Introduction

In several years and during the past decades, at various levels, due to extensive human intervention, attitudes changed towards sustainable management of water resources (Meybeck 2003). The river as vital role in all aspects of human life and health has great impact in future of humanity. The need for water in agricultural, industry and drinking water demand has been increased by population growth and water demand; that imposed many pressure to water resources, while wate is needed for any development (Sedaghat 2008).

Water quality characteristics are components that considered the necessity of water resource management and the health of aquifer areas (Khadam and Kaluarachchi 2006). Nowadays, the water quality is the main issue in the case of surface water. Due to the use of the river waterway in the transfer of industrial sewage, agricultural and fruit plantations, these sources are imposed by different pollutions. Increase in the information about the quality of drinking water for public health and quality of raw water for aquatic life increased the need to survey the quality of surface water (Ouyang, 2005). The quality of surface water in a region is under influence of two agents: natural processes (rate of sedimentation, soil and water conditions and soil corrosive) and human processes such as agricultural and industrial activities (Huang and Chen 2009).

Today, the necessity of qualitative studies of water resources due to the wide variety of contaminant arrivals is inevitable and in most parts of the world is one of the most important challenges faced by humankind during recent years. During the recent decades, several solutions at different stages, identification, prevention and corrective actions, are presented by various researchers to increase the quality of the water resources. Rajaee and et al. studied drinking water wells quality on Ali Abad Katoul plain, they measured significant relationship between metal concentration and did not view any correlation between them on national and international standards (Rajaei et al. 2012). Miranzadeh et al. (2011) to study the concentrations of heavy metals (chromium, copper, zinc, lead, cobalt, silver, nickel, cadmium) in the five areas of water distribution network of Kashan city (in 2010) measured 35 samples in three seasons of spring, summer, autumn that approximately measured 105 samples which were higher than national and international standards.

Among them, identification and informative stage of the status of water resource quality as the first step in the direction of a healthy environment and access to water is a major source of studies and enough attention can be appropriate for the prevention and remedial measures to increase the quality of water resources (Nouri et al., 2011). In addition to the increasing world population, increased water usage has not only reduced the quantity of water available and has met with more restrictions, but also caused pollution and reduction in the quality of water resources (Hajian nejad and Rahsepar 2010).

Various human activities around rivers’ privacy led to the entry of many pollutants into water canvas and affected the quality of river waters (Chen and Chen 2001). Considering the importance of the Balikhlou River as one of the most important sources of drinking water supply in Ardabil, Nir and Sarein cities, maintaining the water quality is one of the most important objectives of this non-notable alternative source. The most important action and management necessity in this regard is continuous knowledge about water quality of different stations. That means that with continuous measurements of index parameters of water quality for drinking consumption, and even its prediction for the future, must be sure the quality of these parameters in comparison with specified standards and if identified a non-authorized pollutants, timely find the source and recovery it. This river includes a wide area and provides agricultural and industrial water for the residents; thus, qualitative studies of the river are necessary for planning and optimum management of water resources.

Methods

Study area

The Balikhlou River is one of the most important rivers of Ardabil Province and is the most important and main branches of Gharesou River. Natural springs, rivers, snow water and rain water are main feeding sources of the river. This enters into the Ardabil city from the east. The north scope of the area is the Sabalan Mountain, in the west and south are Bozghosh Mountains and in the east are parts of the plain because Ardabil originates from the mountains that have greater elevation levels. So 72 percent of the total watershed area of the river has 1500–2500 m height (University of Tehran 1996).

The riverbed is from the above regions to the Illangigh village (range entering field of Ardabil geography) that is mountainous; it is in the bed between plains which bolt out from its full path. River length is 87 km, its watershed is 1600 km and is largely mountainous. The average annual discharge of Balikhlou River water volume is 116.5 million cubic meters.

The Balikhlou River is considered the head of the main branch of the river, it goes to North after joining Aharchai in Dostbaighlo, the river is called Dare road and is interconnected to the Aras River from the east part.

Ardabil, Nir and Sarein Cities as three major urban areas are in the range of Balikhlou River watershed. These cities are a collection of rural area, thats life and culture depend on the environmental potentials of this area. The numbers of these villages, on the basis of contained information in the culture of the Ardabil Province, are 108. Figure 1 shows the position of Balikhlou River and its related field.

Fig. 1
figure 1

The location of the study area in Ardabil Province and Iran

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Research parameters

In the present research, the analysis of the water quality has been done with eight quality parameters and its quality is compared with the World Health Organization standard. Therefore, for the analysis of water quality of the river, one-way t test is used. It shows the significant differences between two groups (Salehi and Porasghar Sangachin 2012). In this study, the first group contains the data which related to the samples and the second group related to national and international standards. For the research are used the water quality data of five stations that have been measured by Ardabil Province Department of Environmental Protection (Department of Environment Ardebil Province 2014). Figure 2 represents the position of the stations in the area:

Fig. 2
figure 2

The location of the five sampling stations in the study area

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For this research, eight qualitative parameters (SO4, No3, BOD5, TDS, turbidity, pH, EC, and COD) are used. Table 1 shows a quick overview of statistical analysis such as minimum, maximum, deviation and average values of each parameter.

Table 1 Summary of statistical parameters in the area
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The statistical information relating to different periods of study stations and statistical different values is as follows (Table 2).

Table 2 Different values of physicochemical parameters in different stations of year 2012
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Results

The results of the comparison about different value measurements of 5 stations, Balikhlou river of Ardabil, in terms of WHO and IRAN standards (Standard Nos. 1091, 2010; WHO 1996; Khosto 2007; Farhadi 2013) has been shown in low-water seasons in Table 3.

Table 3 Comparison of mean values of physicochemical parameters with national and international standards in summer and spring (low-water season)
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As can be observed from Table 3, the average values of pH parameters (8.32) and turbidity (17.1) are more than WHO and Iran standards and other values of the parameters (SO4, No3, BOD5, COD, TDS, EC) in terms of national and international standards are low.

One-sample t test results regarding physicochemical parameters in terms of WHO and IRAN standards in the low-water season are shown in Table 4.

Table 4 One-sample t test to compare the physicochemical values of Balikhlou River with national and international standards in low-water season
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The surveying results showed that measured mean difference on TDS and EC values on WHO standard and only TDS on Iran standard has more significant difference (sig > 0/05). The results showed that measured means of So4, turbidity and No3 on both standards have low significance with standard amount (sig > 0/01). Also, for pH values on both standards and EC on IRAN standard the mean difference is not significant (sig < 0/05).

The comparison results of physicochemical parameters from WHO and IRAN standards in high-water season are shown in Table 5.

Table 5 Comparison of physicochemical values with national and international standards in the fall and winter seasons (high-water season)
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As can be observed from Table 5, the average values of the EC parameters (1082.11) and turbidity (15.133) are more than WHO standard and turbidity value is high only in Iranian standard and the values of other parameters (SO4, No3, BOD5, COD, pH, TDS) are low in terms of national and international standards.

One-sample t test result regarding physicochemical parameters in terms of WHO and IRAN standards in high-water season is shown in Table 6.

Table 6 One-sample t test to compare the physicochemical values of Balikhlou River water with national and international standards in high-water season
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The surveying result showed that measured mean difference on pH and EC is more significant in terms of WHO standard (sig > 0/05). Also the results showed that measured means of So4, No3 and turbidity on WHO standard and BOD5, COD, So4, No3 and turbidity on IRAN standard have low significance with standard amount (sig > 0/01). Also for EC and pH in terms of WHO standard, the mean difference is not significant (sig < 0/05).

Based on the obtained values of the sample analysis results that are determined with national and international standards, in the low-water season, the parameter values (pH, turbidity) exceed maximum specified standards and also in high-water season corresponding values (EC, Turbidity) are more than national and international standards. Figure 3 represents the number of parameters with significant and non-significant difference in high- and low-water season.

Fig. 3
figure 3

The number of parameters and quality changes based on national and international standards during different seasons

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Conclusion

In this study to survey the quality of Balikhlou River as drinking water source, sampling of the physicochemical parameter changes (SO4, No3, BOD5, COD, pH, EC, TDS, turbidity) in two low-water season (spring and summer) and high-water season (fall and winter) in five different stations of river was conducted. For this, national and international standards were used. The Iranian standard organization used standard 1053 reagent as the national standard and the World Health Organization standard was used as an international standard.

Based on results, on IRAN standard in low-water season, means of five parameter values are lower than standards and ideal (SO4, No3, COD, BOD5, turbidity), and two parameter values (pH, EC) are close to standard and danger level and only amount of TDS are more than standard levels. In high-water season, five parameters (SO4, BOD5, No3, COD, and turbidity) are lower than standard and three parameters (TDS, EC, and pH) are close to standards. In low-water seasons on WHO standard, cleared that 3 parameters values (SO4, No3, Turbidity) are significant in 1% and their amount are much lower than standard and parameter values (pH) at 5 percent is close to the standard and risk threshold, But (TDS, EC) parameters are much higher than standard and show the danger limit. In general, it can be stated that the different measurement of TDS and EC in terms of WHO standard and TDS on Iran standard in low-water season and pH and EC parameters in terms of WHO standard on high-water season are not significant. Therefore, it represents high and closeness of average parameters to the standards and shows the risk limit of river water. The pararmeters which are higher than the standards in the region, these reason can be the contaminants sources, that derived from agricultural activities and human sewage (Ardabil, Nir and Sarein cities) absorbed through the area wells that in low-water season because of decrease of water capacity and increase their amounts.