جستجوی مقالات مرتبط با کلیدواژه « نیترات » در نشریات گروه « پزشکی »

Background and Groundwater serves as the primary drinking water source in Golestan Province. Therefore, this study aims to assess the non-cancerous health risks associated with nitrate and fluoride in the province's drinking water sources.  Physicochemical data from 139 drinking water wells were obtained from the Golestan Province Water and Wastewater Company during the spring and autumn. Significant ion variations were analyzed, and factors influencing the chemistry of drinking water sources in Golestan Province were investigated. Non-carcinogenic health risks posed by nitrate and fluoride were assessed using two indicators provided by the United States Environmental Protection Agency.  The maximum nitrate concentration in certain Golestan Province cities exceeds the Iranian drinking water standards (1053) and the World Health Organization's limits. However, fluoride levels in most cities fall below the range stipulated by domestic and international standards. The nitrate risk factor for children in select cities exceeds one, while it remains below one for other age groups. Notably, Khan Bebin City exhibits the lowest nitrate risk factor among the province's cities. Additionally, risk factor values show a slight increase during the autumn season. Non-cancerous health risk assessments for fluoride in drinking water sources across Golestan Province during spring and autumn indicate risk values below one for all age groups, including infants, children, teenagers, and adults.  The health risk assessments for nitrates and fluorides indicate that children in certain cities face a higher risk from nitrates than adults. Moreover, the low fluoride levels in the province's drinking water sources increase the likelihood of tooth decay.

Nitrates have long been considered indicative of drinking water quality and a critical concern for human health. The evolution of advanced models for water quality management has spurred decision-makers to incorporate artificial intelligence technologies into water quality planning. This study aims to employ the AdaBoost model, one of the cutting-edge models in water quality management, to predict nitrate concentrations in groundwater using pH and EC (Electrical Conductivity) as input variables.

Initially, the study analyzed the Pearson correlation matrix and subsequently determined the input variables for multiple AdaBoost models with varying hyperparameters. A sensitivity and dependence analysis of the model's input variables was conducted to assess their impact on nitrate prediction.

The results obtained from the AdaBoost model reveal R-squared (R2) values of 0.915 for the training dataset and 0.924 for the test dataset. Additionally, the Mean Squared Error (MSE), Root Mean Squared Error (RMSE), Mean Absolute Error (MAE), and Mean Absolute Percentage Error (MAPE) scores for the training dataset were recorded as 1.02, 1.01, 0.823, and 7.3%, respectively. For the test dataset, these metrics were observed in the order of 0.228, 0.477, 0.375, and 3.2%. The model's sensitivity analysis identified the pH variable as the most influential factor in nitrate prediction.

The model analysis demonstrates that the proposed method performs well in predicting nitrate concentrations. This approach holds significant potential for implementation as an intelligent system for forecasting water quality parameters.

Today, environmental pollution, including water pollution, has become a global issue, and human life is dependent on the safe drinking water. This study aimed at spatial analysis of minerals and heavy metals in drinking water distribution network in Kurdistan Province’s villages.

In this descriptive-analytical study we assessed the concentrations of nitrate, nitrite, total soluble solids, fluoride, arsenic, lead, and cadmium in drinking water of all villages connected to water distribution network (1524 villages) in Kurdistan Province from 2015 to 2017. To describe the concentrations of the studied chemicals, spatial distribution maps were plotted using Arc GIS V. 10.3 software. Other statistical analyses including the analysis of the mean difference of the concentrations of nitrate, nitrite, and total soluble solids in the studied cities were performed by one-way analysis of variance using SPSS V. 22 software.

According to the results of this study, tap water in 1485 villages of Kurdistan Province (97.44%) contained nitrate and the amount of this ion in the drinking water of 31 villages (2.03%) was above the national and WHO standards. The mean concentration of total soluble solids in Bijar City was significantly higher than that in other cities (P <0.001). The mean concentration of fluoride in the drinking water of rural areas of Kurdistan province was 0.19 ± 0.25 mg/l, which was lower than the value determined by national standard of Iran (0.5-1.5 mg/l). The concentrations of arsenic in the tap water of 47 villages of Bijar (23 villages), Qorveh (11 villages), Saqez (7 villages), Dehgolan (5 villages), and Kamyaran (1 village), respectively, were higher than the maximum permitted value.

Continuation of the current trend, especially in agricultural sector and uncontrolled use of groundwater resources in agriculture, will lead to decreased water quality. Therefore, it is necessary to monitor agricultural activities and use of fertilizers.

In recent years, population growth, lack of rainfall, and increase in urban, industrial, and agricultural activities have caused more use of underground water resources. This will cause many problems for the economy, ecosystem, and human health. Considering the need to investigate and monitor the quality of groundwater, the present research was carried out with the aim of investigating the important chemical parameters of water wells in some cities of Isfahan Province, Iran.

To conduct this research, 181 well water samples were collected from Khansar, Daran, Tiran, Fereydunshahr, Najaf Abad, and Dehaghan cities in Isfahan Province. Then, electrical conductivity (EC), pH, and nitrate concentration were measured. Next, nitrate hazard quotient (HQ) (non-carcinogenic risk of nitrate) was calculated. ArcGIS software was used for mapping the measured features.

The amount of EC, pH, and nitrate varied from 191.4 to 7624 μS/cm, 6.49 to 8.20, and 1.9 to 99.2 mg/l, respectively. The lowest value of HQ (0.03) was calculated for the group of men and the highest value (3.68) was obtained for the group of children. The average value of HQ for men, women, and children was 0.61, 0.74, and 1.40, respectively.

All measured pH values were below the national standard of Iran (1053) and the Environmental Protection Organization of Iran. The studied areas had no limit in terms of nitrate concentration for using well water for agriculture. However, in 78.6% of the study areas where the amount of nitrate was in the range of 22.1-50 mg/l, there is a possibility of increasing nitrate concentration and making it unsuitable for drinking.

The purpose of this study was to model a real wastewater treatment plant in operation with GPS-X software. In the following, the verification of the output results of the software was done with the results of the effluent tests of the discussed sewage treatment plant. Then, the rate of return sludge, recycled sludge, and disposed sludge of the wastewater treatment plant was optimized by Modified Ludzack-Ettinger (MLE) method, so that it has the greatest effect on the quality of the effluent, especially chemical oxygen demand (COD) and nitrate (NO3) parameters.

First, using the available data of an operating wastewater treatment plant, the processes of the treatment plant were modeled in the software and the compatibility of the model with the existing treatment plant was checked. After the validation of the software, in order to check the parameters affecting the activated sludge process, including return sludge rate, excess sludge rate, and internal recirculation sludge rate in the treatment of organic matter and nitrogen, COD, NO3, and ammonia parameters were investigated as indicators of pollution. In addition, the MLE process for nitrogen removal was modeled in the software. After performing the modeling by changing the parameters and checking the resulting outputs, the results regarding the effect of increasing the sludge recirculation rate on the COD concentration in the effluent and the effect of increasing and decreasing the internal recirculation rate and the disposal sludge rate on COD removal were examined. In addition, the mutual effect of changes in internal sludge recycling and return sludge and the amount of excess sludge disposal on NO3 removal was shown by different graphs.

In this study, while validating the software, the results of the experiment design showed that the return sludge rate and the internal recirculation rate had mutual effects on each other in the removal of COD and NO3, and in the optimal mode of operation and design, the ratio of 0.54 for return sludge and one-time internal recycling and ratio of 0.021 for disposal sludge had the greatest effect on COD and NO3 removal target efficiency and increasing the effluent quality.

GPS-X software can be used in the modeling and optimization of wastewater treatment processes.

Nitrate is an essential nutrient for the growth of plants. The presence of it in vegetables, water and other foods, is a serious threat for human health. Human body receives about 80% of nitrate from fruits and vegetables. The purpose was to determine the amount of nitrates in some vegetables and cucurbits (basil, mint, radish and tomato) that are sold in fruit and vegetable market of Zahedan city in 2020 year.

Hundred and twenty samples were selected and their nitrate content were measured by HPLCmethod. The significance level was less than 5%.

Mean of nitrate in, tomato, mint, radish and basil were 20.55, 515.76, 585.73 and 591.7mg/kg respectively. The mean of nitrate in basil was slightly higher than the radish but difference wasn’t statistically significant. There was statistically significantdifference among mean of nitrate in investigated vegetables (p value < 0.05). Mean of nitrate in basil was higher than others (p value < 0.05). A statistically significant difference was observed among mean of nitrate in vegetables namely tomato, mint, radish and basil in the investigated stalls (p value < 0.05).

Amount of nitrate in samples were lower than the national standard limit that is not harmful for human health. It can be concluded that the vegetables sold in Zahedan city are good interms of nitrate content and they don’t cause health problems. As high consumption rate of different type of vegetables by human and variation of their nitrate concentration, additional investigation and permanent control of their nitrate concentration isnecessary.

Excessive intake of nitrite and nitrate threatens human health. The aim of this study was to determine the levels of nitrite and nitrate in some summer vegetables cultivated in Bastam region of Shahroud.

the study was conducted in the summer. The study area was divided and a total of 25 summer vegetables, 15 soil samples, and three water samples were measured to determine the levels of nitrate and nitrite according to the Standard instruction (No. 4106).

The total average of nitrate in cucumber, tomato, potato, eggplant and onion was 850.1 ± 65.2, 642.1± 25.4, 48.6 ± 2.5, 14.8 ± 4.5, 791.3±52.1 mg/kg fresh weight, respectively and this level for nitrite was equal to 9.23 ± 0.1, 7.2 ± 0.8, 0.52 ± 0.04, 0.9± 0.05, 5.3±0.32 mg/kg fresh weight that all values were less than the standard level.The level of nitrate and nitrite in the soil was 1250.68 ±562.2 and 98.1 ± 15.2 mg/kg soil weight, respectively. The level of nitrate and nitrite in the water was 5.68±2.2 and 0.23±0.2 mg/l, respectively.

Due to the high consumption of vegetables and summer vegetables in summer and spring, which are also the fertilizing seasons for plantsand shrubs,it is recommended that managers and farmers pay more attention to the process of cultivation and fertilization of agricultural products, as well as frequent monitoring of the level of nitrite and nitrate in the country's vegetables.

 studies show that antioxidants prevent conversion of NO3/NO2 to nitrosamines compounds. tha aim of this study was to determine the potential effect of interaction between dietary intakes of vitamin C and NO3/NO2 on urinary and serum levels of NO3/NO2.

This cross-sectional study included 251 adults aged >19 years was performed in the phase 6 of  the Tehran Lipid and Glucose Study in 2015. Food intake was assessed using a semi-quantitative food frequency questionnaire. The average daily intake of nitrate and nitrite and vitamin C was estimated. Serum and urine levels of nitrate and nitrite were measured using  the Grease method. In order to determine the effect of vitamin C on the interaction of nitrate and nitrite in urine and serum, linear regression test was used to modify the effects of confounders.

There was a significant correlation between intake of nitrate and its urine level, above the median level of vitamin C intake (B = 0/004, P-value = 0/004). Also, this correlation remained significant after adjusting for age, sex, body mass index, calorie intake (B = 0.03, P-value = 0/001). The effect of vitamin C interactions on nitrate intake and urine level in the adjusted model for nitrate and nitrite was also found to be significant (B = 0/003 P-value = 0/001).

Increased intake of vitamin C significantly increases urinary excretion of nitrate and it is effective in  the interaction between dietary intakes and urinary excretion of nitrate.

Nitrate is one of the most important pollutants in groundwater resources, which is mainly caused by agricultural fertilizers and wastewater disposal and is very important for health hazards. The purpose of this study was to identify the sources of nitrate contamination and zoning in groundwater resources of Tiran and Karvan area in west of Isfahan, Iran, using Geographic Information System (GIS) and investigate the status of nitrate in the groundwater aquifer.

This cross-sectional descriptive study was conducted on 40 underground water sources of Tiran and Karvan in west of Isfahan during a four-year period. Nitrate test was performed by spectrophotometer. The results were analyzed by one-way analysis of variance (ANOVA) in GIS and SPSS software. One-sample t-test was used to compare the mean nitrate content of water sources with the corresponding standard.

The mean concentration of nitrate in 2013, 2014, 2015, and 2016 was 42.29 ± 17.27, 43.33 ± 16.65, 45.09 ± 16.95, 47.29 ± 18.10 mg/l, respectively. The highest amount of nitrate based on the interpolation map was related to the central parts of the city. The best method of interpolation for nitrate, considering the normal distribution of data, was ordinary kriging and Gaussian and exponential models. One-way ANOVA showed that there was no significant difference between the mean concentration in 2016 with the mean values measured in different years (P > 0.05). The one-sample t-test showed that the average nitrate in 2015 and 2016 was below the global standard of 50 mg/l (P > 0.05).

Nitrate concentration in the region's water resources is at the standard level, but considering its values and changes over the past three years, the probability of increasing and exceeding the standard limit is expected. Moreover, according to GIS maps, the average nitrate in the central part of the city is higher than the other parts. In order to prevent the incremental trend of nitrate, proper management in use of nitrogen fertilizers, land use change, construction of sewage treatment plant, and necessary training measures must be done.

Despite the higher prevalence of kidney dysfunction in females, the effects of nitrate have mainly been studied in males. This study aimed to determine the effects of long-term sodium nitrate administration on kidney function in normal adult female rats by assessing estimated Glomerular Filtration Rate (eGFR), serum urea, and serum creatinine.

Female Wistar rats were divided into two groups (n = 10 per group). The control group received tap water, and the nitrate group received tap water containing 100 mg/L sodium nitrate for nine months. Bodyweight, serum urea, and serum creatinine were measured at the beginning and end of the study, and eGFR was calculated. The nitric oxide metabolites (NOx) levels were also measured at the end of the study in serum and kidney tissue.

The body weight, serum urea, and creatinine levels of rats in the control group were significantly higher, and eGFR was significantly lower at the end of the study compared to the beginning of the study. Nitrate administration for nine months prevented increases in body weight, serum urea, and creatinine and decreases in eGFR. Nitrate-treated female rats also had higher NOx levels in serum and kidney tissue.

Nitrate administration improved kidney function in female normal adult rats. These beneficial effects may be associated with increased serum and kidney levels of NOx.

Theexcessive consumption of nitrogen fertilizers leads to the production of vegetables with high concentrations of nitrate. High nitrate concentration in crops causes a variety of diseases, especially due to the production of carcinogen nitrosamine in adults. Because of the increase in cancerous and non-cancerous diseases caused by the consumption of foods containing high nitrate, a detailed and comprehensive assessment of the state of nitrate accumulation in vegetables is required. This study was conducted to evaluate the risk of nitrate in high-consumption vegetables in Kermanshah.

In this study, 120 samples of five kilograms of high-consumption vegetables were sampled in different months of each season and sent to the laboratory. Samples included tomato, cucumber, potato, onion (yellow, white, red), lettuce, celery, watercress, and spinach or beet leaves. After sample preparation and extraction, the nitrate concentration was determined by a spectrophotometer at a wavelength of 410 nm.

The nitrate concentration in all vegetables was less than the WHO and ISRI standard limits in winter. But in the summer, the concentration of nitrate in celery, cress, and sugar beet leaves exceeded the standard limits. The hazard quotient (HQ) was less than 1 in all vegetables and both seasons. In summer, the highest HQ values were observed in cress (0.425), beet leaves (0.363), and celery (0.135), in sequence. In the winter, the highest amount of HQ was seen in cress (0.190).

According to the HQ values (less than 1) in all vegetables, the possibility of exposure to non-carcinogenic diseases caused by nitrate from eating vegetables in this study is not serious, but it is necessary to monitor the concentration of nitrate in consumed vegetables at different intervals.

In the Azna-Aligudarz plain, the drinking water is mainly supplied from groundwater.  Therefore, it is necessary to estimate the concentration of nitrate and nitrite and determine the groundwater vulnerability potential and related risks in the plain to guarantee the health of consumers.

The vulnerability potential of the studied plain to pollutants was investigated by the drastic method. To estimate the concentration of nitrate and nitrite, 25 water wells in the study area were sampled within 2018-2019 and analyzed by standard method. Human health risk related to groundwater in the study area was assessed using the USEPA (the United States Environmental Protection Agency) index.

The results of the DRASTIC method demonstrated that 45% and 65% of the region has a high (southern part of the plain) and a medium vulnerability potential (northern part of the plain), respectively. According to the obtained results, nitrate in Chaqataram and Ashrafabad villages with 56 and 65 mg/liter, respectively, and nitrite in groundwater of Chamzaman, Aliabad, and Darreh Bagh villages with 3.5, 3.3, and 3.4 mg/liter, was higher than the standard of World Health Organization. According to the health risk assessment results, 83%, 8%, and 4% of children, women, and men are prone to health threats due to nitrate concentration (HQ>1). The accuracy of the vulnerability results was confirmed by calibrating the results of the health risk assessment and the results of the nitrate map.

As e evidenced by the obtained results, improper use of nitrate chemical fertilizers and unsafe disposal of human wastewater (urban and rural) is the main cause of increased nitrate and nitrite concentrations in agricultural lands. Based on the results of the present study, the use of contaminated drinking wells is not recommended and continuous monitoring of drinking wells in the study area is essential to protect the health of consumers, especially children.

Atherosclerosis in patients with type 2 diabetes is characterized by endothelial dysfunction that is associated with increases of assymetric dimethyargenin and nitric oxide reduction. The purpose of the present study was to compare the effects of 12 weeks of high-intensity interval (HIIT) and moderate-intensity continuous training (MICT) on plasma levels of vaspin, assymetric dimethyargenin (ADMA), and nitrite/nitrate (NOx) on type 2 diabetes.

The statistical population of the present study included patients with type 2 diabetes, aged 45-60 years old, from Tehran. The sample included 48 type 2 diabetic patients who were randomly assigned into three groups: HIIT (n= 16), MICT (n= 16), and control (n=16). The HIIT group intervention was 12 intervals at 85-90% maximal heart rate (HRmax) and 2 min at 55-60% Hrmax and the MICT group intervention was performed based on ergometer cycle for 42 min of exercise at 70% HRmax for 3 sessions per week during 12 weeks. The blood sample was collected 48-h before and 48-h after the last sessions of exercise training. The vaspin and ADMA were measured using ELISA, and NOx was measured using Griess assay. Data were analyzed using mixed-liner ANOVA in SPPS, version 18.

The results showed that VO2peak and plasama levels of vaspin (P= 0.028) and NOx (P= 0.016) increased significantly in HIIT as compared with those in the MICT group. Insulin resistance (P= 0.041), plasma levels of insulin (P= 0.039), glucose (P= 0.026), and ADMA (P= 0.018) decreased significantly in HIIT as compared with those of the MICT group (p < 0.05).

According to the results, HIIT via increase of vaspin led to a decrease in ADMA which eventually increased plasma levels of NOx in patients with type 2 diabetes.

Today, the supply of qualified drinking water has become the main concern of the competent authorities. Drinking water, in addition to the appropriate quantity, must have appropriate standards regarding physicochemical and microbial properties. Nitrate and nitrite ions are of special importance due to their adverse environmental and health. The aim of this study was to determine the concentration of these ions in the drinking water of Evaz city and to perform calculations related to health risk assessment.

In this study, five points were selected and 50 samples (10 samples from each point) were collected over time intervals. After transferring the samples to the environmental chemistry laboratory, the concentration of nitrate and nitrite ions was determined by the spectrophotometer (DR6000) according to the instructions provided by the HACH.

The concentration of nitrate and nitrite ions in all parts of the network was lower than the standard set by the WHO. The highest and lowest concentrations of nitrate and nitrite ions were obtained at the sampling sites of Patrice Restaurant (1.04 and 0.021 mg/L) and ABFA (0.8 and 0.0162 mg/L), respectively. Also, risk assessment based on the age range of infants, children and adults was 0.125, 0.00375 and 0.043, respectively, which shows that long-term water consumption will not have a negative impact on human health.

The physicochemical quality of Evaz drinking water was acceptable and human exposure to this water has a non-carcinogenic risk of much less than the critical range.

The use of packaged drinking water is on the rise nowadays in most countries, including Iran. Currently, more than 100 different brands of packaged drinking water are produced and distributed in Iran. This study was done to evaluate the quality of Iranian, foreign packaged drinking waters and municipal drinking water in Golestan Province, north of Iran.

This descriptive-analytical study was done on 56 packaged drinking waters of different Iranian and foreign brands, eight brands produced in Golestan province and a number of municipal drinking water samples were collected from Gorgan and Gonbad Kavous cities in northern Iran. To assess the quality of packaged drinking water and drinking water, their physicochemical parameters were compared with National Iranian Standards 1053 and WHO. Stiff and Piper diagrams were plotted to determine the type and hydrochemical facies of water samples. Gibbs and Schoeller diagrams were used to determine the water chemistry controlling factors of water samples and their water quality for drinking, respectively.

The concentrations of physicochemical parameters (except bicarbonate) were within the range of national drinking water standards 1053 and WHO. The average nitrate concentration in all packaged drinking and drinking water was within the standard range. The fluoride concentration of all packaged drinking waters and drinking water was within the range of WHO standard. However, only 14 samples of all packaged drinking and drinking water samples are within the range of 1053 National Iranian Water Standard. The total concentration of soluble solids and the total hardness of packaged drinking water were within the range of 1053 NW. There was also a significant difference (P<0.05) between the chemical parameters of magnesium, sodium, chloride and nitrate in packaged drinking water produced in Golestan province with the municipal drinking water samples.

The amount of fluoride in drinking water in this study was less than desirable and required fluorination. The quality of packaged drinking water in Golestan province is better than the municipal drinking water.

Treatment of Fresh Leachate From Municipal Solid Waste This study aimed at the examination of the efficiency of roughing filter in nitrate and chemical oxygen demand removal (COD), obtained in the fresh leachate from municipal solid waste landfill. Sampling was done in 3 rates 0.5m/h, 1m/h and 1.5 m/h, including simultaneous sampling from input and output filtering, to determine the concentration of nitrate and COD. The average efficiency of COD removal in filtration rates of 0.5 m/h, 1 m/h and 1.5 m/h was equal to 84, 88 and 85 % respectively. The average removal efficiency of nitrate in filtration rates of 0.5 m/h, 1 m/h and 1.5 m/h was equal to 88, 88 and 85 % respectively. Output values of COD and nitrate were lower than the environmental organization standard (p < 0.05). Based on the results of this study, the nitrate removal with a roughing filter was better than that obtained with COD. 

Liver disorders in patients with type 2 diabetes (T2D) are mostly associated with higher serum levels of liver enzymes. This study aimed to investigate the effect of nitrate administration on the serum levels of alanine amino transferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) in rats with T2D.

In this study, 24 male Wistar rats were divided into four groups: control, control+nitrate, diabetes, and diabetes+nitrate. T2D was induced using a combination of high-fat diet and injection of low-dose streptozotocin (30 mg/kg). The rats in the nitrate-treated groups received sodium nitrate (100 mg/L in drinking water) for six months. The serum levels of ALT, AST, and ALP were measured at the beginning of the study and at three and six months after nitrate administration.

Diabetic rats showed increased levels of ALT, AST, and ALP in the serum at six months. Nitrate decreased the serum level of ALT by 17.6% (65.7±4.8 vs. 55.8±2.3 UI/L; P=0.0659), AST by 52.2% (161.3±13.3 vs. 106.0±6.1 UI/L; P<0.0001), and ALP by 15.1% (606.2±35.5 vs. 514.4±12.6 UI/L; P=0.0339) within six months.

Long-term and low-dose nitrate administration improved the liver function of rats with T2D, as reflected by the reduced serum levels of ALT, AST, and ALP.

The presence of nitrate and phosphate in concentrations above the allowable level in surface and groundwater resources leads to disease and problems. The aim of this study was to investigate the adsorption efficiency of magnetic-metallic chitosan nanocomposite in the adsorption of nitrate and phosphate from aqueous solutions.

The adsorbent was synthesized by co-precipitation method. Different concentrations of nitrate (50-300 mg/L) and phosphate (100-400 mg/L) were prepared and their removal was evaluated by different concentrations of synthesized adsorbent (0.1-0.5 g/L). Various parameters such as temperature (20-40 ° C), pH (5-8), contact time (0-90 minutes) and the presence of interfering ions (chloride, phosphate, hardness 1.5 mM) were investigated. SEM, XRD, FTIR and XRF tests were used to determine the synthesized adsorbent characteristics.

Magnetic-metallic chitosan nanocomposite adsorbent is able to effectively remove nitrate and phosphate from aqueous solutions. Nitrate and phosphate removal efficiencies under conditions of  pH=5, nitrate concentration (100 mg/L), phosphate concentration (200 mg/L), 60 min contact time and 0.3 g/L adsorbent concentration were 87.2% and 74.9%, respectively. The adsorption process of both pollutants followed the langmuir model and pseudo second kinetic order. Interfering ions reduced the removal efficiency of contaminants by 73.1% for nitrate and 65.9% for phosphate.

Since the presence of nitrate and phosphate anions, as common contaminants and indicators of water resources, the use of magnetic-metallic chitosan nanocomposite adsorbent is very effective in the removal of these contaminants.

Much of the nitrate consumption by humans in the daily diet comes from vegetables. The high concentration of nitrate in edible parts of vegetables causes toxicity, anemia for children and nitrous amine production in adults. Nitrous amine may results in cancer. Samples were collected from four main vegetable markets in Kermanshah city in summer 2019 to investigate the concentrations of these compounds in edible vegetables with high consumption.

After preparation of the samples in a laboratory, the nitrate were extracted and its concentration was determined by a spectrophotometer at wavelength 410 nm.

The results showed significant differences in nitrate concentrations for the vegetable samples taken from the different markets (p>0.05). The highest concentration of nitrate were observed in the leafy, tuberous, and fruit-bearing vegetables. The highest nitrate concentration among the leafy vegetables was observed in cress with an average of 2052.14 mg/kg Fresh Weight; among tuberous vegetables was potato with an average of 127.01 mg/kg Fresh Weight; and among fruit-bearing vegetables was cucumber with an average of 37.20 mg/kg Fresh Weight.

The nitrate concentrations for celery, and red onion at the Azadi market were higher than the permissible limit, according to the national standard. Also, the nitrate concentrations in sugar beet leave and potato at the Toopkhaneh Market and nitrate concentration in cress at all the markets were higher than the permissible limit. It is recommended that the concentration of nitrate of edible vegetables should be determined at regular time intervals as well as during different seasons.