Hydrochemistry and Uranium Concentration in Brackish Groundwater from an Arid Zone, Chihuahua, Mexico

In arid zones, the principal water supply is from groundwater, which can present high concentration of salts, heavy metals, and radioactive elements. The aim of the study was to determine isotopic uranium concentration in groundwater samples with high concentration of salts and its association with other chemical species. Samples were taken from wells with high salt content. The 238,234U radioisotope concentrations were determined by liquid scintillation and alpha-particle spectrometry. In addition, the physical-chemical parameters were recorded in situ; whereas the dissolved ions and elemental composition were measured by UV-Vis and X-ray fluorescence spectrophotometry, respectively. To obtain isotopic uranium concentrations, three radiochemistry procedures were carried out. An ANOVA test was performed to compare the results from procedures, as well as an analysis of Pearson correlation was used between parameters to obtain their associations. Statistically, the U isotopic concentrations did not show differences (p-value 0.82) between procedures. 238U and 234U showed mean concentrations of 6.7 mBq mL-1 and 16.6 mBq mL-1, respectively, with an Activity Ratioby up 7.2. The groundwater under study showed high concentration of TDS, calcium, sulphate, chloride, nitrate, and nitrite. Isotopic U concentrations tend to increase with NO3>Zn>Cl>Br>SO4>Cu>T>SDT>P; meanwhile their contents decrease with T>Cl->NO2>Fe. These findings help us to understand the uranium behavior in groundwater with high salt contents as well as the influence of agricultural supplies on chemical species presents in groundwater

Partitioning and Availability of Metals from Water Suspended Sediments: Potential Pollution Risk Assessment

The water management initiatives in freshwater systems focus on water availability to preserve this resource for human uses and the health of aquatic ecosystems. This work presents an assessment of the potential pollution risk caused by the metal availability in suspended sediments. The objective of this study was to determine the partitioning, association, and geochemical fractionation of metals in suspended sediments from a surface water body. Additionally, the environmental assessment for this reservoir was estimated using geoaccumulation, enrichment, and pollution indices of metals and the related potential risk by their elemental availability (RAC). Chemical, mineralogical, and morphological characterizations were obtained by inductively coupled plasma spectrometry, alpha spectroscopy, X-ray crystallography, and scanning electron microscopy. Clay, quartz, montmorillonite, and calcite were the main minerals of suspended sediments. Chemical fractionation was the parameter affecting the concentrations of metals in suspended sediments. The sediment composition is of natural origin; however, these finer particles can promote the scavenging of toxic metals. It contributes to obtaining moderate to high levels for enrichment/contamination indices. Although Ca, Mg, and U were the most accessible metals for aquatic biota, metals such as Sr, Mn, Li, Cu, and Ni in the exchangeable phase of suspended sediments are the potentially toxic elements in this aquatic ecosystem

Determination of 234U and 238U Activities in Soil by Liquid Scintillation and High-Resolution Alpha Spectrometry

Uranium is a radioactive element with a special presence in the rocks, waters, sediments, soils, and plants at the state of Chihuahua. The activity ratio of 238U/234U is used to explain the uranium transport by surface water and its deposition in arid environments. In this work, the activity concentration of natural U isotopes is determined by PERALS liquid scintillation and high-resolution alpha spectrometry (AS, Canberra camera 7401VR) in the Environmental Radiological Surveillance Laboratory (LVRA) at CIMAV, Chihuahua. Uranium is extracted from soils through the scintillating liquid extractor URAEX for PERALS, with chemical recovery (CR) of 80 - 85 %, and through the ion exchange resin UTEVA + electrode position by the Hallstadius method, with CR of 85 - 90 %, for AS. The procedures of 234U and 238U activity concentration (AC) determination in soils were validated by their application to the certified reference material IAEA-375. The resulting values were in the reference range of the certified or informative values. Both procedures were applied to 6 representative soil samples, with AC of the same order of magnitude or greater, and similar CR and compatible results. Both procedures are satisfactory for the purposes of LVRA research and in general

Prevalence of Rotavirus Genogroup A and Norovirus Genogroup II in Bassaseachic Falls National Park Surface Waters in Chihuahua, Mexico

Abstract: In areas lacking potable water treatment, drinking contaminated water may represent a public health threat. In addition to enteropathogenic bacteria and parasites, fecal contamination in water environments is associated with the transmission of enteric viruses and other causal agents of infectious disease. Rotavirus and norovirus are the main enteric viral agents responsible for diarrheic outbreaks. The aim of the present study was to detect seasonal variation of rotavirus and norovirus in the surface water at Bassaseachic Falls National Park during 2013. Rivers and streams within and nearby this park were sampled once in each season during 2013. Viral concentration was carried out by a handmade filtration equipment, using a commercial electropositive membrane coupled with the virus absortion elution technique (VIRADEL©). Detection of rotavirus and norovirus was performed by SYBR Green reverse transcription-real time polymerase chain reaction (SYBR GREEN© RT-qPCR) analyses. Norovirus genogroup II was detected in samples collected in June and October 2013. Inthecaseofrotavirus,genogroupAwasdetectedinMarchandJune. Thepresenceofrotavirus and norovirus was related to viral acute diarrhea in children less than five years of age, who were inhabiting the sampled areas. This may indicates that the contaminated water was potentially a risk factor for regional diarrheic outbreaks. Keywords: norovirus; rotavirus; surface water; VIRADEL; virus detection; environmen

Partitioning and Availability of Metals from Water Suspended Sediments: Potential Pollution Risk Assessment

The water management initiatives in freshwater systems focus on water availability to preserve this resource for human uses and the health of aquatic ecosystems. This work presents an assessment of the potential pollution risk caused by the metal availability in suspended sediments. The objective of this study was to determine the partitioning, association, and geochemical fractionation of metals in suspended sediments from a surface water body. Additionally, the environmental assessment for this reservoir was estimated using geoaccumulation, enrichment, and pollution indices of metals and the related potential risk by their elemental availability (RAC). Chemical, mineralogical, and morphological characterizations were obtained by inductively coupled plasma spectrometry, alpha spectroscopy, X-ray crystallography, and scanning electron microscopy. Clay, quartz, montmorillonite, and calcite were the main minerals of suspended sediments. Chemical fractionation was the parameter affecting the concentrations of metals in suspended sediments. The sediment composition is of natural origin; however, these finer particles can promote the scavenging of toxic metals. It contributes to obtaining moderate to high levels for enrichment/contamination indices. Although Ca, Mg, and U were the most accessible metals for aquatic biota, metals such as Sr, Mn, Li, Cu, and Ni in the exchangeable phase of suspended sediments are the potentially toxic elements in this aquatic ecosystem

Partitioning and Availability of Metals from Water Suspended Sediments: Potential Pollution Risk Assessment

The water management initiatives in freshwater systems focus on water availability to preserve this resource for human uses and the health of aquatic ecosystems. This work presents an assessment of the potential pollution risk caused by the metal availability in suspended sediments. The objective of this study was to determine the partitioning, association, and geochemical fractionation of metals in suspended sediments from a surface water body. Additionally, the environmental assessment for this reservoir was estimated using geoaccumulation, enrichment, and pollution indices of metals and the related potential risk by their elemental availability (RAC). Chemical, mineralogical, and morphological characterizations were obtained by inductively coupled plasma spectrometry, alpha spectroscopy, X-ray crystallography, and scanning electron microscopy. Clay, quartz, montmorillonite, and calcite were the main minerals of suspended sediments. Chemical fractionation was the parameter affecting the concentrations of metals in suspended sediments. The sediment composition is of natural origin; however, these finer particles can promote the scavenging of toxic metals. It contributes to obtaining moderate to high levels for enrichment/contamination indices. Although Ca, Mg, and U were the most accessible metals for aquatic biota, metals such as Sr, Mn, Li, Cu, and Ni in the exchangeable phase of suspended sediments are the potentially toxic elements in this aquatic ecosystem