Groundwater quality assessment for drinking and agriculture purposes in Abhar city, Iran

The main objective of this study is to assess the quality of groundwater for drinking consume and agriculture purposes in abhar city. The analytical results shows higher concentration of electrical conductivity (100%), total hardness (66.7%), total dissolved solids (40%), magnesium (23%), Sulfate (13.3%) which indicates signs of deterioration as per WHO and Iranian standards for drinking consume. Agricultural index, in terms of the hardness index, 73.3% of the samples in hard water category and 73.3% in sodium content were classified as good. Therefore, the main problem in the agricultural sector was the total hardness Water was estimated. For the RSC index, all 100% of the samples were desirable. In the physicochemical parameters of drinking water, 100% of the samples were undesirable in terms of electrical conductivity and 100% of the samples were desirable for sodium and chlorine parameters. Therefore, the main water problem in Abhar is related to electrical conductivity and water total hardness.


a b s t r a c t
The main objective of this study is to assess the quality of groundwater for drinking consume and agriculture purposes in abhar city. The analytical results shows higher concentration of electrical conductivity (100%), total hardness (66.7%), total dissolved solids (40%), magnesium (23%), Sulfate (13.3%) which indicates signs of deterioration as per WHO and Iranian standards for drinking consume. Agricultural index, in terms of the hardness index, 73.3% of the samples in hard water category and 73.3% in sodium content were classified as good. Therefore, the main problem in the agricultural sector was the total hardness Water was estimated. For the RSC index, all 100% of the samples were desirable. In the physicochemical parameters of drinking water, 100% of the samples were undesirable in terms of electrical conductivity Agricultural indices such as SAR and SSP indicated 100, 90% of samples in the studied area had SAR and SSP values within the excellent category respectively for irrigation purposes.
Data of this study can help to better understand the quality of groundwater in this area. The present data d study recommends that regular monitoring of groundwater is essential to avoid major environmental threat

Data
Summary of the physical and chemical variables for the collected groundwater samples were presented in Table 1, The analytical results shows higher concentration of electrical conductivity (100%), total hardness (66.7%), total dissolved solids (40%), magnesium (23%), Soulphat (13.3%) which indicates signs of deterioration as per WHO and Iranian standards for drinking consume Table 2. Tables 3, 4, the calculated SAR, SSP, PI, MH, KR and Na% values were compared with the groundwater quality classification, where 100,90% of samples in the studied area had SAR and SSP values within the excellent category respectively for irrigation purposes.

Study area description
Abhar is one of the cities of Zanjan province and Abhar city center. The city with 99,285 people in 2016 is considered as the second most populated city of Zanjan province after Zanjan city. The height of Abhar city is 1540 m. The maximum relative humidity in the city is 94.4% and at least 23.3%. The average annual rainfall is 300 mm. This area is considered as a semi-cold and dry in Iran country [8] (Fig. 1).

Determination of the physico-chemical parameters concentration and agricultural indicators
In order to assess the physico-chemical parameters, a total of 30 samples taken from Abhar County (Fig. 1). Water samples were collected in a plastic container of 1-L capacity for detailed chemical analysis from all observation wells. These containers were washed thoroughly with distilled water and dried before being filled with water samples. The containers were numbered serially along with a proper record of well/sample location, date, static water level, and prior to the sampling. Groundwater samples were collected after the well was subjected to pumping for at least 5-10 min to obtain the composite sample. The pH and EC of the groundwater of the wells were measured by using HACH HQ40d and its in situ values are recorded [9][10][11][12][13][14][15]. The samples were collected and stored below 4°C and analyzed in the Centre for Water Resources Development and Management (CWRDM). Water samples collected in the field for chemical constituents, such as TDS, TH, Ca 2 þ , Mg 2 þ , CO 3 2 À , HCO 3 À , Na þ , Cl À and SO 4 2 À , were analyzed following the BIS standard. EC, pH and chloride (Cl -) were analyzed using multiple parameters ion meter model Thermo Orion 5 Star. Sulfate (SO4 4 À 2 ) was measured using a double beam UV-Vis spectrophotometer model Perkin Elmer Lambda 35 by turbidmetric, stannous chloride, and molybdosilicate, respectively. Sodium (Na þ ), calcium (Ca 2 þ ) and magnesium (Mg 2 þ ) were analyzed using flame photometer model CL-378 (Elico, India). Total hardness was determined by EDTA titrimetric method [1,[16][17][18]. TDS was measured gravimetrically and Agricultural indicator such as SAR, RSC, PI, KR, and MH, % Na, SSP and TH were calculated by their formulas presented in Table 5. Table 5 Summary of water quality indices in present study [1].