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Fluoroquinolone antibiotics have been extensively used in clinical treatments for human and animal diseases. However, their long-term presence in the environment increases the risk of producing resistance genes and creates a potential threat to ecosystems and the health of humans and animals. Batch equilibrium experiments were utilized to investigate the adsorption and retention behavior and mechanism of the quinolone antibiotic enrofloxacin (ENR) in farmland soil in North China. The adsorption and desorption kinetics of ENR in soil were best fitted by pseudo-second-order model (R2 > 0.999). Both the adsorption and desorption processes of ENR in soil reached equilibrium in 1 h. The desorption amounts of ENR were significantly lower than the adsorption amounts, with the hysteresis coefficient (HI) being less than 0.7. The adsorption thermodynamic process of ENR followed the Linear and Freundlich models (0.965 < R2 < 0.985). Hydrophobic distribution and heterogeneous multimolecular layer adsorption were identified as critical factors in the adsorption process. The adsorption amount of ENR gradually decreased with increasing temperature and the initial concentration of ENR. The adsorption rate of ENR was above 80%, while the desorption rate remained below 15%, indicating strong retention ability. The adsorption rate of ENR in soil decreased with increasing pH, the adsorption rate reached 98.3% at pH 3.0 but only 31.5% at pH 11. The influence of coexisting ions on adsorption primarily depended on their properties, such as ion radius, ionic strength, and hydrolysis properties, and the inhibition of adsorption increased with increasing ionic strength. These findings contribute to understanding the fate and risk of veterinary antibiotics in loess soil in North China.
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Antibacterianos , Enrofloxacina , Contaminantes del Suelo , Suelo , Enrofloxacina/química , Adsorción , Contaminantes del Suelo/química , Concentración de Iones de Hidrógeno , Antibacterianos/química , Suelo/química , China , Granjas , Fluoroquinolonas/química , Cinética , Iones/químicaRESUMEN
Animals manure and chemical fertilizers are widely applied to agricultural soils to mitigate soil fertility decline resulting from intensive farming practices. However, the use of antibiotics such as ciprofloxacin (CIP) and enrofloxacin (ENR) in these manures introduces certain environmental risks. The sorption of CIP and ENR in soil is influenced by various factors. Soil cations (i.e., Na+, K+, Mg2+, and Ca2+) and artificially introduced ions (NH4+) can affect the sorption behavior of CIP and ENR in alkaline agricultural soils through mechanisms such as ion exchange and competitive sorption. To investigate the effects of ionic strength and ion type on the sorption of antibiotics in alkaline agricultural soil, batch equilibrium experiments were conducted in this study. The results showed that the affinity of alkaline farmland soil to CIP and ENR was poor, and Kd was only 159 L/kg and 89 L/kg, respectively. Increases in temperature and pH inhibited CIP and ENR sorption on soil. Mineral elements in the soil strongly inhibited CIP and ENR sorption. Conversely, NH4+ promoted the Kd values of CIP and ENR by 46% and 221%, respectively. Additionally, under different influencing factors, both the sorption affinity (Kd) and sorption amount of ENR were lower than those of CIP. These findings indicate that ENR has a greater migration potential and poses a greater environmental risk in agricultural soils. Alkaline soil and mineral elements increase the migration potential of CIP, ENR, but the introduction of NH4+ in agricultural production can weaken the migration potential of them.
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Ciprofloxacina , Enrofloxacina , Contaminantes del Suelo , Suelo , Ciprofloxacina/química , Suelo/química , Concentración de Iones de Hidrógeno , Enrofloxacina/química , Concentración Osmolar , Contaminantes del Suelo/química , Adsorción , Agricultura , Antibacterianos/químicaRESUMEN
BACKGROUND: Lysimachia christinae Hance (LCH) is a traditional medicine used to treat gallstone disease and cholecystitis. Despite its known anti-inflammatory and choleretic effects, its quality has not been extensively evaluated. OBJECTIVE: In this study, we aimed to establish a reliable quality evaluation method for LCH via fingerprint, spectrum-effect relationship, and quantitative analyses of multicomponents by a single marker (QAMS). METHODS: First, the fingerprints and anti-inflammatory and choleretic activities of 14 LCH batches were determined. Then, the gray relation analysis method was used to analyze the peak areas of the fingerprint profile and pharmacodynamic data. Subsequently, the characteristic peaks were tentatively identified using high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry. Finally, rutin was selected as the internal reference material, and QAMS was used to analyze the LCH components. RESULTS: Pharmacodynamic experiments confirmed that LCH exerted anti-inflammatory and choleretic effects. Moreover, 15 flavonoids related to the anti-inflammatory and choleretic effects of LCH were identified. Notably, relative error percentage between the QAMS and external standard method was less than 5%. CONCLUSION: This study successfully established a comprehensive evaluation method for the qualitative and quantitative analyses of LCH.
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Lysimachia , Animales , Masculino , Ratas , Antiinflamatorios/farmacología , Antiinflamatorios/análisis , Cromatografía Líquida de Alta Presión/métodos , Medicamentos Herbarios Chinos/química , Medicamentos Herbarios Chinos/farmacología , Flavonoides/análisis , Lysimachia/química , Control de Calidad , Femenino , RatonesRESUMEN
In this research, the degradation of different types of N-containing heterocycle (NHC) contaminants by Cu-OMS-2 via peroxymonosulfate (PMS) activation in an aqueous environment was investigated. First, the effects of different reaction parameters were optimized using benzotriazole (BTR) as the model contaminant, and the optimal reaction conditions were 8 mM PMS, 0.35 g/L Cu-OMS-2, and 30 °C. Nine different types of NHC contaminants were effectively degraded under these reaction conditions, and the degradation efficiencies and the mineralization rates of those NHCs were more than 68 and 46%, respectively. Moreover, the Cu-OMS-2/PMS process presented excellent performance at a wide pH ranging from 3.0 to 11.0 and in the presence of some representative anions (NO3- and SO42-) and dissolved organic matter (fumaric acid). The inhibition sequence of anions on BTR removal during the Cu-OMS-2/PMS process was H2PO4- > HCO3- > Cl- > CO32- > NO3- > SO42-. It was also found that 74.5 and 71.3% BTR degradation rates were achieved in actual water bodies, such as tap water and Yellow River water, respectively. Besides, the Cu-OMS-2 heterogeneous catalyst had excellent stability and reusability, and the degradation rate of BTR was still at 77.0% after 5 cycles. Finally, electron paramagnetic resonance analysis and scavenging tests showed that 1O2 and SO4-â¯â¢ were the primary reactive oxygen species. Accordingly, Cu-OMS-2 nanomaterial was an efficient and sustainable heterogeneous catalyst to activate PMS for the decontamination of BTR in water remediation.
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BACKGROUND: Hawk tea, a medicinal and edible plant, has been consumed for thousands of years in Southwest China. To date, no unified food safety standard for Hawk tea has been established, and systematic research on the quality of Hawk tea is lacking. OBJECTIVE: The aim of this study was to develop a comprehensive evaluation method for the quality of Hawk tea based on inclusions content, high-performance liquid chromatography (HPLC) fingerprinting combined with the quantitative analysis of multiple components with a single marker (QAMS) method. METHODS: The contents of total flavonoids, total phenols, total polysaccharides, and total protein were determined using the colorimetric method. An effective comprehensive evaluation method was established to classify the 16 batches of samples based on HPLC fingerprint analysis combined with similarity analysis (SA), hierarchical cluster analysis (HCA), principal component analysis (PCA), partial least-squares discrimination analysis (PLS-DA), and the QAMS method. RESULTS: Flavonoids were the main chemical components of Hawk tea. The accuracy of the QAMS method was verified by comparing the calculated results with those of the external standard method (ESM). No significant differences were found between the two methods. Additionally, the fingerprint of Hawk tea was also established. CONCLUSION: The method established in this study can be used for the comprehensive quality evaluation of Hawk tea and can also provide a reference for the quality evaluation of other herbal medicines.
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Medicamentos Herbarios Chinos , Medicamentos Herbarios Chinos/química , Cromatografía Líquida de Alta Presión/métodos , Control de Calidad , Flavonoides/análisis , Té/químicaRESUMEN
Phytoremediation of total petroleum hydrocarbons (TPHs) contamination is a process that uses the synergistic action of plants and rhizosphere microorganisms to degrade, absorb and stabilize pollutants in the soil, and has received increasing attention in recent years. However, this technology still has some challenges under certain conditions (e.g., highly alkaline and saline environments). The present study was selected three native plant species (alfalfa, tall fescue, and ryegrass) to remediate petroleum pollutants in greenhouse pot experiments. The results indicate that TPH contamination not only inhibited plant growth, soil chemical properties and soil fertility (i.e. lower plant biomass, chlorophyll, pH, and electrical conductivity), but also increased the malondialdehyde, glutathione, and antioxidant enzyme activities (catalase and polyphenol oxidase). Further, correlation analysis results illustrated that TPH removal was strongly positively correlated with chlorophyll, soil fertility, and total organic carbon, but was negatively correlated with dehydrogenase, polyphenol oxidase, pH, and electrical conductivity. The highest TPHs removal rate (74.13%) was exhibited by alfalfa, followed by tall fescue (61.79%) and ryegrass (57.28%). The degradation rates of short-chain alkanes and low rings polycyclic aromatic hydrocarbons (PAHs) were substantially higher than those of long-chain alkanes and high rings PAHs. The findings of this study provide valuable insights into petroleum decontamination strategies in the highly saline - alkali environments.
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Contaminantes Ambientales , Lolium , Petróleo , Contaminantes del Suelo , Álcalis , Suelo/química , Petróleo/análisis , Contaminantes del Suelo/análisis , Plantas/metabolismo , Biodegradación Ambiental , Microbiología del Suelo , Hidrocarburos/química , Alcanos , Contaminantes Ambientales/análisisRESUMEN
In this study, a novel 28.6 kDa acidic polysaccharide (HTP-1), containing â 4)-GalpA-(1â, â2)-Rhap-(1 â and â 3,6)-Galp-(1 â residues as the backbone, analogous to pectin, was isolated from mature Hawk tea leaves. HTP-1 exhibited significant immunoregulatory activities on CTX-induced immunosuppressed mice in a dose-depend manner by alleviating jejunum injury and improving the levels of immune organ indexes, cytokines and immunoglobulins. Moreover, HTP-1 supplementation boosted the content of SCFAs, altered the intestinalmicrobiota composition, and raised the abundances of beneficial bacteria Muribaculaceae, Lactobacillaceae, Bacteroidaceae, Prevotellaceae and Ruminococcaceae, which showed a strong positive correlation with most immune indicators. The current findings suggested that the immunomodulatory action of HTP-1 might rely on the regulation of the gut microbiota, and these results may also serve as a foundation for the future exploitation of HTP-1 as functional foods.
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Microbioma Gastrointestinal , Animales , Ratones , Polisacáridos/química , Pectinas/química , Té/químicaRESUMEN
Investigate the effect of soil organic matter (SOM) and low molecular weight organic acids (LMWOAs) on minerals adsorption of PAHs. Batch adsorption experiments have been carried out to study the adsorption of PAHs (Naphthalene (NaP), Phenanthrene (Phe) and Pyrene (Pyr)) by minerals (Montmorillonite (Mnt), kaolinite (Kln) and calcite (Cal)). This research found that compared with Kln and Cal, Mnt showed the maximum adsorption capability for PAHs. And the order of PAHs adsorption by Mnt was: Pyr > Phe > Nap, which corresponds to the octanol-water partition coefficient (Kow) of different PAHs. The adsorption kinetic and isotherm were well fitted by Pseudo-second-order kinetic model, Freundlich and Linear isotherm model. Furthermore, inorganic ions (Ca2+) impacted PAHs adsorption by competitive adsorption and cation-π interactive. Cal has the maximum desorption of PAHs among three minerals, and there was desorption hysteresis phenomenon. Field emission-scanning electron microscope (Fe-SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) analysis indicated that SOM enhanced the sorption of PAHs by van der Waals, hydrogen bonding, π-π interactions, and chemical bonding. LMWOAs significantly inhibited PAHs adsorption and promote PAHs desorption from the minerals. As a result, LMWOAs increased of PAHs bioavailability, which provide a new strategy to improve PAHs cleanup efficiency.
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Fenantrenos , Hidrocarburos Policíclicos Aromáticos , Peso Molecular , Minerales , Hidrocarburos Policíclicos Aromáticos/análisis , Bentonita/química , Suelo , Caolín , Carbonato de Calcio , AdsorciónRESUMEN
Petroleum contamination surrounding oilfields has attracted more concerns. However, the levels, distribution and source of petroleum of Changqing Oilfield soil still remain lots of knowns, which is important for local environmental protection. Given soil contamination issues in Changqiong Oilfield were investigated. The maximum concentrations of total petroleum hydrocarbons (TPHs), N-alkanes (TNAs) and polycyclic aromatic hydrocarbons (PAHs) were determined to be 1960.29, 96.13 and 0.82 mg/kg, respectively. TPHs were higher in the north than the south of the study area. TPHs decreased in the horizontal and vertical distribution as soil depth and distance from oil wells increased. Source analysis showed that TNAs mainly originated from petroleum, PAHs were controlled by petroleum spills, combustion and traffic. Correlation analysis implied that TPHs residues had an effect on soil environmental quality. This study have important implications for understanding the environmental behavior of petroleum and can provide support for petroleum remediation and risk control.
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Contaminantes Ambientales , Petróleo , Hidrocarburos Policíclicos Aromáticos , Contaminantes del Suelo , Petróleo/análisis , Yacimiento de Petróleo y Gas , Suelo/química , Contaminantes del Suelo/análisis , Contaminantes Ambientales/análisis , Hidrocarburos/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , China , Monitoreo del AmbienteRESUMEN
Most oil source correlation indicators are invalid because of the high maturity of the deep marine strata. Thus, a suitable indicator with high thermal stability requires to be established. In this study, to understand the effect of thermal maturation on the carbon isotopic composition of unsubstituted aromatics, we performed a number of anhydrous thermal simulation experiments involving two typical Chinese shales (lacustrine and marine shales), their corresponding expelled oils, three crude oils, and their associated oil fractions, that is, saturates, aromatics, resins, and asphaltenes (SARA). The generated unsubstituted aromatics were examined in terms of molecular distributions and carbon isotopic composition. The results show that unsubstituted aromatics in different types of samples demonstrated similar variation characteristics. Phenanthrene can be formed continuously in 0.45%/0.55-2.30% R o (equivalent vitrinite reflectance), especially in the high-over maturity stage. However, their carbon isotope composition shows minor variations. The unsubstituted aromatic carbon isotopic information in source rocks can be preserved during the whole pyrolysis process. Their carbon isotopic values in source rocks and their corresponding expelled oils are extremely similar. Furthermore, no evident difference exists in the carbon isotopes of unsubstituted aromatics formed by crude oil and associated oil fractions. These results indicate that these types of parameters are suitable for oil-oil/source correlation in deep marine strata with high-over maturity.
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The distribution, composition, sources, and potential ecological risks of polycyclic aromatic hydrocarbons (PAHs) in the sediments of the Lanzhou Reach of the Yellow River, China were investigated. The total concentration of the 18 individual PAHs (∑18PAHs) in the sediments ranged from 638 to 1620 ng/g, with a mean value of 901 ng/g. The pollution level of PAHs in the sediments was low to moderate. Spatially, the distribution of PAHs in the sediments showed an increasing trend along the direction of water flow. ∑18PAHs predominantly consisted of low molecular weight PAHs. The principal component analysis and isomer ratios of PAHs suggested the mixed sources of petroleum and those from the combustion of petroleum, coal, and biomass. The results showed that the PAHs in the sediments of the Lanzhou Reach of the Yellow River have a low ecological risk. However, the BaP equivalent exposure values suggested a potential cancer risk.
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Monitoreo del Ambiente , Hidrocarburos Policíclicos Aromáticos/análisis , Contaminantes Químicos del Agua/análisis , Biomasa , China , Carbón Mineral/análisis , Sedimentos Geológicos/análisis , Petróleo/análisis , Análisis de Componente Principal , Medición de Riesgo , RíosRESUMEN
This work presents a dataset which provides information on the influence of aromatic nuclei on the carbon isotope of gases. Gases analyzed herein were obtained by pyrolysis of model compounds and kerogens. The carbon isotope of gases from paraffin cracking with and without the addition of aromatic nuclei is summarized. We also obtained carbon isotope data for the gases from different type of kerogens, which indicate the role of aromatic nuclei in the formation of natural gases from kerogen cracking. Further interpretation and discussion of these data can be found in the related research article entitled "The methylation of aromatic nuclei - I: Implications for the geochemical evolution of gas" [1].
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The fate of veterinary antibiotics (VAs) in soil environment is determined by the hydrophilic performance and solubility of VAs and the type of soil. In this study, sulfadiazine (SDZ) and chlortetracycline (CTC) were selected as target pollutants, and a batch sorption method was used to find out the single and sorption competitive behavior and mechanism of the target pollutants on loess soil. Kinetic studies showed the apparent sorption equilibrium was reached 0-6 h for CTC and 0-12 h for SDZ. The sorption kinetics of VAs on loess soil were fitted well with a pseudo-second order kinetic model. Sorption thermodynamic data indicated the isotherm sorption of both SDZ and CTC on loess soil was fitted well with Freundlich isothermal (R2, 0.960-0.975) and linear models (R2, 0.908-0.976). The sorption affinity of CTC (Kd, 290-1620 L/kg for CTC) was much greater than that of SDZ (Kd, 0.6-4.9 L/kg for SDZ). The results also suggest that SDZ may be easily mobilized or leached from loess soil at neutral and alkaline pH, while CTC may be easily mobilized or leached at neutral pH. The sorption of each single target pollutant on the outer layer complex decreased with increasing ionic strength. Higher initial concentrations resulted in greater sorption capacity of target pollutants on loess soil increased. The sorption capacities of CTC and SDZ in the mixed system were lower than the sorption capacity of each single system, showing a competitive sorption behavior of CTC and SDZ during the sorption process. Overall, CTC showed the highest sorption potential in loess soil, whereas SDZ showed a high leaching risk in loess soil. These findings contribute to understanding the fate of different VAs in loess in the natural environment.
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Clortetraciclina , Contaminantes del Suelo , Adsorción , China , Cinética , Suelo , Contaminantes del Suelo/análisis , SulfadiazinaRESUMEN
This study investigated the content, distribution, and contamination levels of toxic metals (Cd, Cr, Cu, Pb, and Zn) in street dust in Lanzhou, an industrial city in Northwest China. Meanwhile, the risk these metals posed to the urban ecosystem and human health was also evaluated using the potential ecological risk index and human exposure model. Results showed that concentrations of these metals in the dust are higher than the background value of local soil, with Cu having the highest levels. The districts of Anning and Xigu had the most extreme levels of contamination, while Chengguan and Qilihe districts were lightly contaminated, which can be partly attributed to human activities and traffic densities. In comparison with the concentrations of selected metals in other cities, the concentrations of heavy metals in Lanzhou were generally at moderate or low levels. Heavy metal concentration increased with decreasing dust particle size. The pollution indices of Cr, Cd, Cu, Pb, and Zn were in the range of 0.289-2.09, 0.332-2.15, 1.38-6.21, 0.358-2.59, and 0.560-1.83 with a mean of 1.37, 1.49, 3.18, 1.48, and 0.897, respectively. The geo-accumulation index (I geo) suggested that Zn in street dust was of geologic origin, while Cd, Cr, Pb, and Cu were significantly impacted by anthropogenic sources. The comprehensive pollution index showed that urban dust poses a high potential ecological risk in Lanzhou. Non-carcinogenic and carcinogenic effects due to exposure to urban street dust were assessed for both children and adults. For non-carcinogenic effects, ingestion appeared to be the main route of exposure to dust particles and thus posed a higher health risk to both children and adults for all metals, followed by dermal contact. Hazard index values for all studied metals were lower than the safe level of 1, and Cr exhibited the highest risk value (0.249) for children, suggesting that the overall risk from exposure to multiple metals in dust is low. The carcinogenic risk for Cd and Cr was all below the acceptable level (< 10-6).
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Polvo/análisis , Monitoreo del Ambiente/métodos , Metales Pesados/análisis , Medición de Riesgo/métodos , Adulto , Niño , China , Ciudades , Ecología , Ecosistema , Contaminación Ambiental/análisis , Humanos , Industrias , Suelo/química , Contaminantes del Suelo/análisisRESUMEN
Surface soils from the tourist areas of the northwest Qinling Mountains were analyzed to determine the concentrations, probable sources and potential risks of hydrocarbons. Concentrations of aliphatic and aromatic hydrocarbons ranged from 4.18 to 3240 ng g-1 and 0.0462 to 101 ng g-1 dry weight, respectively. The extent of soil contamination by hydrocarbons was generally typified by unpolluted to slightly polluted levels. The incremental lifetime cancer risks (ILCRs) for exposure to soil-borne PAHs indicated complete safety for tourists. Early diagenesis of natural products, bacteria activities and petroleum were the three main sources of aliphatic hydrocarbons, while the transport of air pollutants from pyrolytic processes was the main origin of PAHs. Because the photochemical reaction of PAHs in the atmosphere would produce lower ratios for Ant/(Ant + Phe), BaA/(BaA + Chr) and IcdP/(IcdP + BghiP), but a higher ratio for Fla/(Fla + Pyr), the source classification highly depended on the diagnostic ratios chosen. The plot of ΣCOM/Σ13PAH vs. ΣLMW/ΣHMWPAH provide additional information to distinguish the origins of PAHs, and it showed a cluster of pyrogenic sources except for sample JFS-8. Four sources were resolved by principal component analysis: (1) a low temperature pyrogenic process related to the use of fossil fuel and biomass, such as charcoal, straw and wood, which contributes 63.1% of the measured PAHs; (2) the potential contribution of diagenetic processes, contributing 18.4%; (3) traffic emissions, contributing 9.27%; and (4) bioconversion/bacterial action, contributing 5.82%. Additionally, there was a good exponential relationship (r2 = 0.969) between the natural n-alkanes ratio (NAR) and carbon preference index for C23-C35 (CPI23-35) for all samples, which is of great use for the determination of the origins of aliphatic hydrocarbon.
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Monitoreo del Ambiente , Ácidos Grasos/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Contaminantes del Suelo/análisis , Suelo/química , China , Contaminación Ambiental/análisis , Medición de RiesgoRESUMEN
The level, distribution, compositional pattern and possible sources of polycyclic aromatic hydrocarbons (PAHs) in Lanzhou urban soil of Northwest China were investigated in this study. The total level of 22 PAHs ranged from 115 to 12,100 µg kg(-1) and that of 16 priority PAHs from 82.4 to 10,900 µg kg(-1). Seven carcinogenic PAHs generally accounted for 6.18-57.4% of total 22 PAHs. Compared with data from those reported about urban areas, PAH contamination in Lanzhou urban soils was moderate. Among different functional areas, higher level of PAHs was found along roadsides and in the industrial district (p<0.01), while lower levels were detected in the commercial, park and residential districts. The composition of PAHs was characterized by high molecular weight PAHs (≥4 rings), among which fluoranthene, benz[a]anthracene and phenanthrene were the most dominant components. Correlation analysis suggested that low molecular weight PAHs and high molecular weight PAHs originated from different sources and further corroborated that TOC was an important factor in the accumulation of PAHs in soil. Isomer ratios and principal component analysis indicated that PAHs in urban soil derived primarily from emissions resulting from the combustion of biomass, coal and petroleum products. Toxic equivalent concentrations (BaP(eq)) of soil PAHs ranged from 6.12 to 1302 µg BaP(eq) kg(-1), with a mean of 138 µg BaP(eq) kg(-1). The results suggested that human exposure to those soils which polluted by high concentrations of PAHs through direct ingestion or inhalation of suspended soil particles probably poses a significant risk to human health from the carcinogenic effects of PAHs.
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Residuos Industriales/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Contaminantes del Suelo/análisis , Suelo/química , China , Ciudades , Carbón Mineral/análisis , Humanos , Análisis de Componente PrincipalRESUMEN
The status, source and health risk of street-dust-borne polycyclic aromatic hydrocarbons (PAHs) in Lanzhou of Northwest China were investigated. The total level of the 21 PAHs ranged from 1470 to 13,700 µg kg(-1) and that of the 16 priority PAHs from 1240 to 10,700 µg kg(-1). Higher levels of PAHs were mainly distributed in the Chengguan and Qilihe districts at Lanzhou central areas, and the lower levels were in Anning and Xigu districts. The level of seven potential carcinogenic PAHs generally accounted for 35-40 percent of total PAHs, and the PAHs contained two to four rings, mainly phenanthrene, benzo[b]fluoranthene and fluoranthene. The total level of PAHs increased with the decreasing particle size in the street dust. The correlation analysis suggested that the total organic carbon (TOC) was only slightly affected the PAH accumulation in street dust. The isomer ratios and principal component analysis indicated that the dust-borne PAHs in the dust were derived primarily from the combustion of biomass, coal and petroleum emission. The toxic equivalent concentrations (BaP(eq)) of dust-borne PAHs ranged from 115 to 827 µg BaP(eq) kg(-1), with a mean of 300 µg BaP(eq) kg(-1). The 95 percent upper confidence limit of Incremental Lifetime Cancer Risk due to human exposure to urban surface dust-borne PAHs in Lanzhou urban area was 2.031 × 10(-6) for children and 1.935 × 10(-6) for adults.
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Ciudades/estadística & datos numéricos , Polvo/análisis , Monitoreo del Ambiente , Hidrocarburos Policíclicos Aromáticos/análisis , Hidrocarburos Policíclicos Aromáticos/química , Carbono/análisis , China , Humanos , Industrias , Tamaño de la Partícula , Análisis de Componente Principal , Medición de RiesgoRESUMEN
The solubilization thermodynamics and kinetics characteristics of hydrophobic pollutants anthracene in the humic acid micellar solutions have been investigated by using batch equilibrium test. The results showed that the solubilization rate of anthracene was significantly enhanced with increasing temperature. The solubilization process of anthracene was spontaneous, endothermic and entropy increasing with deltaG(theta) = -1.682 kJ/mol, deltaH(theta) = 11.96 kJ/mol, deltaS(theta) = 45.78 J/(K x mol) in 25 degrees C, as well as deltaG(theta) = -2.140 kJ/mol and -2.598 kJ/mol in 35 degrees and 45 degrees C, respectively. The solubilization data of anthracene well fitted Elovich kinetics model.