Islam M J, Hakim M A, Hanafi M M, Juraimi Abdul Shukor, Aktar Sharmin, Siddiqa Aysha, Rahman A K M Shajedur, Islam M Atikul, Halim M A
J Environ Biol. 2014 Jul;35(4):765-79.
Agriculture, rapid urbanization and geochemical processes have direct or indirect effects on the chemical composition of groundwater and aquifer geochemistry. Hydro-chemical investigations, which are significant for assessment of water quality, were carried out to study the sources of dissolved ions in groundwater of Dinajpur district, northern Bangladesh. The groundwater samplish were analyzed for physico-chemical properties like pH, electrical conductance, hardness, alkalinity, total dissolved solids and Ca2+, Mg2+, Na+, K+, CO3(2-), HCO3(-), SO4(2-) and Cl- ions, respectively. Based on the analyses, certain parameters like sodium adsorption ratio, soluble sodium percentage, potential salinity, residual sodium carbonate, Kelly's ratio, permeability index and Gibbs ratio were also calculated. The results showed that the groundwater of study area was fresh, slightly acidic (pH 5.3-6.4) and low in TDS (35-275 mg I(-1)). Ground water of the study area was found suitable for irrigation, drinking and domestic purposes, since most of the parameters analyzed were within the WHO recommended values for drinking water. High concentration of NO3- and Cl- was reported in areas with extensive agriculture and rapid urbanization. Ion-exchange, weathering, oxidation and dissolution of minerals were major geochemical processes governing the groundwater evolution in study area. Gibb's diagram showed that all the samples fell in the rock dominance field. Based on evaluation, it is clear that groundwater quality of the study area was suitable for both domestic and irrigation purposes.
农业、快速城市化和地球化学过程对地下水的化学成分和含水层地球化学有着直接或间接的影响。为研究孟加拉国北部迪纳杰布尔地区地下水中溶解离子的来源，开展了对水质评估具有重要意义的水化学调查。分别对地下水样本的pH值、电导率、硬度、碱度、总溶解固体以及Ca2+、Mg2+、Na+、K+、CO3(2-)、HCO3(-)、SO4(2-)和Cl-离子等理化性质进行了分析。基于这些分析，还计算了钠吸附比、可溶性钠百分比、潜在盐度、残留碳酸钠、凯利比率、渗透率指数和吉布斯比率等参数。结果表明，研究区域的地下水水质较淡，呈弱酸性（pH值为5.3 - 6.4），总溶解固体含量较低（35 - 275 mg I(-1)）。由于所分析的大多数参数都在世界卫生组织推荐的饮用水值范围内，因此研究区域的地下水适合用于灌溉、饮用和家庭用途。在农业广泛分布和城市化快速发展的地区，硝酸盐和氯离子浓度较高。离子交换、矿物风化、氧化和溶解是控制研究区域地下水演化的主要地球化学过程。吉布斯图表明，所有样本均落在岩石主导区域。基于评估结果，很明显研究区域的地下水质量适合家庭和灌溉用途。
