RESUMEN
In order to understand the characteristics and origin of groundwater salinization in Taocheng district of Hengshui City, the recharge and salinization procession of shallow groundwater were analyzed with isotopic and geochemical data of the shallow groundwater (buried depth ≤ 100 m) and the soluble salt in boreholes. The results showed that the shallow groundwater was weak alkaline salt water, with the total dissolved solid (TDS) in the groundwater ranging from 176.06 to 17569.65 mg·L-1and the soil total salinity in unconsolidated sediments ranging from 1.830 to 6.509 g·kg-1. The hydrochemical types were mainly SO4·Cl-Na·Mg and Cl·SO4-Na·Ca in the shallow groundwater and the soluble salt. The main recharge resource of shallow groundwater was precipitation with different geological periods. The hydrochemical compositions of shallow groundwater mainly came from the dissolution of halite and sulfate weathering and experienced intense evaporation and the reduction environment. Meanwhile, the groundwater salinization was barely affected by human activities and seawater intrusion.
RESUMEN
To study the hydrochemical characteristics of groundwater and the factors controlling the alluvial-proluvial fan of the Qinhe River, 60 samples were collected including 9 surface water samples and 51 groundwater samples. The distribution characteristics of the hydrochemistry and major controlling factors of hydrochemical evolution processes of surface water and groundwater in the study area were analyzed by using mathematical statistics, the Schakerev classification, Piper diagrams, Schoeller diagrams, Gibbs plots, and ion ratios. The results show that:â the major anions and cations of surface water and groundwater in the study area are Ca2+, Mg2+, SO42-, and HCO3-. The recharge sources of surface water and groundwater are closely related; â¡ the major hydrochemical types of the groundwater are HCO3-Ca, HCO3-Ca·Mg, and HCO3·SO4-Ca·Mg, while the major hydrochemical type of surface water is HCO3·SO4-Ca·Mg; and ⢠the major ions of surface water and groundwater are affected by carbonate mineral weathering and dissolution, ion exchange, and evaporation. Sulfuric acid and carbonic acid were involved in carbonate mineral weathering and dissolution.
RESUMEN
In order to study the hydrochemical characteristics and their possible controls for the chemical composition of the water from the Niyang River Basin, 30 samples were collected from wells, springs, and the river in 2014 and major ion concentrations were measured. Descriptive statistics, the Gibbs figure, an ion ratio, and Piper triangular diagrams were used to investigate the hydrochemical characteristics, influencing factors, and hydrochemical evolution of the water in the basin. The results showed that the major cations in this water were Ca2+ and Mg2+, accounting for more than 84% of cations and the main anions were HCO3- and SO42-, accounting for more than 97% of anions The hydrochemical typology of the water is HCO3·SO4(SO4·HCO3)-Ca·Mg (Mg·Ca). The total dissolved solids (TDS) in the water ranges from 79.11 to 290.48 mg·L-1 with an average of 165.21 mg·L-1. The chemical composition of water samples is located to the left of the Gibbs model, which indicates that the chemical process of Niyang River Basin are controlled by rock weathering. According to the principal component analysis and correlation analysis, the hydrochemical composition is controlled by silicate weathering, however, carbonate weathering also plays an important role.
RESUMEN
An oil-contaminated groundwater sample was collected at an abandoned petrochemical factory.Bacterial genome DNA was extracted for the 16S rDNA gene amplification,and then a bacterial 16S rDNA gene clone library was constructed. After the phylogenetic analysis of 16S rDNA sequences, bacterial diversity and community structure of the groundwater were studied. The results showed the bacteria in the groundwater could be divided into 10 groups, which were as follows: gamma-Proteobacteria (49.1%), alpha-Proteobacteria (12.9%), beta-Proteobacteria (11.1%), Bacteroidetes (9.2%), Verrucomicrobia (6.7%), Acidobacteria (2.5%), delta-Proteobacteria (1.2%), Actinobacteria (1.2%), Planctomycetes (0.6%), unidentified bacteria (5.5%). Gamma-Proteobacteria was predominant in the ecosystem (near 50% of total clones), and especially Pseudomonas accounted for 35.6% of all bacteria. Many clones also affiliated with other degrading bacteria,such as Sphingomornas, Rhodococcus, Brevundimonas. Furthermore, a lot of 16S rDNA sequences in the clone library had high similarity to the ones originated from similar polluted environments, such as soil and groundwater contaminated with chlorinated hydrocarbon, soil and groundwater contaminated with polycyclic aromatic hydrocarbon, soil contaminated with PCBs, antibiotics production wastewater and activated sludge, which proved that there were lots of degrading bacteria population in the oil-contaminated water.