Search results for "environmental engineering"
showing 10 items of 2674 documents
The combined effect of CO2, ozone, and drought on the radical scavenging system of young oak trees (Quercus petraea) — A phytothron study
1998
In order to study the combined effects of CO 2 , ozone, and drought, we simulated in a controlled environment the climatic conditions of a German oak stand with high ozone (daytime: 80 ppb, control: 20 ppb) during one vegetative period under a regime of low and high CO 2 concentration (370 vs 720 ppm) and drought (4 weeks < -800 hPa). To investigate the effects of CO 2 , ozone and drought on the radical scavenging system, we monitored the level of glutathione, ascorbate, and α-tocopherol. However, it is important that, under the regime of elevated CO 2 , the antioxidative behaviour of glutathione and ascorbate appears to be masked by their function as storage molecules for sulfur or carbon.
Microbes and Persistent Organic Pollutants in the Marine Environment
2020
Marine pollution has increased reaching the entire marine environment, from the surface to the deepest sediment, and has become more concerning in the last 70 years. Persistent organic pollutants (POPs) are a fraction of ocean waste that includes, among the others, polycyclic aromatic hydrocarbons (PAHs) and plastic polymers. These chemicals have an extremely long half-life, and (bio)accumulate and damage the marine flora and fauna, and, ultimately, human health. Some organisms have evolved enzymes to attack POPs in the environment and transform them into biomass and CO2. Several microorganisms degrade many POPs in relatively short time. A wide variety of bacteria has been isolated with dif…
Chloroaromatic pollutants in mussels incubated in two finnish watercourses polluted by industry
1997
Abstract Concentrations of different chlorinated compounds were measured in mussels incubated in two polluted watercourses, a river (the River Kymijoki) and a lake (Lake Vanaja) for four weeks in summer 1995. The sum concentrations of polychlorinated phenols (PCP) and biphenyls (PCB) were both about 1 μg/g lipid weight (lw) in Lake Vanaja mussels, while in the River Kymijoki mussels PCPs were non-detectable and PCBs were measured 120 ng/g lIw. The concentrations of toxic polychlorinated dibenzo- p -dioxin (PCDD) and dibenzofuran (PCDF) congeners ranged between
Leaf Biosorbents for the Removal of Heavy Metals
2018
The presence of heavy metals in waters is a global concern. Among various remediation technologies, biosorption is an attractive and promising process since in many cases, it is fast, selective, and highly efficient. Other advantages, such as applicability for various types of pollutants, simplicity, low cost, ease of operation, and the potential reusability of the adsorbents, make it beneficial. Nowadays, more and more green materials, raw or modified, are inclined to be explored instead of conventional adsorbents, within concept of Green Chemistry. This review focuses on the use of leaves-based biosorbents in raw or modified forms to sequestrate heavy metals from waters and wastewaters.
Assessing changes in eco-productivity of wastewater treatment plants: The role of costs, pollutant removal efficiency, and greenhouse gas emissions
2018
Abstract Improving eco-efficiency of wastewater treatment plants (WWTPs) has been identified as being essential for achieving urban sustainability. Several previous papers have evaluated the eco-efficiency of WWTPs using data envelopment analysis (DEA) models. However, those models provided only a static assessment in that they ignored possible fluctuations over time within each plant. To overcome this temporal limitation, this paper evaluates dynamic eco-efficiency (changes in eco-productivity over time) of WWTPs using the dynamic weighted Russell directional distance model (WRDDM). This approach allows one to obtain an eco-productivity change index for each major component of the WRDDM mo…
Platinum and rhodium associated with the leaves of Nerium oleander L.; analytical method using voltammetry; assessment of air quality in the Palermo …
2009
Abstract A rapid accumulation of the catalytic active noble metals in the environmental and biological matrices was observed and concern arose about potential environmental and health risks. The development of reliable analytic methods to measure very low Pt and Rh concentrations is required. The main purpose of this work was to develop a reliable method for the determination of Pt and Rh in environmental matrices because of inherent difficulties in using conventional techniques used, in particular, the ICP-OES technique. A direct determination of Pt using ICP-MS, for instance, is problematic, due to interfering signals. In this work, differential pulse voltammetry (DPV/a) and adsorptive st…
Evaluation of organic compound source and natural attenuation, Liepaja Latvia
2004
Liepaja harbor is a former Soviet military site. Remediation of the harbor basin, including dredging of the sediments heavily contaminated with petroleum hydrocarbons and heavy metals is necessary to convert the harbor for civilian use. Abandoned pollution sources on land still continue to leach contaminants into the harbor basin. Our long-term research objective therefore is to identify transport pathways into the harbor sediments and to assess the in-situ degradation of pollutants in the system. The Liepaja harbor is treated as a complex system, where processes in the water column interact with the sediments and the nepheloid sediment boundary layer. For this research PAHs are used as the…
Traffic-related pollutants in roadside soils of different countries in Europe and Asia
2015
We investigated the magnetic and chemical properties of the roadside soil samples collected from five European and Asian countries. Spots in which cars slowed down and/or accelerated due to the traffic organization (speed limits, junctions, and traffic lights) were selected for sampling. Apart from the Zabrze site (Poland), the magnetic susceptibility and heavy metal contents decreased with increasing distance from the road edge. The highest mass-specific magnetic susceptibility values (χ) were observed in the samples collected from Mumbai (India) and Zabrze (Poland). Moreover, the high contents of Fe, Ni, Mn, and Co were observed in Mumbai, whereas in Zabrze, all the examined elements demo…
Evaluation of the Soil Contamination of Tangier (Morocco) by the Determination of BTEX, PCBs, and PAHs
2009
Benzene, toluene, ethylbenzene, and xylenes (BTEX), twelve polycyclic aromatic hydrocarbons (PAHs) and seven polychlorinated biphenyls (PCBs), were selected as pollutants to evaluate the contamination of soils in the urban and industrial areas of Tangier (Morocco). PAHs and PCBs were determined by gas chromatography-mass spectrometry (GC-MS) after a microwave-assisted extraction (MAE) and gel permeation chromatography (GPC) clean-up. BTEX were directly determined by head-space GC-MS. Results obtained in this study show the presence of high levels of BTEX and PAHs in the soil near the urban waste deposit. However, the analysis of pollutants in the other sampling sites provided comprehensive …
Pb-210 isotope as a pollutant emission indicator= Izotop Pb-210 jako znacznik emisji zanieczyszczeń
2015
Abstract Passive biomonitoring using 210Pb was used in the paper to evaluate pollutant deposition. Well-developed epiphytic foliose lichens Hypogymnia physodes growing on spruce branches were used in the studies. The samples of mosses Pleurozium schreberi and soil (raw humus) were collected from the area around the tree from which the samples of lichens were collected. The studies have shown that it is possible to identify dust emission sources using a radioactive lead isotope (210Pb). The highest activity of 210Pb was observed in areas with increased deposition of other pollutants, such as Ni, Cd, Cu and Pb, which may indicate that 210Pb is one of the emission components