Hydrochemical Characteristic Research Articles

Hydrochemical characteristic of coastal aquifer from Tuticorin, Tamil Nadu, India

This article deals with a systematic hydrochemical study carried out in coastal aquifers, Tuticorin, Tamil Nadu, to assess groundwater quality. A total of 29 groundwater samples were collected and analyzed. Results showed that total dissolved solids (TDS), sodium (Na+), magnesium (Mg2+), chloride (Cl-), and sulfate (SO₄²⁻) significantly damaged groundwater systems. The degree of salinization due to seawater mixing in a well or a given area could be indicated by an increase in nearly all major cations and anions. Toxic elements (i.e., Pb and As) were higher than the maximum permissible limits of drinking water. Cross plot of HCO₃⁻/Cl- (molar ratios) versus TDS indicated that about 62% of the analyzed samples were saline. Factor analysis showed that groundwaters, affected by seawater intrusion/industrial activity, were separated from the clusters. An attempt was made to identify the hydrochemical processes that accompany current intrusion of seawater using ionic changes. It was estimated that the mixing rate of seawater intrusion was about 5.81% during April 2007. An index, called 'Seawater Mixing Index' (SMI), was also adopted and its value was SMI>1.18 with EC>3,000 μS/cm about 62% of the sampled waters, were saline. Further, a few trace elements (i.e., Sr, B, and Li) were used as indicators for responding to the change in fresh to saline groundwater environments in coastal aquifers.

Hydrochemical characteristic of different modifications of Antarctic waters

The report considers the distribution of several hydrochemical components (dissolved oxygen, mineral phosphorus, dissolved silicon, and nitrate nitrogen) depending on the disposition of different structural water modifications constituting the unified Antarctic structural type. It is shown that the character of the silicon distribution in the waters of the South Polar zone is mainly determined by large-scale circulation features. The distribution of mineral phosphorus and nitrate nitrogen is characterized by a certain patchiness related to the photosynthesis intensity. An attempt was made to follow the supply and transformation of dissolved silicon, nitrates, and phosphates in the Antarctic.

Mineralogia y geoquimica de los sedimentos de algunas lagunas del N de la provincia de Málaga (S de España)

Similar compositional and genetic characteristics for the recently deposited sediments in some lakes and ponds of the north of the Malaga province have been observed. Nevertheless, it seems to exist some differences in their mineralogical and geochemical evolution as well as in the degree of alteration of the original sediment. The mineral alterations produced in these confined lacustrine basins, with pH higher than 8, are controlled by ionic exchange between water and sediment. According to the mineral alteration degree three stadiums of mineral evolution have been detected. In addition the mineralogical and geochemical evolution and the hydrochemical characteristic of the aqueous environment are related. The study has shown that some neoformation processes of Mgrich minerals also occur.