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Biofuel components change the ecology of bacterial volatile petroleum hydrocarbon degradation in aerobic sandy soil Full text
2013
Elazhari-Ali, Abdulmagid | Singh, Arvind K. | Davenport, Russell J. | Head, I. M. (Ian M.) | Werner, David
We tested the hypothesis that the biodegradation of volatile petroleum hydrocarbons (VPHs) in aerobic sandy soil is affected by the blending with 10 percent ethanol (E10) or 20 percent biodiesel (B20). When inorganic nutrients were scarce, competition between biofuel and VPH degraders temporarily slowed monoaromatic hydrocarbon degradation. Ethanol had a bigger impact than biodiesel, reflecting the relative ease of ethanol compared to methyl ester biodegradation. Denaturing gradient gel electrophoresis (DGGE) of bacterial 16S rRNA genes revealed that each fuel mixture selected for a distinct bacterial community, each dominated by Pseudomonas spp. Despite lasting impacts on soil bacterial ecology, the overall effects on VHP biodegradation were minor, and average biomass yields were comparable between fuel types, ranging from 0.40 ± 0.16 to 0.51 ± 0.22 g of biomass carbon per gram of fuel carbon degraded. Inorganic nutrient availability had a greater impact on petroleum hydrocarbon biodegradation than fuel composition.
Show more [+] Less [-]Soil contamination by phthalate esters in Chinese intensive vegetable production systems with different modes of use of plastic film Full text
2013
Wang, Jun | Luo, Yongming | Teng, Ying | Ma, Wenting | Christie, Peter | Li, Zhengao
The concentrations of six priority phthalic acid esters (PAEs) in intensively managed suburban vegetable soils in Nanjing, east China, were analyzed using gas chromatography–mass spectrometry (GC–MS). The total PAE concentrations in the soils ranged widely from 0.15 to 9.68 mg kg−1 with a median value of 1.70 mg kg−1, and di-n-butyl phthalate (DnBP), bis-(2-ethylhexyl) phthalate (DEHP) and di-n-octyl phthalate (DnOP) were the most abundant phthalate esters. Soil PAE concentrations depended on the mode of use of plastic film in which PAEs were incorporated as plasticizing agents and both the plastic film and poultry manure appeared to be important sources of soil PAEs. Vegetables in rotation with flooded rice led to lower concentrations of PAEs in soil. The results indicate that agricultural plastic film can be an important source of soil PAE contamination and further research is required to fully elucidate the mechanisms of PAE contamination of intensive agricultural soils with different use modes of use of plastic film.
Show more [+] Less [-]Effects of ozone on crops in north-west Pakistan Full text
2013
Ahmad, Muhammad Nauman | Büker, Patrick | Khalid, Sofia | Van Den Berg, Leon | Shah, Hamid Ullah | Wahid, Abdul | Emberson, Lisa | Power, Sally A. | Ashmore, Mike
Although ozone is well-documented to reduce crop yields in the densely populated Indo-Gangetic Plain, there is little knowledge of its effects in other parts of south Asia. We surveyed crops close to the city of Peshawar, in north-west Pakistan, for visible injury, linking this to passive measurements of ozone concentrations. Foliar injury was found on potato, onion and cotton when mean monthly ozone concentrations exceeded 45 ppb. The symptoms on onion were reproduced in ozone fumigation experiments, which also showed that daytime ozone concentrations of 60 ppb significantly reduce the growth of a major Pakistani onion variety. Aphid infestation on spinach was also reduced at these elevated ozone concentrations. The ozone concentrations measured in April–May in Peshawar, and used in the fumigation experiment, are comparable to those that have been modelled to occur over many parts of south Asia, where ozone may be a significant threat to sensitive crops.
Show more [+] Less [-]Salinisation of rivers: An urgent ecological issue Full text
2013
Cañedo-Argüelles, Miguel | Kefford, Ben J. | Piscart, Christophe | Prat i Fornells, Narcís | Schäfer, Ralf B. | Schulz, Claus-Jürgen
Secondary salinisation of rivers and streams is a global and growing threat that might be amplified by climate change. It can have many different causes, like irrigation, mining activity or the use of salts as de-icing agents for roads. Freshwater organisms only tolerate certain ranges of water salinity. Therefore secondary salinisation has an impact at the individual, population, community and ecosystem levels, which ultimately leads to a reduction in aquatic biodiversity and compromises the goods and services that rivers and streams provide. Management of secondary salinization should be directed towards integrated catchment strategies (e.g. benefiting from the dilution capacity of the rivers) and identifying threshold salt concentrations to preserve the ecosystem integrity. Future research on the interaction of salinity with other stressors and the impact of salinization on trophic interactions and ecosystem properties is needed and the implications of this issue for human society need to be seriously considered.
Show more [+] Less [-]Cadmium and associated metals in soils and sediments of wetlands across the Northern Plains, USA Full text
2013
Jacob, Donna L. | Yellick, Alex H. | Kissoon, La Toya T. | Asgary, Aida | Wijeyaratne, Dimuthu N. | Saini-Eidukat, Bernhardt | Otte, Marinus L.
Cadmium, present locally in naturally high concentrations in the Northern Plains of the United States, is of concern because of its toxicity, carcinogenic properties, and potential for trophic transfer. Reports of natural concentrations in soils are dominated by dryland soils with agricultural land uses, but much less is known about cadmium in wetlands. Four wetland categories – prairie potholes, shallow lakes, riparian wetlands, and river sediments – were sampled comprising more than 300 wetlands across four states, the majority in North Dakota. Cd, Zn, P, and other elements were analyzed by ICP-MS, in addition to pH and organic matter (as loss-on-ignition). The overall cadmium content was similar to the general concentrations in the area's soils, but distinct patterns occurred within categories. Cd in wetland soils is associated with underlying geology and hydrology, but also strongly with concentrations of P and Zn, suggesting a link with agricultural land use surrounding the wetlands.
Show more [+] Less [-]Characterising metal build-up on urban road surfaces Full text
2013
Egodawatta, Prasanna | Ziyath, Abdul M. | Goonetilleke, Ashantha
Reliable approaches for predicting pollutant build-up are essential for accurate urban stormwater quality modelling. Based on the in-depth investigation of metal build-up on residential road surfaces, this paper presents empirical models for predicting metal loads on these surfaces. The study investigated metals commonly present in the urban environment. Analysis undertaken found that the build-up process for metals primarily originating from anthropogenic (copper and zinc) and geogenic (aluminium, calcium, iron and manganese) sources were different. Chromium and nickel were below detection limits. Lead was primarily associated with geogenic sources, but also exhibited a significant relationship with anthropogenic sources. The empirical prediction models developed were validated using an independent data set and found to have relative prediction errors of 12–50%, which is generally acceptable for complex systems such as urban road surfaces. Also, the predicted values were very close to the observed values and well within 95% prediction interval.
Show more [+] Less [-]Determination and occurrence of secondary alkane sulfonates (SAS) in aquatic environments Full text
2013
Baena-Nogueras, Rosa María | González-Mazo, Eduardo | Lara-Martín, Pablo A.
Determination and occurrence of secondary alkane sulfonates (SAS) in aquatic environments Full text
2013
Baena-Nogueras, Rosa María | González-Mazo, Eduardo | Lara-Martín, Pablo A.
A new methodology has been developed for the determination of secondary alkane sulfonates (SAS), an anionic surfactant, in environmental matrices. Sediment and sludge samples were extracted using pressurized liquid extraction and sonication, whereas wastewater and surface water samples were processed using solid-phase extraction. Extraction recoveries were acceptable for both aqueous (78–120%) and solid samples (83–100%). Determination of SAS was carried out by high or ultra performance liquid chromatography – mass spectrometry using ion trap and time-of-flight detectors. The methodology was applied to samples from Guadalete River (SW Spain), where SAS concentrations below 1 μg L−1 were measured in surface water, and from 72 to 9737 μg kg−1 in sediments. Differential partitioning was observed for SAS homologues as those having a longer hydrocarbon chain which preferentially sorbed onto particulate matter. A preliminary environmental risk assessment also showed that SAS measured levels were not harmful to the aquatic community in the sampling area.
Show more [+] Less [-]Determination and occurrence of secondary alkane sulfonates (SAS) in aquatic environments Full text
Baena Nogueras, Rosa María | González Mazo, Eduardo | Lara Martín, Pablo Antonio | Química Física
A new methodology has been developed for the determination of secondary alkane sulfonates (SAS), an anionic surfactant, in environmental matrices. Sediment and sludge samples were extracted using pressurized liquid extraction and sonication, whereas wastewater and surface water samples were processed using solid-phase extraction. Extraction recoveries were acceptable for both aqueous (78-120%) and solid samples (83-100%). Determination of SAS was carried out by high or ultra performance liquid chromatography e mass spectrometry using ion trap and time-of-flight detectors. The methodology was applied to samples from Guadalete River (SW Spain), where SAS concentrations below 1 mg L 1 were measured in surface water, and from 72 to 9737 mg kg 1 in sediments. Differential partitioning was observed for SAS homologues as those having a longer hydrocarbon chain which preferentially sorbed onto particulate matter. A preliminary environmental risk assessment also showed that SAS measured levels were not harmful to the aquatic community in the sampling area.
Show more [+] Less [-]Mycorrhizal colonization affects the elemental distribution in roots of Ni-hyperaccumulator Berkheya coddii Roessler Full text
2013
Orłowska, Elżbieta | Przybyłowicz, Wojciech | Orlowski, Dariusz | Mongwaketsi, Nametso P. | Turnau, Katarzyna | Mesjasz-Przybyłowicz, Jolanta
The effect of arbuscular mycorrhizal fungi (AMF) on the distribution and concentration of elements in roots of Ni-hyperaccumulating plant Berkheya coddii was studied. Micro-PIXE (particle-induced X-ray emission) analysis revealed significant differences between AMF-inoculated and non-inoculated plants as well as between main and lateral roots. The accumulation of P, K, Mn and Zn in the cortical layer of lateral roots of inoculated plants confirmed the important role of AMF in uptake and accumulation of these elements. Higher concentration of P, K, Fe, Ni, Cu and Zn in the vascular stele in roots of AMF-inoculated plants than in the non-inoculated ones indicates more efficient translocation of these elements to the aboveground parts of the plant. These findings indicate the necessity of including the influence of AMF in studies on the uptake of elements by plants and in industrial use of B. coddii for Ni extraction from polluted soils.
Show more [+] Less [-]Influence of fine process particles enriched with metals and metalloids on Lactuca sativa L. leaf fatty acid composition following air and/or soil-plant field exposure Full text
2013
Schreck, Eva | Laplanche, Christophe | Le Guédard, Marina | Bessoule, Jean-Jacques | Austruy, Annabelle | Xiong, Tiantian | Foucault, Yann | Dumat, Camille
We investigate the effect of both foliar and root uptake of a mixture of metal(loid)s on the fatty acid composition of plant leaves. Our objectives are to determine whether both contamination pathways have a similar effect and whether they interact. Lactuca sativa L. were exposed to fine process particles enriched with metal(loid)s in an industrial area. Data from a first experiment were used to conduct an exploratory statistical analysis which findings were successfully cross-validated by using the data from a second one. Both foliar and root pathways impact plant leaf fatty acid composition and do not interact. Z index (dimensionless quantity), weighted product of fatty acid concentration ratios was built up from the statistical analyses. It provides new insights on the mechanisms involved in metal uptake and phytotoxicity. Plant leaf fatty acid composition is a robust and fruitful approach to detect and understand the effects of metal(loid) contamination on plants.
Show more [+] Less [-]Estimation of main greenhouse gases emission from household energy consumption in the West Bank, Palestine Full text
2013
Abu-Madi, Maher | Rayyan, Ma'moun Abu
The main GHGs (CO2, NOx, and SO2) have been quantified based on national energy and population statistics. The results show that the contribution of households' energy consumption in the West Bank to global CO2 emission is about 0.016%, while contribution of total energy consumption by all sectors is about 0.041%. The results show that wood is the most polluting energy source in terms of CO2 and NOx emission, while electricity is the most polluting source in terms of SO2. Other sources like diesel, kerosene, and LPG that contribute to the GHGs emission are also quantified. The total amounts of CO2, NOx, and SO2 by households in the West Bank are 4.7 million tonne per year, 3.02 thousand tonne per year, and 2.23 thousand tonne per year respectively. This study presents a set of measures that might help in reducing the level of GHGs emission and protect the environment.
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