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Testing a Soil Magnetometry Technique in a Highly Polluted Industrial Region in North-Eastern Germany 全文
2009
Fürst, Christine | Lorz, C (Carsten) | Makeschin, Franz
The paper presents the results of a study in the region Dübener Heide (Central Germany) testing the suitability of field measurements of magnetic susceptibility for the detection of historical fly-ash deposition. The measurements supported the verification of historically documented deposition zones along an emission gradient. Mean values, standard deviation, and coefficient of variation can be used to characterize the former deposition zones, although the study revealed several problems, which will be the subject of future work: (1) the volume susceptibility measurements used in the study do not allow the calculation of the actual fly-ash amount stored in the soil and thus must be calibrated with correction factors from laboratory measurements; and (2) measurements in regions with similar conditions but without fly-ash deposition are needed to obtain reference values for the natural range of magnetic susceptibility.
显示更多 [+] 显示较少 [-]Degradation Kinetics of an Aged Hydrocarbon-Contaminated Soil 全文
2009
Maletić, Snežana | Dalmacija, Božo | Rončević, Srđan | Agbaba, Jasmina | Petrović, Olgica
This work presents kinetic parameters for the degradation of petroleum hydrocarbons, under field conditions found in a biopile created for the remediation of soil which has been heavily polluted with aged oil and oil derivatives (27,600 mg kg⁻¹ of mineral oil, 41,400 mg kg⁻¹ total hydrocarbons and 3.57 mg kg⁻¹ of total polycyclic aromatic hydrocarbon, (PAH)). The kinetics of the biodegradation process can be described by two equations: [graphic removed] (1) and [graphic removed] (2). According to Eq. 1, biodegradation kinetics constant rates were in the range from 0.58 x 10⁻³ to 1.32 x 10⁻³ day⁻¹ for mineral oil and total hydrocarbons and 6.7 x 10⁻³ to 8.8 x 10⁻³ day⁻¹ for PAHs. According to Eq. 2, biodegradation kinetics constant rates were in the range from 1.6 x 10⁻² to 3.0 x 10⁻² day⁻⁰.⁵ for mineral oil and total hydrocarbons and 0.92 x 10⁻¹ to 1.3 x 10⁻¹ day⁻⁰.⁵ for PAHs.
显示更多 [+] 显示较少 [-]A Valuation of the Influence of Particulate Atmospheric Aerosol in Constructions of the Cultural and Architecture Patrimony of the Urban Area of Castellon (NE, Spain) 全文
2009
Jordan, M. M. | Sanfeliu, T. | Gómez, E. T. | Pallarés, S. | Vicente, A. B.
The constructions of Cultural and Architecture Patrimony are influenced by pollutants. Many of degenerative processes in the materials which constitute them have their origin in pollutants. That is the reason why a physical-chemical characterisation of the particulate pollutants in the air has been carried out. The deposition and, as a consequence of that, the interaction of the pollutants with the different materials of the monuments depend on the reactivity of the chemical elements that form the atmospheric particulate. Studies of both, bulk dust deposition and total suspended matter, a mineralogical and chemical characterisation of them have been made. Lastly, starting from these data, it can be established that the interactions and degenerative processes are taking place in the monuments of the studied locations. In the present work, the methodology carried out in the study of the particulate atmospheric pollutants, which are capable of accumulating on monuments and buildings with artistic and historical interest in the area of Castellon, is displayed. By means of a network of captors, important samples of sedimentary and suspension atmospheric pollutants, total suspension particles (TSP) were obtained. Firstly, by gravimetric methods, we have obtained the concentration levels of these kinds of pollutants in milligrams per day in busk dust samples and micrograms per cubic meter in TSP. Due to the fact that the corrosivity of these pollutants fundamentally depends on their compositions, the study has been completed with a mineralogical and chemical characterisation. By X-ray diffraction and scanning electron microscopy, we have analysed the particles of the two kinds of samples. The chemical analysis was carried out by inductively coupled plasma-atomic spectroscopy and inductively coupled plasma-mass spectrometry (multielement analysis techniques) in TSP samples and in the soluble fraction of the depositing particulate matter. The results have shown as main compounds: clay minerals, calcite, and carbonaceous matter coming from non-perfect combustion of vehicles. The chemical analysis indicates a high Ca/S ratio and high levels of concentration in chemical elements associated to this representative industrial cluster of ceramics industry in Europe.
显示更多 [+] 显示较少 [-]Changes in Rainwater pH associated with Increasing Atmospheric Carbon Dioxide after the Industrial Revolution 全文
2009
Bogan, Robert A. J. | Ohde, Shigeru | Arakaki, Takeshi | Mori, Ikuko | McLeod, Cameron W.
This paper examines the historical change in the pH of natural rainwater due to increased atmospheric CO₂ from 1800 until 2007, giving predicted change in 2100. During 1800-2007, the rainwater pH at 25°C and 1 atm is calculated to decrease by 0.06 units, from 5.68 to 5.62. In 2100, the predicted rainwater pH is calculated at 5.49 using the projected pCO₂ (700 ppmv; IS92a) at 25°C and 1 atm. Equilibrium calculations were made in an attempt to elucidate the calcium carbonate (calcite) dissolution by rainwater. From 1800 to 2007, the dissolution of calcite with pCO₂ of those time at 25°C and 1 atm increase the dissolved calcium concentration from 466 to 516 μmol kg⁻¹. This value is calculated to reach 633 μmol kg⁻¹ in the year 2100. Rainwater is found to become more acidic with decreasing temperature. In the year 2007 (pCO₂ = 384 ppmv), a total difference of 0.08 units in rainwater pH is calculated between areas at 0°C and 30°C. The equilibrium pH with respect to calcite was found to increase with decreasing temperature. At lower temperatures, rainwater pH is found to decrease, whilst CaCO₃ dissolution increases. Limestone landmarks and buildings might be affected through the dissolution of calcium carbonate by rainwater acidification. The effects of rainwater acidification on overall chemical weathering may result in influences on agriculture, forestry, landslides and flooding.
显示更多 [+] 显示较少 [-]Mobilisation and Transport of Sediment-Associated Phosphorus by Surface Runoff 全文
2009
Ballantine, Deborah | Walling, Desmond E. | Leeks, Graham J. L.
Surface runoff transporting sediment with high phosphorus (P) concentrations has been identified as a major hydrological pathway for sediment-associated P delivery to surface waters and is considered a major threat to water quality, due to the ability of P to cause eutrophication in fresh water. Not all P-rich sediment that is mobilised by erosion will however be delivered directly to the channel. Some may instead be deposited in intermediate storage away from its source area. The aim of this contribution was to determine the influence of land use and soil type on the P content of surface runoff sediment and sediment deposited in intermediate storage and was undertaken in the largely agricultural and rural catchments of the Rivers Frome and Piddle in Dorset, UK. The study formed part of a larger investigation of hydrological and hydrogeochemical processes and fluxes in lowland permeable catchments in the UK (LOCAR). Soil samples were collected from the main land use types; freshly deposited sediment was sampled from ditches, hedge boundaries and depressions in fields, and sediment-laden runoff was collected during heavy rainfall events. The concentrations of total phosphorus (TP) and the P fractions found in the surface runoff sediment were significantly different from those measured in the original source soils, with a greater degree of enrichment associated with surface runoff sediment from cultivated land than from pasture land. For cultivated land, concentrations of TP and the P fractions in deposited sediment were higher than those in the original source material, while for pasture soils, concentrations of TP and the P fractions tended to be lower than in the original source soils. The relative importance of the P fractions associated with surface runoff sediment and sediment deposits also differed from that for the original soil samples. Surface runoff sediment was finer than source pasture and cultivated soils, reflecting the particle size selectivity of sediment mobilisation and transport. Soil physical properties and land use can both influence the P content of surface runoff and deposited sediment.
显示更多 [+] 显示较少 [-]Determination of Heavy Metals and Comparison to Gross Radioactivity Concentration in Soil and Sediment Samples of the Bendimahi River Basin (Van, Turkey) 全文
2009
Selçuk Zorer, Özlem | Ceylan, Hasan | Doğru, Mahmut
An investigation of radioactivity and some heavy metal distribution in soil and sediment of the river basin (Bendimahi River, Van-Turkey) was conducted in two seasons of 2005. The samples of soil and sediment were collected from the basin and investigated for concentrations of some heavy metal and natural radioactivity. Concentrations of Pb, Cr, Mn, Fe, Co, Cu, Zn and Cd have been determined by Atomic Absorption Spectrometry (AAS), gross-alpha and gross-beta activity concentrations have been obtained by using gas-flow proportional counter in nuclear spectroscopic system. Correlation analysis was made for radioactivity and heavy metal concentrations and the Pearson correlation coefficients between gross-alpha and gross-beta radioactivity and heavy metal were determined.
显示更多 [+] 显示较少 [-]Reduction of Hexavalent Chromium in Soil and Ground Water Using Zero-Valent Iron Under Batch and Semi-Batch Conditions 全文
2009
Franco, Débora V. | Da Silva, Leonardo M. | Jardim, Wilson F.
Chemical remediation of soil and groundwater containing hexavalent chromium (Cr(VI)) was carried out under batch and semi-batch conditions using different iron species: (Fe(II) (sulphate solution); Fe⁰ G (granulated elemental iron); ZVIne (non-stabilized zerovalent iron) and ZVIcol (colloidal zerovalent iron). ZVIcol was synthesized using different experimental conditions with carboxymethyl cellulose (CMC) and ultra-sound. Chemical analysis revealed that the contaminated soil (frank clay sandy texture) presented an average Cr(VI) concentration of 456 ± 35 mg kg⁻¹. Remediation studies carried out under batch conditions indicated that 1.00 g of ZVIcol leads to a chemical reduction of ~280 mg of Cr(VI). Considering the fractions of Cr(VI) present in soil (labile, exchangeable and insoluble), it was noted that after treatment with ZVIcol (semi-batch conditions and pH 5) only 2.5% of these species were not reduced. A comparative study using iron species was carried out in order to evaluate the reduction potentialities exhibited by ZVIcol. Results obtained under batch and semi-batch conditions indicate that application of ZVIcol for the “in situ” remediation of soil and groundwater containing Cr(VI) constitutes a promising technology.
显示更多 [+] 显示较少 [-]Evaluation of Coal Fly Ash-Based Synthetic Aggregates as a Soil Ameliorant for the Low Productive Acidic Red Soil 全文
2009
Jayasinghe, G. Y. | Tokashiki, Y. | Kitou, M.
A potential new way of producing coal fly ash-based granular synthetic aggregates (CSA) using waste coal fly ash (CFA), paper waste, lime, and gypsum and their utilization as a soil ameliorant to improve crop production in low productive acidic red soil in Okinawa, Japan were studied. The red soil was amended with CSA at three different mixing ratios (i.e., CSA/soil—1:1, 1:5, and 1:10) for the cultivation of Brassica rapa var. Pervidis commonly known as Komatsuna, and the physico-chemical parameters of CSA-soil mixtures and plant growth were analyzed. Incorporation of CSA to the red soil improved the physical and chemical properties of the soil such as water holding capacity, hydraulic conductivity, bulk density, pH, exchangeable cation concentration, cation exchange capacity, particle size distribution, soil pH, electrical conductivity, and carbon content. CSA amendment at ratios of 1:1, 1:5, and 1:10 decreased bulk density by 29.39%, 14.28% and 11.11%, respectively, compared to the original red soil. The acidic pH of the red soil (5.12) was increased to 7.13 and 6.37 by CSA/soil ratios of 1:5 and 1:10, respectively. CSA amendment in soil at 1:5 ratio increased water holding capacity, saturated hydraulic conductivity, electrical conductivity, cation exchange capacity, carbon, potassium (K), magnesium (Mg), and calcium (Ca) content by 0.06 kg kg⁻¹, ten times, 15.95 mS m⁻¹, 1.76 cmolc kg⁻¹, 6.07 g kg⁻¹, 0.42 g kg⁻¹, 0.24 g kg⁻¹, and 3.38 g kg⁻¹, respectively, in comparison to the original red soil. Heavy metal contents of the CSA-soil mixtures were below the maximum pollutant concentrations suggested by the US Environmental Protection Agency. Moreover, Na, K, Mg, Ca, copper (Cu), and zinc (Zn) contents in the CSA-soil mixtures increased in comparison with the original red soil. CSA amendment in soil at the ratio of 1:5 and 1:10 resulted in an increase in plant height and plant fresh weight by three and 12 times, respectively, and there was increase in N, K, Mg, Ca, Cu, and Zn contents of the shoots. The results suggest that utilization of eccentric CSA as soil amendment agent can be regarded as an effective waste management practice.
显示更多 [+] 显示较少 [-]Long-term Performance of a Permeable Reactive Barrier in Acid Sulphate Soil Terrain 全文
2009
Regmi, Gyanendra | Indraratna, Buddhima | Nghiem, Long Duc
Deep drainage technique utilised for flood mitigation in low-land coastal areas of Australia during the late 1960s has resulted in the generation of sulphuric acid in soil by the oxidation of pyritic materials. Further degradation of the subsurface environment with widespread contamination of the underlying soil and groundwater presents a major and challenging environmental issue in acid sulphate soil (ASS) terrains. Although several ASS remediation techniques recently implemented in the floodplain of Southeast Australia including operation of gates, tidal buffering and lime injections could significantly control the pyrite oxidation, they could not improve the long-term water quality. More recently, permeable reactive barriers (PRBs) filled with waste concrete aggregates have received considerable attention as an innovative, cost-effective technology for passive in situ clean up of groundwater contamination. However, long-term efficiency of these PRBs for treating acidic groundwater has not been established. This study analyses and evaluates the performance of a field PRB for treating the acidic water over 2.5 years. The pilot-scale alkaline PRB consisting of recycled concrete was installed in October 2006 at a farm of southeast New South Wales for treating ASS-impacted groundwater. Monitoring data of groundwater quality over a 30 month period were assessed to evaluate the long-term performance of the PRB. Higher pH value (~pH 7) of the groundwater immediately downstream of the PRB and higher rates of iron (Fe) and aluminium (Al) removal efficiency (>95%) over this study period indicates that recycled concrete could successfully treat acidic groundwater. However, the overall pH neutralising capacity of the materials within the barrier declined with time from an initial pH 10.2 to pH 7.3. The decline in the performance with time was possibly due to the armouring of the reactive material surface by the mineral precipitates in the form of iron and aluminium hydroxides and oxyhydroxides as indicated by geochemical modelling.
显示更多 [+] 显示较少 [-]A New and Sound Technology for Biogas from Solid Waste and Biomass 全文
2009
Busch, G | Großmann, J | Sieber, M | Burkhardt, M
Organic waste, as a main constituent of municipal solid waste, has as well as solid biomass a high potential for biogas generation. Despite the importance of biogas generation from these materials, the availability of large-scale biogas processes lacks behind the demand. A newly developed double-stage solid-liquid biogas process, consisting of an open hydrolysis stage and a fixed-bed methane reactor, allows the biogas production from almost all biodegradable solid waste and renewable resources like maize, grass, sugar cane, etc. Furthermore, residues from industrial processes, like the glycerine waste water from biodiesel production, can also be converted into biogas successfully. Due to the strong separation of hydrolysis and methanation, the process is extremely stable. No malfunction has been detected so far. The open hydrolysis releases CO₂ and allows oxidation of sulfur. Consequently, the biogas has a high methane (>72%) and low H₂S concentration (<100 ppm). Stirrers or other agitation equipment are not necessary; only liquids are pumped. The biogas generation becomes controllable for the first time; thus, the actual generation can be easily adapted to the consumption.
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