جستجوی مقالات مرتبط با کلیدواژه "groundwater pollution" در نشریات گروه "محیط زیست"

The purpose of this study is to determine the quality of underground drinking water sources in Torbat Jam and Saleh Abad cities using quality index (WQI) and their zoning. In order to determine the quality index of water resources, the results of testing 9 parameters including: (PH, hardness, dissolved solids, calcium, magnesium, sodium, nitrate, chlorine and sulfate) were studied. Samples were taken from 110 spring wells and aqueducts in the region and transferred to the central laboratory of Khorasan Water and Wastewater Company headquarters, which has a standard certificate of 17025 for water chemical tests and the experiments were measured according to the latest standard version of the method in 2005 by the IC chromatograph device. In the final stage, after determining the quality status of drinking water wells, their quality zoning was done in ARC GIS10.2 software. Zoning maps of water resources quality showed that most of the water resources of Torbat Jam city are in the range of excellent and good water quality in terms of WQI index. Also, the results of statistical techniques (multiple regression) showed that sodium (Na) parameter had the highest influence coefficient in determining the WQI index, followed by sulfate, total hardness, chlorine and dissolved solids. Investigating the significance level of land use with quality index by Kruskal-Wallis test showed a significant difference between land use and water quality index.

Despite the wide application of de-icing substances to the roadways, the sewage produced can have negative impacts on local ecosystems. Hence, the present study was conducted for assessing the effects of road salt use throughout the winter in Hamedan on the hydro-chemical quality of Hamedan-Bahar basin. Hamedan is one of the major tourist destinations and one of the main agricultural poles in Iran, and thus, its water resources contamination may pose serious risk to the health of the whole country.

The modeling of under-ground water flow paths in the study area revealed that the flow of rain and snow water in the city is mainly towards Hamedan-Bahar basin (as one of the main drinking water and agricultural water supplies in the region). Therefore, the 24 wells in the study area were sampled and the hydro-chemical characteristics of the obtained water samples as well as their changing trends over the past 10 years were determined and analyzed.   

The results indicated a gradual increase in the minerals and solid materials in the water of the basin. This, considering the meaningful correlation values obtained (R2≥0.89) between the salt contents and Cl- and Na+ concentrations, could be attributed to the use of de-icing materials. The rate of pollutants in some of the samples was found to be 10 times as much as the permissible national standard and international values. Moreover, based on the Wilcox diagram, the water in most stations could be classified as C3S1 (decreasing the soil fertility and resulting in ecophysiological abnormalities in crops) and even as C4S1 (completely harmful for irrigation). A similar distribution of de-icing compounds and arsenic were observed in the under-ground water of the basin. 

The increase in the pollution and the decline in hydro-chemical properties of the basin due to the accumulation of de-icing materials, not only pose direct hazardous effects to human health and agricultural lands but can also intensify the mobility of the heavy metals in soil-water profiles of the region. Therefore, it is suggested that winter operations in the city be planned and carried out using modern methods and facilities (such as anti-icing program, eco-friendly deicers, asphalt mixture with anti-icing additives, hydronic heating pavement), so that the negative environmental impacts can be controlled as much as possible.

The objective of this study is evaluating hydrochemical properties of groundwater in Maragheh area, including: Cations, Anions, Total Dissolved Solids, Electrical Conductivity, pH and Heavy metals (As, Fe, Mn) and investigating the statistical relations between these parameters and Probable Origins of contamination.

In order to carry out ground water quality monitoring, and evaluate the controlling processes and to determine cations and anions sources of the groundwater, 34 wells were selected for sampling from July 2014 and April 2015and water quality parameters were measured and sent to the Laboratory Applied Research Center of Geological Survey & Mineral Explorations of Iran (Elburz).  Data analysis was performed through SPSS software and Factor Analysis & Pearson correlation coefficient test.

The chemical composition of the surface and groundwater is controlled by several processes such as mineral dissolution, increasing evaporation from the aquifer, irrigation return flow, saline water intrusion in the Ajbashir Plain, geological status of the area, anthropogenic inputs.

The concentration of arsenic based on WHO standard is 10μg/L, while the maximum arsenic concentration in the study area is 308.5μg/L and the mean concentration is 44μg/L. According to the results, it relies that arsenic probable sources can be concerned to industrial waste water in Maragheh and Bonab industrial complex, agricultural activities (using pesticides and insecticides) and geological factors (existence of Shemshak formation), rocks and sediments derived from the erosion of these rocks and coal mines (Khormazard).

Nowadays, pollution of groundwater by heavy metals is encreasing. Heavy metals are one of the most widespread cause of pollution in water and the presence of increasing levels of these metals in the environment is causing serious concern in public opinion owing to their toxicity.
This study aims to assess the concentration and distribution pattern of heavy metals (Cadmium, Chrome, Nickel, Lead and Zink) in groundwater of an industrialized region in Eslamshahr which located in the southeastern of Tehran
Presently, groundwater is the predominant source of drinking water in this town. For this purpose, 92 samples were taken from 23 wells in 4 seasons.The concentration of heavy metals in the samples was measured by flame atomic absorption spectrophotometry. ARC GIS software was applied for preparing the distribution patterns.
The results showed that chrome and zinc concentrations were lower than the permissible level in the drinking water. However, the concentration of cadmium in 8.7% of samples taken in winter were higher than the permissible level determined in drinking water standard of Iran. Nickel concentration in winter was 8.7% higher than the permissible level. Lead concentration of samples in 47.8% and 4.35% of samples taken in summer and winter were higher than the permissible level, respectively. The high level of water pollution in southern part of Eslamshahr is attributed to the large number of industries, big farm lands, application of chemical fertilizers and the pesticides containing heavy metals, busy main and secondary roads , and most importantly, the hydraulic slope from northwest to southeast of this region.