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1.
Artigo em Inglês | MEDLINE | ID: mdl-35066595

RESUMO

Perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) levels were determined in surface water, groundwater and sediments of the Jin River Basin, southeastern China. PFOA was detected in most of the samples, and its concentrations ranged from 0.53 to 8.77 ng/L, 0.26 to 15.1 ng/L and not detected (ND) to 23.9 ng/g in surface water, groundwater and sediments, respectively. Unlike PFOA, the detection frequency of PFOS was lower than 32%, and its concentrations ranged from ND to 2.56 ng/L, ND to 7.01 ng/L, ND to 11.1 ng/g in surface water, groundwater and sediments, respectively. The environmental risk assessment showed that PFOA could pose a high risk to surface water and groundwater, and both PFOA and PFOS posed a high risk to sediments. Moreover, the adults living in the Jin River Basin were at insignificant health risk to exposure to PFOA and PFOS through water consumption.

2.
Chem Commun (Camb) ; 58(5): 633-636, 2022 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-34897326

RESUMO

Michler's ethylketone (MEK, 4,4'-bis(diethylamino)benzophenone), commonly-known as an intermediate in the synthesis of dyes and pigments, was successfully screened and optimized as a novel matrix for the enhancement of lipid in situ detection and imaging in tissues by MALDI-MSI. The results show several properties of MEK as a powerful MALDI matrix, including strong UV absorption, µm-sized crystals and uniform matrix-coating, super high vacuum chemical stability, low matrix-related ion interference, super soft ionization, and high lipid ionization efficiency.


Assuntos
Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
3.
Sci Total Environ ; 802: 149909, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34525690

RESUMO

Groundwater of alluvial fan plains is the foremost water source, especially in arid/semiarid regions. Its contaminants are big issues for water supply and public health concern. To reveal the groundwater chemistry, contaminants sources and health threats in alluvial aquifers, 81 groundwaters were collected from a typical alluvial fan plain of northern China for nitrogen, fluoride and major ions analysis. Statistical analysis and hydrochemical diagrams as well as human health risk assessment were performed. Nitrate is widely distributed and 53% of groundwaters exceed the permissible limit with the maximum concentration up to 326 mg/L. The distributions of nitrite, ammonia and fluoride contaminants are sporadic in spatial, and the concentrations of fluoride in groundwaters are slightly beyond the permissible limit of 1 mg/L. The hydrochemical facies shift from HCO3-Ca or Mixed HCO3-Na·Ca type to Mixed Cl-Mg·Ca and ClCa type with the increase of nitrate content. Two factors (Factor-1 and Factor-2) are extracted by factor analysis and account 63% of the total variances. The positive loading of F- and negative loading of NO3- on Factor-2 reveal geogenic and anthropogenic origins, respectively. The significant positive loadings of TDS, TH, SO42-, Cl-, Ca2+, Mg2+ on Factor-1 reveal the governing mechanisms on groundwater chemistry by intermixed sources of geogenic origins and anthropogenic inputs. Hydrogeochemical evolution in the study area is driven by both water-rock interaction and anthropogenic forces. Anthropogenic inputs/influences are the dominated forces increasing groundwater nitrate content and salinity in the piedmont zone and the residential and industrial zone of the southeastern lower parts, and would pose potential non-carcinogenic risks to various populations via oral intake pathway. Rational measures should be taken to protect groundwater quality out of the threats of anthropogenic pollution. The geogenic fluoride in groundwater would threat the health of children through oral pathway and should be also concerned. CAPSULE: The driving forces of groundwater chemistry in alluvial fan plains were revealed using integrated approach of factor analysis and geostatistical modelling.


Assuntos
Água Subterrânea , Poluentes Químicos da Água , Monitoramento Ambiental , Fluoretos/análise , Humanos , Nitratos/análise , Poluentes Químicos da Água/análise
4.
Anal Chem ; 93(35): 11920-11928, 2021 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-34405989

RESUMO

To our knowledge, this was the first study in which caffeic acid (CA) was successfully evaluated as a matrix to enhance the in situ detection and imaging of endogenous proteins in three biological tissue sections (i.e., a rat brain and Capparis masaikai and germinating soybean seeds) by matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI). Our results show several properties of CA, including strong ultraviolet absorption, a super-wide MS detection mass range close to 200,000 Da, micrometer-sized matrix crystals, uniform matrix deposition, and high ionization efficiency. More high-molecular-weight (HMW) protein ion signals (m/z > 30,000) could be clearly detected in biological tissues with the use of CA, compared to two commonly used MALDI matrices, i.e., sinapinic acid (SA) and ferulic acid (FA). Notably, CA shows excellent performance for HMW protein in situ detection from biological tissues in the mass range m/z > 80,000, compared to the use of SA and FA. Furthermore, the use of a CA matrix also significantly enhanced the imaging of proteins on the surface of selected biological tissue sections. Three HMW protein ion signals (m/z 50,419, m/z 65,874, and m/z 191,872) from a rat brain, two sweet proteins (mabinlin-2 and mabinlin-4) from a Capparis masaikai seed, and three HMW protein ion signals (m/z 94,838, m/z 134,204, and m/z 198,738) from a germinating soybean seed were successfully imaged for the first time. Our study proves that CA has the potential to become a standard organic acid matrix for enhanced tissue imaging of HMW proteins by MALDI-MSI in both animal and plant tissues.


Assuntos
Lasers , Proteínas , Animais , Ácidos Cafeicos , Peso Molecular , Ratos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
5.
Environ Sci Pollut Res Int ; 28(35): 48312-48329, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33905060

RESUMO

Groundwater resource is significantly important for sustainable development of the world, especially for arid endorheic watersheds. A total of 28 groundwaters were collected for hydrogeochemical analysis from the arid Chaka watershed on Tibetan plateau to illustrate the hydrochemical evolution, formation mechanisms and feasibility of groundwater in small arid endorheic watersheds where groundwater is much scarcer. The results showed groundwater has a slightly alkaline nature, and varies from soft fresh HCO3-Ca type to hard brackish/saline Cl-Na type along the groundwater flow path in the watershed with the total hardness in the range of 270-2,127 mg/L and the total dissolved solids in the range of 282-41,770 mg/L. Nitrogen and fluoride in phreatic water are found sporadically exceeding the permissible limits with the maximum value of 118 mg/L for nitrate, 1.2 mg/L for ammonia and 1.2 mg/L for fluoride. Hydrochemistry of phreatic and confined groundwater is naturally governed by water-rock interactions including minerals (halite, gypsum and anhydrite) dissolution, silicate weathering and cation-exchange reaction. The salinity of phreatic water is also dominantly controlled by the strong evaporation. Human activity is one of the important mechanisms influencing the hydrochemical signature of groundwater regardless of the depth. Groundwater has a great hydrogeochemical discrepancy spatially across the watershed and varies from excellent to extremely poor quality in phreatic aquifers. A better water quality that under the good to medium categories was observed in the confined aquifers with 80% of samples having the EWQI value less than 100 and others in the range of 100-150. Phreatic groundwater away from the river and in the downstream area has a relatively poor quality for domestic and agricultural purposes, and should be avoided to direct utilization. This research can improve the understanding of groundwater hydrogeochemical feature, genesis, and its constraints on the availability and feasibility of groundwater resources in small arid watersheds worldwide.


Assuntos
Água Subterrânea , Poluentes Químicos da Água , Monitoramento Ambiental , Humanos , Desenvolvimento Sustentável , Tibet , Poluentes Químicos da Água/análise
6.
Artigo em Inglês | MEDLINE | ID: mdl-30813230

RESUMO

The widespread use of reclaimed water has alleviated the water resource crisis worldwide, but long-term use of reclaimed water for irrigation, especially in agricultural countries, might threaten the soil environment and further affect groundwater quality. An in-situ experiment had been carried out in the North China Plain, which aimed to reveal the impact of long-term reclaimed water irrigation on soil properties and distribution of potentially toxic elements (As, Cd, Cr, Hg, Zn and Pb) in the soil profile as well as shallow groundwater. Four land plots were irrigated with different quantity of reclaimed water to represent 0, 13, 22 and 35 years' irrigation duration. Pollution Load Index (PLI) values of each soil layer were calculated to further assess the pollution status of irrigated soils by potentially toxic elements (PTEs). Results showed that long-term reclaimed water irrigation caused appreciable increase of organic matter content, and might improve the soil quality. High soil organic matter concentrations conduced to high adsorption and retention capacity of the soils toward PTEs, which could reduce the risk of PTEs leaching into deep layers or shallow groundwater. Highest levels of Cr, Pb and Zn were observed at 200⁻240 cm and 460⁻500 cm horizons in plots. Longer irrigation time (35 years and 22 years) resulted in a decreasing trend of As, Cd, Hg, Pb and Zn in lower part of soil profiles (>540 cm) compared with that with 13-years' irrigation years. Long-term reclaimed water irrigation still brought about increases in concentrations of some elements in deep soil layer although their content in soils and shallow groundwater was below the national standard. Totally speaking, proper management for reclaimed water irrigation, such as reduction of irrigation volume and rate of reclaimed water, was still needed when a very long irrigation period was performed.


Assuntos
Irrigação Agrícola/métodos , Agricultura/métodos , Monitoramento Ambiental , Poluentes do Solo/análise , Águas Residuárias/análise , China , Reciclagem
7.
Artigo em Inglês | MEDLINE | ID: mdl-29794989

RESUMO

Solute transport modeling resolves advection, dispersion, and chemical reactions in groundwater systems with its accuracy depending on the resolution of domain at all scales, thus the computational efficiency of a simulator becomes a bottleneck for the wide application of numerical simulations. However, the traditional serial numerical simulators have reached their limits for the prohibitive computational time and memory requirement in solving large-scale problems. These limitations have greatly hindered the wide application of groundwater solute transport modeling. Thus, the development of an efficient method for handling large-scale groundwater solute transport simulation is urgently required. In this study, we developed and assessed a parallelized MT3DMS (Modular Three-Dimensional Multispecies Transport Model) by using OpenMP (Open specifications for Multi-Processing) to accelerate the solute transport simulation process. The parallelization was achieved by adding OpenMP compile directives (i.e., defining various types of parallel regions) into the most time-consuming packages, including the Advection package (ADV), Dispersion package (DSP), and Generalized Conjugate Gradient Solver package (GCG). This allows parallel processing on shared-memory multiprocessors, i.e., both the memory requirement and computing efforts are automatically distributed among all processors. Moreover, we discussed two different parallelization strategies for handling numerical models with either many layers or few layers. The performance of parallelized MT3DMS was assessed by two benchmark numerical models with different model domain sizes via a workstation with two quad-core processors. Results showed that the running time of parallelized MT3DMS can be 4.15 times faster than that using sequential MT3DMS. The effects of using different preconditioners (procedures that transform a given problem into a form that is more suitable for numerical solving methods) in the GCG package were additionally evaluated. The modified strategy for handling numerical models with few layers also achieved satisfactory results with running time two times faster than that via sequential simulation. Thus, the proposed parallelization allows high-resolution groundwater transport simulation with higher efficiency for large-scale or multimillion-cell simulation problems.


Assuntos
Água Subterrânea/química , Modelos Teóricos , Movimentos da Água
8.
Environ Monit Assess ; 189(10): 514, 2017 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-28940044

RESUMO

In this study, the hydrochemical characteristics of shallow groundwater were analyzed to get insight into the factors affecting groundwater quality in a typical agricultural dominated area of the North China Plain. Forty-four shallow groundwater samples were collected for chemical analysis. The water type changes from Ca·Na-HCO3 type in grass land to Ca·Na-Cl (+NO3) type and Na (Ca)-Cl (+NO3+SO4) type in construction and facility agricultural land, indicating the influence of human activities. The factor analysis and geostatistical analysis revealed that the two major factors contributing to the groundwater hydrochemical compositions were the water-rock interaction and contamination from sewage discharge and agricultural fertilizers. The major ions (F, HCO3) and trace element (As) in the shallow groundwater represented the natural origin, while the nitrate and sulfate concentrations were related to the application of fertilizer and sewage discharge in the facility agricultural area, which was mainly affected by the human activities. The values of pH, total dissolved solids, electric conductivity, and conventional component (K, Ca, Na, Mg, Cl) in shallow groundwater increased from grass land and cultivated land, to construction land and to facility agriculture which were originated from the combination sources of natural processes (e.g., water-rock interaction) and human activities (e.g., domestic effluents). The study indicated that both natural processes and human activities had influences on the groundwater hydrochemical compositions in shallow groundwater, while anthropogenic processes had more contribution, especially in the reclaimed water irrigation area.


Assuntos
Irrigação Agrícola/métodos , Monitoramento Ambiental/métodos , Água Subterrânea/química , Atividades Humanas , Esgotos/análise , Poluentes Químicos da Água/análise , China , Fertilizantes/análise , Água Subterrânea/normas , Humanos , Qualidade da Água
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