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The environmental fate of polybrominated diphenyl ethers (PBDEs) in western Taiwan and coastal waters: evaluation with a fugacity-based model 全文
2016
O’Driscoll, Kieran | Robinson, Jill | Chiang, Wen-Son | Chen, Yang-Yih | Kao, Ruey-Chy | Doherty, Rory
The environmental fate of polybrominated diphenyl ethers (PBDEs), a group of flame retardants that are considered to be persistent organic pollutants (POPs), around the Zhuoshui River and Changhua County regions of Taiwan was assessed. An investigation into emissions, partitioning, and fate of selected PBDEs was conducted based on the equilibrium constant (EQC) fugacity model developed at Trent University, Canada. Emissions for congeners PBDE 47, PBDE 99, and PBDE 209 to air (4.9–92 × 10⁻³ kg/h), soil (0.91–17.4 × 10⁻³ kg/h), and water (0.21–4.04 × 10⁻³ kg/h), were estimated by modifying previous models on PBDE emission rates by considering both industrial and domestic rates. It was found that fugacity modeling can give a reasonable estimation of the behavior, partitioning, and concentrations of PBDE congeners in and around Taiwan. Results indicate that PBDE congeners have a high affinity for partitioning into sediments then soils. As congener number decreases, the PBDEs then partition more readily into air. As the degree of bromination increases, congeners more readily partition to sediments. Sediments may then act as a long-term source of PBDEs which can be released back into the water column due to resuspension during storm events.
显示更多 [+] 显示较少 [-]Use of mixed solid waste as a soil amendment for saline-sodic soil remediation and oat seedling growth improvement 全文
2016
Fan, Yuan | Ge, Tian | Zheng, Yanli | Li, Hua | Cheng, Fangqin
Soil salinization has become a worldwide problem that imposes restrictions on crop production and food quality. This study utilizes a soil column experiment to address the potential of using mixed solid waste (vinegar residue, fly ash, and sewage sludge) as soil amendment to ameliorate saline-sodic soil and enhance crop growth. Mixed solid waste with vinegar residue content ranging from 60-90 %, sewage sludge of 8.7–30 %, and fly ash of 1.3–10 % was added to saline-sodic soil (electrical conductivity (EC₁:₅) = 1.83 dS m⁻¹, sodium adsorption ratio (SAR₁:₅) = 129.3 (mmolc L⁻¹)¹/², pH = 9.73) at rates of 0 (control), 130, 260, and 650 kg ha⁻¹. Results showed that the application of waste amendment significantly reduced SAR, while increasing soil soluble K⁺, Ca²⁺, and Mg²⁺, at a dose of 650 kg ha⁻¹. The wet stability of macro-aggregates (>1 mm) was improved 90.7–133.7 % when the application rate of amendment was greater than 260 kg ha⁻¹. The application of this amendment significantly reduced soil pH. Germination rates and plant heights of oats were improved with the increasing rate of application. There was a positive correlation between the percentage of vinegar residue and the K/Na ratio in the soil solutions and roots. These findings suggest that applying a mixed waste amendment (vinegar residue, fly ash, and sewage sludge) could be a cost-effective method for the reclamation of saline-sodic soil and the improvement of the growth of salt-tolerant plants.
显示更多 [+] 显示较少 [-]Degradation of oxcarbazepine by UV-activated persulfate oxidation: kinetics, mechanisms, and pathways 全文
2016
Bu, Lingjun | Zhou, Shiqing | Shi, Zhou | Deng, Lin | Li, Guangchao | Yi, Qihang | Gao, Naiyun
The degradation kinetics and mechanism of the antiepileptic drug oxcarbazepine (OXC) by UV-activated persulfate oxidation were investigated in this study. Results showed that UV/persulfate (UV/PS) process appeared to be more effective in degrading OXC than UV or PS alone. The OXC degradation exhibited a pseudo-first order kinetics pattern and the degradation rate constants (k ₒbₛ) were affected by initial OXC concentration, PS dosage, initial pH, and humic acid concentration to different degrees. It was found that low initial OXC concentration, high persulfate dosage, and initial pH enhanced the OXC degradation. Additionally, the presence of humic acid in the solution could greatly inhibit the degradation of OXC. Moreover, hydroxyl radical (OH•) and sulfate radical (SO₄ ⁻••) were identified to be responsible for OXC degradation and SO₄ ⁻• made the predominant contribution in this study. Finally, major intermediate products were identified and a preliminary degradation pathway was proposed. Results demonstrated that UV/PS system is a potential technology to control the water pollution caused by emerging contaminants such as OXC.
显示更多 [+] 显示较少 [-]Inhibitory effects of tributyl phosphate on algal growth, photosynthesis, and fatty acid synthesis in the marine diatom Phaeodactylum tricornutum 全文
2016
Song Hào, | Fan, Xiaoji | Liu, Guangfu | Chui, Kawai | Li, Xingxing | Tan, Yuzhu | Qian, Haifeng
The widely used solvent extractant, tributyl phosphate (TBP), primarily used as a solvent for the conventional processing of nuclear fuel, has come under scrutiny recently due to concerns surrounding potential environmental contamination and toxicity. In this study, we found that, in Phaeodactylum tricornutum, administration of TBP severely inhibited algal cell growth by reducing photosynthetic efficiency and inducing oxidative stress. We further explored the effect of TBP by examining the gene expression of the photosynthetic electron transport chain and its contribution to reactive oxygen species (ROS) burst. Our data revealed that TBP affected both fatty acid content and profile by regulating the transcription of genes related to glycolysis, fatty acid biosynthesis, and β-oxidation. These results demonstrated that TBP did in fact trigger the synthesis of ROS, disrupting the subcellular membrane structure of this aquatic organism. Our study brings new insight into the fundamental mechanism of toxicity exerted by TBP on the marine alga P. tricornutum.
显示更多 [+] 显示较少 [-]Biosorption of cadmium (II) from aqueous solutions by natural and modified non-living leaves of Posidonia oceanica 全文
2016
Meseguer, Víctor F. | Ortuño, Juan F. | Aguilar, M Isabel | Pinzón-Bedoya, Martha L. | Lloréns, Mercedes | Sáez, José | Pérez-Marín, Ana B.
Natural, HCl-treated, and formaldehyde-treated non-living leaves of Posidonia oceanica, a marine plant, were investigated as potential biosorbents to remove Cd²⁺ from aqueous solutions. The studied biosorbents were characterized by elemental analysis and Fourier transform infrared spectroscopy (FTIR) and it was observed that the adsorption capacity of the biosorbents strongly depended on the pH, increasing as the pH rises. The adsorption process was fast. The adsorption kinetic was analyzed using five kinetic models: pseudo-first order, pseudo-second order, Elovich, intraparticle diffusion, and Bangham models. The adsorption isotherms were analyzed by the Langmuir, Freundlich, Dubinin-Radushkevich, Sips, Redlich-Peterson, and Toth models. The maximum biosorption capacity was attained by the biosorbent treated with HCl (1.11 mmol g⁻¹). The distribution equilibrium constant and the Gibbs free energy change were calculated. The effects of the presence of Na⁺, K⁺, Mg²⁺, and Ca²⁺ ions in the solution on Cd²⁺ uptake were studied. Results indicate that non-living leaves of P. oceanica, natural or treated, can be considered as effective and low-cost biosorbents for the removal of cadmium from aqueous solutions.
显示更多 [+] 显示较少 [-]Cross-sectional biomonitoring study of pesticide exposures in Queensland, Australia, using pooled urine samples 全文
2016
Heffernan, AL | English, K | Toms, LML | Calafat, AM | Valentin-Blasini, L | Hobson, P | Broomhall, S | Ware, RS | Jagals, P | Sly, PD | Mueller, JF
A range of pesticides are available in Australia for use in agricultural and domestic settings to control pests, including organophosphate and pyrethroid insecticides, herbicides, and insect repellents, such as N,N-diethyl-meta-toluamide (DEET). The aim of this study was to provide a cost-effective preliminary assessment of background exposure to a range of pesticides among a convenience sample of Australian residents. De-identified urine specimens stratified by age and sex were obtained from a community-based pathology laboratory and pooled (n = 24 pools of 100 specimens). Concentrations of urinary pesticide biomarkers were quantified using solid-phase extraction coupled with isotope dilution high-performance liquid chromatography–tandem mass spectrometry. Geometric mean biomarker concentrations ranged from <0.1 to 36.8 ng/mL for organophosphate insecticides, <0.1 to 5.5 ng/mL for pyrethroid insecticides, and <0.1 to 8.51 ng/mL for all other biomarkers with the exception of the DEET metabolite 3-diethylcarbamoyl benzoic acid (4.23 to 850 ng/mL). We observed no association between age and concentration for most biomarkers measured but noted a “U-shaped” trend for five organophosphate metabolites, with the highest concentrations observed in the youngest and oldest age strata, perhaps related to age-specific differences in behavior or physiology. The fact that concentrations of specific and non-specific metabolites of the organophosphate insecticide chlorpyrifos were higher than reported in USA and Canada may relate to differences in registered applications among countries. Additional biomonitoring programs of the general population and focusing on vulnerable populations would improve the exposure assessment and the monitoring of temporal exposure trends as usage patterns of pesticide products in Australia change over time.
显示更多 [+] 显示较少 [-]Occupational exposure to phthalates in relation to gender, consumer practices and body composition 全文
2016
Petrovičová, Ida | Kolena, Branislav | Šidlovská, Miroslava | Pilka, Tomáš | Wimmerová, Soňa | Trnovec, Tomáš
The aim of our work was to find associations between urinary phthalate metabolite concentrations and occupation, consumer practices and body composition. We divided our cohort (n = 129) into occupationally exposed subjects, community service workers (group A; n = 45) and workers from plastic industry (group B; n = 35) and group of general population (control group C, n = 49). To estimate levels of five phthalate metabolites, we used high-performance liquid chromatography and tandem mass spectrometry analysis. We found in plastic industry workers compared to community service workers and subjects of the control group significantly higher urinary concentration mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono (2-ethyl-5-oxohexyl) phthalate (MEOHP), mono (2-etylhexyl) phthalate (MEHP), sum di-(2-ethyl-5-oxohexyl) phthalate (DEHP), mono-iso-butyl phthalate (MiBP) and mono-n-butyl phthalate (MnBP). We identified by multivariate analysis of covariance inverse relationship between MEHP and body parameters as waist-to-height ratio, body mass index, waist-to-hip ratio, hip circumference and waist circumference among females, whereas in males, no significant association was found. Results of our study show, despite of variability in terms of occupational exposure to phthalates, that plastic manufactory represents a higher occupational risk in comparison with waste management. The differences in anthropometric parameters between the two occupationally exposed groups and the general population are suggesting a detrimental effect of occupational exposure on body weight homeostasis.
显示更多 [+] 显示较少 [-]Immobilization of Mn and NH4 +-N from electrolytic manganese residue waste 全文
2016
Chen, Hongliang | Liu, Renlong | Liu, Zuohua | Shu, Jiancheng | Tao, Changyuan
The objective of this work was the immobilization of soluble manganese (Mn) and ammonium nitrogen (NH₄ ⁺-N) leached from electrolytic manganese residue (EMR). Immobilization of Mn was investigated via carbonation using carbon dioxide (CO₂) and alkaline additives. NH₄ ⁺-N immobilization was evaluated via struvite precipitation using magnesium and phosphate sources. Results indicated that the immobilization efficiency of Mn using CO₂ and quicklime (CaO) was higher than using CO₂ and sodium hydroxide (NaOH). This higher efficiency was likely due to the slower release of OH⁻ during CaO hydrolysis. The immobilization efficiency of Mn was >99.99 % at the CaO:EMR mass ratio of 0.05:1 for 20-min reaction time. The struvite precipitation of NH₄ ⁺-N was conducted in the carbonated EMR slurry and the immobilization efficiency was 89 % using MgCl₂ · 6H₂O + Na₃PO₄ · 12H₂O at the Mg:P:N molar ratio of 1.5:1.5:1 for 90-min reaction time. A leaching test showed that the concentrations of Mn and NH₄ ⁺-N in the filtrate of the treated EMR were 0.2 and 9 mg/L, respectively. The combined immobilization of Mn and NH₄ ⁺-N was an effective pretreatment method in the harmless treatment of the EMR.
显示更多 [+] 显示较少 [-]Are seed and dispersal characteristics of plants capable of predicting colonization of post-mining sites? 全文
2016
Horáčková, Martina | Řehounková, Klára | Prach, Karel
Seed characteristics play an important role in the colonization and subsequent persistence of species during succession in disturbed sites and thus may contribute to being able to predict restoration success. In the present study, we investigated how various seed characteristics participated in 11 spontaneous successional series running in different mining sites (spoil heaps, extracted sand and sand-gravel pits, extracted peatlands, and stone quarries) in the Czech Republic, Central Europe. Using 1864 samples from 1- to 100-years-old successional stages, we tested whether species optimum along the succession gradient could be predicted using 10 basic species traits connected with diaspores and dispersal. Seed longevity, diaspore mass, endozoochory, and autochory appeared to be the best predictors. The results indicate that seed characteristics can predict to a certain degree spontaneous vegetation succession, i.e., passive restoration, in the mining sites. A screening of species available in the given landscape (regional and local species pools) may help to identify those species which would potentially colonize the disturbed sites. Extensive databases of species traits, nowadays available for the Central European flora, enable such screening.
显示更多 [+] 显示较少 [-]Application of Faecalibacterium 16S rDNA genetic marker for accurate identification of duck faeces 全文
2016
Sun, Da | Duan, Chuanren | Shang, Yaning | Ma, Yunxia | Tan, Lili | Zhai, Jun | Gao, Xu | Guo, Jingsong | Wang, Guixue
The aim of this study was to judge the legal duty of pollution liabilities by assessing a duck faeces-specific marker, which can exclude distractions of residual bacteria from earlier contamination accidents. With the gene sequencing technology and bioinformatics method, we completed the comparative analysis of Faecalibacterium sequences, which were associated with ducks and other animal species, and found the sequences unique to duck faeces. Polymerase chain reaction (PCR) and agarose gel electrophoresis techniques were used to verify the reliability of both human and duck faeces-specific primers. The duck faeces-specific primers generated an amplicon of 141 bp from 43.3 % of duck faecal samples, 0 % of control samples and 100 % of sewage wastewater samples that contained duck faeces. We present here the initial evidence of Faecalibacterium-based applicability as human faeces-specificity in China. Meanwhile, this study represents the initial report of a Faecalibacterium marker for duck faeces and suggests an independent or supplementary environmental biotechnology of microbial source tracking (MST).
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