Iranian Journal of

Background and Objective: Surface water is usually highly variable in chemical composition due to contact with different geological formationsand other surface and groundwater resources.  Knowledge on water quality and the impact of human activities are particularly important for sustainable management and planning of water resources. The aim of this study was to investigate the physicochemical and hydrochemical quality of Chehelchai river water in Golestan province.
Materials and Methods: In this study, 6 sampling stations were selected based on standard criteria including land use type, accessibility and standard distributions along the river in 2018. 10 river water quality parameters including pH, electrical conductivity, total soluble solids, sulfate, chloride, bicarbonate, sodium, potassium, calcium and magnesium - were measured according to standard methods for one year period. Piper, Schuler, Durov, Wilcox and Gibbs diagrams were applied for hydrochemical analysis using RockWorks.17 software.  Statistical analysis was performed using one-way ANOVA.
Results:  Results indicated the abundance of major ions was found in the order of HCO₃^- > SO₄^2- > Cl^- and Ca²⁺ > Na⁺ > Mg²⁺ > K⁺. The river water type was predominantly determined as calcic bicarbonate. The findings revealed that the water of the study area is acceptable for drinking purpose based on Schuler diagram and also appropriate for agricultural uses considering Wilcox diagram (80% of the samples in class S1-C3 (saline - usable for agriculture)) and the average sodium uptake ratio (0.79).
Conclusion: The presence of dolomite ores, the absence of factories and domestic sewage and adhering to hygiene regulations by the residents, are the main reasons which have increased the quality of Chehelchai river water.

Background and Objective: The aim of this study was to evaluate the chemical and microbial quality of bottled water in Iran and to calculate the water quality index (WQI).
Materials and Methods: Different brands of bottled water (4 samples from 71 brands) were randomly collected from the market. Chemical and microbial characteristics of the samples were examined and determined. Finally, the calculations related to the WQI index were performed and the water samples were classified as excellent, good, poor, very poor and unsuitable.
Results: None of the samples exhibited concentration of heavy metals beyond Iranian water standards, and the concentration of sulfate (SO₄), chloride (Cl) and fluoride (F) did not exceed international standards. However, in some samples, nitrite (NO₂) and nitrate (NO₃) concentrations were higher than recommended standards. With Regard to other water quality parameters, 8% to 89% of the samples exhibited concentration higher than the values provided on the water bottle label. 5 species of different bacteria were found in 15 water samples. According to the WQI index, about 63% of the samples were of excellent quality. Also, the water quality of 34% and 3% of the samples fell in good and poor quality categories, respectively. None of the bottled water samples was of very poor quality.
Conclusion: The quality of bottled water investigated in this study was generally suitable, but due to the wide range of bottled water in Iran based on brand and seasons, continuous evaluation of water treatment methods in companies and careful monitoring of chemical and microbial quality of bottled water in all seasons is recommended.

Background and Objective: Groundwater is the primary water source for drinking and agricultural activities in arid and semi-arid regions. Rainfall, land use, geological structure, aquifer mineralogy, and duration of water contact with the environment in the basement are the main factors affecting the chemical quality of groundwater. This study aimed to determine the physicochemical properties of groundwater by considering the water quality index (WQI) and its quality assessment for drinking water.
Materials and Methods: In this study, 71 wells of Kashan were sampled in summer 2020 with three samplings from each well, and physical and chemical parameters were studied, water quality index was determined using mathematical methods, and Pearson correlation coefficient was determined. Correlation analysis was used. Finally, the collected data were analyzed using SPSS-16 software, Excel 2013, and statistical tests. 
Results: The calculated WQI of 71 wells in Kashan shows that 67% of the wells were of excellent quality, and 33% were of good quality in terms of water quality parameters. In total, out of 71 samples, the numerical index of water quality was 44.94, and the water was of excellent quality.
Conclusion: The results show that ions such as sodium, sulfate, and chlorine are directly related to the counting in an area and increase the concentrations of EC and TDS, and can impair the balance of anionic and cationic aqueous solution. It was also found that more than half of the wells have excellent quality due to using water wells for drinking.

Background and Objective: With the industrialization of communities, population increase and use of surface water, river pollution has been increased by agricultural, industrial pollutants and urban wastewater. Therefore, investigation of river pollution for regional and environmental planning is of great importance. To evaluate surface water pollution, a number of surface water quality indices have been investigated.
Materials and Methods: Iran water quality index for surface water resources (IRWQI_SC) approach was used to evaluate the water quality of the Mahabadchai river, Iran. Sampling was carried out along the Mahabadchai river based on some criteria such as approximately to drainage areas for landfills/domestic and agricultural effluents.
Results: Pearson correlation coefficient between physical, chemical and microbial parameters of water showed that fecal coliform, BOD, COD, nitrate, ammonium, phosphate, turbidity and total hardness had a significant positive relationship with each other at 99% confidence. According to this index, upstream samples of the river are classified as good, mid-stations relatively good to moderate category, and downstream samples of the river are classified as relatively bad.
Conclusion: Based on the relationship between each variable, fecal coliform, BOD, COD, ammonium, and turbidity were more effective in determining the IRWQI_SC. Most of the examined variables showed low concentrations in upstream areas of the river while their concentration gradually increased along the river to downstream areas, especially close to urban and industrial districts.
 

Background and Objective: Increasing the productivity of surface water, the unsustainable development of agriculture in the boundaries of rivers, and human sewage have reduced the quality of these water resources. Therefore, investigating the amount of pollution and its sources is very necessary for regional planning. This study aimed to evaluate the water quality of the Golin River using WQI and Liou indexes.
Materials and Methods: Sampling of Golin river water was performed to check water quality based on (WQI) and (Liou) indices in Najjar village station for one year from April 2019 to March 2020.
Results: Water quality, according to the Liou index, during the research period in the sampling station in September and March, was in a good category and other months were slightly polluted. According to the results of the WQI index, water quality in September and March were in the excellent descriptive category, with values of 47.82 and 49.74, respectively, but in other months it was in a good category. In September and March, water quality improved compared to other months because of lower BOD5 due to reduced agricultural activities, and both indicators showed these quality changes well.
Conclusion: Due to the lack of stable conditions in water quality affected by seasonal changes and its departure from the category of high-quality water according to the results of the WQI index and also a little water pollution according to the Liou index, the direct use of Golin River water for drinking purposes is recommended and for this purpose, regular purification should be done and accurate and continuous evaluations of water quality in Golin River are necessary.
 

Background and Objective: Identifying the quality of non-conventional waters and exploring their optimal utilization are fundamental measures for maintaining public health. This study aims to investigate the effluent quality of the irrigation canals in Pakdasht farms.
Materials and Methods: In this cross-sectional descriptive study, 120 samples were collected from 6 irrigation canals in Pakdasht fields over a period of 5 months. The physicochemical and microbial characteristics of the canal effluents were determined based on the standard methods of water and wastewater tests. The concentration of heavy metals was measured using an ICP device. To determine the possibility of using the effluent of Pakdasht canals for agricultural purposes, the Environmental Protection Organization of Iran and FAO standards were used.
Results: The average concentrations of COD, BOD₅, TSS, TDS, NO₃^-, SO₄^-2, PO₄^-3 parameters were 259, 125, 105, 697, 4.5, 94.4, 13.5 mg/L. Additionally, the average number of total and fecal coliforms in the effluent of the canals exceeded the standard values set by IRNDOE and FAO. The mean pH was 6.97, the electrical conductivity (EC) was 1014 μm/cm, and the turbidity was 76.2 NTU. The detected concentrations of heavy metals were awithin the following ranges: Cr (0.025-0.045 mg/L), Cd (0.0006-0.001 mg/L), Pb (0.0006-0.001 mg/L), Co (0.038-0.059 mg/L), and Ni (0.05-0.06 mg/L), which were roughly lower than the suggested standards. However, both HEI and WWQI indices confirmed that the water was unsuitable for agricultural irrigation.
Conclusion: Based on the comparison of the results of the parameters measured in this study with the environmental and FAO standards, the effluent from the irrigation canals of Pakdasht city is deemed unsuitable for the irrigation of warm-season crops but suitable for fodder and industrial crops.