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Examination of the Dissolved Inorganic Nitrogen Budget in Three Experimental Microbasins with Contrasting Land Cover—A Mass Balance Approach
2010
Onderka, Milan | Pekarova, Pavla | Miklanek, Pavol | Halmova, Dana | Pekar, Jan
A long-term hydrological and water chemistry research was conducted in three experimental microbasins differing in land cover: (1) a purely agricultural fertilized microbasin, (2) a forested microbasin dominated by Carpinus betulus (European hornbeam), and (3) a forested microbasin dominated by Picea abies (L.) (Norway spruce). The dissolved inorganic nitrogen (DIN: NH ₄ ⁺ , NO ₂ ⁻ , NO ₃ ⁻ ) budget was examined for a period of 3 years (1991-1993). Mean annual loads of DIN along with sulfate SO ₄ ²⁻ and base cations Ca²⁺, Mg²⁺, Na⁺, K⁺, and HCO ₃ ⁻ were calculated from ion concentrations measured in stream water, open-area rainfall, throughfall (under tree canopy), and streamwater at the outlets from the microbasins. Comparison of the net imported/exported loads showed that the amount of NO ₃ ⁻ leached from the agricultural microbasin is ∼3.7 times higher (43.57 kg ha⁻¹ a⁻¹) than that from the spruce dominated microbasin (11.86 kg ha⁻¹ a⁻¹), which is a markedly higher export of NO ₃ ⁻ compared to the hornbeam dominated site. Our analyses showed that land cover (tree species) and land use practices (fertilization in agriculture) may actively affect the retention and export of nutrients from the microbasins, and have a pronounce impact on the quality of streamwater. Sulfate export exceeded atmospheric rainfall inputs (measured as wet deposition) in all three microbasins, suggesting an additional dry depositions of SO ₄ ²⁻ and geologic weathering.
Afficher plus [+] Moins [-]Mercury Emission from Anthropogenic Sources in Poland and Their Scenarios to the Year 2020
2010
Glodek, Anna | Panasiuk, Damian | Pacyna, Jozef M.
This paper reviews the current state of knowledge regarding sources of anthropogenic mercury emission in Poland for the year 2005 and presents projection of mercury emission in perspective to the year 2020. These projections are treated separately as emissions from by-product sources and from product use since abatement strategies for these two source categories are very different. Emission projections until the year 2020 were prepared for: Status Quo scenario, Extended Emission Control scenario (EXEC) as well as for Maximum Feasible Technical Reduction scenario (MFTR). The general results were that Hg emission in Status Quo scenario, where no further action is taken to reduce mercury emission is predicted to rise between 2005 and 2020 for by-product sources, as a consequence of growing production of industrial goods and the consumption of raw materials, and is expected to be at the same level for the year 2020 for product use sources in comparison to the base year 2005, where no changes in consumption model were assumed. For EXEC and MFTR scenarios, assuming implementation of efficient control devices and changes in consumption model, decrease of mercury emission from by-product sources is expected between 2005 and 2020. Emission from mercury use in products for these scenarios is also predicted to decrease as a result of drop in mercury consumption. This paper presents also the social benefits for Poland result from Hg emission reduction and considered separately for ingestion and inhalation pathway. The costs and the social benefits related to the reduction of the heavy metals and PM2.5 are also presented.
Afficher plus [+] Moins [-]An Application of Landsat-5TM Image Data for Water Quality Mapping in Lake Beysehir, Turkey
2010
Nas, Bilgehan | Ekercin, Semih | Karabörk, Hakan | Berktay, Ali | Mulla, David J.
The main goal of this study was to investigate spatial patterns in water quality in Lake Beysehir, which is the largest freshwater reservoir in Turkey, by using Landsat-5TM (Thematic Mapper) data and ground surveys. Suspended sediment (SS), turbidity, Secchi disk depth (SDD), and chlorophyll-a (chl-a) data were collected from 40 sampling stations in August, 2006. Spatial patterns in these parameters were estimated using bivariate and multiple regression (MR) techniques based on Landsat-5TM multispectral data and water quality sampling data. Single TM bands, band ratios, and combinations of TM bands were estimated and correlated with the measured water quality parameters. The best regression models showed that the measured and estimated values of water quality parameters were in good agreement (0.60 < R ² < 0.71). TM3 provided a significant relationship (R ² = 0.67, p < 0.0001) with SS concentration. MR between chl-a and various combinations of TM bands showed that TM1, TM2, and TM4 are strongly correlated with measured chl-a concentrations (R ² = 0.60, p < 0.0001). MR of turbidity showed that TM1, TM2, and TM3 explain 60% (p < 0.0001) of the variance in turbidity. MR of SDD showed a strong relationship with measured SDD, with R ² = 0.71 (p < 0.0001) for the ratio TM1/TM3 and TM1 band combinations. The spatial distribution maps present apparent spatial variations of selected parameters for the study area covering the largest freshwater lake and drinking water reservoir in Turkey. Interpretation of thematic water quality maps indicated similar spatial distributions for SS, turbidity, and SDD. A large area in the middle portion of the lake showed very low chl-a concentrations as it is far from point and nonpoint sources of incoming nutrients. The trophic state index values were calculated from chl-a and SDD measurements. Lake Beysehir was classified as a mesotrophic or eutrophic lake according to chl-a or SDD parameters, respectively.
Afficher plus [+] Moins [-]Fractionation and Distribution of Metals in Guadiamar River Sediments (SW Spain)
2010
Santos, Antonio | Santos, Juan Luis | Aparicio, Irene | Alonso, Esteban
Traditionally, the Guadiamar River (Seville, Southwest Spain) has received pollution from two different sources, in its upper section, from a pyrite exploitation (Los Frailes mine) and, in its lower section, from untreated urban and industrial wastes and from intensive agricultural activities. In 1998, the accidental spillage of about 6 million m3 of acid water and sludge from mine tailings to Guadiamar River worsened the pollution of an already contaminated area. The main polluting agents of the spillage were heavy metals. The total concentration of a metal provides scarce information about the effects on environmental processes or about the toxicity of the sediment samples. A more sophisticated fractionation of the sediment samples based on a species distribution can help to understand the behaviour and fate of the metals. This article describes a distribution study of the metals Al, Cd, Cu, Fe, Mn, Pb and Zn by fractionation analysis of sediments from eleven sample sites alongside the Guadiamar Riverbed. The samples were collected in summer 2002, four years after the spillage and after the area had been cleaned. Sequential extraction analysis resulted in the definition of four fraction categories: exchangeable metal (the most available fraction), reducible metal (bound to hydrous oxides of Fe and Mn), oxidizable metal (bound to organic matter and sulphides) and a residual fraction (bound to minerals). Significant increases in the available fraction of several potentially toxic metal ions like Cd, Mn and Zn were found. The distribution pattern was variable along the River. At the site closest to the mineworks, the soluble forms of Cd, Mn and Zn were significantly more abundant that those downstream. Cu and Pb were present in the reducible fraction while Fe was present associated in the residual fraction.
Afficher plus [+] Moins [-]The Pollution Load by Nitrogen and Phosphorus in the Cetina River
2010
Štambuk-Giljanović, Nives
The objective of the investigations of the Cetina River, located in southern Croatia, was to record specific characteristics and properties of the Cetina waters at nine stations. In addition to measurements undertaken in the Cetina River, the water quality of its most significant springs and tributaries, such as Kosinac, Šilovka, Studenci and Mala Ruda, Velika Ruda and Grab, has also been measured. The water quality in the Cetina watershed has been evaluated in the following storage reservoirs: Peruča, Buško Blato and Prančevići. The nitrogen compounds and phosphorus concentrations have been estimated at all these sampling sites over a 3-year period (2005-2008). Concentration levels at the Cetina-Vinalić sampling site for total N (from August 2005 to December 2008) ranged from 0 to 1.759 mg/L, for NH₃-N from 0 to 0.374 mg/L, for NO₃-N from 0.063 to 0.916 mg/L and for PO₄-P from 0 to 0.099 mg/L. The results prove that the Cetina-Vinalić sampling site is not polluted by nitrogen and phosphorus compounds. The river section from Trilj to the Prančevići dam, where the water is used for the water supply of Omiš, Makarska and Dalmatian islands, has been polluted by wastewater because the majority of agricultural area, roads, industry and settlements are located upstream of it. The highest concentration for total N of 1.128 mg/L and of 1,527 total coliforms in 100 mL, expressed as a mean value for a 3-year period of investigations, was found at the sampling site Trilj. The results of concentration changes at the Čikotina Lađa and Cetina Radmanove Mlinice sampling sites show no regularities. The highest concentration for total N of 0.941 mg/L was measured at the Cetina Radmanove Mlinice during 2007. The highest concentration for NO₃-N of 0.916 mg/L was measured at the same sampling site. According to the investigations of the water quality of the Cetina springs and tributaries, the bacteriological most polluted river spring is Kosinac, and the bacteriological most polluted river tributary is Grab. With reference to the water quality in the Cetina storage reservoirs, it may be concluded that the lowest quality standard has been found within the Prančevići storage reservoir regarding nitrogen compounds and phosphorus concentration levels.
Afficher plus [+] Moins [-]Constructed Wetlands Treating Runoff Contaminated with Nutrients
2010
Scholz, M. | Hedmark, Å
The aim was to assess the role of Phragmites australis (Cav.) Trin. ex Steud. in experimental, mature, and temporarily flooded vertical flow wetland filters treating urban runoff rich in organic matter. During the experiment, ammonium chloride was added to sieved concentrated road runoff to simulate primary treated urban runoff contaminated with nitrogen. Five days at 20°C N-allylthiourea biochemical oxygen demand (BOD) and chemical oxygen demand removal efficiencies were relatively lower for planted than unplanted filters. Moreover, there was no significant difference for BOD removal for all filters under fluctuating inflow concentrations of sulfate. The nitrogen removal performances of planted filters were more efficient and stable throughout the seasons compared to those of unplanted filters. A substantial load of nitrogen (approximately 500 mg per filter) was removed by harvesting P. australis. Plant uptake was the main removal mechanism for nitrogen during high concentrations (10 mg/L) of ammonia-nitrogen in the urban runoff.
Afficher plus [+] Moins [-]Lethal Effects of Pulsed High-Voltage Discharge on Marine Plankton and Escherichia coli
2010
Hwang, Chung Yeon | Jung, Soonwook | Hwang, Y. S. | Cho, Byung Cheol
Ballast seawater is considered globally as a major vector for invasions of non-indigenous organisms. Several technologies have been tested for their ability to remove organisms from ballast water. In the present study, we constructed a novel pulsed high-voltage discharge (PHVD) system that could operate in either high current mode with several hundred amperes or shockwave generating mode with relatively lower current in seawater. In laboratory-scale experiments, the PHVD system with shockwave-generating mode was found to be more effective in killing zooplankton (1.9- to 4.0-fold) and phytoplankton (3.3-fold) than high current mode at discharge with 300-500 pulses at 7.1 kV. Further experiments were carried out at different voltages and pulse-numbers to examine effects of the shockwave-generating PHVD system on viabilities of one zooplankton larva, two phytoplankton species, and an indicator bacterium suspended in seawater in a static chamber. For zooplankton, live cells were not detected at discharge with 400 pulses at 13 kV. For phytoplankton, the initial live cells of a dinoflagellate was decreased by 77 ± 0.5%, and the initial chl a concentration of a diatom was decreased by 76 ± 6% at discharge with 700 pulses at 13 kV. For an indicator bacterium Escherichia coli, live cells were not detected at discharges with 200 or 700 pulses at 13 kV. Measurements of ATP content of organisms showed congruent results with those obtained by the above methods, suggesting it may be a rapid method for evaluating treatment efficiency. Though further scale-up studies are necessary, these results suggest that the PHVD system have a high potential for applying to ballast seawater treatment.
Afficher plus [+] Moins [-]Co-disposal of Heavy Metals Containing Waste Water and Medical Waste Incinerator Fly Ash by Hydrothermal Process with Addition of Sodium Carbonate: A Case Study on Cu(II) Removal
2010
Jin, Jian | Li, Xiaodong | Chi, Yŏng | Yan, Jianhua
Fly ash generated from medical waste incinerator and wastewater produced from electroplating plants contains various hazardous contaminants such as heavy metals and chlorinated organic compounds. The primary goal of this research was to investigate the feasibility of removing heavy metals from wastewater using medical waste incinerator fly ash as the treatment reagent with addition of small amount of sodium carbonate (Na₂CO₃) in a hydrothermal process. Copper (Cu) was used as the model heavy metal contaminant in the process. The results revealed that medical waste incinerator fly ash could effectively stabilize Cu(II) ion from wastewater, the crystal phase and simple substance formed during the treatment played a significant role in the fixation of heavy metals in wastewater and fly ash. The heavy metal leachability of treated ash was also measured after removal process. The co-disposal of Cu-containing wastewater and heavy metals-bearing medical waste incinerator fly ash by hydrothermal treatment with addition of a small amount of Na₂SO₃ was found promising as an effective way of removing Cu from wastewater. The reutilization feasibility of fly ash and the formation mechanism of copper-containing substances were also discussed in this paper.
Afficher plus [+] Moins [-]Side Effects of Liming - A Study of Four Dimictic Lakes in Southern Norway
2010
Grøterud, Olav | Haaland, Ståle
Side effects related to liming have been studied in four dimictic lakes (553-642 m a.s.l.; 59°57′N) in Finnemarka, a forested area in Southern Norway with poor catchment buffer capacity. Data series from lake profiles have been sampled two decades apart; 10 years prior to liming and after 10 years of liming. Water samples were collected during spring after ice breakup and during summer after the development of thermal stratification. Before liming, there were very low concentrations of bicarbonate (HCO ₃ ⁻ ; or alkalinity) in the lakes. After 10 years of liming, up to 90% of the ions in hypolimnion originate from lime products. Hence, liming strengthened the chemical stratification and increased the vertical stability. Differences in chemocline developments between lakes were explained by differences in physical properties, i.e. their depth/surface area ratio. The chemocline developments lead to increased concentrations of organic matter in the hypolimnion with a subsequent reduction in oxygen concentrations. Lime additions during late spring, as an alternative to early autumn, lead to pronounced anoxic conditions in the hypolimnion.
Afficher plus [+] Moins [-]Simulation of Groundwater Flow in a Sedimentary Aquifer System Subjected to Overexploitation
2010
Kallioras, Andreas | Pliakas, Fotios | Diamantis, Ioannis
Groundwater flow models are applied to a large variety of hydrogeological conditions in different aquifer types, in order to simulate the groundwater flow of the investigated system. This paper aims to present the application of a groundwater flow model for the simulation of a sedimentary aquifer, located in Northern Greece. The simulation involves the period between April 2003 and April 2004, and the model is divided into two distinct stress periods, each containing two different time steps. The simulation of the aquifer is found to be satisfactory, conclusion which is based on both graphical as well as arithmetical verifications. The groundwater flow simulation was achieved by the application of the MODFLOW code.
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