Hydrogeochemical characteristics of springs around Ramsar with special attitude on their drinking quality

1-Introduction
The studied area is located in the westernmost part of Mazandaran province around Ramsar city and is part of the southern coast of the Caspian Sea. Elika, Nesen, Ruteh, Mobarak, Dorood, and Javaherdeh formation are exposed (Baharfiroozi et al., 2000). The general strike of geological structures of the area is northwest-southeast and dominated by abundant faults (Alavi, 1996). Studied springs of this area are including Kachanak, Katalom, Rishboraz Darreh, Namak Darreh, and Giash. Kachanak and Katalom springs are located in the plain areas, and Rishboraz Darreh, Namak Darreh, and Giash are in highlands of Ramsar city.
Hydrogeologically, the aquifer of the study area is unconfined, and its hydraulic gradient is toward the sea. In this research, the quality of water of springs has been considered because it represents not only the quality of underground water but also the people of the area drinks it, and it can affect the native’s health. So, the aim of this research is the specification of the hydrogeochemical properties and define the water quality of 5 selected springs around the Ramsar city for drinking.
 
2-Methodology
The springs were sampled according to the required standards using polyethylene bottles in the last days of summer. Dual-purpose conductor and acidity measured electrical conductivity, and total dissolved solids were measured by pH meter. BOD was estimated in five days using incubator (equipped with oxygen meter sensor) in 200C temperature. The alkalinity and chloride contents were measured through titration. Alkalinity was obtained by addition of Phenolphthalein and Methyl Orange to the samples and performing titration until reaching the final point (orange-pink color) and presented in milligram per liter of calcium carbonate. Bicarbonate also was measured by using calcium carbonate contents and applying related coefficients. Potassium chromate was used as a marker for measuring centration of chloride contents in the titration process. Nitrate and sulfate were evaluated using ultraviolet (UV) and spectrophotometry methods, respectively. Major and trace elements concentration obtained through inductively coupled plasma mass spectrometry (ICP-MS) in the laboratory of Act Labs Company in Canada. Hydrogeochemical processing of the samples was done by AqQa software.
 
3-Findings 
Data processing results indicated that except Kachanak spring (which is of Si-HCO3 type), all the springs are of Si-Cl water type (table 1). The plot of hydrogeochemical data of the studied springs on the Piper diagrams suggested that alkaline earth metals (Ca+, Mg2+) are more than alkaline elements (K+, Na+) and anions of strong acids (SO2-4) are more than weak acids ones (HCO-3), and noncarbonate hardness is over 50%. Water quality also considered through comparing of physicochemical parameters of the springs with different standards (Table 1).
Table 1- Correlation the physiochemical parameters of the springs with different standards.





Ca²⁺
(mg/l)


Mg²⁺
(mg/l)


SO₄^2-
(mg/l)


Cl^-
(mg/l)


NO₃^-(mg/l)


pH
 


TDS
(mg/l)


TH
(mg/l)


Correlation with


Water Type


Sample




non drinkable


bad


acceptable


good


good


good


good


acceptable


(Schoeller, 1965)


 
 
 
 
Si-HCO3


 
 
 
 
SH1
 




desirable


desirable


desirable and permissive


desirable and permissive


desirable


desirable


desirable and permissive


undesirable and permissive


Iran 1053




permissive


permissive


permissive


permissive


permissive


permissive


permissive


permissive


WHO (2011)




-


-


permissive


permissive


permissive


permissive


permissive


-


U.S.EPA




bad


moderate


acceptable


good


good


-


good


good


(Schoeller, 1965)


 
 
 
Si-Cl


 
 
 
SH2




desirable


desirable


desirable


desirable


desirable


impermissible


desirable


desirable


Iran 1053




permissive


permissive


permissive


permissive


permissive


impermissible


permissive


permissive


WHO (2011)




-


-


permissive


permissive


permissible


impermissible


permissible


-


U.S.EPA




acceptable for emergency conditions


moderate


good


acceptable


good


good


good


good


(Schoeller, 1965)


 
 
 
 
Si-Cl


 
 
 
 
SH3




desirable


desirable


desirable


desirable


desirable


desirable


desirable


desirable


Iran 1053




permissive


permissive


permissive


permissive


permissive


permissive


permissive


permissive


WHO (2011)




-


-


permissive


permissive


permissive


permissive


permissive


-


U.S.EPA




bad


moderate


good


good


good


-


good


good


(Schoeller, 1965)


 
 
 
 
Si-Cl


 
 
 
 
SH4




desirable


desirable


desirable


desirable


desirable


desirable


desirable


desirable


Iran 1053




permissive


permissive


permissive


permissive


permissive


permissive


permissive


permissive


WHO (2011)




-


-


permissive


permissive


permissive


permissive


permissive


-


U.S.EPA




بد


acceptable


acceptable


good


-


good


good


good


(Schoeller, 1965)


 
 
 
Si-Cl


 
 
 
SH5




desirable


desirable


desirable


desirable


desirable


desirable


desirable


desirable


Iran 1053




permissive


permissive


permissive


permissive


-


permissive


permissive


permissive


WHO (2011)




-


-


permissive


permissive


permissive


permissive


permissive


-


U.S.EPA





 
Measured parameters indicated that according to the standards of World Health Organization (WHO, 2011) all the springs (except Katalom which is somewhat acidic) are in permissive and desirable limit in respect of total dissolved solids (TDS), electric conductivity and acidity (pH). BOD values also showed that due to wastewater pollution there are many aerobic microorganisms and organic materials in the water of Giash spring while in the other springs, this parameter is zero and so there is no microorganism. Electric conductivity rates in all springs are in permissive range, but in Kachanak spring exceeds it. Comparing the anions contents with that provided by WHO, indicated that anions also are in the permissive ranges. Bicarbonate content in Kachanak spring is higher than other springs and nitrate in the Giash spring is the highest. Comparing the major cations in 5 studied springs showed that the lowest sodium and potassium contents are in the Giash and the greatest in Katalom spring. The highest contents of both calcium and magnesium were in Kachanak but the lowest ones in Rishboraz Darreh and Giash respectively. Silicon amount in Katalom was the greatest and the lowest in Giash. It seems that the unusually high amount of silicon is due to mixing of magmatic hot water with groundwater. According to WHO all the cations are in permissive range. Metal index (MI) (Tamasi et al., 2004) and Heavy Metal Pollution Index (HPI) (Mohan et al., 1996) are indicators to determine the pollution extent in the water resources in respect of heavy metals. MI is used to evaluate the potability, and HPI is used to examine the effects of the heavy metal on human health. To determine these indices, 13 elements data including Ba, As, Cd, Cr, Pb, Ni, Mo, Zn, Se, Mn, Sb, V, Cu were used. In all the springs, calculated MI and HPI were in the permissive range, which suggests a lack of severe pollution in terms of heavy metals. Katalom and Kachanak springs have the highest, and Namak Darreh has the lowest indices values (table 2). Geothermal activities in the vicinity of Katalom, Sadat Shahr and Ramsar, presence of thermal springs (and mixing of their water with mentioned springs), old mining activities in Katalom and agriculture activities in the area are among the reasons for these high indices’ values in Katalom and Kachanak springs.
 
Table 2- Calculated MI and HPI indices for the studied springs.





Giash
SH5


Namak Darreh
SH4


Rishboraz Darreh
SH3


Katalom
SH2


Kachanak
SH1


Spring name
Index




0.098


0.082


0.123


0.449


0.302


MI




0.009


0.0078


0.0106


0.026


0.012


HPI





 
4-Conclusion
Based on the interpretation and processing of the information obtained from chemical analysis and evaluation of physical parameters, results on the studied springs are as follow:
Kachanak spring is of Si-HCO3 type, and the others are of Si-Cl type. Silicon contents are higher than other elements. Alkaline earth metals (Ca2+, Mg2+) are more than alkaline elements (Na+, K+) and anions of strong acids (SO2-4) are more than weak acids (HCO3-). Noncarbonated hardness exceeds 50%. 
According to Schoeller standard, Kachanak spring is in non-drinkable and bad classes concerning calcium and magnesium contents, respectively. In Katalom spring, pH value is out of the limit of Schoeller standard and calcium, and magnesium contents were bad and moderate respectively. In Rishboraz Darreh calcium and magnesium, parameters are in acceptable for emergency conditions and moderate classes, respectively. In Namak Darreh spring, calcium is in unsuitable class, and magnesium is in moderate one. Moreover, pH parameter is also lower than the defined limit in this classification. In Giash spring, only in respect of calcium parameters is unsuitable class. All the springs of the studied area are in a good or acceptable group concerning other parameters. According to the Iranian standard (1053), in Kachanak spring, total hardness (TH) is unsuitable in undesirable range but is permissive, in Rishboraz Darreh, Namak Darreh, and Giash springs, parameters are desirable. According to WHO (2011) and U.S Environmental Protection Agency (U.S.EPA), pH parameter of Katalom is out of permissive limit, but TDS and total alkalinity in all springs are in the permissive range. Also, MI and concentration of heavy metals such as nickel, arsenic, lead, chromium in Katalom spring are most significant among other springs.