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Impacts of Pollution from Different Sources on Ecological Quality of a Multiple-use Coast
2008
Wu, Jianyong | Wang, Jinhui
Investigation of pollution sources and their impacts on ecosystems is important, not only for better understanding the responses of an ecosystem to pollutants, but also for making practicable prevention and control plans. In this study, ecological quality of three areas which received different source pollutants in Shanghai coast were evaluated and compared in four seasons using Shannon-Wiener index (H'), a benthic diversity index as an indicator of ecological quality of coastal waters. The genotoxicity and physical-chemical variables of water samples were also analyzed. The H' value indicated the ecological quality of Shanghai coastal waters was seriously impacted, and the ecological quality of two areas receiving waste discharges were significantly worse than that of the natural protection zone but not significantly different in four seasons. The positive genotoxic response was detected in most samples from two discharge zones but not detected in the samples from the natural protection zone. However, no significant difference was observed in water quality variables in the different coastal areas. Our study suggested that the point source pollution had significantly contributed to the genotoxicity of the coastal waters and impaired benthic assemblages, while the deterioration of ecological quality status was also critically impacted by the stressors from other sources.
Afficher plus [+] Moins [-]Toxicity of Lead to Freshwater Invertebrates (Water fleas; Daphnia magna and Cyclop sp) in Fish Ponds in a Tropical Floodplain
2008
Offem, Benedict O. | Ayotunde, Ezekiel O.
Acute toxicity of Pb to the water flea; (Daphnia sp) and Copepod, (Cyclop sp) both important component of zooplankton diet of fish was determined by static assay. A positive relationship between percentage mortality and exposure concentration was found in all tests. Mean 24-h LC50, 48-h LC50 and 96-h LC50 values were 2.51 ± 0.0.04 mg l⁻¹, 1.88 ± 0.06 mg l⁻¹ and 1.65 ± 0.19 mg l⁻¹ for Daphnia spp and 3.11 ± 0.03 mg l⁻¹, 2.97 ± 0.05 mg l⁻¹ and 2.61 ± 0.09 mg l⁻¹ for Cyclop spp, respectively. For all tested species did the LC50 values decrease with time; the decrease was more marked for Daphnia spp. Observed symptoms include spiral movement followed by change of body colour to white and rapid disintegration of the skin. The Daphnia spp. appear to be more sensitive to Pb poison than Cyclop spp. The results showed that concentrations of Lead (Pb) in excess of 0.19 mg l⁻¹ and 0.30 mg l⁻¹ can be potentially harmful to Daphnia magna and Cyclop spp respectively.
Afficher plus [+] Moins [-]Speciation of Zinc and Copper in Stormwater Pavement Runoff from Airside and Landside Aviation Land Uses
2008
Gnecco, I. | Sansalone, J. J. | Lanza, L. G.
The transport, bioavailability and fate of aqueous metals in rainfall-runoff are determined, in part, by speciation. In the framework of a monitoring program to investigate the predominant species of zinc, copper, and water chemistry in runoff subject to aviation land use and activities, two rainfall-runoff monitoring stations were installed at the international airport of Genoa (Italy). One catchment was a boarding area (airside) apron and the other a parking area for vehicles (landside). Utilizing water chemistry analyses, ion balances and speciation modelling for a series of five event loadings for each site, results indicated that Zn²⁺ dominated Zn speciation and Cu complexes with carbonate or dissolved organic matter, dominated Cu speciation. With respect to wash-off processes a mass limited behaviour was generally observed for particulate matter (measured as TSS) and TOC; while the mass delivery of aqueous metal species tended to be more proportionate with respect to runoff volume.
Afficher plus [+] Moins [-]Assessment of the Impact Produced by the Traffic Source on VOC Level in the Urban Area of Canosa di Puglia (Italy)
2008
Bruno, Paolo | Caselli, Maurizio | de Gennaro, Gianluigi | Scolletta, Lucia | Trizio, Livia | Tutino, Maria
Volatile organic compounds (VOC) have been monitored in 12 sites of Canosa di Puglia, a city located in the Southern of Italy, in order to identify the main VOC source--vehicular traffic or industrial--and to evaluate the critical situations in the city. Monitoring, carried out by using Radiello® diffusive samplers, has been planned taking into account the traffic density and the architecture of the city. From the study of the data it has been emerged that, among all considered VOC, benzene, toluene, ethylbenzene and xylenes (BTEX) are the pollutants at higher concentration. However no critical situation has appared from the present monitoring. Maps of daily benzene and toluene concentrations have shown that the most significant pollution phenomena happens in the center of the urban area which is in a valley with narrow roads and high buildings that do not allow an efficient dispersion of pollutants. The study of the diagnostic ratios between the toluene and benzene concentrations in the several areas (average T/B = 3.4) and the high Pearson's coefficient among the pollutants, and in particular between benzene and toluene concentrations (r = 0.9505), have suggested that in urban area these pollutants are emitted from the same source: the vehicular traffic.
Afficher plus [+] Moins [-]Environmental Controls on the Fate of Escherichia coli in Soil
2008
Habteselassie, M. | Bischoff, M. | Blume, E. | Applegate, B. | Reuhs, B. | Brouder, S. | Turco, R. F.
An improved understanding of factors that influence the survival and/or growth of Escherichia coli (E. coli) in soil is essential to allow the formation of land management practices to control the spread of the pathogenic strains of the bacteria, whose transmission to fresh produce is a threat to food safety. Persistence of E. coli in soils held at different water potentials and with carbon additions then subjected to post-freezing incubation temperatures and in the presence of Klebsiella terrigena (K. terrigena) were investigated. Soil samples adjusted to different water potentials (-0.03, -0.1 and -1.5 MPa) were inoculated with a multi-antibiotic resistant strain of E. coli (E. coli 2+), which allowed recovery of the organism from soil samples. In addition to manipulation of water content, different C levels were added and samples were frozen for varying lengths of time, thawed and incubated. In freezing studies, initial soil moisture content significantly affected E. coil 2+ survival in soils following thawing, resulting in lower survival rate (k) at water potential of -0.03 than at -0.1 and -1.5 MPa. The effect of length of freezing time was significant only at -0.03 MPa. Glucose addition at 1.25 mg C g⁻¹ improved survival rate versus glucose at 0.125. The low level glucose increased die-off rate versus no addition, suggesting that unless amendments provide C above a certain threshold level, they might facilitate the death of the bacteria. E. coli 2+ survival improved in the presence of K. terrigena at 6°C but not at 23°C. Persistence of E. coli under the interactive influence of various environmental factors highlights the urgency and importance of understanding its potential for transmission to fresh produce and water bodies.
Afficher plus [+] Moins [-]Freshwater Fish Mercury Concentrations in a Regionally High Mercury Deposition Area
2008
Hutcheson, Michael S. | Smith, C Mark | Wallace, Gordon T. | Rose, Jane | Eddy, Barbara | Sullivan, James | Pancorbo, Oscar | West, Carol Rowan
We sampled and analyzed individually, edible dorsal muscle from largemouth bass (LMB), Micropterus salmoides (n = 138) and yellow perch (YP), Perca flavescens (n = 97) from 15 lakes to investigate potential local impacts of mercury emission point sources in northeastern Massachusetts (MA), USA. This area was identified in three separate modeling exercises as a mercury deposition hotspot. In 1995, 55% of mercury emissions to the environment from all MA sources came from three municipal solid waste combustors (trash incinerators) and one large regional medical waste incinerator in the study area. We determined the mercury accumulation history in sediments of a lake centrally located in the study area. Recent maximum mercury accumulation rates in the sediment of the lake of ~ 88 μg/m²/year were highly elevated on a watershed area adjusted basis compared to other lakes in the Northeast and Minnesota. Fish from the study area lakes had significantly (p = 0.05) greater total mercury concentrations than fish from 24 more rural, non-source-impacted lakes in other regions of the state (LMB n = 238, YP n = 381) (LMB: 1.5–2.5 x; YP: 1.5 x). The integration of this extensive fish tissue data set, depositional modeling projections, historical record of mercury accumulation in sediments of a lake in the area, and knowledge of substantial mercury emissions to the atmosphere in the area support designation of this area as a mercury depositional and biological concentration hotspot in the late 1990s, and provides further evidence that major mercury point sources may be associated with significant local impacts on fisheries resources.
Afficher plus [+] Moins [-]Biosorption of Chromium (III) and Chromium (VI) by Untreated and Pretreated Cassia fistula Biomass from Aqueous Solutions
2008
ʻAbbās, Maẓhar | Nadeem, Raziya | Zafar, Muhammad Nadeem | Arshad, Mamoona
The present study explained the effect of pretreatments on the biosorption of Cr (III) and Cr (VI) by Cassia fistula biomass from aqueous solutions. For this purpose Cassia fistula biomass was pretreated physically by heating, autoclaving, boiling and chemically with sodium hydroxide, formaldehyde, gluteraldehyde, acetic acid, hydrogen peroxide, commercial laundry detergent, orthophosphoric, sulphuric acid, nitric acid, and hydrochloric acid. The adsorption capacity of biomass for Cr (III) and Cr (VI) was found to be significantly improved by the treatments of gluteraldehyde (95.41 and 96.21 mg/g) and benzene (85.71 and 90.81 mg/g) respectively. The adsorption capacity was found to depend on pH, initial metal concentration, dose, size, kinetics, and temperature. Maximum adsorption of both the Cr (III) and Cr (VI) was observed at pH 5 and 2. When Freundlich and Langmuir isotherms were tested, the latter had a better fit with the experimental data. The kinetic studies showed that the sorption rates could be described better by a second order expression than by a more commonly applied Lagergren equation.
Afficher plus [+] Moins [-]Effect of Microorganisms on the Sorption of Lanthanides by Quartz and Goethite at the Different pH Values
2008
Perelomov, L. V. | Yoshida, S.
The effect of Rhodopseudomonas pallustris bacterium on the sorption of 16 isotopes of lanthanides by quartz and goethite at different pHs values was studied. pH of sorption solution and affinity of elements to surface seems to be most important parameters in the interactions between metal ions and surfaces of biological and mineral sorbents. At acidic (pH°4) and neutral (pH°7) conditions these interactions was affected by electrostatic forces; at alkaline conditions (pH°9) the mechanism of lanthanides precipitation was dominant. Microorganisms sufficiently affected on lanthanides sorption by quartz at acidic and neutral conditions, but largest one was at pH°7. They increased sorption of all elements by goethite at pH°4. There was negligible effect of bacteria on the sorption of lanthanides at pH°7 and 9 by goethite that demonstrates greater affinity of the elements to goethite surface. Microorganisms increased concentration of lanthanides in the nonexchangeable states on the surfaces of quartz at pH°7 and 9, and on the surface of goethite at pH°7 in comparison to the minerals alone. It may be attributed to formation of low-soluble complexes of lanthanides with organic substances, produced by bacterium.
Afficher plus [+] Moins [-]Using Synchronous Fluorescence Technique as a Water Quality Monitoring Tool for an Urban River
2008
Hur, Jin | Hwang, Soon-Jin | Shin, Jae-Ki
The development of a monitoring tool for predicting water quality and tracing pollution sources are important for the management of sustainable aquatic ecosystems in urban areas. In this study, synchronous fluorescence technique was applied to 18 sampling sites of a typical urban watershed in Korea, some of which are directly affected by the effluent from a wastewater treatment plant (WWTP), to investigate the capability of the technique for biochemical oxygen demand (BOD) prediction and source discrimination. Sampling was conducted three times at the same sites during the low flow period between October and November, 2005. Protein-like fluorescence intensities of the samples showed a positive linear relationship with the BOD values (Spearman’s rho = 0.90, p < 0.0001). The BOD prediction capability was superior to other monitoring tools such as UV absorption and conductivity measurements particularly for the upstream sites from the WWTP, which ranged from 0.0 to 5.0 mg/l as BOD. The protein-like fluorescence and a ratio of protein-like/fulvic-like fluorescence were suggested as good fluorescence signatures to discriminate different sources of dissolved organic matter (DOM). The samples collected from four different DOM source regions including upstream sites from the WWTP, downstream sites, discharge from a reservoir, and headwater were distinguished from one another by varying ranges of the two selected fluorescence signatures. Our results suggest that the synchronous fluorescence technique has the potential to be developed into a real-time water quality management tool for the comprehensive monitoring of urban rivers.
Afficher plus [+] Moins [-]Anthropogenic lead distribution in soils under arable land and permanent grassland estimated by Pb isotopic compositions
2008
Fernandez, Christelle | Monna, Fabrice | Labanowski, Jérome | Loubet, Michel | Van Oort, Folkert
The role of land use on fate of metals in soils is poorly understood. In this work, we studied the incorporation of lead in two neighboring soils with comparable pedogenesis but under long-term different agricultural management. Distributions of anthropogenic Pb were assessed from concentrations and isotopic compositions determined on bulk horizon samples, systematical 5–10 cm increment samples, and on 24-h EDTA extracts. Minor amounts of anthropogenic lead were detected until 1-m depth under permanent grassland, linked to high earthworm activity. In arable land, exogenous Pb predominantly accumulated at depths <60 cm. Although the proximity between the two sites ensured comparable exposition regarding atmospheric Pb deposition, the isotopic compositions clearly showed the influence of an unidentified component for the cultivated soil. This work highlights the need for exhaustive information on historical human activities in such anthropized agrosystems when fate of metal pollution is considered.
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