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Ethanol traces in natural waters checked using a new DMFC enzymatic device Full text
2018
Tomassetti, Mauro | Angeloni, Riccardo | Castrucci, Mauro | Visco, Giovanni | Campanella, Luigi
The use of fuels with strong percentage of ethanol that is done in countries such as Brazil and Australia causes a more and more relevant presence of traces of ethanol in natural waters. The ethanol present in these fuels seems to contribute to increase, through various mechanisms, the concentration of hydrocarbons in the same waters and soil. The ethanol content in natural waters must therefore be monitored frequently. It was therefore proposed a very simple innovative method, based on a catalytic fuel cell with the alcohol dehydrogenase enzyme immobilized in the anodic compartment of the device. The analytical performances of this new device were then evaluated by checking traces of alcohol in different types of natural waters (rain, river, and groundwater), with a good degree of precision and with an acceptable level of accuracy.
Show more [+] Less [-]Heavy metal and nutrient uptake in plants colonizing post-flotation copper tailings Full text
2018
Kasowska, Dorota | Gediga, Krzysztof | Spiak, Zofia
Copper ore mining and processing release hazardous post-flotation wastes that are difficult for remediation. The studied tailings were extremely rich in Cu (1800 mg kg⁻¹) and contaminated with Co and Mn, and contained very little available forms of P, Fe, and Zn. The plants growing in tailings were distinctly enriched in Cu, Cd, Co, Ni, and Pb, and the concentration of copper achived the critical toxicity level in shoots of Cerastium arvense and Polygonum aviculare. The redundancy analysis demonstrated significant relationship between the concentration of available forms of studied elements in substrate and the chemical composition of plant shoots. Results of the principal component analysis enabled to distinguish groups of plants which significantly differed in the pattern of element accumulation. The grass species Agrostis stolonifera and Calamagrostis epigejos growing in the tailings accumulated significantly lower amounts of Cu, but they also had the lowest levels of P, Fe, and Zn in comparison to dicotyledonous. A. stolonifera occurred to be the most suitable species for phytostabilization of the tailings with regard to its low shoot Cu content and more efficient acquisition of limiting nutrients in relation to C. epigejos. The amendments improving texture, phosphorus fertilization, and the introduction of native leguminous species were recommended for application in the phytoremediation process of the tailings.
Show more [+] Less [-]Community reporting of ambient air polychlorinated biphenyl concentrations near a Superfund site [Errata: June 2018, v. 25 (17), p.16401] Full text
2018
Tomsho, Kathryn S. | Basra, Komal | Rubin, Staci M. | Miller, Claire B. | Juang, Richard | Broude, Sylvia | Martinez, Andres | Hornbuckle, Keri C. | Heiger-Bernays, Wendy | Scammell, Madeleine K.
In this manuscript, we describe the process of establishing partnerships for community-based environmental exposure research, the tools and methods implemented for data report-back to community members, and the results of evaluations of these efforts. Data discovery and report-back materials developed by Statistics for Action (SFA) were employed as the framework to communicate the environmental data to community members and workshops. These data communication and research translation efforts are described in detail and evaluated for effectiveness based on feedback provided from community members who attended the workshops. Overall, the methods were mostly effective for the intended data communication.
Show more [+] Less [-]Spatiotemporal variation and exposure risk to human health of potential toxic elements in suburban vegetable soils of a megacity, SW China, 2012–2016 Full text
2018
Bing, Haijian | Xiang, Zhongxiang | Zhu, He | Wu, Yanhong
Trace element contamination in soils of vegetable fields can threat public health. Seven potential toxic elements (As, Cd, Cr, Cu, Ni, Pb, and Zn) in suburban vegetable soils of Chengdu city, Southwest China, in 2012 and 2016, were analyzed to identify their sources with the spatiotemporal variation and assess their contamination and health risk for residents. The results showed that the concentrations of soil elements did not increase significantly in 2016 compared with that in 2012, whereas their spatial distributions altered markedly. The hot spots of soil As, Cd, and Pb as well as Cu and Zn in 2016 revealed the anthropogenic sources including agricultural activities, industrial emissions, road dust with heavy traffic, and open burning of solid waste. The apparent spatial difference of anthropogenic elements was related to the layout of land use surrounding the vegetable field. The contamination of soil elements decreased in the order of Cd > As ≈ Zn > Cu ≈ Pb > Cr ≈ Ni in 2012 and Cd > Zn > As ≈ Cu ≈ Pb > Cr ≈ Ni in 2016, and the vegetable soils were slightly to moderately contaminated by these elements through integrated contamination index. The sites affected by the trace elements did not increase in 2016 than in 2012, whereas the sites with relatively high contamination increased markedly. The non-carcinogenic risk of trace elements was generally acceptable, and children showed higher health risk than adults. The As carcinogenic risk for children varied between 5.48 × 10⁻⁵ and 1.59 × 10⁻⁴ in 2012 and between 4.40 × 10⁻⁵ and 1.82 × 10⁻⁴ in 2016, and the sites above acceptable levels (> 10⁻⁴) reached 60.6% and 48.5% in 2012 and 2016, respectively. The health risk of As in the vegetable soils should be paid more attention due to its high toxicity.
Show more [+] Less [-]Cu(II)-catalyzed degradation of ampicillin: effect of pH and dissolved oxygen Full text
2018
Guo, Yiming | Tsang, Daniel C. W. | Zhang, Xinran | Yang, Xin
Cu(II)-catalyzed hydrolysis of β-lactam antibiotics has been well-identified and recognized as the key mechanism of antibiotic degradation. However, the overlooked Cu(II) oxidation susceptibly also plays an important role comparably with hydrolysis. This study evaluated the roles of hydrolysis and oxidation in Cu(II)-catalyzed degraded ampicillin (AMP), as a typical β-lactam antibiotic, under relevant environmental conditions (pH 5.0, 7.0, and 9.0; oxygen 0.2 and 6.2 mg/L). Under AMP and Cu(II) molar ratio of 1:1, AMP degradation was the fastest at pH 9.0, followed by pH 5.0 and pH 7.0. The facilitation of oxygen on AMP degradation was notable at pH 5.0 and 7.0 rather than pH 9.0. AMP degradation rate increased from 21.8% in 0.2 mg/L O₂ solution to 85.9% in 6.2 mg/L O₂ solution at pH 7.0 after 4-h reaction. AMP oxidation was attributed to both oxygen-derived Cu(I)/Cu(II) cycle and intermediate reactive oxygen species (HO. and O₂.⁻). Several intermediate and final products in AMP degradation were firstly identified by LC-quadrupole time-of-flight-MS analysis. Phenylglycine primary amine on the AMP structure was the essential complexation site to proceed with the oxidation reaction. The oxidation of AMP preferentially occurred on the β-lactam structure. The inherent mechanisms related to pH and oxygen conditions were firstly investigated, which could enhance the understanding of both oxidation and hydrolysis mechanisms in AMP degradation. This study not only has an important implication in predicting β-lactam antibiotic transformation and fate in natural environment but also benefits the developing of strategies of antibiotic control to reduce the environmental risk.
Show more [+] Less [-]Distribution and health risks of aerosol black carbon in a representative city of the Qinghai-Tibet Plateau Full text
2018
Wu, Jun | Lu, Jian | Min, Xiuyun | Zhang, Zhenhua
Although aerosol black carbon (BC) exerts strong influences on human health, research on potential health risks of aerosol BC around the Qinghai-Tibet Plateau is very limited. This is the very first study to investigate the distribution of aerosol BC in a typical city of the Qinghai-Tibet Plateau and the resulting health risks. The results showed that the maximal real-time (5-min monitoring interval) concentration of aerosol BC was 22.34 μg/m³, much higher than day- and week-averaged concentrations which were in the range of 1.28–6.15 and 1.93–4.63 μg/m³, respectively. The health risks were evaluated using four different health endpoints including low birth weight (LBW), percentage lung function decrement of school-aged children (PLFD), cardiovascular mortality (CM), and lung cancer (LC). The highest risks of LBW, PLFD, CM, and LC had reached 69.5, 184.4, 67.4, and 31.8 numbers of equivalent passively smoked cigarettes (PSC), respectively. The concentrations and health risks of aerosol BC in the study area are at a middle level among the global cities/regions. In comparison, the cities of the Qinghai-Tibet Plateau are experiencing high potential health risks resulting from aerosol BC to need more effective prevention and control of air pollution.
Show more [+] Less [-]Microbial removal and plant uptake of nitrogen in constructed wetlands: mesocosm tests on influencing factors Full text
2018
Tao, Wendong
Macrophytes and bacteria are key drivers of nitrogen removal in constructed wetlands. Through mesocosm experiments with vegetated submerged beds and free water surface wetlands in various operational modes, wetland configurations, and system layouts, this study developed empirical models for non-destructive estimation of plant biomass growth and associated nitrogen assimilation and explored the combined effects of multiple factors that influence microbial nitrogen removal. The above-ground biomass of individual plants was a power function of plant height for both Cyperus alternifolius and Typha angustifolia. Below- to above-ground biomass ratio was 0.38 for C. alternifolius and 2.73 for T. angustifolia. Because of greater tolerance to ammonia stress, C. alternifolius and C. papyrus grew faster than T. angustifolia. There were no significant effects of wetland type, vegetation, and plant species on microbial nitrogen removal. Microbial nitrogen removal was inhibited by free ammonia at 13.3–16.2 mg N/L. Denitrification and anammox were suppressed at dissolved oxygen greater than 1.9 mg/L. Microbial removal of ammonia in vegetated submerged beds was sensitive mainly to dissolved oxygen, pH, and influent ammonia concentration, while in free water surface wetlands, it was sensitive to influent ammonia concentration, pH, and temperature.
Show more [+] Less [-]Radon and PM10 concentrations in underground parking lots and subway stations with health risks in South Korea Full text
2018
Hwang, Sŭng-ho | Park, Wha Me
This study examined the environmental factors that affect indoor radon (Rn) and particulate matter (PM₁₀) concentrations in underground public facilities such as subway stations and underground parking lots. Rn and PM₁₀ concentrations from March 2014 to October 2015 were evaluated at 40 subway stations and 19 underground parking lots. Average underground concentrations of Rn and PM₁₀ were 37.3 ± 17.1 Bq/m³ and 78.6 ± 15.1 μg/m³, respectively. There were significant difference in Rn concentration between sampling points, with the highest concentration 41.8 ± 18.1 Bq/m³ on subway platforms, while the highest concentration of PM₁₀ was 83.7 ± 13.8 μg/m³ in transfer pathways. Rn concentration showed positive correlation with PM₁₀ concentration (r = 0.380, p < 0.001). The highest Rn concentration occurred during fall season, followed by summer and spring. At 60-h exposure duration in underground subway stations and parking lots, the hazard quotient (HQ) of Rn exceeded 1 for children less than 1 year old and those between 8 and 10 years old.
Show more [+] Less [-]Does heavy metal exposure affect the condition of Whitethroat (Sylvia communis) nestlings? Full text
2018
Turzańska-Pietras, Katarzyna | Chachulska, Justyna | Polechońska, Ludmiła | Borowiec, Marta
Anthropogenic pollution results in high concentrations of heavy metals in the environment. Due to their persistence and a high potential for bioaccumulation, metals are a real threat for birds breeding in industrial areas. The aim of the present study has been to explore the contents of heavy metals (arsenic As, cadmium Cd, chromium Cr, copper Cu, iron Fe, nickel Ni, lead Pb and zinc Zn) in the excreta of Whitethroat (Sylvia communis) nestlings living in polluted environment and to investigate the relationship between these contents and the nestlings’ condition. Excrement samples contained all the studied elements. The contents of arsenic, cadmium, copper and zinc in the excreta of nestlings from nests located close to a slag dump were several times higher than in the soil near the dump, which suggested accumulation in food consumed by the birds. Condition parameters (body mass and haemoglobin concentration) were not related to heavy metal concentrations in the nestlings’ excreta, except of Zn. It is possible that Whitethroats are able to detoxicate heavy metals to a certain extent. Detailed, multi-element analysis of the environment, food and bird tissues or excreta should be performed to explore relations between different chemicals and bird condition.
Show more [+] Less [-]The effect of anthropogenic activities on the phosphorus-buffering intensity of the two contrasting rivers in northern China Full text
2018
Jin, Xin | Zhang, Wenqiang | Zhu, Yaoyao | Shan, Baoqing
The phosphorus (P)-buffering ability of suspended particulate matter (SPM) from the Ziya River Mainstream (ZRM) and the Luanhe River (LR) of northern China was investigated in this study. Forty samples of SPM from the ZRM and LR were collected in October and November of 2016. The ZRM has slow flow and poor water quality, while the LR has fast flow and reasonably good water quality. Under a scanning electron microscope, the SPM from the ZRM had a more complex microstructure than that from the LR, perhaps because of the slower flow and heavier pollution in the ZRM. P fractions in both SPM and water samples were determined using standard measurement and testing program methods. The equilibrium P concentration was used to determine the influence of SPM on soluble reactive P (SRP) concentrations. These SRP fractions were used to evaluate the P-buffering intensity of the two rivers. Differences in SPM microstructure resulted in the SPM from ZRM having a stronger P-buffering ability than the LR, making SPM an effective vector for SRP. Anthropogenic activities likely contributed to the differences in both microstructures of the SPM and P-buffering intensity of the rivers. A conceptual model was developed to show how anthropogenic activities influence the P-buffering intensity of the two rivers. As far as we know, this is the first time that the P-buffering intensity has been compared between two rivers that have been severely impacted by anthropogenic activities. Our findings provide an important reference for similar rivers worldwide.
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