细化搜索
结果 851-860 的 6,473
Groundwater pollution early warning based on QTR model for regional risk management: A case study in Luoyang city, China
2020
Huan, Huan | Li, Xiang | Zhou, Jun | Liu, Weijiang | Li, Juan | Liu, Bing | Xi, Beidou | Jiang, Yonghai
Groundwater pollution early warning has been regarded as an effective tool for regional groundwater pollution prevention, especially in China. In this study, the systemic model was established to assess the groundwater pollution early warning by integrating the present situation of groundwater quality (Q), groundwater quality trend (T) and groundwater pollution risk (R). The model integrated spatial and temporal variation of groundwater quality, and combined the state and process of the groundwater pollution. Q, T and R were assessed by the methods of fuzzy comprehensive assessment, Spearman or nonparametric Mann-Kendall trend test, and overlay index, respectively. Taking the Luoyang City as an example, the groundwater pollution early warning mapping was generated, and verified by corresponding the groundwater quality classes and the early warning degrees. The results showed that the groundwater was dominated by the levels of no warning and light warning, which accounted for 77% of the study area. The serious and tremendous warning areas were affected by the worse trend and relatively bad/bad present situations of groundwater quality with the typical contaminants of total hardness, nitrate, Hg and COD. In summary, the present situation of groundwater quality was the most important factor of groundwater pollution early warning mapping in the study area. The worse trend of groundwater quality played equally a key role in the local regions, as well as the high pollution risk, which was mainly affected by the pollution source loading. Targeted measures for groundwater pollution prevention were proposed in the corresponding degrees of groundwater pollution early warning. The QTR model was proved to be effective for assessing the regional groundwater pollution early warning. The accuracy of the model could be improved if there is further data acquisition of groundwater quality in longer time series and in larger number, and further investigation of pollution sources.The QTR model is proposed and proved to be effective for assessing regional groundwater pollution early warning.
显示更多 [+] 显示较少 [-]Occurrence of short- and medium-chain chlorinated paraffins in soils and sediments from Dongguan City, South China
2020
Wu, Yang | Gao, Shutao | Ji, Bingjing | Liu, Zhiyang | Zeng, Xiangying | Yu, Zhiqiang
As a group of emerging organic pollutants, chlorinated paraffins (CPs) have attracted rising global attention due to their persistence and toxicity. In this study, we have investigated the concentration levels and profiles of short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) in soils and sediments from Dongguan City, an industrial area in South China, and have also screened very short-chain chlorinated paraffins (vSCCPs) by means of ultra-high resolution liquid chromatograph coupled with an Orbitrap Fusion Tribrid mass spectrometer. The results indicated that total SCCP concentrations ranged from 6.75 to 993 ng/g (mean 172 ng/g) in soils and from 4.00 to 613 ng/g (mean 153 ng/g) in sediments, respectively. Higher MCCP levels were observed with a range of 23.9–2427 ng/g (mean 369 ng/g) in soils and 14.0–1581 ng/g (mean 493 ng/g) in sediments, respectively. The results indicated that MCCPs dominated over SCCPs in the studied region. The dominant homologues in soils and sediments were C₁₃Cl₆–₇ and C₁₄Cl₇–₈, C₁₃Cl₇, and C₁₄Cl₇–₈, respectively. Furthermore, six vSCCP homologues (C₈Cl₇–₈ and C₉Cl₅–₈) in soils and four vSCCPs (C₉Cl₅–₈) in sediments have been identified. Because of their higher detection frequencies, further studies should focus on the transformation mechanisms and toxicities of these vSCCPs in environmental media and biota.
显示更多 [+] 显示较少 [-]Gut microbiome alterations induced by tributyltin exposure are associated with increased body weight, impaired glucose and insulin homeostasis and endocrine disruption in mice
2020
Zhan, Jing | Ma, Xiaoran | Liu, Donghui | Liang, Yiran | Li, Peize | Cui, Jingna | Zhou, Zhiqiang | Wang, Peng
Tributyltin (TBT), an organotin compound once widely used in agriculture and industry, has been reported to induce obesity and endocrine disruption. Gut microbiota has a strong connection with the host’s physiology. Nevertheless, the influences of TBT exposure on gut microbiota and whether TBT-influenced gut microbiota is related to TBT-induced toxicity remain unclear. To fill these gaps, ICR (CD-1) mice were respectively exposed to TBT at NOEL (L-TBT) and tenfold NOEL (H-TBT) daily by gavage for 8 weeks in the current study. The results showed that TBT exposure significantly increased body weight as well as epididymal fat, and led to adipocyte hypertrophy, dyslipidemia and impaired glucose and insulin homeostasis in mice. Additionally, TBT exposure significantly decreased the levels of T4, T3 and testosterone in serum. Also of note, TBT exposure changed gut microbiota composition mainly by decreasing Bacteroidetes and increasing Firmicutes proportions. To confirm the role of gut microbiota in TBT-induced overweight and hormonal disorders, fecal microbiota transplantation was performed and the mice receiving gut microbiota from H-TBT mice had similar phenotypes with their donor mice including significant body weight and epididymal fat gain, glucose and insulin dysbiosis and hormonal disorders. These results suggested that gut microbiome altered by TBT exposure was involved in the TBT-induced increased body weight, impaired glucose and insulin homeostasis and endocrine disruption in mice, providing significant evidence and a novel perspective for better understanding the mechanism by which TBT induces toxicity.
显示更多 [+] 显示较少 [-]The associations between prenatal exposure to polycyclic aromatic hydrocarbon metabolites, umbilical cord blood mitochondrial DNA copy number, and children’s neurobehavioral development
2020
Cao, Xiaomin | Li, Jinyu | Cheng, Lin | Deng, Yunjun | Li, Yanning | Yan, Zhiwei | Duan, Lei | Yang, Jin | Niu, Qiao | Perera, Frederica | Nie, Jisheng | Tang, Deliang
Exposure to polycyclic aromatic hydrocarbons (PAHs) during pregnancy is a risk factor for adverse neurobehavioral development outcomes. Mitochondrial DNA are sensitive to environmental toxicants due to the limited ability of repairing. The change of mitochondrial DNA copy number (mtDNAcn) might be a biologically mechanism linking PAH exposure and children’s neurobehavioral impairment. Our aims are to explore whether PAH metabolites in maternal urine were associated with children’s neurobehavioral development at 2 years old and umbilical cord blood mtDNAcn, and whether mtDNAcn was a mediator of PAH-related neurobehavioral development. We included 158 non-smoking pregnant women from Taiyuan City, Shanxi Province. Maternal urinary eleven PAH metabolites were detected by high performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS). MtDNAcn in cord blood was detected by real time quantitative polymerase chain reaction (RT-PCR). Children’s neurodevelopment was measured by Gesell Developmental Schedules (GDS) when children were two years age. Generalized linear models and restricted cubic spline models were applied to assess the relationships between PAH metabolites in maternal urine and GDS scores and mtDNAcn. A mediation analysis was also conducted. Generalized linear models showed the relationships of sum of PAH metabolites (Σ-OHPAHs) in maternal urine with decreased motor score, and Σ-OHPAHs with increased mtDNAcn (p for trend < 0.05). Urinary levels of Ln (Σ-OHPAHs) increased one unit was related to a 2.08 decreased in motor scores, and Ln (Σ-OHPAHs) increased one unit was related to 0.15 increased in mtDNAcn. Mediation analysis did not find mtDNAcn can be a mediator between PAH metabolites and neurobehavioral development. Our results suggest that prenatal exposure to PAH decreased children’s neurobehavioral development scores and increased mtDNAcn. And reducing exposure to PAH during pregnancy will benefit to improving neurobehavioral development in children.In our present cohort study, sum of PAH metabolites in urine of pregnant women were related with motor score and were positively associated with umbilical cord blood mtDNA copy number.
显示更多 [+] 显示较少 [-]Composition characterization and biotransformation of dissolved, particulate and algae organic phosphorus in eutrophic lakes
2020
Feng, Weiying | Yang, Fang | Zhang, Chen | Liu, Jing | Song, Fanhao | Chen, Haiyan | Zhu, Yuanrong | Liu, Shasha | Giesy, John P.
Characteristics and transformation of organic phosphorus in water are vital to biogeochemical cycling of phosphorus and support of blooms of phytoplankton and cyanobacteria. Using solution ³¹P nuclear magnetic resonance (NMR), combined with field surveys and lab analyses, composition and structural characteristics of dissolved phosphorus (DP), particulate phosphorus (PP) and organic P in algae were studied in two eutrophic lakes in China, Tai Lake and Chao Lake. Factors influencing migration and transformation of these constituents in lake ecosystems were also investigated. A method was developed to extract, flocculate and concentrate DP and PP from lake water samples. Results showed that orthophosphate (Ortho-P) constituted 32.4%–81.3% of DP and 43.7%–54.9% of PP, respectively; while monoester phosphorus (Mono-P) was 13.2%–54.0% of DP and 32.9%–43.7% of PP, respectively. Phosphorus in algae was mostly organic P, especially Mono-P, which was ≥50% of TP. Environmental factors and water quality parameters such as temperature (T), electrical conductivity (EC), pH, secchi depth (SD), dissolved oxygen (DO), chemical oxygen demand (CODcᵣ), chlorophyll-a (Chl-a), affected the absolute and relative concentrations of various P components in the two lakes. Increased temperature promoted bioavailable P (Ortho-P and Mono-P) release to the lake waters. The results can provide an important theoretical basis for the mutual conversion process of organic P components between various media in the lake water environment.
显示更多 [+] 显示较少 [-]Biological effects from environmental pollution by toxic metals in the “land of fires” (Italy) assessed using the biomonitor species Lunularia cruciata L. (Dum)
2020
Maresca, Viviana | Sorbo, Sergio | Loppi, Stefano | Funaro, Federica | Del Prete, Davide | Basile, Adriana
The liverwort Lunularia cruciata was collected from the town of Acerra, in the heart of the so-called ‘Land of Fires’ a large area in the eastern part of Campania region of Italy affected by burning of waste and fraudulent dumping and one of the vertices of the “Italian Triangle of Death” so said for the high incidence and mortality from tumors. The data obtained from these samples were compared with samples collected in two other sites representing two different environmental conditions. The soil below the samples, and gametophytes, were collected and analyzed for the concentration of Al, As, Ba, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, V. DNA damage, Reactive Oxygen Species production and localization, activity of antioxidant enzymes and presence of chelating molecules were investigated. All biomarkers provided an answer closely related to the pollution conditions at the 3 sites. We discuss the data considering the possibility of using these biological changes as environmental pollution biomarkers. Finally, it is underlined the importance of phytochelatins due to of their specificity for metal pollution.
显示更多 [+] 显示较少 [-]Pilot-scale study on the effects of cyanobacterial blooms on Vallisneria natans and biofilms at different phosphorus concentrations
2020
Li, Qi | Gu, Peng | Luo, Xin | Zhang, Hao | Huang, Suzhen | Zhang, Jibiao | Zheng, Zheng
Cyanobacterial blooms cause potential risk to submerged macrophytes and biofilms in eutrophic environments. This pilot-scale study investigated the growth, oxidative responses, and detoxification activity of aquatic plants in response to cyanobacterial blooms under different phosphorus concentrations. Variations of extracellular polymeric substances (EPSs) and microbial community composition were also assessed. Results showed that the biomass of Vallisneria natans increased with exposure to cyanobacterial blooms at higher phosphorous concentrations (P > 0.2 mg L⁻¹). The amount of microcystin compounds (MC-LR) released into the water and the accumulation of MC-LR into both plant tissue and biofilms changed according to the phosphorus concentration. Furthermore, a certain degree of oxidative stress was induced in the plants, as evidenced by increased activity of superoxide dismutase, catalase, and peroxidase, as well as increased malondialdehyde concentrations; significant differences were also seen in acid phosphatase and glutathione S-transferase activities, as well as in glutathione concentrations. Together, these responses indicate potential mechanisms of MC-LR detoxification. Broader α-D-glucopyranose polysaccharides (PS) increased with increasing phosphorous and aggregated into clusters in biofilm EPS in response to the cyanobacterial blooms. In addition, alterations were seen in the abundance and structure of the microbial communities present in exposed biofilms. These results demonstrate that cyanobacterial blooms under different concentrations of phosphorus can induce differential responses, which can have a significant impact on aquatic ecosystems.
显示更多 [+] 显示较少 [-]Impact of harbour activities on local air quality: A review
2020
Sorte, Sandra | Rodrigues, Vera | Borrego, C. | Monteiro, Alexandra
Several harbour activities cause negative environmental impacts in the harbours’ surrounding areas, namely the degradation of air quality. This paper intends to comprehensively review the status of the air quality measured in harbour areas. The published studies show a limited number of available air quality monitoring data in harbours areas, mostly located in Europe (71%). Measured concentrations of the main air pollutants were compiled and intercompared, for different countries worldwide allowing a large spatial representativeness. The higher NO₂ and PM₁₀ concentrations were found in Europe - ranging between 12 and 107 μg/m³ and 2–50 μg/m³, respectively, while the higher concentrations of PM₂.₅ were found in Asia (25–70 μg/m³). In addition, the lower levels of SO₂ monitored in recent years suggest that current mitigation strategies adopted across Europe were very efficient in promoting the reduction of SO₂ concentrations.Part of the reviewed studies also estimated the contributions from ship emissions to PM concentration through the application of source apportionment methods, with an average of 5–15%. In some specific harbour areas in Asia, ships can contribute up to 7–26% to the local fine particulate matter concentrations. This review confirms that emissions from the maritime transport sector should be considered as a significant source of particulate matter in harbour areas, since this pollutant concentrations are frequently exceeding the established standard legal limit values. Therefore, the results from this review boost the implementation of mitigation measures, aiming to reduce, in particular, particulate matter emissions.
显示更多 [+] 显示较少 [-]Low temperature advanced nitrogen and sulfate removal from landfill leachate by nitrite-anammox and sulfate-anammox
2020
Wu, Linuo | Yan, Zhibin | Li, Jin | Huang, Shan | Li, Zhi | Shen, Mingyu | Peng, Yongzhen
Under anaerobic conditions, ammonium (NH₄⁺) can react with nitrite (NO₂⁻) and sulfate (SO₄²⁻), termed nitrite-anammox (NirAnammox) and sulfate-anammox (Sulfammox), respectively. However, how to remove NH₄⁺ and SO₄²⁻ together from leachate is unclear. In this study, NirAnammox and Sulfammox cooperatively achieved nitrogen and sulfate removal from leachate using a biological process at low temperature (14–15 °C). NH₄⁺, total nitrogen (TN), and SO₄²⁻ concentrations in the influent were 610–700, 670–900, 1870–1920 mg/L, respectively, and 10 ± 1, 35 ± 3, and 897.7 ± 10 mg/L, respectively, in the effluent. Sulfammox, and NirAnammox (including partial nitrification) removed 44.2% and 35.46% of the NH₄⁺, respectively. Therefore, because leachate contains high concentrations of NH₄⁺ and SO₄²⁻, NirAnammox and Sulfammox can easily occur together, with nitrogen removal by Sulfammox being more than NirAnammox. The relative abundance of dominant bacteria of the Sulfammox were 10–20 times that of Candidatus Kuenenia (NirAnammox) in each reactor. Organic matter negatively affected NirAnammox, but not Sulfammox. Dissolved oxygen negatively affected both.
显示更多 [+] 显示较少 [-]Spatial distribution and factors influencing the different forms of ammonium in sediments and pore water of the aquitard along the Tongshun River, China
2020
Liu, Rui | Ma, Teng | Zhang, Dongtao | Lin, Chaohong | Chen, Juan
Nitrogen pollution of groundwater has created problems worldwide. Riparian zones form a connection hub for terrestrial and aquatic ecosystems. As a potential source of ammonium in groundwater, aquitards have an important effect on the environment of riparian zones. The spatial distribution and factors influencing the ammonium content in the riparian zone aquitard of a small watershed were analyzed through three geological boreholes with increasing distances from the river: boreholes A > B > C. The results show that the distribution of ammonium was closely related to the lithology of sediments. Under the influence of the river and floods, the average content of ion exchange form of ammonium of sediments in borehole A (stable sedimentary environment) was 94.31 mg kg⁻¹, accounting for 21.2% of the transferable ammonium. The average proportions of ion exchange form of ammonium in the transferable ammonium of boreholes B and C (unstable sedimentary environment) were 19.1% and 17.4%, respectively. The carbonate and iron-manganese oxide forms of ammonium content of sediments in three boreholes were 0.96–15.28 mg kg⁻¹ and 2.3–54.4 mg kg⁻¹, respectively; this was mainly affected by the pH and Eh of the sedimentary environment. Organic sulfide, the form of transferable ammonium of sediments mainly exists in organic matter. The ammonium content in pore water generally increased with depth and was mainly derived from the mineralization of humic-like organic matter in borehole A. The ammonium in pore water in boreholes B and C mixed with ammonium from the mineralization of organic matter and the desorption of ion exchange form ammonium within sediments. The ammonium content in the pore water (up to 5.34 mg L⁻¹) was much higher than the limit for drinking water of 0.5 mg L⁻¹ in China. Therefore, the aquitard has a high risk of releasing ammonium and poses a certain threat to the quality of groundwater.
显示更多 [+] 显示较少 [-]