Natural and anthropogenic sources of solutes in the wet precipitation of a densely populated city of Southern South America.

The chemistry of rainwater is controlled by the interaction among water, airborne particles and gas sources, whether natural or human-made. This article analyzes the chemical composition dynamics of individual rainfall events collected over a three-year period in the densely populated city of Córdoba (Argentina). The main purpose is to identify the natural and/or anthropogenic sources, and the extent to which they determine the seasonal chemical signature exhibited by wet precipitation in the heart of the South Eastern South America.

Geochemical behavior of an acid drainage system: the case of the Amarillo River, Famatina (La Rioja, Argentina).

The Amarillo River (Famatina range, Argentina, ~29° S and ~67° W) is unusual because acid mine drainage (AMD) is superimposed on the previously existing acid rock drainage (ARD) scenario, as a Holocene paleolake sedimentary sequence shows. In a markedly oxidizing environment, its water is currently ferrous and of the sulfate-magnesium type with high electrical conductivity (>10 mS cm in uppermost catchments). At the time of sampling, the interaction of the mineralized zone with the remnants of mining labors determined an increase in some elements (e.

Mechanisms of fluoride release in sediments of Argentina's central region.

We analyze the sources and mechanisms that control the release of fluoride from sediments collected from two types of aquatic reservoirs in the central region of Argentina: 1) mountainous rivers draining crystalline rocks from the Sierras Pampeanas ranges, and 2) shallow aquifers in loessic sediments. The assessment was performed on the basis of experimental work and the study of chemical and mineralogical characteristics of sediments in contact with F-rich waters of the studied region. The chemical and mineralogical compositions of sediments were analyzed by ICP/OES, DRX, and SEM-EDS.

Continuous flow method for the simultaneous determination of phosphate/arsenate based on their different kinetic characteristics.

This paper proposes a new automated spectrophotometric method for the simultaneous determination of phosphate and arsenate without pre-treatment, which is faster, simpler, less expensive and hazardous than other well-known methods used with water samples. Such method is based on the different kinetic characteristics of complex formation of phosphate and arsenate with ammonium molybdate. A flow system was used in order to achieve good mixing and to provide precise time control.