Identification of the nitrate and nitrite content in leafy vegetables from the city of Zliten: تحديد محتوى النترات والنتريت في الخضار الورقية من مدينة زليتن

The study identifies the nitrate (NO3) and nitrite (NO2) content in leafy vegetables (parsley, chard, coriander) in three agricultural areas in Zliten (Azdo, Dafniya, Madjer) using the colorimeter dr / 980 device, and assesses whether the content is within the comparatively with allowable concentrations. The results obtained from this study show that the nitrate concentrations in all samples examined are within the global standards, with the highest level of 5.5 ppm found in chard samples collected from the area of Azdo. As for nitrite, the concentrations found in the studied samples are higher than nitrate concentrations. Overall, the nitrate and nitrite content are found to be within the permitted concentrations based on international standards, where the highest concentration of nitrite of 60 ppm is recorded in parsley samples from the Dafniya area.

Nitrate Removal and Woodchip Properties across a Paired Denitrifying Bioreactor Treating Centralized Agricultural Ditch Flows

Treatment of nitrate loads by denitrifying bioreactors in centralized drainage ditches that receive subsurface tile drainage may offer a more effective alternative to end-of-pipe bioreactors. A paired denitrifying bioreactor design, consisting of an in-ditch bioreactor (18.3 × 2.1 × 0.2 m) treating ditch base flow and a diversion bioreactor (4.6 × 9.1 × 0.9 m) designed to treat high-flow events, was designed and constructed in an agricultural watershed (3.2 km2 drainage area) in Illinois, USA. Flow and water chemistry were monitored for three years and the woodchip and bioreactor-associated soil were analyzed for denitrification potential and chemical properties after 25 months. The in-ditch bioreactor did not significantly reduce nitrate concentrations in the ditch, likely due to low hydraulic connectivity with stream water and sedimentation. The diversion bioreactor significantly reduced nitrate concentrations (58% average reduction) but treated only ~2% of annual ditch flow. Denitrification potential was significantly higher in the in-ditch bioreactor woodchips versus the diversion bioreactor after 25 months (2950 ± 580 vs. 620 ± 310 ng N g−1 dry media h−1). The passive flow design was simple to construct and did not restrict flow in the drainage ditch but resulted in low hydraulic exchange, limiting nitrate removal.

Prenatal nitrosatable prescription drug intake, drinking water nitrate, and the risk of stillbirth: a register- and population-based cohort of Danish pregnancies, 1997–2017

Background Nitrosatable drugs commonly prescribed during pregnancy can react with nitrite to form N-nitroso compounds which have been associated with an increased risk of stillbirth. Whether maternal residential drinking water nitrate modifies this association is unknown. We investigated, if household drinking water nitrate was associated with stillbirth, and if it modified the association between nitrosatable prescription drug intake and the risk of stillbirth. Methods We conducted an individual-level register- and population-based cohort study using 652,810 women with the first recorded singleton pregnancy in the Danish Medical Birth Registry between 1997 and 2017. Nitrosatable drug exposure was recorded by use of the Danish National Patient Registry defined as women with a first redeemed prescription of a nitrosatable drug the first 22 weeks of pregnancy. The reference group was women with no redeemed prescription of a nitrosatable drug in this period. The average individual drinking water nitrate concentration level (mg/L) was calculated in the same period. We categorized nitrosatable drugs as secondary amines, tertiary amines, and amides. Cox hazard regression was used to estimate crude and adjusted hazard ratios with 95% confidence intervals for stillbirth stratified into five categories of nitrate concentrations: ≤1 mg/L, > 1- ≤ 2 mg/L, > 2- ≤ 5 mg/L, > 5- ≤ 25 mg/L, and > 25 mg/L. Results Drinking water nitrate exposure in the population was not associated with the risk of stillbirth. Among 100,244 women who had a nitrosatable prescription drug redeemed ≤22 weeks of pregnancy of pregnancy, 418 (0.42%) had a stillbirth compared to 1993 stillbirths (0.36%) among 552,566 referent women. Women with any nitrosatable prescription drug intake and > 1- ≤ 2 mg/L nitrate concentration had an increased risk of stillbirth [adjusted hazard ratio 1.55 (95% confidence interval, 1.15–2.09)] compared with referent women. In the stratified analyses, the highest risk of stillbirth was found among women with secondary amine intake and > 25 mg/L nitrate concentrations [adjusted hazard ratio 3.11 (95% CI, 1.08–8.94)]. Conclusions The association between nitrosatable prescription drug intake and the risk of stillbirth may depend on the level of nitrate in household drinking water. Evaluations of the effect of nitrosatable drug intake on perinatal outcomes might consider nitrate exposure from drinking water.

An Evaluation of Groundwater Vulnerability Assessment Methods in a Rapidly Urbanizing City: Evidence From Dakar, Senegal

In rapidly growing cities in the tropics, unregulated urban development presents a major risk to groundwater quality. Here, we assess the vulnerability of an unconfined aquifer of Quaternary sands in the Thiaroye area of Dakar (Senegal) to contamination using four GIS-based indices (DRASTIC, DRASTIC_N, SINTACS, SI). Our correlation of assessed vulnerability to observed impact is semi-quantitative, relating observed groundwater quality, based on nitrate concentrations and tryptophan-like fluorescence to vulnerability degrees (i.e. coincidence rates). We show that considerably more of the Thiaroye area has a “very high vulnerability” according to SI (36%) relative to DRASTIC (5%) and SINTACS (9%); “high vulnerability” is estimated using DRASTIC_N (100%), DRASTIC (66%) and SINTACS (69%). Single-parameter sensitivity tests show that groundwater depth, soil, topography, land use and redox parameters strongly influence assessments of groundwater vulnerability. Correlation with observed nitrate concentrations reveals aquifer vulnerability is better represented by SI (coincidence rates of 56%) relative to DRASTIC_N (43%), SINTACS (38%) and DRASTIC (34%). The underestimation of groundwater vulnerability in Dakar using DRASTIC, DRASTIC_N and SINTACS is attributed to their reliance on an assumed capacity of the unsaturated zone to attenuate surface or near-surface contaminant loading, which in the low-income (Thiaroye) area of Dakar is thin and affords limited protection. The inclusion of a land-use parameter in SI improves the characterization of groundwater vulnerability in this low-income, rapidly urbanizing area of Dakar.

Exploring the sensitivity of atmospheric nitrate concentrations to nitric acid uptake rate using the Met Office's Unified Model

Ammonium nitrate is a major aerosol constituent over many land regions and contributes to air pollution episodes, ecosystem destruction, regional haze, and aerosol-induced climate forcing. Many climate models that represent ammonium nitrate assume that the ammonium–sulfate–nitrate chemistry reaches thermodynamic equilibrium instantaneously without considering kinetic limitations on condensation rates. The Met Office's Unified Model (UM) is employed to investigate the sensitivity of ammonium nitrate concentrations to the nitric acid uptake coefficient (γ) in a newly developed nitrate scheme in which first-order condensation theory is utilised to limit the rate at which thermodynamic equilibrium is attained. Two values of γ representing fast (γ=0.193) and slow (γ=0.001) uptake rates are tested in 20-year global UM integrations. The global burden of nitrate associated with ammonium in the “fast” simulation (0.11 Tg[N]) is twice as great as in the “slow” simulation (0.05 Tg[N]), while the top-of-the-atmosphere radiative impact of representing nitrate is −0.19 W m−2 in the fast simulation and −0.07 W m−2 in the slow simulation. In general, the fast simulation exhibits better spatial correlation with observed nitrate concentrations, while the slow simulation better resolves the magnitude of concentrations. Local near-surface nitrate concentrations are found to be highly correlated with seasonal ammonia emissions, suggesting that ammonia is the predominant limiting factor controlling nitrate prevalence. This study highlights the high sensitivity of ammonium nitrate concentrations to nitric acid uptake rates and provides a novel mechanism for reducing nitrate concentration biases in climate model simulations. The new UM nitrate scheme represents a step change in aerosol modelling capability in the UK across weather and climate timescales.

Distribution of Dissolved Nitrogen Compounds in the Water Column of a Meromictic Subarctic Lake

In order to better understand the biogeochemical cycle of nitrogen in meromictic lakes, which can serve as a model for past aquatic environments, we measured dissolved concentrations of nitrate, nitrite, ammonium, and organic nitrogen in the deep (39 m maximal depth) subarctic Lake Svetloe (NW Russia). The lake is a rare type of freshwater meromictic water body with high concentrations of methane, ferrous iron, and manganese and low concentrations of sulfates and sulfides in the monimolimnion. In the oligotrophic mixolimnion, the concentration of mineral forms of nitrogen decreased in summer compared to winter, likely due to a phytoplankton bloom. The decomposition of the bulk of the organic matter occurs under microaerophilic/anaerobic conditions of the chemocline and is accompanied by the accumulation of nitrogen in the form of N-NH4 in the monimolimnion. We revealed a strong relationship between methane and nitrogen cycles in the chemocline and monimolimnion horizons. The nitrate concentrations in Lake Svetloe varied from 9 to 13 μM throughout the water column. This fact is rare for meromictic lakes, where nitrate concentrations up to 13 µM are found in the monimolimnion zone down to the bottom layers. We hypothesize, in accord with available data for other stratified lakes that under conditions of high concentrations of manganese and ammonium at the boundary of redox conditions and below, anaerobic nitrification with the formation of nitrate occurs. Overall, most of the organic matter in Lake Svetloe undergoes biodegradation essentially under microaerophilic/anaerobic conditions of the chemocline and the monimolimnion. Consequently, the manifestation of the biogeochemical nitrogen cycle is expressed in these horizons in the most vivid and complex relationship with other cycles of elements.

PSXIII-10 Effects of nitrate concentration in drinking water on water and feed consumption, total tract digestibility and health implications in Holstein bulls fed high-concentrate diets

The aim of this study was to evaluate the effect of nitrate concentration in drinking water on water and feed consumption, total tract apparent digestibility and its potential toxicity on animal health in fattening Holstein bulls. Twenty-four Holstein bulls (161 ± 19.9 kg of initial BW, and 183 ± 25.3 d of age) were housed individually and fed ad libitum. Animals were assigned to 4 treatments according to nitrate concentration in drinking water: 0, 44, 110 and 220 mg / L. The different nitrate concentrations were achieved by the addition of different potassium nitrate 0.22 M doses. Water consumption and animal health status was recorded daily. Every 2 wks feed consumption, BW were recorded, and nitrate concentration in drinking water was analyzed by photometry. At d 0, 14, 112 and 168 blood samples were collected to determine ammonia and methemoglobin concentrations. At d 14 and 168 total tract apparent digestibility was estimated. Data were analyzed with a mixed effects model. Water consumption decreased (P < 0.05) when nitrate concentration in water was above ≥ 110 mg / L (30.2, 27.4, 24.4 and 26.4 ± 1.38 L/d for 0, 44, 110 and 220 mg/L nitrates in water, respectively). Water nitrate concentration did not affect serum ammonia and methemoglobin concentration (58.0 ± 2.17 µmol / L and 2.4 0.09 %, respectively). In addition, water nitrate concentration did not affect performance, total DMI, and nutrient digestibility. Drinking water for a long period with nitrate concentrations up to 110 mg/L did not have detrimental effects on performance and health. Beyond this threshold a reduction of water consumption of 16 % was observed and blood parameters (methemoglobin) and health registers did not indicate that the concentration of 220 mg/L of nitrates in drinking water may have health side-effects in fattening bulls fed high-concentrate diets.

التغيرات الدموية في مستويات الهيموغلوبين و المتهيموغلوبين بعد التسمم بالنترات في دجاج اللحم

This study was aimed to understand the hematological changes in the level of Hb and Met-Hb which produced after potassium nitrate intake via water and feed to broiler chicks for 6 weeks and indifferent concentration also after stoppage for 4 weeks of nitrate intake. A number of 135 chicks one day old faobro breed were used. After two weeks aclimitiztiation ,chicks were separated in to seven groups , one was control and other six were given potassium nitrate in drinking water or in feed at 0.25, 0.5, 0.75 gm/ kg body weigh to each group. The results showed significant statistical in the Hb rates and the different nitrate concentrations used. Also there were significant differences in the 2nd week of the experiment and indicated a decrease in Hb concentrations. Statistical significant of difference was obvious in the groups fed on concentrations 0.25, 0.5 gm/ kg b.w. and in groups given nitrate in drinking water in concentrations 0.25, 0.5, 0.75 gm/kg b.w. There were significant statistical differences in Met-Hb rates formed and the amount of nitrate used and the weeks in all animal groups treated with nitrate which started at the 3rd week from the start of the experiment. The increase in the rates of Met-Hb indicate an important statistical differences or significances especially in groups fed 0.25 gm/kg b.w. nitrate concentration and in drinking water groups at 0.5 and 0.75 gm/kg b.w. concentrations. no significant statistical differences between the control group from week 8th till the week 10th of the experiment.