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Occurrence and fate of perfluorinated acids in two wastewater treatment plants in Shanghai, China
2015
Zhang, Chaojie | Yan, Hong | Li, Fei | Zhou, Qi
Perfluorinated acids (PFAs) have drawn much attention due to their environmental persistence, ubiquitous existence, and bioaccumulation potential. The discharge of wastewater effluent from municipal wastewater treatment plants (WWTPs) is a significant source of PFAs to the environment. In this study, wastewater and sludge samples were collected from two WWTPs in Shanghai, China, to investigate the contamination level and fate of PFAs in different stages of processing. The total concentrations of PFAs (∑PFAs) in influent from plants A and B were 2,452 and 292 ng L⁻¹, respectively. Perfluoropentanoic acid (1,520 ± 80 ng L⁻¹ in plant A and 89.2 ± 12.1 ng L⁻¹ in plant B) was the predominant PFA in influent waters, followed by perfluorooctanoic acid. The concentration of ∑PFAs ranged from 75.0 to 126.0 ng g⁻¹ dry weight in sludge samples from plant B, with perfluorooctanesulfonic acid as the predominant contaminant. The concentrations and fate of PFAs in different WWTPs vary. The ∑PFAs entering plant A decreased significantly in the final effluent of activated sludge process, while that in plant B increased significantly in the final effluent of sequencing batch reactor system. The concentration changes could be due to the sorption onto sludge, or the degradation of PFAs precursors.
Afficher plus [+] Moins [-]Alternatives to neonicotinoid insecticides for pest control: case studies in agriculture and forestry
2015
Furlan, Lorenzo | Kreutzweiser, David
Neonicotinoid insecticides are widely used for control of insect pests around the world and are especially pervasive in agricultural pest management. There is a growing body of evidence indicating that the broad-scale and prophylactic uses of neonicotinoids pose serious risks of harm to beneficial organisms and their ecological function. This provides the impetus for exploring alternatives to neonicotinoid insecticides for controlling insect pests. We draw from examples of alternative pest control options in Italian maize production and Canadian forestry to illustrate the principles of applying alternatives to neonicotinoids under an integrated pest management (IPM) strategy. An IPM approach considers all relevant and available information to make informed management decisions, providing pest control options based on actual need. We explore the benefits and challenges of several options for management of three insect pests in maize crops and an invasive insect pest in forests, including diversifying crop rotations, altering the timing of planting, tillage and irrigation, using less sensitive crops in infested areas, applying biological control agents, and turning to alternative reduced risk insecticides. Continued research into alternatives is warranted, but equally pressing is the need for information transfer and training for farmers and pest managers and the need for policies and regulations to encourage the adoption of IPM strategies and their alternative pest control options.
Afficher plus [+] Moins [-]Formaldehyde exposure in gross anatomy laboratory of Suranaree University of Technology: a comparison of area and personal sampling
2015
Saowakon, Naruwan | Ngernsoungnern, Piyada | Watcharavitoon, Pornpun | Ngernsoungnern, Apichart | Kosanlavit, Rachain
Cadavers are usually preserved by embalming solution which is composed of formaldehyde (FA), phenol, and glycerol. Therefore, medical students and instructors have a higher risk of exposure to FA inhalation from cadavers during dissection. Therefore, the objective of this study was to evaluate the FA exposure in indoor air and breathing zone of medical students and instructors during dissection classes in order to investigate the relationship between them. The indoor air and personal air samples in breathing zone were collected three times during anatomy dissection classes (in January, August, and October of 2014) with sorbent tubes, which were analyzed by high-performance liquid chromatography (HPLC). The air cleaner machines were determined by weight measurement. Pulmonary function tests and irritation effects were also investigated. The mean of FA concentrations ranged from 0.117 to 0.415 ppm in the indoor air and from 0.126 to 1.176 ppm in the breathing zone of students and instructors. All the personal exposure data obtained exceeded the threshold limit of NIOSH and WHO agencies. The air cleaner machines were not significant difference. The pulmonary function of instructors showed a decrease during attention of classes and statistically significant decreasing in the instructors more than those of the students. Clinical symptoms that were observed in nose and eyes were irritations with general fatigue. We suggested that the modified exhaust ventilation and a locally ventilated dissection work table were considered for reducing FA levels in the gross anatomy dissection room.
Afficher plus [+] Moins [-]Assessment of amendments for the immobilization of Cu in soils containing EDDS leachates
2015
Yang, Li | Jiang, Longfei | Wang, Guiping | Chen, Yahua | Shen, Zhenguo | Luo, Chunling
In this study, the effectiveness of six soil amendments (ferrihydrite, manganese dioxide, gibbsite, calcium carbonate, biochar, and organic fertilizer) was investigated to assess the feasibility of minimizing possible environmental contaminant leaching during S,S-ethylenediaminedisuccinic acid (EDDS)-enhanced phytoextraction process based on 0.01-M CaCl₂ extraction. Results showed that the application of EDDS could significantly increase Cu concentrations in the leaching solution. Compared with control, incorporation of six amendments (excluding organic fertilizer) significantly decreased CaCl₂-extractable Cu concentrations in both soils. When EDDS-containing solutions leached from the soil columns (mimicking the upper soil layers) were added to soils with different amendments (mimicking the subsoil), CaCl₂-extractable Cu in the soils amended with ferrihydrite, manganese dioxide, gibbsite, and calcium carbonate was significantly lower than that in the control soil (no amendments) and remained relatively constant during the first 14 days. Incorporation of biochar or organic fertilizer had no positive effect on the immobilization of Cu in EDDS leachates in soils. After 14 days, CaCl₂-extractable Cu concentration decreased rapidly in soils incorporated with various amendments. Integrating soil washing with biodegradable chelating agents or chelant-enhanced phytoextraction and immobilization of heavy metals in subsoil could be used to rapidly reduce the concentration of bioavailable metal fractions in the upper soil layers and minimize environmental risks of secondary pollution.
Afficher plus [+] Moins [-]Do coal consumption and industrial development increase environmental degradation in China and India?
2015
Shahbaz, Muhammad | Farhani, Sahbi | Ozturk, Ilhan
The present study is aimed to explore the relationship between coal consumption, industrial production, and CO₂emissions in China and India for the period of 1971–2011. The structural break unit root test and cointegrating approach have been applied. The direction of causal relationship between the variables is investigated by applying the VECM Granger causality test. Our results validate the presence of cointegration among the series in both countries. Our results also validate the existence of inverted U-shaped curve between industrial production and CO₂emissions for India, but for China, it is a U-shaped relationship. Coal consumption adds in CO₂emissions. The causality analysis reveals that industrial production and coal consumption Granger cause CO₂emissions in India. In the case of China, the feedback effect exists between coal consumption and CO₂emissions. Due to the importance of coal in China and India, any reduction in coal consumption will negatively affect their industrial value added as well as economic growth.
Afficher plus [+] Moins [-]Isolation and cultivation of xylanolytic and cellulolytic Sarocladium kiliense and Trichoderma virens from the gut of the termite Reticulitermes santonensis
2015
Tarayre, Cédric | Bauwens, Julien | Brasseur, Catherine | Mattéotti, Christel | Millet, Catherine | Guiot, Pierre Alexandre | Destain, Jacqueline | Vandenbol, Micheline | Portetelle, Daniel | De Pauw, Edwin | Haubruge, Eric | Francis, Frédéric | Thonart, Philippe
The purpose of this work was the isolation and cultivation of cellulolytic and xylanolytic microorganisms extracted from the gut of the lower termite Reticulitermes santonensis. Microcrystalline cellulose (with and without lignin) and beech wood xylan were used as diets instead of poplar wood in order to select cellulose and hemicellulose-degrading fungi. The strain Sarocladium kiliense (Acremonium kiliense) CTGxxyl was isolated from the termites fed on xylan, while the strain Trichoderma virens CTGxAviL was isolated from the termites fed on cellulose (with and without lignin). Both molds were cultivated in liquid media containing different substrates: agro-residues or purified polymers. S. kiliense produced maximal β-glucosidase, endo-1,4-β-D-glucanase, exo-1,4-β-D-glucanase and endo-1,4-β-D-xylanase activities of 0.103, 3.99, 0.53, and 40.8 IU/ml, respectively. T. virens produced maximal β-xylosidase, endo-1,4-β-D-glucanase, exo-1,4-β-D-glucanase, and endo-1,4-β-D-xylanase activities of 0.38, 1.48, 0.69, and 426 IU/ml. The cellulase and the xylanase of S. kiliense, less common than T. virens, were further investigated. The optimal activity of the xylanase was observed at pH 9–10 at 60 °C. The cellulase showed its maximal activity at pH 10, 70 °C. Zymography identified different xylanases produced by both molds, and some fragment sizes were highlighted: 35, 100, and 170 kDa for S. kiliense and 20, 40, 80, and 170 kDa for T. virens. In both cases, endo-1,4-β-D-xylanase activities were confirmed through mass spectrometry.
Afficher plus [+] Moins [-]Transport and bioaccumulation of polychlorinated dibenzo-p-dioxins and dibenzofurans at the Bien Hoa Agent Orange hotspot in Vietnam
2015
Van Thuong, Nguyen | Hung, Nguyen Xuan | Mo, Nguyen Thi | Thang, Nguyen Manh | Huy, Pham Quang | Van Binh, Hoang | Nam, Vu Duc | Van Thuy, Nguyen | Lê, Kế Sơn | Minh, Nguyen Hung
The Bien Hoa airbase (south of Vietnam) is known as one of the Agent Orange hotspots which have been seriously contaminated by Agent Orange/dioxin during the Vietnam War. Hundreds of samples including soil, sediment and fish were collected at the Bien Hoa Agent Orange hotspot for assessment of the environmental contamination caused by dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs). The toxicity equivalency quotient (TEQ) concentration of PCDD/Fs in soil and sediment varied from 7.6 to 962,000 and 17 to 4860 pg/g dry wt, respectively, implying very high contamination of PCDD/Fs in several areas. PCDD/F levels in fish ranged between 1.8 and 288 pg/g TEQ wet wt and was generally higher than advisory guidelines for food consumption. 2,3,7,8-Tetrachlorinated dibenzo-p-dioxins (2,3,7,8-TCDD) contributed 66–99 % of TEQ for most of the samples, suggesting 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) from Agent Orange as the major source of the contamination. The vertical transport of PCDD/Fs was observed in soil column with high TEQ levels above 1000 pg/g dry wt (Vietnamese limit for necessary remediation activities- TCVN 8183:2009 (2009)) even at a depth of 1.8 m. The vertical transport of PCDD/Fs has probably mainly taken place during the “Ranch Hand” defoliant spray activities due to the leaks and spills of phenoxy herbicides and solvents. The congener patterns suggest that transports of PCDD/Fs by weathering processes have led to their redistribution in the low-land areas. Also, an estimate for the total volume of contaminated soil requiring remediation to meet Vietnamese regulatory limits is provided.
Afficher plus [+] Moins [-]Insecticidal activity of Jatropha curcas extracts against housefly, Musca domestica
2015
Chauhan, Nitin | Kumar, Peeyush | Mishra, Sapna | Verma, Sharad | Malik, Anushree | Sharma, Satyawati
The hexane and ether extracts of leaves, bark and roots of Jatropha curcas were screened for their toxicity against different developmental stages of housefly. The larvicidal, pupicidal and adulticidal activities were analysed at various concentrations (0.78–7.86 mg/cm²) of hexane and ether extracts. The lethal concentration values (LC₅₀) of hexane extract of J. curcas leaves were 3.0 and 0.27 mg/cm² for adult and larval stages of housefly, respectively, after 48 h. Similarly, the ether extract of leaf showed the LC₅₀ of 2.20 and 4.53 mg/cm² for adult and larval stages of housefly. Least toxicity was observed with hexane root extract of J. curcas with LC₅₀ values of 14.18 and 14.26 mg/cm² for adult and larvae of housefly, respectively, after 48 h. The variation in LC₅₀ against housefly pupae was found to be 8.88–13.10 mg/cm² at various J. curcas extract concentrations. The GC-MS analysis of J. curcas leaf extract revealed the presence of trans-phytol (60.81 %), squalene (28.58 %), phytol (2.52 %) and nonadecanone (1.06 %) as major components that could be attributed for insecticidal activity of J. curcas extracts.
Afficher plus [+] Moins [-]Potential impacts of climate change on water quality in a shallow reservoir in China
2015
Zhang, Chen | Lai, Shiyu | Gao, Xueping | Xu, Liping
To study the potential effects of climate change on water quality in a shallow reservoir in China, the field data analysis method is applied to data collected over a given monitoring period. Nine water quality parameters (water temperature, ammonia nitrogen, nitrate nitrogen, nitrite nitrogen, total nitrogen, total phosphorus, chemical oxygen demand, biochemical oxygen demand and dissolved oxygen) and three climate indicators for 20 years (1992–2011) are considered. The annual trends exhibit significant trends with respect to certain water quality and climate parameters. Five parameters exhibit significant seasonality differences in the monthly means between the two decades (1992–2001 and 2002–2011) of the monitoring period. Non-parametric regression of the statistical analyses is performed to explore potential key climate drivers of water quality in the reservoir. The results indicate that seasonal changes in temperature and rainfall may have positive impacts on water quality. However, an extremely cold spring and high wind speed are likely to affect the self-stabilising equilibrium states of the reservoir, which requires attention in the future. The results suggest that land use changes have important impact on nitrogen load. This study provides useful information regarding the potential effects of climate change on water quality in developing countries.
Afficher plus [+] Moins [-]Airborne mineral components and trace metals in Paris region: spatial and temporal variability
2015
Poulakis, E. | Theodosi, C. | Bressi, M. | Sciare, J. | Ghersi, V. | Mihalopoulos, N.
A variety of mineral components (Al, Fe) and trace metals (V, Cr, Mn, Ni, Cu, Zn, Cd, Pb) were simultaneously measured in PM₂.₅ and PM₁₀ fractions at three different locations (traffic, urban, and suburban) in the Greater Paris Area (GPA) on a daily basis throughout a year. Mineral species and trace metal levels measured in both fractions are in agreement with those reported in the literature and below the thresholds defined by the European guidelines for toxic metals (Cd, Ni, Pb). Size distribution between PM₂.₅ and PM₁₀ fractions revealed that mineral components prevail in the coarse mode, while trace metals are mainly confined in the fine one. Enrichment factor analysis, statistical analysis, and seasonal variability suggest that elements such as Mn, Cr, Zn, Fe, and Cu are attributed to traffic, V and Ni to oil combustion while Cd and Pb to industrial activities with regional origin. Meteorological parameters such as rain, boundary layer height (BLH), and air mass origin were found to significantly influence element concentrations. Periods with high frequency of northern and eastern air masses (from high populated and industrialized areas) are characterized by high metal concentrations. Finally, inner city and traffic emissions were also evaluated in PM₂.₅ fraction. Significant contributions (>50 %) were measured in the traffic site for Mn, Fe, Cr, Zn, and Cu, confirming that vehicle emissions contribute significantly to their levels, while in the urban site, the lower contributions (18 to 33 %) for all measured metals highlight the influence of regional sources on their levels.
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