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Antibiotic concentration and antibiotic-resistant bacteria in two shallow urban lakes after stormwater event Texte intégral
2016
Zhang, Songhe | Pang, Si | Wang, Peifang | Wang, Chao | Han, Nini | Liu, Bin | Han, Bing | Li, Yi | Anim-Larbi, Kwaku
Stormwater runoff is generally characterized as non-point source pollution. In the present study, antibiotic concentration and antibiotic susceptibilities of cultivable heterotrophic bacteria were investigated in two small shallow urban lakes before and after strong storm event. Several antibiotics, lactose-fermenting bacteria and cultivable heterotrophic bacteria concentrations increased in surface water and/or surface sediment of two small urban lakes (Lake Xuanwu and Wulongtan) after strong storm event. In general, the frequencies of bacteria showing resistance to nine antibiotics increased after storm event. Based on the 16S rRNA genes of 50 randomly selected isolates from each water sample of two lakes, Aeromonas and Bacillus were dominant genera in samples from two lakes, while genera Proteus and Lysinibacillus were the third abundant genera in Lake Xuanwu and Wulongtu, respectively. Presences of nine antibiotic resistance genes (ARGs) in the 100 isolates were detected and most of these isolates harbored at least two ARGs with different functions. The detection frequency of ARGs in Gram-negative isolates was higher than that in Gram-positive isolates. The most prevalent integron in 100 isolates was int(II) (n = 28), followed by int(I) (n = 17) and int(III) (n = 17). Our results indicate that strong storm events potentially contribute to the transfer of ARGs and antibiotic-resistant bacteria from land-sewer system to the urban Lakes.
Afficher plus [+] Moins [-]Radioactivity measurements and dose rate calculations using ERICA tool in the terrestrial environment of Greece Texte intégral
2016
Sotiropoulou, Maria | Florou, Heleny | Manolopoulou, Metaxia
In the present study, the radioactivity levels to which terrestrial non-human biota were exposed are examined. Organisms (grass and herbivore mammals) and abiotic components (soil) were collected during the period of 2010 to 2014 from grasslands where sheep and goats were free-range grazing. Natural background radionuclides (²²⁶Ra, ²²⁸Ra, ²²⁸Th) and artificial radionuclides (¹³⁷Cs, ¹³⁴Cs, ¹³¹I) were detected in the collected samples using gamma spectrometry. The actual measured activity concentrations and site-specific data of the studied organisms were imported in ERICA Assessment Tool (version 1.2.0) in order to provide an insight of the radiological dose rates. The highest activity concentrations were detected in samples collected from Lesvos island and the lowest in samples collected from Attiki and Etoloakarnania prefectures. The highest contribution to the total dose rate was clearly derived from the internal exposure and is closely related to the exposure to alpha emitters of natural background (²²⁶Ra and ²²⁸Th). The Fukushima-derived traces of ¹³⁷Cs, ¹³⁴Cs, and ¹³¹I, along with the residual ¹³⁷Cs, resulted in quite low contribution to the total dose rate. The obtained results may strengthen the adaptation of software tools to a wider range of ecosystems and may be proved useful in further research regarding the possible impact of protracted low level ionizing radiation on non-human biota. This kind of studies may contribute to the effective incorporation of dosimetry tools in the development of integrated environmental and radiological impact assessment policies.
Afficher plus [+] Moins [-]Phosphorus released from sediment of Dianchi Lake and its effect on growth of Microcystis aeruginosa Texte intégral
2016
Liu, Junzhuo | Luo, Xiongxin | Zhang, Naiming | Wu, Yonghong
Phosphorus stored in lake sediments is an inner nutrient source and can be released into overlying water to exacerbate algal blooms. A simulated microcosm of Dianchi Lake was built to investigate phosphorus release from sediments to overlying water and its effect on the growth of Microcystis aeruginosa. The sediments of Dianchi Lake had a total phosphorus (TP) content of 1.7–1.8 mg g⁻¹ with Ca bound phosphorus (Ca-P, 50–54 %) and organic phosphorus (Org-P, 28–32 %) as the main fractions. The sediments released 8 % of TP into the overlying water with Fe/Al bound phosphorus (Fe/Al-P, 26 %) and Org-P (65 %) being the main fractions released. The phosphorus concentration of the overlying water increased from 0.14–0.16 to 0.28–0.33 mg L⁻¹. The biomass density of M. aeruginosa was positively correlated (R ² = 0.825) with the concentration of orthophosphate, which was the predominant bioavailable phosphorus fraction for algal growth. Org-P can be partly utilized by M. aeruginosa but will not cause a bloom. A good understanding of the geochemical cycles of phosphorus is needed for regulating phosphorus release from sediments and thereby reducing the risk of cyanobacterial blooms.
Afficher plus [+] Moins [-]Transference factors as a tool for the estimation of arsenic milk concentration Texte intégral
2016
Pérez-Carrera, Alejo | Alvarez-Gonçalvez, Cristina V. | Fernández Cirelli, A. (Alicia)
The Chaco Pampean Plain of central Argentina represents one of the largest regions with high levels of arsenic (As) in groundwater. The aim of this study was the assessment of a biotransference factor (BTF) as a tool for the estimation of As concentration in cow’s milk from As drinking water concentration. Total As content in livestock drinking water, soil, forage, and milk was determined in farms located in an area of high As groundwater, in order to analyze the relation between As uptake and its transfer to milk. The concentrations of As in milk ranged from 0.5 to 8.0 μg/L. From the results obtained, drinking water may be considered the main source of exposure to As, and the biotransference factor for milk ranges from 1.5 × 10⁻⁵ to 4.3 × 10⁻⁴. Therefore, BTF provides a simple tool for the estimation of arsenic levels in milk through the As livestock drinking water content.
Afficher plus [+] Moins [-]Study of the degradation of butyltin compounds in surface water samples under different storage conditions using multiple isotope tracers and GC-MS/MS Texte intégral
2016
Rodríguez-Cea, Andrés | Rodriguez-González, Pablo | Garcia Alonso, J. Ignacio
The degradation of butyltin compounds in surface water samples under different storage conditions has been studied. A triple spike solution, containing monobutyltin (MBT), dibutyltin (DBT) and tributyltin (TBT) labelled with a different tin isotope, was added to the sample to calculate the extent of the interconversion reactions among butyltin compounds. Real surface water samples (river water) were collected and stored in glass, polypropylene or polytetrafluoroethylene (PTFE) containers. The presence of light, addition of acetic acid, storage temperature (22, 4 or −18 °C), and the influence of a filtration step were evaluated. Moreover, Milli-Q water with and without the addition of a high concentration of humic acids was prepared in parallel and the results compared to those obtained from the real samples. The water samples were analysed by gas chromatography–tandem mass spectrometry (GC-MS/MS) in selected reaction monitoring (SRM) mode at two different storage times (2 weeks and 4 months after its preparation) to carry out both a short- and a long-term stability study. The lowest butyltin degradation was obtained when the samples were stored at −18 °C in the dark. Under these conditions, both TBT and DBT showed negligible dealkylation factors after 2 weeks. After 4 months, DBT dealkylation to MBT increased up to 19 % but TBT degradation was not observed.
Afficher plus [+] Moins [-]The accumulation and health risk of heavy metals in vegetables around a zinc smelter in northeastern China Texte intégral
2016
Li, Bo | Wang, Yanhong | Jiang, Yong | Li, Guochen | Cui, Jiehua | Wang, Ying | Zhang, Hong | Wang, Shicheng | Xu, Sheng | Wang, Pi
Mining and smelting activities engender soil contamination by metals severely. A field survey was conducted to investigate the present situation and health risk of heavy metals (Cd, Pb, Zn, Cu, Cr, As, and Hg) in soils and vegetables in the surrounding area of an 80-year-old zinc smelter in northeastern China. Soil pH, organic matter (SOM), and cation exchange capacity (CEC) were determined, and their relations with heavy metal contents in edible parts of vegetables were analyzed. Results showed that the smelting had led to the significant contamination of the local soils by Cd and Zn, with average concentrations of 3.88 and 403.89 mg kg⁻¹, respectively. Concentrations of Cd and Zn in greenhouse soils were much lower than those in open farmland soils. Cd concentrations in vegetable edible parts exceeded the permissible limits severely, while other metal concentrations were much lower than the corresponding standards. Leaf and root vegetables had higher concentrations and bioaccumulation factors (BCFs) of Cd than fruit vegetables. Hazard quotient and hazard index showed that cadmium is imposing a health risk to local residents via vegetable consumption. Cd uptake of some vegetables can be predicted by empirical models with the following parameters: soil pH, SOM, CEC, Zn concentrations, and Cd concentrations. Vegetables such as cabbage, Chinese cabbage, tomato, cucumber, and green bean were screened out as being suitable to grow in the studied area.
Afficher plus [+] Moins [-]Heavy metals in sediments, soils, and aquatic plants from a secondary anabranch of the three gorges reservoir region, China Texte intégral
2016
Gao, Jun-min | Sun, Xiu-qian | Jiang, Wen-chao | Wei, Yun-mei | Guo, Jin-song | Liu, Yuanyuan | Zhang, Ke
We investigated the occurrence of cadmium (Cd), copper (Cu), chromium (Cr), nickel (Ni), lead (Pb), Znic (Zn), iron (Fe), manganese (Mn), and magnesium (Mg) in sediments, as well as in related soils and aquatic plants in the Liangtan River, a typical secondary anabranch of the Yangtze River in the Three Gorges Reservoir Region (TGRR) of China. We found that sediments accumulated more metals than soils and aquatic plants. Concentrations of the nine metals in sediments and soils followed the same sequence, while their concentrations in aquatic plants followed a different sequence. Potential adverse effects of contaminated sediments on benthic fauna were evaluated, and the results showed that the toxic effect on benthic organisms followed the sequence Zn > Ni > Cr > Cu > Cd > Pb. The potential ecological risk index analysis indicated that Cd in sediments had considerable ecological risk, whereas Cr, Cu, Zn, Ni, and Pb had low ecological risk. The potential ecological risk index (RI) of the heavy metals in sediments of the Liangtan River was 174.9, indicating moderate ecological risk. The transfer factor trend of metals for aquatic plants showed that Cd and Ni had the most and least accumulation, respectively. For Cu, Cd, Mg, Pb, and Cr, a significant positive correlation of the metal concentrations was observed between sediments and soils, but no correlations (excluding Cr) were detected between sediments and aquatic plants. Our study indicated that anthropogenic input may be the primary source of metal contamination in the Liangtan River, and that Zn and Cd pollution in the Liangtan River should be further explored.
Afficher plus [+] Moins [-]Soil ecotoxicology in Brazil is taking its course Texte intégral
2016
Niva, Cintia Carla | Niemeyer, Julia Carina | Júnior, Flávio Manoel Rodrigues Da Silva | Nunes, Maria Edna Tenório | De Sousa, Danilo Lourenço | Aragão, Clara Wandenkolck Silva | Sautter, Klaus Dieter | Espindola, Evaldo Gaeta | Sousa, José Paulo | Römbke, Jörg
Soil ecotoxicology has been motivated by the increasing global awareness on environmental issues. Northern Hemisphere has been the main driver of this science branch; however, the number and quality of contributions from the Southern Hemisphere are increasing quickly. In this case study, Brazil is taken as an example of how soil ecotoxicology has developed over the last 30 years. It starts with a brief historical overview depicting the main events on soil ecotoxicology in the country. Following, an overview on the Brazilian legislation related to soil ecotoxicology is given, covering regulations with prospective focus, mainly on the registration of pesticides. Regulations with retrospective focus in contaminated areas are also given. Then, an outline of the actors in soil ecotoxicology and examples of prospective ecotoxicological studies performed with soil organisms and plants are given by stressor groups: pesticides, pharmaceuticals, metals, and residues. Experiences from retrospective studies, mainly looking at the assessment of industrial sites, are also covered. Emphasis is given on methodological aspects, pointing to needed actions, mainly regarding the different biotic and abiotic conditions of a tropical country. Finally, the last session discusses how soil ecotoxicology could be improved in methodological adaptations as well as legal requirements.
Afficher plus [+] Moins [-]Managing the drinking water catchment areas: the French agricultural cooperatives feed back Texte intégral
2016
Charrière, Séverine | Aumond, Claire
The quality of raw water is problematic in France, largely polluted by nitrates and pesticides (Mueller and Helsel, Nutrients in the nation’s waters—too much of a good thing? Geological Survey (U.S.), 1996; European Environment Agency, European waters—assessment of status and pressures, 2012).This type of pollution, even though not always due to agriculture (example of the catchment of Ambleville, county 95, France where the nitrate pollution is mainly due to sewers (2012)), has been largely related to the agricultural practices (Sci Total Environ 407:6034–6043, 2009).Taking note of this observation, and instead of letting it paralyze their actions, the agricultural cooperatives decided with Agrosolutions to act directly on the field with their subscribers to change the agricultural practices impacting the water and the environment.This article shows how the French agricultural cooperatives transformed the awareness of the raw water quality problem into an opportunity for the development and implementation of more precise and responsible practices, to protect their environment. They measure in order to pilot, co-construct and build the best action plans possible according to the three pillars of environment, economy and agronomy.
Afficher plus [+] Moins [-]Use of RSM modeling for optimizing decolorization of simulated textile wastewater by Pseudomonas aeruginosa strain ZM130 capable of simultaneous removal of reactive dyes and hexavalent chromium Texte intégral
2016
Maqbool, Zahid | Ḥussain, Ṣābir | Aḥmad, Tanvīr | Nadeem, Habibullah | Imran, Muhammad | Khalid, Azeem | Abid, Mohamed | Martin-Laurent, Fabrice
Use of RSM modeling for optimizing decolorization of simulated textile wastewater by Pseudomonas aeruginosa strain ZM130 capable of simultaneous removal of reactive dyes and hexavalent chromium Texte intégral
2016
Maqbool, Zahid | Ḥussain, Ṣābir | Aḥmad, Tanvīr | Nadeem, Habibullah | Imran, Muhammad | Khalid, Azeem | Abid, Mohamed | Martin-Laurent, Fabrice
Remediation of colored wastewater loaded with dyes and metal ions is a matter of interest nowadays. In this study, 220 bacteria isolated from textile wastewater were tested for their potential to decolorize each of the four reactive dyes (reactive red-120, reactive black-5, reactive yellow-2, and reactive orange-16) in the presence of a mixture of four different heavy metals (Cr, Zn, Pb, Cd) commonly found in textile effluents. Among the tested bacteria, the isolate ZM130 was found to be the most efficient in decolorizing reactive dyes in the presence of the mixture of heavy metals and was identified as Pseudomonas aeruginosa strain ZM130 by 16S rRNA gene analysis. The strain ZM130 was highly effective in simultaneously removing hexavalent chromium (25 mg L⁻¹) and the azo dyes (100 mg L⁻¹) from the simulated wastewater even in the presence of other three heavy metals (Zn, Pb, Cd). Simultaneous removal of chromium and azo dyes ranged as 76.6–98.7 % and 51.9–91.1 %, respectively, after 180 h incubation. On the basis of quadratic polynomial equation and response surfaces given by the response surface methodology (RSM), optimal salt content, pH, carbon co-substrate content, and level of multi-metal mixtures for decolorization of reactive red-120 in a simulated textile wastewater by the strain ZM130 were predicted to be 19.8, 7.8, and 6.33 g L⁻¹ and a multi-metal mixture (Cr 13.10 mg L⁻¹, Pb 26.21 mg L⁻¹, Cd 13.10 mg L⁻¹, Zn 26.21 mg L⁻¹), respectively. Moreover, the strain ZM130 also exhibited laccase and nicotinamide adenine dinucleotide (reduced)-dichlorophenolindophenol reductase (NADH-DCIP reductase) activity during the decolorization of reactive red-120. However, the laccase activity was found to be maximum in the presence of 300 mg L⁻¹ of the dye as compared to other concentrations. Hence, the isolation of this strain might serve as a potential bio-resource required for developing the strategies aiming at bioremediation of the wastewater contaminated with dyes and heavy metals.
Afficher plus [+] Moins [-]Use of RSM modeling for optimizing decolorization of simulated textile wastewater by Pseudomonas aeruginosa strain ZM130 capable of simultaneous removal of reactive dyes and hexavalent chromium Texte intégral
2016
Maqbool, Zahid | Hussain, Sabir | Ahmad, Tanvir | Nadeem, Habibullah | Imran, Muhammad | Khalid, Azeem | Abid, Muhammad | Martin-Laurent, Fabrice | Department of Environmental Sciences and Engineering ; University of North Carolina [Chapel Hill] (UNC) ; University of North Carolina System (UNC)-University of North Carolina System (UNC) | University College Dublin [Dublin] (UCD) | Government College University [Lahore] (GCU) | Nuclear Institute for Agriculture and Biology ; Partenaires INRAE | Muhammad Nawaz Shareef University of Agriculture | Pir Mehr Ali Shah Arid Agriculture University = PMAS-Arid Agriculture University Rawalpindi (AAUR) | Bahauddin Zakariya University (BZU) | Agroécologie [Dijon] ; Institut National de la Recherche Agronomique (INRA)-Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement | Higher Education Commission (HEC) of Pakistan; Government College University Faisalabad, Pakistan
International audience | Remediation of colored wastewater loaded with dyes and metal ions is a matter of interest nowadays. In this study, 220 bacteria isolated from textile wastewater were tested for their potential to decolorize each of the four reactive dyes (reactive red-120, reactive black-5, reactive yellow-2, and reactive orange-16) in the presence of a mixture of four different heavy metals (Cr, Zn, Pb, Cd) commonly found in textile effluents. Among the tested bacteria, the isolate ZM130 was found to be the most efficient in decolorizing reactive dyes in the presence of the mixture of heavy metals and was identified as Pseudomonas aeruginosa strain ZM130 by 16S rRNA gene analysis. The strain ZM130 was highly effective in simultaneously removing hexavalent chromium (25 mg L-1) and the azo dyes (100 mg L-1) from the simulated wastewater even in the presence of other three heavy metals (Zn, Pb, Cd). Simultaneous removal of chromium and azo dyes ranged as 76.6-98.7 % and 51.9-91.1 %, respectively, after 180 h incubation. On the basis of quadratic polynomial equation and response surfaces given by the response surface methodology (RSM), optimal salt content, pH, carbon co-substrate content, and level of multi-metal mixtures for decolorization of reactive red-120 in a simulated textile wastewater by the strain ZM130 were predicted to be 19.8, 7.8, and 6.33 g L-1 and a multi-metal mixture (Cr 13.10 mg L-1, Pb 26.21 mg L-1, Cd 13.10 mg L-1, Zn 26.21 mg L-1), respectively. Moreover, the strain ZM130 also exhibited laccase and nicotinamide adenine dinucleotide (reduced)-dichlorophenolindophenol reductase (NADH-DCIP reductase) activity during the decolorization of reactive red-120. However, the laccase activity was found to be maximum in the presence of 300 mg L-1 of the dye as compared to other concentrations. Hence, the isolation of this strain might serve as a potential bio-resource required for developing the strategies aiming at bioremediation of the wastewater contaminated with dyes and heavy metals.
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