Showing 8 results for Water Resources
M Khodadadi, M.t Samadi, A.r Rahmani, R Maleki, A Allahresani, R Shahidi,
Volume 2, Issue 4 (3-2010)
Abstract
Backgrounds and Objectives: Water contamination by pesticides is considered as an environmentalproblem today. In terms of agricultural development and diversity of plant pests, the use of pesticides has been increasing. Hamedan province has a suitable agricultural condition, it has enjoyed significant development in this respect. Among all the cities of Hamedan province, Hamedan city has the highest rank in tiller crops. Therefore, yearly use of pesticides is increasing in this area which could be a serious threat to water resources of the city. The aim of this survey was determinaton of Organophosphorous and Carbamat pesticides residue in drinking water resources of Hamadan in 2007.
Materials and Methods: In this survey, 126 water samples were collected from 7 drinking water resources of Hamedan during 12 consecutive months in 2007. for determination of these pesticides,two methods (solid- phase extraction and Liquid-Liquid extraction) were adopted .and samples were analyzed by means of HPLC and GC/MS applying standard methods.
Results: Final results showed that the most concentration of Chlorpyrifos and Carbaryl pesticides were found to be about 3.85 ppb (part per billion) and 1.8 ppb in spring and June respectively the maximum concentration of Diazinon was about 36.5ppb in October (autumn).The minimum concentration of the three pesticides was detected in winter. According to the statistical test Two - Way ANOWA there were significant differences among pesticides concentrations in the water samples in different seasons (p<0.05) . However, there wasn't a significant difference in pesticides concentrations in surface and ground water samples(p>0.05).
Conclusion: Different studies have shown that pesticides residue concentration in water samples have a relationship with the amount of pesticides used in an area, physical and chemical refractory properties of pesticides and environmental conditions. Thus, using resistant pollutants such as pesticides will be a serious threat to health of water consumers if they are not properly controlled.
Mohaad-Reza Mohebbi, Koshyar Azam Vaghefi, Ahmad Montazeri, Mehrnoosh Abtahi, Sogol Oktahi, Reza Gholamnia, Fatemeh Aliasgari, Reza Saeedi,
Volume 6, Issue 2 (9-2013)
Abstract
Background and objectives: In this research, an innovative drinking water quality index for assessing water resources as “modified drinking water quality index (MDWQI)” was developed and applied for evaluating all of the groundwater resources utilized for community water supply in urban areas of Iran during 2011. Materials and methods: Twenty-three water quality parameters and relevant Iranian standards for drinking water quality were selected as input parameters and benchmarks respectively. The MDWQI is calculated using three factors including the number of parameters that excurse benchmarks, the number of measurements in a dataset that excurse benchmarks and the magnitude of excursions. The MDWQI scores range from 0 to 100 and classify water quality in five categories as excellent (95-100), good (80-94), fair (65-79), marginal (45-64), and poor (0-44). Results: According to the MDWQI value, about 95% of the groundwater resources were in the good condition and the others were in the fair or marginal condition also the best and the worst water quality of water resources were observed in Ardebil Province and Qom Province respectively. The three parameters of fluoride, magnesium, and nitrate recorded the highest rates of violation to be 74, 32, and 13% respectively. Conclusion: The nationwide average score of the MDWQI was 85 (good description). This study indicated that the MDWQI and its sub-indices could describe the overall water quality of water bodies easily, reliably and correctly and have the potential suitability for extensive application all over the world.
Amir Hossein Mahvi, Noushin Rastkari, Ramin Nabizadeh Nodehi, Shahrokh Nazmara, Simin Nasseri, Mahboobeh Ghoochani,
Volume 6, Issue 3 (12-2013)
Abstract
Background and Objectives:Chlorination is the most common method of water disinfection. Chlorine reaction with natural organic compounds nor removed completely during treatment process would result in forming disinfection byproducts. Followed by trihalomethanes, Haloaceticacides are the second main byproducts of chlorination in water. The research works conducted in Iran have assessed trihalomethanes. Hence, this is the first time we are reporting haloacetic acids in Iran.
Materials and Methodology: We collected samples from surface water resources and treated water in Tehran for six consecutive months (first half, 2010). We measured temperature, pH, UV adsorption at 254 nm and TOC in each surface water sample and analyzed pH, residual chlorine, and haloacetic acids in the treated water samples.
Results: We found that TOC in surface water resources is 3.6-4.42 and 1.78-2.71 mg/l in spring and summer respectively. Moreover, haloacetic acids concentration was found to be 41.7-55.56 and 34.83-43.73 μg/l in spring and summer respectively.
Conclusion: Our results revealed that concentration of NOM, TOC, and HAAs was more in spring than summer. In addition, concentration of HAAs was depended up on NOM and TOC. Considering maximum permeable concentration of HAAs (60 μg/l) by EPA, it can be claimed that concentration of HAAs was less than the maximum permissible level in all of the samples. However, the immanency of the monitored values to the standard values can be a warning for concerned authorities in water industry.
Samira Akhavan, Hamid Zare Abyaneh, Maryam Bayat Varkeshi,
Volume 7, Issue 2 (10-2014)
Abstract
The objective of this study was to collect all the conducted studies on nitrate concentration in water resources of Iran. To achieve this purpose, the published papers in ISC and ISI journals as well as conferences and seminars were evaluated. The results of this survey showed that 116 studies have been carried out in 26 provinces of Iran. But,there was no published paper in Ilam, Alborz, South Khorasan, Kohgiluyeh and Boyer-Ahmad, and Lorestan provinces. According to these studies, the largest number of studies was performed in Hamadan province (14 cases), Khuzestan, and Mazandaran provinces (10 cases) and the least number of studies was conducted in Ardabil, Bushehr, Qazvin, Qom, and Kermanshah provinces. In Hamadan province, more than 1435 water samples were collected from water resources of this province, which is representative of large number of studies in this region. Maximum nitrate concentration (318 mg/L) was reported in Isfahan province and then in Zahedan city (295 mg/L), Sistan and Baluchestan Province. Based on the reported results in these studies, the nitrate pollution in water resources of Iran is at medium level. In most of the studies, high nitrate concentrations are due to lack of sewage collection network, discharge of urban and industrial sewage to water resources, and agricultural activities, which use high amounts of manure and fertilizer.
R.s Hajimirmohammad Ali, H Karyab,
Volume 8, Issue 4 (3-2016)
Abstract
Background and Objective: The concentration of nitrate, factors affecting the balance sheet, and the changes in an aquifer is of utmost importance. Because modeling is an efficient method to predict the concentration of ions in water resources, in this study using lumped-parameter model and Monte Carlo simulation model, the nitrate concentrations in groundwater resources of Qazvin Plain were estimated and analyzed.
Materials and Methods: A total of 19 wells in different climates of saline watershed in Qazvin Plain were selected and entry and exit routes of nitrate to these sources were analyzed using lumped-parameter model. Finally, Monte Carlo simulation was used to determine the probability of the estimated nitrate concentration in aquifer.
Results: Application of lumped-parameter model for a part of a part of groundwater resources in Qazvin Plain watershed predicted the nitrate concentration in the range of 8.12 to 15.94 mg/l. The maximum concentration was estimated in cold-dry climate with 12.8±0.04 mg/L. Moreover, it was found that the difference between the estimated nitrate concentration and factors affecting its concentration in different climates was significant (p<0.05).
Conclusion: Despite the predicted concentrations of nitrate in the study area were in accordance with the Iran national standard for drinking purposes, the cumulative probability of Monte Carlo simulation showed that the possible violation of nitrate from the safe limit of 10 mg/l in the study area is 90% (p = 0.005).
L Karam, M Alimohammadi, L Yadegarian,
Volume 11, Issue 2 (9-2018)
Abstract
Background and Objective: Climate change in recent years has led to a crisis of drought in many countries around the world, including Iran. In such a situation, the supply of safe drinking water is very important and knowing the climate impacts on the chemical quality of these resources can play a significant role in their proper exploitation.
Materials and Methods: Using GIS geomorphology models, the effect of climatic factors including minimum and maximum temperatures, mean precipitation, evaporation, transpiration and vegetation index on the quality of groundwater resources of Varamin Plain include pH, electrical conductivity, total dissolved solid, anions and cations concentrations and total hardness were studied and their maps were produced. Correlation between these factors was investigated using spatial correlation analysis tool at a confidence level of 0.95 (p = 0.05).
Results: The results showed that these parameters (except pH) along the plain are highly variable and the spatial distribution of data in this region is not normal around the mean, and the frequency of pixels with values less than the spatial mean of the region is higher. Spatial distribution of the factors showed that their amounts (except pH) are low in the central area of the plain and reach its peak in the western and northwest regions. The spatial distribution of pH was almost uniform in all the plain.
Conclusion: Correlation analysis showed that the quality of water resources is influenced by climatic factors and the maximum temperature has the highest impact.
M Hadi, Z Aboosaedi, H Pasalari,
Volume 12, Issue 1 (5-2019)
Abstract
Background and Objective: Scaling and corrosion both are destructive to materials (usually metals) in water supply systems. A dataset (from 2002 to 2013) of groundwater resources (including springs, qanats, deep wells and semi-deep wells) were examined for water tendency to corrosion or scaling in rural regions of Kashan, a city in Isfahan, central Iran.
Materials and Methods: Water quality parameters including pH, temperature, Ca (mg/L), CO32- (mg/L), HCO3-(mg/L) and TDS (mg/L) were used to estimate water stability indices. Value of qualitative indices including Langelier (LSI), Ryznar (RSI), Puckorius (PSI) and trend of Calcium Carbonate Precipitation Potential (CCPP) as a quantitative index were calculated and analyzed for all water resources.
Results: Mean of LSI, RSI and PSI for all water resources were estimated to be 0.41±0.02, 6.39 ± 0.03, and 7.40±0.02, respectively. The CCPP value found to be 17.23±3.16, 15.66±1.38, 41.23±11.22, and 23.15±4.46 mg/L for springs, qanats, deep wells and semi-deep wells, respectively. The CCPP index was significantly increased from 2002 to 2013, with an average of 1.6 units per year.
Conclusion: A significant scaling tendency was observed. This tendency in decreasing order was observed in deep wells, semi-deep wells, springs and qanats. The estimated CaCO3 scale weight per cubic meter of water was 21 g on average, which may be problematic for water distribution systems. Water withdrawal management and reduction in TDS of water resources, perhaps through decrease in agricultural drainage, can be effective to reduce the scaling tendency.
Mohsen Pourkhosravani, Fatemeh Jamshidi Gohari, Nasrin Sayari,
Volume 16, Issue 2 (9-2023)
Abstract
Background and Objective: This research tries to analyze the spatial distribution and trend of arsenic level changes in the underground water resources of the Sirjan basin, and also to evaluate and analyze the factors affecting the concentration of this element in these water resources.
Materials and Methods: Sampling of underground water sources in the study area was done by systematic-random method and arsenic concentration was done by ICP-MS method in the laboratory. Also, to evaluate the factors affecting the concentration of arsenic in the underground water resources of Sirjan bathe sin, the method of land systems analysis was used.
Results: The results of the research show that the amount of arsenic in all samples is higher than the Guidelines provided by the World Health Organization so the amount of this element in the underground water sources of the study area varies between 30 and 390 µg/L. Samples No. 9, 13, and 16, which are located in the deepest parts of the basin, have the highest amount of arsenic. For this reason, the durability of water in this part of the basin increases. This reduces the intensity of the current. As a result, according to the cumulative effect law, this process can lead to an increase in arsenic concentration.
Conclusion: The evaluation of changes in the concentration of arsenic in the underground water resources of the study area indicates that the concentration of this element had a high increasing trend. According to the results, the location of the studied area in the center of hydrothermal and geothermal processes (copper mineralization belt in Iran), the cumulative effect, and the effect of pH on the absorption and desorption of arsenic are among the most important factors affecting the increase of arsenic in the underground water resources of Sirjan Basin.
