ORIGINAL ARTICLE
Geochemistry characterization of groundwater in an agricultural
area of Razan, Hamadan, Iran
Mohsen Jalali
Received: 15 August 2007 / Accepted: 6 February 2008 / Published online: 23 February 2008
Ó Springer-Verlag 2008
Abstract This study was conducted to evaluate factors
regulating groundwater quality in an area with agriculture
as main use. Thirty groundwater samples have been col-
lected from Razan area (Hamadan, Iran) for hydrochemical
investigations to understand the sources of dissolved ions
and assess the chemical quality of the groundwater. The
chemical compositions of the groundwater are dominated
by Na
+
,Ca
2+
, HCO
3
-
,Cl
-
and SO
4
2-
, which have been
derived largely from natural chemical weathering of car-
bonate, gypsum and anthropogenic activities of fertilizer’s
source. The production of SO
4
2-
has multiple origins,
mainly from dissolution of sulphate minerals, oxidation of
sulphide minerals and anthropogenic sources. The major
anthropogenic components in the groundwater include Na
+
,
Cl
-
,SO
4
2-
and NO
3
-
, with Cl
-
and NO
3
-
being the main
contributors to groundwater pollution in Razan area.
Keywords Hydrochemistry Á Anthropogenic Á
Groundwater Á Chemical composition
Introduction
Groundwater resource assessments and sustainability con-
siderations are of utmost importance in the arid and semi-
arid regions, where water is commonly of critical eco-
nomical and social significance. Continued population
growth in Iran is rapidly depleting groundwater supplies in
some areas. Intense agricultural and urban development has
placed a high demand on groundwater resources in arid and
semi-arid regions and also these resources at greater risk to
contamination. Groundwater is the primary source of water
for domestic, agricultural and industrial uses in many
countries, and its contamination has been recognized as one
of the most serious problems in Iran (Jalali 2005c, 2007).
Further intensive use for irrigation makes groundwater a
critical resource for human activities. Among the sources
of contamination, agriculture affects both direct and indi-
rect effects on groundwater chemistry (Bo
¨
hlke 2002).
Agriculture constitutes the largest user of the resource,
averaging about 70% of all freshwater supplies on a global
scale (Ongley 1996). The quality of groundwater in rural
areas is sensitive to the contaminants originated from the
agricultural chemicals (Kelly 1997; Stigter et al. 1998;
Chae et al. 2004; Jalali 2005b). In Iran, some aquifers
throughout the Hamadan province, western Iran have been
degraded by overuse of fertilizers, and pesticides are now
unsuitable for human consumption especially due to the
high content of NO
3
-
(Jalali 2005b).
Despite importance of groundwater in Iran, little is
known about the natural phenomena that govern the
chemical composition of groundwater or anthropogenic
factors that presently affect them. The chemical composi-
tion of groundwater is controlled by many factors that
include composition of precipitation, geological structure
and mineralogy of the watersheds and aquifers, and geo-
logical processes within the aquifer (Andre et al. 2005). The
interaction of all factors leads to various water types.
Increased knowledge of geochemical evolution of ground-
water in arid and semi-arid regions could lead to improved
understanding of hydrochemical systems in such areas,
leading to sustainable development of water resources and
effective management of groundwater resource.
The aims of this study were to characterize water/rock
interaction and its effects on the chemistry of the
M. Jalali (&)
Department of Soil Science, College of Agriculture,
Bu-Ali Sina University, Hamadan, Iran
e-mail: Jalali@basu.ac.ir
123
Environ Geol (2009) 56:1479–1488
DOI 10.1007/s00254-008-1245-9