed by a number of examples. In this model, the additivity of the properties of the salting- out agents, taking into account the concentration of “free” water, is assumed, which allows calculation of the composition of the bottoms and distillate when evaporating waste of any composition from radiochemical plants.

Variation of nitrate content among randomly selected taro (Colocasia esculenta (L.) Schott) genotypes and the distribution of nitrate within a corm

Taro (Colocasia esculenta) is an important staple crop distributed throughout many tropical and subtropical regions. Very little information is available about the nitrate content and its distribution within taro corms. The aim of this study, based on ion chromatography, was to analyze the concentration and distribution of nitrate within four crucial parts (upper, central, marginal, basal) of taro corms of 8 representative cultivars. The results revealed that the levels of nitrate in taro corms were variable depending on the cultivar and corm parts. The highest levels were determined in the upper part of the corm which is used for the multiplication and establishment of a new crop. Therefore, the size of this part is closely associated with the quality of the planting material. As there are no roots, the initial growth of the new taro plant depends entirely on the nutrients accumulated in the upper part of the corm. During the growth season, this part of the corm gradually becomes the lower (basal) part containing the oldest and the least biochemically active tissue, which has the lowest concentration of nitrate ions. The nitrate content in the central part, which is the most important for human nutrition, was relatively low and varied between 29 and 313mg/kg fresh weight.

Soil Pollution by the Cement Industry in the Bazian Vicinity, Kurdistan Region

The three most significant things in our life are air, water, and soil which are essential for life and any imbalance of these three cause a big problem in nature. Soil is one of the most common agents in life and supplies us with all the basic necessities. Portland cement is one of the common types of cement which is used in construction nowadays. But soil can be polluted by cement plants, where cement industries are established. The chemical composition of cement is a mixture of calcium aluminum silicate also, a trace amount of Cd, Pb, Fe, Ti and silica. According to several chemical analyses the area surrounding industries show that the further the area is from the factory, the better as soil pollution decreases. In this research paper, we checked the physiochemical pH, electrical conductivity, nitrate ions, sulphate ions, Lead ions and calcium ions content in soil in the Bazian area. The area is far from the surrounding industries and this shows that the further the area is from the factory, the better as soil pollution decreases. There is positive correlation between the calcium ions and electrical conductivity. There is negative correlation between pH and concentration of lead ions. There is also weak correlation between sulphate and nitrate ions concentrations in soil samples.

Determination of Nitrate Ion Concentration in Fresh Vegetable Juices Using Ion-Pair Ultra Performance Liquid Chromatography (IP-UPLC)

Determination of Nitrate Ion Concentration in Fresh Vegetable Juices Using Ion-Pair Ultra Performance Liquid Chromatography (IP-UPLC)

The Effects of Bridge Abutments on the Benthic Macroinvertebrate Community

This paper presents the results of determination of concentrations of chloride, sulfate, phosphate, ammonium, sodium, potassium, calcium and magnesium ions along with total nitrogen, pH and electrolytic conductivity for precipitation collected in nonindustrialized regions near Gdansk (Poland). A station used for the collection of samples of precipitation consisted of two substations, one of which was located in a deforested area (clearing), while the second was situated in a spruce forest. The samples were collected over a period of one year, from March 2, 1996 to February 1, 1997. Concentrations of chloride, sulfate, phosphate, nitrate and ammonium ions and of total nitrogen were determined spectrophotometrically . Sodium, potassium and calcium ions were determined using flame photometry while magnesium ions were determined by atomic absorption spectroscopy. pH and electrolytic conductivity of the samples were also measured.

Thermodynamic investigation of extraction of cerium(III) by tributyl phosphate from phosphoric acid solutions

A mechanism of extraction of cerium by tributyl phosphate (TBP) from phosphate solutions using model and production solutions containing, %: 26–28 P2O5, 1,2–2,8 SO3, 0,3–0,8 CaO, 0,1–0,4 Al2O3, 0,3–0,4 Fe2O3, and 0,09–0,1 REM(NO3)3. A model solution of phosphoric acid corresponded to the industrial solution of extraction phosphoric acid (EPA) by the content of P2O5 and Ce(NO3)3 and value of pH (0,6). Dependences of extraction parameters on the TBP concentration in o-xylene and concentration of nitrate ions introduced by magnesium and calcium nitrates, which are used as a salting-out agent, are found. The composition of the extracted organic complex of cerium Ce(H2PO4)(NO3)2·TBPorg is determined. A constant of extraction equilibrium and the Gibbs energy of extraction are calculated. It is concluded by the results of the experiment that it is unreasonable to use TBP to extract Ce from phosphoric acid systems without introducing a considerable amount of the salting-out agent.

Distribution Behavior of Neptunium by Extraction with N,N-dialkylamides (DEHDMPA and DEHBA) in Mixer-Settler Extractors

ABSTRACTThe extraction properties of N,N-di(2-ethylhexyl)-2,2-dimethylpropanamide (DEHDMPA) and N,N-di(2-ethylhexyl)butanamide (DEHBA) for Np(V) and Np(VI) were studied by a batch method using various nitrate ion concentrations. The distribution ratios of Np(VI) obtained with DEHDMPA and DEHBA exceeded unity when the nitrate ion concentration was > 3 mol/dm3, while DEHDMPA and DEHBA barely extracted Np(V). A continuous counter-current experiment using mixer-settler extractors was performed to evaluate the behavior of Np in a process comprising two cycles using DEHDMPA and DEHBA as extractants. The feed was nitric acid containing U, Pu, Np, and several fission products. The results indicated that part of Np(V) changed its valence state to Np(IV) or Np(VI) after the 1st experimental cycle. The recoveries of Np in the streams of U fraction and U-Pu fraction were 63.7% and 29.1%, respectively.

Modeling of the chemical composition of fine particulate matter: Development and performance assessment of EASYWRF-Chem

The European emission Adaptation SYstem for the WRF-Chem model (EASYWRF-Chem) has been developed to generate chemical information supporting the WRF-Chem requirements from any emission inventory based on the CORINAIR methodology. Using RADM2 and RACM2 mechanisms, “emission species” are converted into “model species” thanks to the SAPRC methodology for gas phase pollutant and the PM10 and PM2.5 fractions. Furthermore, by adapting US EPA PM2.5 profiles, the processing of aerosol chemical speciation profiles separates the unspeciated PM2.5 emission into five chemical families: sulfates, nitrates, elemental carbon, organic aerosol and unspeciated aerosol. The evaluation of the model has been performed by separately comparing model outcomes with (i) meteorological measurements; (ii) NO2, O3, PM10 and PM2.5 mass concentrations from the regional air quality monitoring network; (iii) hourly-resolved data from four field campaign measurements, in winter and in summer, on two sites in the French northern region. In the latter, a High Resolution — Time of Flight — Aerosol Mass Spectrometer (HR-ToF-AMS) provided non-refractory PM1 concentrations of sulfate, nitrate and ammonium ions as well as organic matter (OM), while an aethalometer provided black carbon (BC) concentrations in the PM2.5 fraction.Meteorological data (temperature, wind, relative humidity) are well simulated for all the time series data except for specific events as wind direction changes or rainfall. For particulate matter, results are presented by considering firstly the total mass concentration of PM2.5 and PM10. EASYWRF-Chem simulations overestimated the PM10 mass concentrations by +22% and +4% for summer and winter periods respectively, whereas for the finer PM2.5 fraction, mass concentrations were overestimated by +20% in summer and underestimated by −13% in winter.Simulated sulfate concentrations were underestimated and nitrate concentrations were overestimated but hourly variations were well represented. Ammonium particulate matter was well simulated for all seasons. Although simulated particulate OM concentrations in PM2.5 were underestimated, their hourly variations were well reproduced by the model. At least BC measurements revealed that EASYWRF-Chem forecast performance was higher in winter than during summer when BC concentrations were very low.

U(VI) reduction by Shewanella oneidensis mediated by anthraquinone-2-sulfonate

Anthraquinone-2-sulfonate (AQS) was employed in humus substitutes to evaluate the effects and influencing factors of U(VI) reduction by Shewanella oneidensis MR-1 (S. oneidensis MR-1) under anaerobic condition. The removal rate of U(VI) at 30 °C reaches 99.0% afterd 96 h with the pH value of 7.0 and AQS concentration of 1.0 mmol/L. The effective concentrations of AQS as the accelerator for U(VI) bioreduction are approximately 0.5-1.0 mmol/L. The bioreduction of U(VI) is inhibited when the concentration of AQS exceeds 2.0 mmol/L. The coexistence of ions, such as Cu2+, Cr6+, Mn2+, shows a remarkable negative effect on the U(VI) reduction, and Zn2+ shows less influence on the process compared with other tested ions. The U(VI) reduction is remarkably inhibited when the concentration of nitrate ion exceeds 1.0 mmol/L. Otherwise, no difference is found when the nitrate ion concentration is less than 0.5 mmol/L. Sulfate ion (<5.0 mmol/L) slightly promotes the U(VI) reduction. Zero-valent iron (ZVI) promotes the U(VI) reduction by S. oneidensis, and the reduction rate improves with increasing the amount of ZVI in the range of 0-2.0 g/L. The XPS result indicates that uranium deposits on the cell surface are in U(VI) and U(IV) forms, and the majority of uranium in the solution is stable UO2.

Compared Some Water Characteristics of Tigris River With Euphrates River

: A number of physical and chemical ambient water characteristics of the Tigris and Euphrates rivers were studied on a monthly basis over the year (2011). Samples through 61 sampling station was collected, which distributed by 39 stations along the Tigris river and 22 station along the Euphrates river. Samples collected were analyzed to find a number of variables. The variables measured include cations group (Ca, Mg Mg, Na Na), anions group (Cl, SO4), nitrate NO3, phosphate PO4, total dissolved solids TDS, in addition to measuring pH.Data were analyzed statistically to extract the results. Results showed that average concentrations of calcium ions to the Tigris River 69 mg /L, and the Euphrates River 139 mg /L. The average concentration of magnesium ions of the Tigris River is 34 mg /L, while of the Euphrates River is 67 mg /L. Average concentration of sodium ions of the Tigris River is 58 mg /L, and the Euphrates River is 247 mg /L. Average concentration of sulfate ions of the Tigris River is 154 mg /L, and the Euphrates River is 425 mg /L. Average concentration of chloride ions of the Tigris River is 98 mg / L, and the Average of the Euphrates River is 375 mg /L. Average concentration of nitrate ions of the Tigris River is 3.48 mg /L and the same average value registered to the Euphrates River. Phosphate ions concentration rate of the Tigris River is 0.24 mg / L, and the Euphrates River is 0.20 mg /L. Average concentration of total dissolved solids of the Tigris River is 530 mg / L, while the Euphrates River is 1419 mg /L. Average pH value of the water for the Tigris River is 7.6 and 7.8 for Euphrates River. Water quality of the Tigris and Euphrates rivers varies from one section to another. Water quality is better in the upstream sections of the rivers. There is a general trend to increase salinity and degradation of water quality whenever river stream Turn south because of decreasing water level and accumulation of pollution loads. Water quality of the Tigris generally better than the quality of waters of the Euphrates, where many tributaries supply Tigris river with freshwater inside Iraqi territory while Euphrates River exposed to different effluent inside Syrian territory before entering the Iraqi border. Recorded values of most variables measured of the Euphrates river greater than the values of Tigris River at the beginning of the entry of the rivers into the Iraqi border. Euphrates River compared with the Tigris River was exposed to different effluent discharges especially agricultural discharge in the central and southern regions in addition to changing hydrological conditions.

Thermodynamic investigation into extraction of cerium(III) by tributyl phosphate from phosphoric acid solutions

A mechanism of extraction of cerium by tributyl phosphate (TBP) from phosphate solutions using model and production solutions containing, %: 26–28 P2O5, 1.2–2.8 SO3, 0.3–0.8 CaO, 0.1–0.4 Al2O3, 0.3–0.4 Fe2O3, and 0.09–0.1 REE(NO3)3 is investigated. The model solution of phosphoric acid corresponds to the industrial solution of extraction phosphoric acid (EPA) by the content of P2O5 and Ce(NO3)3 and value of pH (0.6). Dependences of extraction parameters on the TBP concentration in o-xylene and concentration of nitrate ions introduced by magnesium and calcium nitrates, which are used as a salting-out agent, are found. The composition of the extracted organic complex of cerium Ce(H2PO4)(NO3)2TBPorg is determined. A constant of extraction equilibrium and the Gibbs energy of extraction are calculated. It is concluded by the results of the experiment that it is unreasonable to use TBP to extract Ce from phosphoric acid systems without introducing a considerable amount of the salting-out agent.

Analysis of bulk precipitation chemistry in Serbia for the period from 1982 to 2010

Bulk precipitation samples collected daily through bulk collectors at eight meteorological stations in Serbia were analyzed for their chemical composition. The data covers time series, from 20 to 28 years, in the period between 1982 and 2010. The most abundant ion in the samples was sulfate. Only 0.17 % of all samples were from strong acid rains (pH < 3.5). The relatively high average pH values (5.94–6.26) of the collected precipitation indicate the neutral or alkaline nature of local rainwater. Trends in both the annual amount and the composition of precipitation were tested by the nonparametric Mann–Kendall test and Sen’s slope estimator. Significant increasing trend of precipitation was identified for almost all stations. Rebuilding activities after the bombing of Serbia in 1999 were identified as a possible anthropogenic cause of the sharp increase of some ions (Ca2+) in the first year following the bombing. The origin of air masses arriving at one particular station was examined using two-dimensional backward trajectories. Western sectors (W, SW and NW) accounted for almost half (44.3 %) of all rainy days, while eastern sectors (SE, E and NE) brought only 10.4 % of all rainy days. The distribution, per sector, of volume-weighted concentrations of sulfate, nitrate, ammonium, calcium, potassium, magnesium, chloride and sodium ions, as well as the amount of precipitation and its pH values for one station, was also analyzed. Rainwater from the SE and S sectors was the most polluted.