zahra jafari; Amir Salemi
Abstract
AbstractIntroduction: Reaction of disinfection reagents, particularly chlorine, with natural organic material existing in raw water, results in production of a wide range of organic compounds, also known as disinfection byproducts. Despite their sever impacts on human health, only a tiny fraction of ...
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AbstractIntroduction: Reaction of disinfection reagents, particularly chlorine, with natural organic material existing in raw water, results in production of a wide range of organic compounds, also known as disinfection byproducts. Despite their sever impacts on human health, only a tiny fraction of disinfection byproducts is regulated and controlled.Materials and methods: In the present work, a novel solid-phase microextraction Arrow coupled with GC-MS has been developed, optimized and implemented for determination of seven non regulated disinfection byproducts; trichloroacetonitrile, dichloroacetonitrile, 1,1-dichloro-2-propanone, chloropicrin, bromochloroacetonitrile, 1,1,1-trichloro-2- propanone and dibromoacetonitrile. A central composite design was used to optimize the extraction parameters. Results and discussion: The method was sensitive enough to detect traces of the target compounds, with LOD values of 1.4-62 ng L-1. Also, quantitative analysis was possible over a wide linear range of about four orders of magnitude (50 to 100000 ng L-1 with R2 values of more than 0.997) with reasonable precision (RSD% values of less than 21.6% at 50 ng L-1. relative recoveries were between 60 and 95 %.Conclusion: The optimized technique was also successfully implemented for determination of the target compounds in ten drinking water samples and as result, most of them were observed in various concentration levels.
Mojtaba Ghareh Mahmoodlu; Ali Heshmatpoor; Nader Jandaghi; Ali Zare; Hossein Mehrabi
Abstract
Introduction: Groundwater quality study is one of the important tools for the sustainable development of a region and provides crucial information for managing water in different sectors. In recent years, water withdrawal from Iran's aquifers has reduced the groundwater quality in most of the plains. ...
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Introduction: Groundwater quality study is one of the important tools for the sustainable development of a region and provides crucial information for managing water in different sectors. In recent years, water withdrawal from Iran's aquifers has reduced the groundwater quality in most of the plains. This research was conducted to investigate the groundwater quality of Seydan-Farooq plain for agricultural and drinking purposes and also mapping some effective chemical parameters in these two sections. Material and methods: In this research, the results of chemical analysis of twelve wells in 2016 were used. First, groundwater type and hydrogeochemical facies were determined. Factors controlling groundwater chemistry were determined using Gibbs diagram and plot of Ca+Mg versus SO4+HCO3. To classify water for irrigation, electrical conductivity (EC), sodium adsorption ratio (SAR), sodium percentage (%Na), magnesium ratio, corrosivity ratio, and permeability index were used. Then, the map of some important parameters for irrigation water was prepared. To classify water for drinking purposes, chemical parameters were first compared with World Health Organization (WHO) guidelines. Next, some important parameters for drinking such as total dissolved solids, total hardness, and chloride ion concentration were compared with existing standards and their effects on human health were discussed. Then, the map of these parameters for the study plain was prepared. Finally, the quality of water for drinking purposes was evaluated using the Schoeller diagram. Results and discussion: The distribution pattern of samples in Durov diagram indicated the tendency of some samples to reach the end of the hydrogeochemical evolutionary cycle. As such, the bicarbonate type was changed into chloride type in a short time. Based on Gibbs diagram and the plot of Ca+Mg versus SO4+HCO3, rock-water interaction and dissolution of carbonate rocks were the main factors changing the groundwater chemical quality of the plain. According to SAR value, all samples fell in the excellent category which is suitable for irrigation and there is no risk of soil alkalinity. While in terms of salinity (EC), they are acceptable in the agricultural sector. Based on the percentage of sodium, samples were categorized as excellent, which are suitable for irrigation. According to the permeability index, all samples, except for one sample, showed good irrigation quality and did not change the soil permeability. In the majority of samples, the magnesium ratio was less than 50, which is suitable for irrigation. Comparison of chemical parameters with the WHO guidelines showed that none of the parameters exceeded the permissible limit. Comparison of TDS and chloride in samples with other existing standards showed that only one sample was brackish, which is not suitable for drinking purposes. Based on the groundwater hardness, water of the study plain was classified as high hardness water. According to the Schoeller diagram, the water quality of the study plain was classified in the good category. Conclusion: According to the hydrogeochemical results, water-rock interaction and weathering of carbonate minerals are the main factors in changing water chemistry. Since the majority of rocks recharging the aquifer are calcareous, it seems obvious that calcium and bicarbonate ions are dominant in the groundwater. In all samples, except those wells with possible saltwater intrusion, parameters such as salinity risk, SAR, sodium solution, and permeability index were acceptable for irrigation and there was no risk of soil alkalinity. Aquifer recharge by limestone-dolomite and dolomitic rocks in some regions has increased the magnesium ratio of groundwater in about 40% of samples. It has also increased the groundwater hardness. None of the chemical parameters exceeded the permissible limit set by the WHO and Schoeller diagram indicated that the water quality of the study plain was classified in the good category.
Ozeair Abessi; Mohesn Saeedi
Volume 8, Issue 3 , April 2011
Abstract
In this paper, a simple methodology based on multivariate analysis is developed to create a groundwater quality index (GWQI). The methodology is based on three general stages, selection, standardization and aggregation, to develop a groundwater quality index in an area using regional and local standards. ...
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In this paper, a simple methodology based on multivariate analysis is developed to create a groundwater quality index (GWQI). The methodology is based on three general stages, selection, standardization and aggregation, to develop a groundwater quality index in an area using regional and local standards. In this method, through selecting a set of similar parameters, standard values of the parameters are obtained by dividing the averaged concentration of parameters by their maximum allowable concentration cited in Iran’s Water Quality Standard. Final indices for ground water quality are derived through weighting the standard magnitudes of the parameters. In order to appraise the approach, existing water quality data for the ground water of the Qazvin plateau were used. In the selection phase, eight important parameters (K+ , Na+, Ca2+, Mg2+, SO2-4, Cl-, TDS, pH) for the potability of ground water were selected. These parameters were more accurately monitored and documented in the study area and are very important in desirable drinking water. In order to identify the suitable range of indices, the derived indices were compared with those obtained for some mineral waters. Sketching a comparative ground water iso-index map in the study area makes it possible to have a comprehensive and easily interpretable picture of the ground water quality in the area of Qazvin plateau. Results show the proximity of the derived indices to those obtained for mineral water in some regions of Qazvin Province. It is clear that evaluating the overall suitability of the ground water for drinking usage in an area essentially needs survey of other parameters in addition to those observed here.
