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Sample records for landfill cover soils

  1. Characterization of H2S removal and microbial community in landfill cover soils.

    PubMed

    Xia, Fang-Fang; Zhang, Hong-Tao; Wei, Xiao-Meng; Su, Yao; He, Ruo

    2015-12-01

    H2S is a source of odors at landfills and poses a threat to the surrounding environment and public health. In this work, compared with a usual landfill cover soil (LCS), H2S removal and biotransformation were characterized in waste biocover soil (WBS), an alternative landfill cover material. With the input of landfill gas (LFG), the gas concentrations of CH4, CO2, O2, and H2S, microbial community and activity in landfill covers changed with time. Compared with LCS, lower CH4 and H2S concentrations were detected in the WBS. The potential sulfur-oxidizing rate and sulfate-reducing rate as well as the contents of acid-volatile sulfide, SO4 (2-), and total sulfur in the WBS and LCS were all increased with the input of LFG. After exposure to LFG for 35 days, the sulfur-oxidizing rate of the bottom layer of the WBS reached 82.5 ?mol g dry weight (d.w.)(-1)?day(-1), which was 4.3-5.4 times of that of LCS. H2S-S was mainly deposited in the soil covers, while it escaped from landfills to the atmosphere. The adsorption, absorption, and biotransformation of H2S could lead to the decrease in the pH values of landfill covers; especially, in the LCS with low pH buffer capacity, the pH value of the bottom layer dropped to below 4. Pyrosequencing of 16S ribosomal RNA (rRNA) gene showed that the known sulfur-metabolizing bacteria Ochrobactrum, Paracoccus, Comamonas, Pseudomonas, and Acinetobacter dominated in the WBS and LCS. Among them, Comamonas and Acinetobacter might play an important role in the metabolism of H2S in the WBS. These findings are helpful to understand sulfur bioconversion process in landfill covers and to develop techniques for controlling odor pollution at landfills. PMID:26206130

  2. Effects of biochar amendment on geotechnical properties of landfill cover soil.

    PubMed

    Reddy, Krishna R; Yaghoubi, Poupak; Yukselen-Aksoy, Yeliz

    2015-06-01

    Biochar is a carbon-rich product obtained when plant-based biomass is heated in a closed container with little or no available oxygen. Biochar-amended soil has the potential to serve as a landfill cover material that can oxidise methane emissions for two reasons: biochar amendment can increase the methane retention time and also enhance the biological activity that can promote the methanotrophic oxidation of methane. Hydraulic conductivity, compressibility and shear strength are the most important geotechnical properties that are required for the design of effective and stable landfill cover systems, but no studies have been reported on these properties for biochar-amended landfill cover soils. This article presents physicochemical and geotechnical properties of a biochar, a landfill cover soil and biochar-amended soils. Specifically, the effects of amending 5%, 10% and 20% biochar (of different particle sizes as produced, size-20 and size-40) to soil on its physicochemical properties, such as moisture content, organic content, specific gravity and pH, as well as geotechnical properties, such as hydraulic conductivity, compressibility and shear strength, were determined from laboratory testing. Soil or biochar samples were prepared by mixing them with 20% deionised water based on dry weight. Samples of soil amended with 5%, 10% and 20% biochar (w/w) as-is or of different select sizes, were also prepared at 20% initial moisture content. The results show that the hydraulic conductivity of the soil increases, compressibility of the soil decreases and shear strength of the soil increases with an increase in the biochar amendment, and with a decrease in biochar particle size. Overall, the study revealed that biochar-amended soils can possess excellent geotechnical properties to serve as stable landfill cover materials. PMID:25898984

  3. Assessment of the methane oxidation capacity of compacted soils intended for use as landfill cover materials

    SciTech Connect

    Rachor, Ingke; Gebert, Julia; Groengroeft, Alexander; Pfeiffer, Eva-Maria

    2011-05-15

    The microbial oxidation of methane in engineered cover soils is considered a potent option for the mitigation of emissions from old landfills or sites containing wastes of low methane generation rates. A laboratory column study was conducted in order to derive design criteria that enable construction of an effective methane oxidising cover from the range of soils that are available to the landfill operator. Therefore, the methane oxidation capacity of different soils was assessed under simulated landfill conditions. Five sandy potential landfill top cover materials with varying contents of silt and clay were investigated with respect to methane oxidation and corresponding soil gas composition over a period of four months. The soils were compacted to 95% of their specific proctor density, resulting in bulk densities of 1.4-1.7 g cm{sup -3}, reflecting considerably unfavourable conditions for methane oxidation due to reduced air-filled porosity. The soil water content was adjusted to field capacity, resulting in water contents ranging from 16.2 to 48.5 vol.%. The investigated inlet fluxes ranged from 25 to about 100 g CH{sub 4} m{sup -2} d{sup -1}, covering the methane load proposed to allow for complete oxidation in landfill covers under Western European climate conditions and hence being suggested as a criterion for release from aftercare. The vertical distribution of gas concentrations, methane flux balances as well as stable carbon isotope studies allowed for clear process identifications. Higher inlet fluxes led to a reduction of the aerated zone, an increase in the absolute methane oxidation rate and a decline of the relative proportion of oxidized methane. For each material, a specific maximum oxidation rate was determined, which varied between 20 and 95 g CH{sub 4} m{sup -2} d{sup -1} and which was positively correlated to the air-filled porosity of the soil. Methane oxidation efficiencies and gas profile data imply a strong link between oxidation capacity and diffusive ingress of atmospheric air. For one material with elevated levels of fine particles and high organic matter content, methane production impeded the quantification of methane oxidation potentials. Regarding the design of landfill cover layers it was concluded that the magnitude of the expected methane load, the texture and expected compaction of the cover material are key variables that need to be known. Based on these, a column study can serve as an appropriate testing system to determine the methane oxidation capacity of a soil intended as landfill cover material.

  4. Strategies to Optimize Microbially-Mediated Mitigation of Greenhouse Gas Emissions from Landfill Cover Soils

    SciTech Connect

    Jeremy Semrau; Sung-Woo Lee; Jeongdae Im; Sukhwan Yoon; Michael Barcelona

    2010-09-30

    The overall objective of this project, 'Strategies to Optimize Microbially-Mediated Mitigation of Greenhouse Gas Emissions from Landfill Cover Soils' was to develop effective, efficient, and economic methodologies by which microbial production of nitrous oxide can be minimized while also maximizing microbial consumption of methane in landfill cover soils. A combination of laboratory and field site experiments found that the addition of nitrogen and phenylacetylene stimulated in situ methane oxidation while minimizing nitrous oxide production. Molecular analyses also indicated that methane-oxidizing bacteria may play a significant role in not only removing methane, but in nitrous oxide production as well, although the contribution of ammonia-oxidizing archaea to nitrous oxide production can not be excluded at this time. Future efforts to control both methane and nitrous oxide emissions from landfills as well as from other environments (e.g., agricultural soils) should consider these issues. Finally, a methanotrophic biofiltration system was designed and modeled for the promotion of methanotrophic activity in local methane 'hotspots' such as landfills. Model results as well as economic analyses of these biofilters indicate that the use of methanotrophic biofilters for controlling methane emissions is technically feasible, and provided either the costs of biofilter construction and operation are reduced or the value of CO{sub 2} credits is increased, can also be economically attractive.

  5. Adsorption and transport of methane in landfill cover soil amended with waste-wood biochars.

    PubMed

    Sadasivam, Bala Yamini; Reddy, Krishna R

    2015-08-01

    The natural presence of methane oxidizing bacteria (MOB) in landfill soils can stimulate the bio-chemical oxidation of CH4 to CO2 and H2O under suitable environmental conditions. This mechanism can be enhanced by amending the landfill cover soil with organic materials such as biochars that are recalcitrant to biological degradation and are capable of adsorbing CH4 while facilitating the growth and activity of MOB within their porous structure. Several series of batch and small-scale column tests were conducted to quantify the CH4 sorption and transport properties of landfill cover soil amended with four types of waste hardwood biochars under different levels of amendment percentages (2, 5 and 10% by weight), exposed CH4 concentrations (0-1 kPa), moisture content (dry, 25% and 75% water holding capacity), and temperature (25, 35 and 45 °C). The linear forms of the pseudo second-order kinetic model and the Langmuir isotherm model were used to determine the kinetics and the maximum CH4 adsorption capacity of cover materials. The maximum CH4 sorption capacity of dry biochar-amended soils ranged from 1.03 × 10(-2) to 7.97 × 10(-2) mol kg(-1) and exhibited a ten-fold increase compared to that of soil with 1.9 × 10(-3) mol kg(-1). The isosteric heat of adsorption for soil was negative and ranged from -30 to -118 kJ/mol, while that of the biochar-amended soils was positive and ranged from 24 to 440 kJ/mol. The CH4 dispersion coefficients for biochar-amended soils obtained through predictive transport modeling indicated that amending the soil with biochar enhanced the methane transport rates by two orders of magnitude, thereby increasing their potential for enhanced exchange of gases within the cover system. Overall, the use of hardwood biochars as a cover soil amendment to reduce methane emissions from landfills appears to be a promising alternative to conventional soil covers. PMID:25935750

  6. Structure and function of methanotrophic communities in a landfill-cover soil.

    PubMed

    Henneberger, Ruth; Lüke, Claudia; Mosberger, Lona; Schroth, Martin H

    2012-07-01

    In landfill-cover soils, aerobic methane-oxidizing bacteria (MOB) convert CH(4) to CO(2), mitigating emissions of the greenhouse gas CH(4) to the atmosphere. We investigated overall MOB community structure and assessed spatial differences in MOB diversity, abundance and activity in a Swiss landfill-cover soil. Molecular cloning, terminal restriction-fragment length polymorphism (T-RFLP) and quantitative PCR of pmoA genes were applied to soil collected from 16 locations at three different depths to study MOB community structure, diversity and abundance; MOB activity was measured in the field using gas push-pull tests. The MOB community was highly diverse but dominated by Type Ia MOB, with novel pmoA sequences present. Type II MOB were detected mainly in deeper soil with lower nutrient and higher CH(4) concentrations. Substantial differences in MOB community structure were observed between one high- and one low-activity location. MOB abundance was highly variable across the site [4.0 × 10(4) to 1.1 × 10(7) (g soil dry weight)(-1)]. Potential CH(4) oxidation rates were high [1.8-58.2 mmol CH(4) (L soil air)(-1) day(-1) ] but showed significant lateral variation and were positively correlated with mean CH(4) concentrations (P < 0.01), MOB abundance (P < 0.05) and MOB diversity (weak correlation, P < 0.17). Our findings indicate that Methylosarcina and closely related MOB are key players and that MOB abundance and community structure are driving factors in CH(4) oxidation at this landfill. PMID:22172054

  7. Above- and below-ground methane fluxes and methanotrophic activity in a landfill-cover soil

    SciTech Connect

    Schroth, M.H.; Eugster, W.; Gomez, K.E.; Gonzalez-Gil, G.; Niklaus, P.A.; Oester, P.

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer We quantify above- and below-ground CH{sub 4} fluxes in a landfill-cover soil. Black-Right-Pointing-Pointer We link methanotrophic activity to estimates of CH{sub 4} loading from the waste body. Black-Right-Pointing-Pointer Methane loading and emissions are highly variable in space and time. Black-Right-Pointing-Pointer Eddy covariance measurements yield largest estimates of CH{sub 4} emissions. Black-Right-Pointing-Pointer Potential methanotrophic activity is high at a location with substantial CH{sub 4} loading. - Abstract: Landfills are a major anthropogenic source of the greenhouse gas methane (CH{sub 4}). However, much of the CH{sub 4} produced during the anaerobic degradation of organic waste is consumed by methanotrophic microorganisms during passage through the landfill-cover soil. On a section of a closed landfill near Liestal, Switzerland, we performed experiments to compare CH{sub 4} fluxes obtained by different methods at or above the cover-soil surface with below-ground fluxes, and to link methanotrophic activity to estimates of CH{sub 4} ingress (loading) from the waste body at selected locations. Fluxes of CH{sub 4} into or out of the cover soil were quantified by eddy-covariance and static flux-chamber measurements. In addition, CH{sub 4} concentrations at the soil surface were monitored using a field-portable FID detector. Near-surface CH{sub 4} fluxes and CH{sub 4} loading were estimated from soil-gas concentration profiles in conjunction with radon measurements, and gas push-pull tests (GPPTs) were performed to quantify rates of microbial CH{sub 4} oxidation. Eddy-covariance measurements yielded by far the largest and probably most representative estimates of overall CH{sub 4} emissions from the test section (daily mean up to {approx}91,500 {mu}mol m{sup -2} d{sup -1}), whereas flux-chamber measurements and CH{sub 4} concentration profiles indicated that at the majority of locations the cover soil was a net sink for atmospheric CH{sub 4} (uptake up to -380 {mu}mol m{sup -2} d{sup -1}) during the experimental period. Methane concentration profiles also indicated strong variability in CH{sub 4} loading over short distances in the cover soil, while potential methanotrophic activity derived from GPPTs was high (v{sub max} {approx} 13 mmol L{sup -1}(soil air) h{sup -1}) at a location with substantial CH{sub 4} loading. Our results provide a basis to assess spatial and temporal variability of CH{sub 4} dynamics in the complex terrain of a landfill-cover soil.

  8. Spatial Variability of Soil Properties and Their Effect on Methane Generation, Oxidation, and Emission from Soils Covering Landfills

    NASA Astrophysics Data System (ADS)

    Imhoff, P. T.; Mei, C.; Yazdani, R.; Han, B.; Mostafid, M.

    2013-12-01

    Soils covering landfills mitigate gas emissions from degrading refuse, particularly emissions of methane, a potent greenhouse gas. To enhance the oxidative capacity of these soils, materials with high organic matter are proposed for landfill covers, e.g., compost and aged greenwaste. We report field tests of these materials in pilot-scale test cells. While moisture conditions and gas transport were initially uniform, after one year significant spatial variability of gas flow developed that was associated with spatially variable dry bulk density and volumetric water content. For a test cell with organic matter content of 38%, a single-domain porous medium model was adequate for describing water retention and continuum modeling was capable of describing spatially variable gas flow and methane oxidation. A second test cell with organic matter of 61% was best described as a dual-domain porous medium, and continuum modeling was inadequate for describing spatially variable gas flow. Here, the dual-domain medium resulted in significant subgrid scale variability in moisture conditions that affected gas transport and methane oxidation. The results from these field tests suggest that proposed one-dimensional models of gas transport and methane oxidation in landfill cover soils may be inadequate for soils composed of high organic matter that require dual-domain models for water retention.

  9. Modelling of stable isotope fractionation by methane oxidation and diffusion in landfill cover soils

    SciTech Connect

    Mahieu, Koenraad De Visscher, Alex; Vanrolleghem, Peter A.; Van Cleemput, Oswald

    2008-07-01

    A technique to measure biological methane oxidation in landfill cover soils that is gaining increased interest is the measurement of stable isotope fractionation in the methane. Usually to quantify methane oxidation, only fractionation by oxidation is taken into account. Recently it was shown that neglecting the isotope fractionation by diffusion results in underestimation of the methane oxidation. In this study a simulation model was developed that describes gas transport and methane oxidation in landfill cover soils. The model distinguishes between {sup 12}CH{sub 4}, {sup 13}CH{sub 4}, and {sup 12}CH{sub 3}D explicitly, and includes isotope fractionation by diffusion and oxidation. To evaluate the model, the simulations were compared with column experiments from previous studies. The predicted concentration profiles and isotopic profiles match the measured ones very well, with a root mean square deviation (RMSD) of 1.7 vol% in the concentration and a RMSD of 0.8 per mille in the {delta}{sup 13}C value, with {delta}{sup 13}C the relative {sup 13}C abundance as compared to an international standard. Overall, the comparison shows that a model-based isotope approach for the determination of methane oxidation efficiencies is feasible and superior to existing isotope methods.

  10. ENGINEERING BULLETIN: LANDFILL COVERS

    EPA Science Inventory

    Landfill covers are used at Superfund sites to minimize surface water infiltration and control gas migration. In many cases covers are used in conjunction with other waste treatment technologies, such as slurry walls, ground water pump-and-treat systems, and gas collection. This ...

  11. Evaluation of soil top-cover systems to minimize infiltration into a sanitary landfill: A case study

    NASA Astrophysics Data System (ADS)

    Weeks, Olaf L.; Mansell, Robert S.; McCallister, Scott W.

    1992-09-01

    The design of a top-cover system is a very important aspect of the closure of sanitary landfills. Soil material properties, sequencing, and vegetation are critical to top-cover design. To date, very few field investigations have been undertaken to determine the effectiveness of these designs. Results from a field investigation of top-covers proposed for an active landfill site in south Florida are reported here. Measurements were made of each component of the water balance equation: ? S = [ P + I] - [ ET + R + Q] where S, P, I, ET, R, and Q represent water storage, rainfall, irrigation, evapotranspiration, surface runoff, and deep seepage, respectively. Deep seepage, determined using soil water tensiometers, is the amount of water infiltrating the landfill top-cover and is therefore the upper limit of potential leachate generation. Results indicate that the locally available rock tailings (carbonate silt) is an effective topliner component of the top-cover system. The results of the field investigation also showed that the EPA water balance model used to estimate infiltration during landfill design was greater than the actual field measurements.

  12. CH4/CO2 ratios indicate highly efficient methane oxidation by a pumice landfill cover-soil.

    PubMed

    Pratt, Chris; Walcroft, Adrian S; Deslippe, Julie; Tate, Kevin R

    2013-02-01

    Landfills that generate too little biogas for economic energy recovery can potentially offset methane (CH(4)) emissions through biological oxidation by methanotrophic bacteria in cover soils. This study reports on the CH(4) oxidation efficiency of a 10-year old landfill cap comprising a volcanic pumice soil. Surface CH(4) and CO(2) fluxes were measured using field chambers during three sampling intervals over winter and summer. Methane fluxes were temporally and spatially variable (-0.36 to 3044 mgCH(4)m(-2)h(-1)); but were at least 15 times lower than typical literature CH(4) fluxes reported for older landfills in 45 of the 46 chambers tested. Exposure of soil from this landfill cover to variable CH(4) fluxes in laboratory microcosms revealed a very strong correlation between CH(4) oxidation efficiency and CH(4)/CO(2) ratios, confirming the utility of this relationship for approximating CH(4) oxidation efficiency. CH(4)/CO(2) ratios were applied to gas concentrations from the surface flux chambers and indicated a mean CH(4) oxidation efficiency of 72%. To examine CH(4) oxidation with soil depth, we collected 10 soil depth profiles at random locations across the landfill. Seven profiles exhibited CH(4) removal rates of 70-100% at depths <60 cm, supporting the high oxidation rates observed in the chambers. Based on a conservative 70% CH(4) oxidation efficiency occurring at the site, this cover soil is clearly offsetting far greater CH(4) quantities than the 10% default value currently adopted by the IPCC. PMID:23186636

  13. Modeling the effects of vegetation on methane oxidation and emissions through soil landfill final covers across different climates.

    PubMed

    Abichou, Tarek; Kormi, Tarek; Yuan, Lei; Johnson, Terry; Francisco, Escobar

    2015-02-01

    Plant roots are reported to enhance the aeration of soil by creating secondary macropores which improve the diffusion of oxygen into soil as well as the supply of methane to bacteria. Therefore, methane oxidation can be improved considerably by the soil structuring processes of vegetation, along with the increase of organic biomass in the soil associated with plant roots. This study consisted of using a numerical model that combines flow of water and heat with gas transport and oxidation in soils, to simulate methane emission and oxidation through simulated vegetated and non-vegetated landfill covers under different climatic conditions. Different simulations were performed using different methane loading flux (5-200 g m(-2) d(-1)) as the bottom boundary. The lowest modeled surface emissions were always obtained with vegetated soil covers for all simulated climates. The largest differences in simulated surface emissions between the vegetated and non-vegetated scenarios occur during the growing season. Higher average yearly percent oxidation was obtained in simulations with vegetated soil covers as compared to non-vegetated scenario. The modeled effects of vegetation on methane surface emissions and percent oxidation were attributed to two separate mechanisms: (1) increase in methane oxidation associated with the change of the physical properties of the upper vegetative layer and (2) increase in organic matter associated with vegetated soil layers. Finally, correlations between percent oxidation and methane loading into simulated vegetated and non-vegetated covers were proposed to allow decision makers to compare vegetated versus non-vegetated soil landfill covers. These results were obtained using a modeling study with several simplifying assumptions that do not capture the complexities of vegetated soils under field conditions. PMID:25475118

  14. Estimation of mass transport parameters of gases for quantifying CH{sub 4} oxidation in landfill soil covers

    SciTech Connect

    Im, J.; Moon, S.; Nam, K.; Kim, Y.-J.; Kim, J.Y.

    2009-02-15

    Methane (CH{sub 4}), which is one of the most abundant anthropogenic greenhouse gases, is produced from landfills. CH{sub 4} is biologically oxidized to carbon dioxide, which has a lower global warming potential than methane, when it passes through a cover soil. In order to quantify the amount of CH{sub 4} oxidized in a landfill cover soil, a soil column test, a diffusion cell test, and a mathematical model analysis were carried out. In the column test, maximum oxidation rates of CH{sub 4} (V{sub max}) showed higher values in the upper part of the column than those in the lower part caused by the penetration of O{sub 2} from the top. The organic matter content in the upper area was also higher due to the active microbial growth. The dispersion analysis results for O{sub 2} and CH{sub 4} in the column are counter-intuitive. As the upward flow rate of the landfill gas increased, the dispersion coefficient of CH{sub 4} slightly increased, possibly due to the effect of mechanical dispersion. On the other hand, as the upward flow rate of the landfill gas increased, the dispersion coefficient of O{sub 2} decreased. It is possible that the diffusion of gases in porous media is influenced by the counter-directional flow rate. Further analysis of other gases in the column, N{sub 2} and CO{sub 2}, may be required to support this hypothesis, but in this paper we propose the possibility that the simulations using the diffusion coefficient of O{sub 2} under the natural condition may overestimate the penetration of O{sub 2} into the soil cover layer and consequently overestimate the oxidation of CH{sub 4}.

  15. Field-Scale Stable-Isotope Probing of Active Methanotrophs in a Landfill-Cover Soil

    NASA Astrophysics Data System (ADS)

    Schroth, M. H.; Henneberger, R.; Chiri, E.

    2012-12-01

    The greenhouse gas methane (CH4) is an important contributor to global climate change. While its atmospheric concentration is increasing, a large portion of produced CH4 never reaches the atmosphere, but is consumed by aerobic methane-oxidizing bacteria (MOB). The latter are ubiquitous in soils and utilize CH4 as sole source of energy and carbon. Among other methods, MOB may be differentiated based on characteristic phospholipid fatty acids (PLFA). Stable-isotope probing (SIP) on PLFA has been widely applied to identify active members of MOB communities in laboratory incubation studies, but results are often difficult to extrapolate to the field. Thus, novel field-scale approaches are needed to link activity and identity of MOB in their natural environment. We present results of field experiments in which we combined PLFA-SIP with gas push-pull tests (GPPTs) to label active MOB at the field-scale while simultaneously quantifying CH4 oxidation activity. During a SIP-GPPT, a mixture of reactive (here 13CH4, O2) and non-reactive tracer gases (e.g., Ar, Ne, He) is injected into the soil at a location of interest. Thereafter, gas flow is reversed and the gas mixture diluted with soil air is extracted from the same location and sampled periodically. Rate constants for CH4 oxidation can be calculated by analyzing breakthrough curves of 13CH4 and a suitable non-reactive tracer gas. SIP-GPPTs were performed in a landfill-cover soil, and feasibility of this novel approach was tested at several locations along a gradient of MOB activity and soil temperature. Soil samples were collected before and after SIP-GPPTs, total PLFA were extracted, and incorporation of 13C in the polar lipid fraction was analyzed. Potential CH4 oxidation rates derived from SIP-GPPTs were similar to those derived from regular GPPTs (using unlabeled CH4) performed at the same locations prior to SIP-GPPTs, indicating that application of 13CH4 did not adversely affect bacterial CH4 oxidation rates. Rates calculated for different locations ranged from 0.2 to 52.8 mmol CH4 (L soil air)-1 d-1. PLFA analyses showed high levels of 13C incorporation into different 14C and 16C fatty acids (FA), typically found in Type I MOB, and 18C FAs, typical for Type II MOB. The amount of 13C incorporated into biomass clearly increased with increasing activity, and ?13C values of >1500 ‰ were observed for selected FAs at high-activity locations. In addition, the range of labeled FAs also changed with activity, and no Type II MOB specific FAs were labeled at the low-activity location. The novel SIP-GPPT approach was shown to be a valuable field-scale method to detect and identify active MOB over a wide range of activities.

  16. LANDFILL CONTAINMENT AND COVER SYSTEMS

    EPA Science Inventory

    The U.S. Environmental Protection Agency through its research and field experiences has developed control strategies for hazardous and municipal solid waste landfills and surface impoundments. hese control strategies include liner and cover systems. he liner systems include doubl...

  17. Methane oxidation in a neutral landfill cover soil: Influence of moisture content, temperature, and nitrogen-turnover

    SciTech Connect

    Boeckx, P.; Van Cleemput, O.

    1996-01-01

    Well-managed, aerated cover soils can have a mitigating effect on methane emission from landfills. The influence of moisture content, soil temperature, and N on the methane uptake capacity of a neutral landfill cover soil was examined. A soil moisture content of 15% w/w gave the maximum CH{sub 4} oxidation rate (2.36 ng CH{sub 4}{sup -1}g{sup -1} soil). When wetter, CH{sub 4} consumption was slower (e.g., 1.6 ng CH{sub 4} h{sup -1} g {sup -1} at 30% w/w) because of a limited gas diffusion. At lower soil moisture, microbial activity was reduced and consequently the oxidation capacity decreased (e.g., 0.84 ng CH{sub 4} {sup -1} g{sup -1} at 5% w/w). Optimum temperature was between 25 and 30{degrees}C. The calculated activation energy of the CH{sub 4} oxidation was 56.5 kj K{sup -1} mol{sup -1}. After NH4{sub 4}{sup +} addition, a negative linear correlation was found between the methane oxidation rate and the nitrous oxide flux (R{sup 2} = 0.96 Y1 = 2.7 - 0.44 x Y2). Addition of NO{sub 3}{sup -} had no significant effect on CH{sub 4} oxidation. The effect of organic residue amendments depended on their C/N ratios. Crop residues with a high C/N ratio (wheat [Triticum sativum L.] and maize [Zea mays L.] straw) stimulated N-immobilization and did not affect the methane-oxidizing capacity. On the other hand, addition of crop residues with low C/N ratios (potato [Solanum tuberosum L.] and sugar beet [Beta vulgaris cv. Altissima] leaves) stimulated N-mineralization, resulting in a strong inhibition of the methane oxidation. 38 refs., 4 figs., 2 tabs.

  18. Effects of dry bulk density and particle size fraction on gas transport parameters in variably saturated landfill cover soil.

    PubMed

    Wickramarachchi, Praneeth; Kawamoto, Ken; Hamamoto, Shoichiro; Nagamori, Masanao; Moldrup, Per; Komatsu, Toshiko

    2011-12-01

    Landfill sites are emerging in climate change scenarios as a significant source of greenhouse gases. The compacted final soil cover at landfill sites plays a vital role for the emission, fate and transport of landfill gases. This study investigated the effects of dry bulk density, ?(b), and particle size fraction on the main soil-gas transport parameters - soil-gas diffusivity (D(p)/D(o), ratio of gas diffusion coefficients in soil and free air) and air permeability (k(a)) - under variably-saturated moisture conditions. Soil samples were prepared by three different compaction methods (Standard and Modified Proctor compaction, and hand compaction) with resulting ?(b) values ranging from 1.40 to 2.10 g cm(-3). Results showed that D(p) and k(a) values for the '+gravel' fraction (<35 mm) became larger than for the '-gravel' fraction (<2mm) under variably-saturated conditions for a given soil-air content (?), likely due to enhanced gas diffusion and advection through less tortuous, large-pore networks. The effect of dry bulk density on D(p) and k(a) was most pronounced for the '+gravel' fraction. Normalized ratios were introduced for all soil-gas parameters: (i) for gas diffusivity D(p)/D(f), the ratio of measured D(p) to D(p) in total porosity (f), (ii) for air permeability k(a)/k(a)(,pF4.1), the ratio of measured k(a) to k(a) at 1235 kPa matric potential (=pF 4.1), and (iii) for soil-air content, the ratio of soil-air content (?) to total porosity (f) (air saturation). Based on the normalized parameters, predictive power-law models for D(p)(?/f) and k(a)(?/f) models were developed based on a single parameter (water blockage factor M for D(p) and P for k(a)). The water blockage factors, M and P, were found to be linearly correlated to ?(b) values, and the effects of dry bulk density on D(p) and k(a) for both '+gravel' and '-gravel' fractions were well accounted for by the new models. PMID:21813272

  19. Field-scale tracking of active methane-oxidizing communities in a landfill cover soil reveals spatial and seasonal variability.

    PubMed

    Henneberger, Ruth; Chiri, Eleonora; Bodelier, Paul E L; Frenzel, Peter; Lüke, Claudia; Schroth, Martin H

    2015-05-01

    Aerobic methane-oxidizing bacteria (MOB) in soils mitigate methane (CH4 ) emissions. We assessed spatial and seasonal differences in active MOB communities in a landfill cover soil characterized by highly variable environmental conditions. Field-based measurements of CH4 oxidation activity and stable-isotope probing of polar lipid-derived fatty acids (PLFA-SIP) were complemented by microarray analysis of pmoA genes and transcripts, linking diversity and function at the field scale. In situ?CH4 oxidation rates varied between sites and were generally one order of magnitude lower in winter compared with summer. Results from PLFA-SIP and pmoA transcripts were largely congruent, revealing distinct spatial and seasonal clustering. Overall, active MOB communities were highly diverse. Type Ia MOB, specifically Methylomonas and Methylobacter, were key drivers for CH4 oxidation, particularly at a high-activity site. Type II MOB were mainly active at a site showing substantial fluctuations in CH4 loading and soil moisture content. Notably, Upland Soil Cluster-gamma-related pmoA transcripts were also detected, indicating concurrent oxidation of atmospheric CH4 . Spatial separation was less distinct in winter, with Methylobacter and uncultured MOB mediating CH4 oxidation. We propose that high diversity of active MOB communities in this soil is promoted by high variability in environmental conditions, facilitating substantial removal of CH4 generated in the waste body. PMID:25186436

  20. Effects of dry bulk density and particle size fraction on gas transport parameters in variably saturated landfill cover soil

    SciTech Connect

    Wickramarachchi, Praneeth; Kawamoto, Ken; Hamamoto, Shoichiro; Nagamori, Masanao; Moldrup, Per; Komatsu, Toshiko

    2011-12-15

    Highlights: > The effects of soil physical properties on gas transport parameters were investigated. > Higher values of D{sub p} and k{sub a} exhibited in the '+gravel' than the '-gravel' fraction at same soil-air content ({epsilon}). > Recent power law models for D{sub p} (WLR) and k{sub a} (RPL) were modified. > Model parameters were linearly related to easily measurable dry bulk density ({rho}{sub b}). - Abstract: Landfill sites are emerging in climate change scenarios as a significant source of greenhouse gases. The compacted final soil cover at landfill sites plays a vital role for the emission, fate and transport of landfill gases. This study investigated the effects of dry bulk density, {rho}{sub b}, and particle size fraction on the main soil-gas transport parameters - soil-gas diffusivity (D{sub p}/D{sub o}, ratio of gas diffusion coefficients in soil and free air) and air permeability (k{sub a}) - under variably-saturated moisture conditions. Soil samples were prepared by three different compaction methods (Standard and Modified Proctor compaction, and hand compaction) with resulting {rho}{sub b} values ranging from 1.40 to 2.10 g cm{sup -3}. Results showed that D{sub p} and k{sub a} values for the '+gravel' fraction (<35 mm) became larger than for the '-gravel' fraction (<2 mm) under variably-saturated conditions for a given soil-air content ({epsilon}), likely due to enhanced gas diffusion and advection through less tortuous, large-pore networks. The effect of dry bulk density on D{sub p} and k{sub a} was most pronounced for the '+gravel' fraction. Normalized ratios were introduced for all soil-gas parameters: (i) for gas diffusivity D{sub p}/D{sub f}, the ratio of measured D{sub p} to D{sub p} in total porosity (f), (ii) for air permeability k{sub a}/k{sub a,pF4.1}, the ratio of measured k{sub a} to k{sub a} at 1235 kPa matric potential (=pF 4.1), and (iii) for soil-air content, the ratio of soil-air content ({epsilon}) to total porosity (f) (air saturation). Based on the normalized parameters, predictive power-law models for D{sub p}({epsilon}/f) and k{sub a}({epsilon}/f) models were developed based on a single parameter (water blockage factor M for D{sub p} and P for k{sub a}). The water blockage factors, M and P, were found to be linearly correlated to {rho}{sub b} values, and the effects of dry bulk density on D{sub p} and k{sub a} for both '+gravel' and '-gravel' fractions were well accounted for by the new models.

  1. Field Water Balance of Landfill Final Covers

    EPA Science Inventory

    Landfill covers are critical to waste containment, yet field performance of specific cover designs has not been well documented and seldom been compared in side-by-side testing. A study was conducted to assess the ability of landfill final covers to control percolation into unde...

  2. TDR calibration for the alternative landfill cover demonstration (ALCD)

    SciTech Connect

    Lopez, J.; Dwyer, S.F.; Swanson, J.N.

    1997-09-01

    The Alternative Landfill Cover Demonstration is a large scale field test that compares the performance of various landfill cover designs in dry environments. An important component of the comparison is the change in the moisture content of the soils throughout the different cover test plots. Time Domain Reflectometry (TDR) is the primary method for the measurement of the volumetric moisture content. Each of the covers is composed of layers of varying types and densities of soils. The probes are therefore calibrated to calculate the volumetric moisture content in each of the different soils in order to gain the optimum performance of the TDR system. The demonstration plots are constructed in two phases; a different probe is used in each phase. The probe that is used in Phase 1 is calibrated for the following soils: compacted native soil, uncompacted native soil, compacted native soil mixed with 6% sodium bentonite by weight, and sand. The probe that is used in Phase 2 is calibrated for the following soils: compacted native soil, uncompacted native soil, and sand. In addition, the probes are calibrated for the varying cable lengths of the TDR probes. The resulting empirically derived equations allow for the calculation of in-situ volumetric moisture content of all of the varying soils throughout the cover test plots in the demonstration.

  3. Assessment of methane emission and oxidation at Air Hitam Landfill site cover soil in wet tropical climate.

    PubMed

    Abushammala, Mohammed F M; Basri, Noor Ezlin Ahmad; Elfithri, Rahmah

    2013-12-01

    Methane (CH?) emissions and oxidation were measured at the Air Hitam sanitary landfill in Malaysia and were modeled using the Intergovernmental Panel on Climate Change waste model to estimate the CH? generation rate constant, k. The emissions were measured at several locations using a fabricated static flux chamber. A combination of gas concentrations in soil profiles and surface CH? and carbon dioxide (CO?) emissions at four monitoring locations were used to estimate the CH? oxidation capacity. The temporal variations in CH? and CO? emissions were also investigated in this study. Geospatial means using point kriging and inverse distance weight (IDW), as well as arithmetic and geometric means, were used to estimate total CH? emissions. The point kriging, IDW, and arithmetic means were almost identical and were two times higher than the geometric mean. The CH? emission geospatial means estimated using the kriging and IDW methods were 30.81 and 30.49 gm(?2) day(?1), respectively. The total CH? emissions from the studied area were 53.8 kg day(?1). The mean of the CH? oxidation capacity was 27.5 %. The estimated value of k is 0.138 year(?1). Special consideration must be given to the CH? oxidation in the wet tropical climate for enhancing CH? emission reduction. PMID:23797636

  4. GEOSYNTHETIC CLAY LINERS (GCLS) IN LANDFILL COVERS

    EPA Science Inventory

    Low permeability, compacted clay linters are commonly required as a barrier to water infiltration in landfill covers. elatively new material, known as geosynthetic clay liner (GCL), has been proposed as an alternative to a compacted clay liner. CL has the practical advantages of ...

  5. Report: landfill alternative daily cover: conserving air space and reducing landfill operating cost.

    PubMed

    Haughey, R D

    2001-02-01

    Title 40, Part 258 of the Code of Federal Regulations, Solid Waste Disposal Facility Criteria, commonly referred to as Subtitle D, became effective on October 9, 1993. It establishes minimum criteria for solid waste disposal facility siting, design, operations, groundwater monitoring and corrective action, and closure and postclosure maintenance, while providing EPA-approved state solid waste regulatory programs flexibility in implementing the criteria. Section 258.21(a) [40 CFR 258.21(a)] requires owners or operators of municipal solid waste landfill (MSWLF) units to cover disposed solid waste with 30cm of earthen material at the end of the operating day, or at more frequent intervals, if necessary, to control disease vectors, fires, odours, blowing litter, and scavenging. This requirement is consistent with already existing solid waste facility regulations in many states. For many MSWLFs, applying daily cover requires the importation of soil which increases landfill operating costs. Daily cover also uses valuable landfill air space, reducing potential operating revenue and the landfill's operating life. 40 CFR 258.21 (b) allows the director of an approved state to approve alternative materials of an alternative thickness if the owner or operator demonstrates that the alternative material and thickness will control disease vectors, fires, odours, blowing litter, and scavenging without presenting a threat to human health and the environment. Many different types of alternative daily cover (ADC) are currently being used, including geosynthetic tarps, foams, garden waste, and auto shredder fluff. These materials use less air space than soil and can reduce operating costs. This paper discusses the variety of ADCs currently being used around the country and their applicability to different climates and operating conditions, highlighting the more unusual types of ADC, the types of demonstrations necessary to obtain approval of ADC, and the impact on landfill air space and operating costs of ADC use. PMID:11525478

  6. Analysis and Design of Evapotranspirative Cover for Hazardous Waste Landfill

    E-print Network

    Zornberg, Jorge G.

    Analysis and Design of Evapotranspirative Cover for Hazardous Waste Landfill Jorge G. Zornberg, M, Inc. OII Superfund landfill in southern California. This cover system constitutes the first ET cover flow analyses performed for closure design at the OII site show that an ET cover is feasible for a wide

  7. Migration barrier covers for radioactive and mixed waste landfills

    SciTech Connect

    Hakonson, T.E.; Manies, K.L.; Warren, R.W.; Bostick, K.V.; Trujillo, G.; Kent, J.S.; Lane, L.J.

    1993-03-01

    Migration barrier cover technology will likely serve as the remediation alternative of choice for most of DOE`s radioactive and mixed waste landfills simply because human and ecological risks can be effectively managed without the use of more expensive alternatives. However, very little testing and evaluation has been done, either before or after installation, to monitor how effective they are in isolating waste or to develop data that can be used to evaluate model predictions of long term performance. Los Alamos National Laboratory has investigated the performance of a variety of landfill capping alternatives since 1981 using large field lysimeters to monitor the fate of precipitation falling on the cap surface. The objective of these studies is to provide the risk manager with a variety of field tested capping designs, of various complexities and costs, so that design alternatives can be matched to the need for hydrologic control at the site. Four different landfill cap designs, representing different complexities and costs, were constructed at Hill Air Force Base (AFB) in October and November, 1989. The designs were constructed in large lysimeters and instrumented to provide estimates of all components of water balance including precipitation, runoff (and soil erosion), infiltration, leachate production, evapotranspiration, and capillary/hydraulic barrier flow. The designs consisted of a typical soil cover to serve as a baseline, a modified EPA RCRA cover, and two versions of a Los Alamos design that contained erosion control measures, an improved vegetation cover to enhance evapotranspiration, and a capillary barrier to divert downward flow of soil water. A comprehensive summary of the Hill AFB demonstration will be available in October 1993, when the project is scheduled to terminate.

  8. Geosynthetics International, 2010, 17, No.3 Design of a landfill final cover system

    E-print Network

    cover systems. The case history involves an unlined landfill located on the east coast of the U11ited is flat and is underlain by sandy soils with groundwater near the ground surface. The closed portion groundwater contamination. The applicable state regulations require a minimum of 0.6 m of interim soil cover

  9. METHANE PHYTOREMEDIATION BY VEGETATIVE LANDFILL COVER SYSTEMS

    EPA Science Inventory

    Landfill gas, consisting of methane and other gases, is produced from organic compounds degrading in landfills, contributes to global climate change, is toxic to various types of vegetation, and may pose a combustion hazard at higher concentrations. New landfills are required to ...

  10. EVALUATION OF MUNICIPAL SOLID WASTE LANDFILL COVER DESIGNS

    EPA Science Inventory

    The HELP (Hydrologic Evaluation of Landfill Performance) Model was used to evaluate the hydrologic behavior of a series of one-, two-, and three-layer cover designs for municipal solid waste landfill cover designs were chosen to isolate the effects of features such as surface veg...

  11. SETTLEMENT AND COVER SUBSIDENCE OF HAZARDOUS WASTE LANDFILLS

    EPA Science Inventory

    Numerical models using equations for linearly elastic deformation were developed to predict the maximum expected amount of settlement and cover subsidence and potential cracking of the cover by differential settlement in uniformly, horizontally layered hazardous waste landfills. ...

  12. EVAPOTRANSPIRATION AND CAPILLARY BARRIER FINAL LANDFILL COVERS FACT SHEET

    EPA Science Inventory

    The fact sheet provides an overview of two alternative landfill cover designs. It briefly describes advantages and limitations, performance, costs, design and site considerations, and monitoring parameters associated with these cover designs. The document also includes 20 site ...

  13. Field measurements of frost penetration into a landfill cover that uses a paper sludge barrier

    SciTech Connect

    Moo-Young, H.K.; LaPlante, C.; Zimmie, T.F.; Quiroz, J.

    1999-07-01

    Frost penetration is a major environmental concern in landfill design. Freezing and thawing cycles may deteriorate the permeability of the liner or cap. In this study, the depth of frost penetration into a landfill cover that uses paper sludge as the impermeable barrier (the Hubbardston landfill in Massachusetts) was measured using a frost measurement system. A thermistor probe measured the temperature at various depths. Although temperature measurements are important, soil resistivity measurements are required to accurately predict the freezing level, since soil resistivity increases greatly upon freezing. A conductivity probe measured the half-bridge voltage between conductivity rings and a ground rod. Data were collected in data loggers. The data collected from 1992--1996 showed that the frost level did not penetrate the paper sludge capping layer. Heavy snow cover throughout the winters decreased the depth of frost penetration by insulating the landfill. The high water content in the sludge also contributed to the lack of freezing.

  14. On the performance of capillary barriers as landfill cover

    NASA Astrophysics Data System (ADS)

    Kämpf, M.; Montenegro, H.

    Landfills and waste heaps require an engineered surface cover upon closure. The capping system can vary from a simple soil cover to multiple layers of earth and geosynthetic materials. Conventional design features a compacted soil layer, which suffers from drying out and cracking, as well as root and animal intrusion. Capillary barriers consisting of inclined fine-over-coarse soil layers are investigated as an alternative cover system. Under unsaturated conditions, the textural contrast delays vertical drainage by capillary forces. The moisture that builds up above the contact will flow downdip along the interface of the layers. Theoretical studies of capillary barriers have identified the hydraulic properties of the layers, the inclination angle, the length of the field and the infiltration rate as the fundamental characteristics of the system. However, it is unclear how these findings can lead to design criteria for capillary barriers. To assess the uncertainty involved in such approaches, experiments have been carried out in a 8 m long flume and on large scale test sites (40 m x 15 m). In addition, the ability of a numerical model to represent the relevant flow processes in capillary barriers has been examined.

  15. 75 FR 6597 - Determination to Approve Alternative Final Cover Request for the Lake County, MT Landfill...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-10

    ...Alternative Final Cover Request for the Lake County, MT Landfill; Opportunity for...approve an alternative final cover for the Lake County landfill, a municipal solid waste landfill (MSWLF) owned and operated by Lake County, Montana on the Confederated...

  16. Landfill cover performance monitoring using time domain reflectometry

    SciTech Connect

    Neher, E.R.; Cotten, G.B.; McElroy, D.

    1998-03-01

    Time domain reflectometry (TDR) systems were installed to monitor soil moisture in two newly constructed landfill covers at the Idaho National Engineering and Environmental Laboratory. Each TDR system includes four vertical arrays with each array consisting of four TDR probes located at depths of 15, 30, 45, and 60 cm. The deepest probes at 60 cm were installed beneath a compacted soil layer to analyze infiltration through the compacted layer. Based on the TDR data, infiltration through the two covers between March and October, 1997 ranged from less than measurable to 1.5 cm. However, due to a prohibition on penetrating the buried waste and resulting limits on probe placement depths, deeper percolation was not evaluated. Some of the advantages found in the application of TDR for infiltration monitoring at this site are the relative low cost and rugged nature of the equipment. Also, of particular importance, the ability to collect frequent moisture measurements allows the capture and evaluation of soil moisture changes resulting from episodic precipitation events. Disadvantages include the inability to install the probes into the waste, difficulties in interpretation of infiltration during freeze/thaw periods, and some excessive noise in the data.

  17. Potential application of biocover soils to landfills for mitigating toluene emission.

    PubMed

    Su, Yao; Pei, Junshen; Tian, Baohu; Fan, Fengxi; Tang, Mengling; Li, Wei; He, Ruo

    2015-12-15

    Biocover soils have been demonstrated to be a good alternative cover material to mitigate CH4 emission from landfills. To evaluate the potential of biocover soil in mitigating emissions of non-methane volatile organic compounds (NMVOCs) from landfills, simulated cover soil columns with the influx of toluene (chosen as typical of NMVOCs) concentrations of 102-1336mgm(-3) in the presence or absence of the major landfill gas components (i.e., CH4 and CO2) were conducted in this study. In the two experimental materials (waste biocover soils (WBS) and landfill cover soils (LCS)), higher toluene reduction was observed in WBS with respect to LCS. After the introduction of landfill gas, an increase of microbial diversity and relative abundance of toluene-degrading bacteria and methanotrophs occurred in WBS. To illustrate the role of toluene-degrading activity in mitigating toluene emissions through landfill covers, an analytical model was developed by incorporating the steady-state vapor transport with the first-order kinetics of aerobic biodegradation limited by O2 availability. This study demonstrated that biocover soils have great potential in applying to landfills for mitigating toluene emission to the atmosphere. PMID:26073517

  18. Soil gas investigations at the Sanitary Landfill

    SciTech Connect

    Wyatt, D.E.; Pirkle, R.J.; Masdea, D.J.

    1992-07-01

    A soil gas survey was performed at the 740-G Sanitary Landfill of Savannah River Plant during December, 1990. The survey monitored the presence and distribution of the C[sub 1]C[sub 4] hydrocarbons; the C[sub 5]-C[sub 10] normal paraffins; the aromatic hydrocarbons, BTXE; selected chlorinated hydrocarbons; and mercury. Significant levels of several of these contaminants were found associated with the burial site. In the northern area of the Landfill, methane concentrations ranged up to 63% of the soil gas and were consistently high on the western side of the access road. To the east of the access road in the northern and southern area high concentrations of methane were encountered but were not consistently high. Methane, the species found in highest concentration in the landfill, was generated in the landfill as the result of biological oxidation of cellulose and other organics to carbon dioxide followed by reduction of the carbon dioxide to methane. Distributions of other species are the result of burials in the landfill of solvents or other materials.

  19. Soil gas investigations at the Sanitary Landfill

    SciTech Connect

    Wyatt, D.E.; Pirkle, R.J.; Masdea, D.J.

    1992-07-01

    A soil gas survey was performed at the 740-G Sanitary Landfill of Savannah River Plant during December, 1990. The survey monitored the presence and distribution of the C{sub 1}C{sub 4} hydrocarbons; the C{sub 5}-C{sub 10} normal paraffins; the aromatic hydrocarbons, BTXE; selected chlorinated hydrocarbons; and mercury. Significant levels of several of these contaminants were found associated with the burial site. In the northern area of the Landfill, methane concentrations ranged up to 63% of the soil gas and were consistently high on the western side of the access road. To the east of the access road in the northern and southern area high concentrations of methane were encountered but were not consistently high. Methane, the species found in highest concentration in the landfill, was generated in the landfill as the result of biological oxidation of cellulose and other organics to carbon dioxide followed by reduction of the carbon dioxide to methane. Distributions of other species are the result of burials in the landfill of solvents or other materials.

  20. Hydrologic studies of multilayered landfill covers for closure of waste landfills at Los Alamos, New Mexico

    SciTech Connect

    Nyhan, J.W.; Langhorst, G.J.; Martin, C.E.; Martinez, J.L.; Schofield, T.G.

    1993-06-01

    The Los Alamos National Laboratory examined water balance relationships for four different landfill cover designs containing engineered barriers. These field experiments were performed at Los Alamos, New Mexico, USA, in 1.0- by 10.0-m plots with downhill slopes of 5, 10, 15 and 25%. Field measurements of seepage, precipitation, interflow, runoff, and soil water content were collected in each of the 16 plots representing four slopes each with four cover designs: Conventional, EPA, Loam Capillary Barrier and Clay Loam Capillary Barrier. A seepage collection system was installed beneath each cover design to evaluate the influence of slope length on seepage using a series of four metal pans filled with medium gravel that were placed end-to-end in the bottom of each field plot. An automated waterflow datalogging system was used to collect hourly seepage, interflow and runoff data and consisted of 100 100-liter tanks, each of which was equipped with an ultrasonic liquid-level sensor and a motor-operated ball valve used to drain the tank. Soil water content was routinely monitored every six hours at each of 212 locations throughout the 16 plots with time domain reflectrometry (TDR) techniques using an automated and multiplexed measurement system.

  1. Analysis of Vegetative on Six Different Landfill Cover Profiles in an Arid Environment.

    SciTech Connect

    Dwyer, Stephen F.; McClellan, Yvonne; Reavis, Bruce A.; Dwyer, Brian P.; Newman, Gretchen; Wolters, Gale

    2005-05-01

    A large-scale field demonstration comparing final landfill cover designs was constructed and monitored at Sandia National Laboratories in Albuquerque, New Mexico. Two conventional designs (a RCRA Subtitle 'D' Soil Cover and a RCRA Subtitle 'C' Compacted Clay Cover) were constructed side-by-side with four alternative cover test plots designed for arid environments. The demonstration was intended to evaluate the various cover designs based on their respective water balance performance, ease and reliability of construction, and cost. A portion of this project involves the characterization of vegetation establishment and growth on the landfill covers. The various prototype landfill covers were expected to have varying flux rates (Dwyer et al 2000). The landfill covers were further expected to influence vegetation establishment and growth, which may impact site erosion potential and long-term site integrity. Objectives of this phase were to quantify the types of plants occupying each site, the percentage of ground covered by these plants, the density (number of plants per unit area) of plants, and the plant biomass production. The results of this vegetation analysis are presented in this report.3 DRAFT07/06/14AcknowledgementsWe would like to thank all technical and support staff from Sandia and the USDA Forest Service's Rocky Mountain Station not included in the authors' list of this document for their valuable contributions to this research. We would also like to acknowledge the Department of Energy's Subsurface Contaminants Focus Area for funding this work.4

  2. Field Performance Of Three Compacted Clay Landfill Covers

    EPA Science Inventory

    A study was conducted at sites in subtropical Georgia, seasonal and humid Iowa, and arid southeastern California to evaluate the field hydrology of compacted clay covers for final closure of landfills. Water balance of the covers was monitored with large (10 by 20 m ), instrumen...

  3. Large-Scale Field Study of Landfill Covers at Sandia National Laboratories

    SciTech Connect

    Dwyer, S.F.

    1998-09-01

    A large-scale field demonstration comparing final landfill cover designs has been constructed and is currently being monitored at Sandia National Laboratories in Albuquerque, New Mexico. Two conventional designs (a RCRA Subtitle `D' Soil Cover and a RCRA Subtitle `C' Compacted Clay Cover) were constructed side-by-side with four alternative cover test plots designed for dry environments. The demonstration is intended to evaluate the various cover designs based on their respective water balance performance, ease and reliability of construction, and cost. This paper presents an overview of the ongoing demonstration.

  4. Impact of different plants on the gas profile of a landfill cover

    SciTech Connect

    Reichenauer, Thomas G.; Watzinger, Andrea; Riesing, Johann; Gerzabek, Martin H.

    2011-05-15

    Research highlights: > Plants influence gas profile and methane oxidation in landfill covers. > Plants regulate water content and increase the availability of oxygen for methane oxidation. > Plant species with deep roots like alfalfa showed more stimulation of methane oxidation than plants with shallow root systems like grasses. - Abstract: Methane is an important greenhouse gas emitted from landfill sites and old waste dumps. Biological methane oxidation in landfill covers can help to reduce methane emissions. To determine the influence of different plant covers on this oxidation in a compost layer, we conducted a lysimeter study. We compared the effect of four different plant covers (grass, alfalfa + grass, miscanthus and black poplar) and of bare soil on the concentration of methane, carbon dioxide and oxygen in lysimeters filled with compost. Plants were essential for a sustainable reduction in methane concentrations, whereas in bare soil, methane oxidation declined already after 6 weeks. Enhanced microbial activity - expected in lysimeters with plants that were exposed to landfill gas - was supported by the increased temperature of the gas in the substrate and the higher methane oxidation potential. At the end of the first experimental year and from mid-April of the second experimental year, the methane concentration was most strongly reduced in the lysimeters containing alfalfa + grass, followed by poplar, miscanthus and grass. The observed differences probably reflect the different root morphology of the investigated plants, which influences oxygen transport to deeper compost layers and regulates the water content.

  5. LANDFILL LEACHATE CLOGGING OF GEOTEXTILE (AND SOIL) FILTERS

    EPA Science Inventory

    The primary leachate collection system of most solid waste landfills contains a filter layer which has historically been a granular soil. ecently, however, various types of geotextile filters have been used to replace the natural soil filters. roject using six different landfill ...

  6. DESIGN AND CONSTRUCTION OF COVERS FOR SOLID WASTE LANDFILLS

    EPA Science Inventory

    The report provides guidelines in selection, design, and construction of cover for management of municipal, industrial, and hazardous solid wastes (with the exception of radioactive waste). Natural soils as cover are the principal subject; however, synthetic membranes, chemicals,...

  7. 75 FR 50930 - Final Determination To Approve Alternative Final Cover Request for the Lake County, Montana Landfill

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-18

    ...Alternative Final Cover Request for the Lake County, Montana Landfill AGENCY: Environmental...approve an alternative final cover for the Lake County landfill, a municipal solid waste landfill (MSWLF) owned and operated by Lake County, Montana on the Confederated...

  8. Soil contaminations in landfill: a case study of the landfill in Czech Republic

    NASA Astrophysics Data System (ADS)

    Adamcová, D.; Vaverková, M. D.; Barto?, S.; Havlí?ek, Z.; B?oušková, E.

    2015-10-01

    Phytotoxicity test was determined to assess ecotoxicity of landfill soil. Sinapis alba L. was used as heavy metals bioindicator. Soil samples 1-8, which were taken from the landfill body, edge of the landfill body and its vicinity meet the limits for heavy metals Co, Cd, Pb, and Zn specified in the applicable legislation. Hg and Mn threshold values are not established in legislation, but values have been determined for the needs of the landfill operator. For heavy metals Cr, Cu, and Ni sample 2 exceeded the threshold values, which attained the highest values of all the samples tested for Cr, Cu and Ni. For Cr and Ni the values were several times higher than values of the other samples. The second highest values for Cr, Cu, and Ni showed sample 6 and 7. Both samples exceeded the set limits. An increase in plant biomass was observed in plants growing on plates with soil samples, but no changes in appearance, slow growth or necrotic lesions appeared. Ecotoxicity tests show that tested soils (concentration of 50 %) collected from the landfill body, edge of the landfill body and its vicinity reach high percentage values of germination capacity of seeds of Sinapis alba L. (101-137 %). At a concentration of 25 %, tested soil samples exhibit lower values of germination capacity; in particular samples 3 to 8, yet the seed germination capacity in all 8 samples of tested soils range between 86 and 137 %.

  9. Impact of using high-density polyethylene geomembrane layer as landfill intermediate cover on landfill gas extraction.

    PubMed

    Chen, Zezhi; Gong, Huijuan; Zhang, Mengqun; Wu, Weili; Liu, Yu; Feng, Jin

    2011-05-01

    Clay is widely used as a traditional cover material for landfills. As clay becomes increasingly costly and scarce, and it also reduces the storage capacity of landfills, alternative materials with low hydraulic conductivity are employed. In developing countries such as China, landfill gas (LFG) is usually extracted for utilization during filling stage, therefore, the intermediate covering system is an important part in a landfill. In this study, a field test of LFG extraction was implemented under the condition of using high-density polyethylene (HDPE) geomembrane layer as the only intermediate cover on the landfill. Results showed that after welding the HDPE geomembranes together to form a whole airtight layer upon a larger area of landfill, the gas flow in the general pipe increased 25% comparing with the design that the HDPE geomembranes were not welded together, which means that the gas extraction ability improved. However as the heat isolation capacity of the HDPE geomembrane layer is low, the gas generation ability of a shallow landfill is likely to be weakened in cold weather. Although using HDPE geomembrane layer as intermediate cover is acceptable in practice, the management and maintenance of it needs to be investigated in order to guarantee its effective operation for a long term. PMID:21232931

  10. Gas breakthrough and emission through unsaturated compacted clay in landfill final cover.

    PubMed

    Ng, C W W; Chen, Z K; Coo, J L; Chen, R; Zhou, C

    2015-10-01

    Determination of gas transport parameters in compacted clay plays a vital role for evaluating the effectiveness of soil barriers. The gas breakthrough pressure has been widely studied for saturated swelling clay buffer commonly used in high-level radioactive waste disposal facility where the generated gas pressure is very high (in the order of MPa). However, compacted clay in landfill cover is usually unsaturated and the generated landfill gas pressure is normally low (typically less than 10 kPa). Furthermore, effects of clay thickness and degree of saturation on gas breakthrough and emission rate in the context of unsaturated landfill cover has not been quantitatively investigated in previous studies. The feasibility of using unsaturated compacted clay as gas barrier in landfill covers is thus worthwhile to be explored over a wide range of landfill gas pressures under various degrees of saturation and clay thicknesses. In this study, to evaluate the effectiveness of unsaturated compacted clay to minimize gas emission, one-dimensional soil column tests were carried out on unsaturated compacted clay to determine gas breakthrough pressures at ultimate limit state (high pressure range) and gas emission rates at serviceability limit state (low pressure range). Various degrees of saturation and thicknesses of unsaturated clay sample were considered. Moreover, numerical simulations were carried out using a coupled gas-water flow finite element program (CODE-BRIGHT) to better understand the experimental results by extending the clay thickness and varying the degree of saturation to a broader range that is typical at different climate conditions. The results of experimental study and numerical simulation reveal that as the degree of saturation and thickness of clay increase, the gas breakthrough pressure increases but the gas emission rate decreases significantly. Under a gas pressure of 10 kPa (the upper bound limit of typical landfill gas pressure), a 0.6m or thicker compacted clay is able to prevent gas breakthrough at degree of saturation of 60% or above (in humid regions). Furthermore, to meet the limit of gas emission rate set by the Australian guideline, a 0.6m-thick clay layer may be sufficient even at low degree of saturation (i.e., 10% like in arid regions). PMID:26184895

  11. Scaling methane oxidation: From laboratory incubation experiments to landfill cover field conditions

    SciTech Connect

    Abichou, Tarek; Mahieu, Koenraad; Chanton, Jeff; Romdhane, Mehrez; Mansouri, Imane

    2011-05-15

    Evaluating field-scale methane oxidation in landfill cover soils using numerical models is gaining interest in the solid waste industry as research has made it clear that methane oxidation in the field is a complex function of climatic conditions, soil type, cover design, and incoming flux of landfill gas from the waste mass. Numerical models can account for these parameters as they change with time and space under field conditions. In this study, we developed temperature, and water content correction factors for methane oxidation parameters. We also introduced a possible correction to account for the different soil structure under field conditions. These parameters were defined in laboratory incubation experiments performed on homogenized soil specimens and were used to predict the actual methane oxidation rates to be expected under field conditions. Water content and temperature corrections factors were obtained for the methane oxidation rate parameter to be used when modeling methane oxidation in the field. To predict in situ measured rates of methane with the model it was necessary to set the half saturation constant of methane and oxygen, K{sub m}, to 5%, approximately five times larger than laboratory measured values. We hypothesize that this discrepancy reflects differences in soil structure between homogenized soil conditions in the lab and actual aggregated soil structure in the field. When all of these correction factors were re-introduced into the oxidation module of our model, it was able to reproduce surface emissions (as measured by static flux chambers) and percent oxidation (as measured by stable isotope techniques) within the range measured in the field.

  12. Methane oxidation potential of boreal landfill cover materials: The governing factors and enhancement by nutrient manipulation.

    PubMed

    Maanoja, Susanna T; Rintala, Jukka A

    2015-12-01

    Methanotrophs inhabiting landfill covers are in a crucial role in mitigating CH4 emissions, but the characteristics of the cover material or ambient temperature do not always enable the maximal CH4 oxidation potential (MOP). This study aimed at identifying the factors governing MOPs of different materials used for constructing biocovers and other cover structures. We also tested whether the activity of methanotrophs could be enhanced at cold temperature (4 and 12°C) by improving the nutrient content (NO3(-), PO4(3-), trace elements) of the cover material. Compost samples from biocovers designed to support CH4 oxidation were exhibiting the highest MOPs (4.16?molCH4gdw(-1)h(-1)), but also the soil samples collected from other cover structures were oxidising CH4 (0.41?molCH4gdw(-1)h(-1)). The best predictors for the MOPs were the NO3(-) content and activity of heterotrophic bacteria at 72.8%, which were higher in the compost samples than in the soil samples. The depletion of NO3(-) from the landfill cover material limiting the activity of methanotrophs could not be confirmed by the nutrient manipulation assay at 4°C as the addition of nitrogen decreased the MOPs from 0.090?molCH4gdw(-1)h(-1) to <0.085?molCH4gdw(-1)h(-1). At 12°C, all nutrient additions reduced the MOPs. The inhibition was believed to result from high ionic concentration caused by nutrient addition. At 4°C, the addition of trace elements increased the MOPs (>0.096?molCH4gdw(-1)h(-1)) suggesting that this was attributable to stimulation of the enzymatic activity of the psychrotolerant methanotrophs. PMID:26298483

  13. Design of top covers supporting aerobic in situ stabilization of old landfills - An experimental simulation in lysimeters

    SciTech Connect

    Hrad, Marlies; Huber-Humer, Marion; Wimmer, Bernhard; Reichenauer, Thomas G.

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Tested engineered covers as surrogate to gas extraction during and after in situ aeration. Black-Right-Pointing-Pointer Examined how covers influence gas emissions, water balance and leachate generation. Black-Right-Pointing-Pointer Investigated effect of top covers on air-distribution in waste mass during aeration. Black-Right-Pointing-Pointer We suggest criteria and cover design to meet the demands during and after aeration. Black-Right-Pointing-Pointer Such cover systems may offer greenhouse gas emission reduction also after active aeration. - Abstract: Landfill aeration by means of low pressure air injection is a promising tool to reduce long term emissions from organic waste fractions through accelerated biological stabilization. Top covers that enhance methane oxidation could provide a simple and economic way to mitigate residual greenhouse gas emissions from in situ aerated landfills, and may replace off-gas extraction and treatment, particularly at smaller and older sites. In this respect the installation of a landfill cover system adjusted to the forced-aerated landfill body is of great significance. Investigations into large scale lysimeters (2 Multiplication-Sign 2 Multiplication-Sign 3 m) under field conditions have been carried out using different top covers including compost materials and natural soils as a surrogate to gas extraction during active low pressure aeration. In the present study, the emission behaviour as well as the water balance performance of the lysimeters has been investigated, both prior to and during the first months of in situ aeration. Results reveal that mature sewage sludge compost (SSC) placed in one lysimeter exhibits in principle optimal ambient conditions for methanotrophic bacteria to enhance methane oxidation. Under laboratory conditions the mature compost mitigated CH{sub 4} loadings up to 300 l CH{sub 4}/m{sup 2} d. In addition, the compost material provided high air permeability even at 100% water holding capacity (WHC). In contrast, the more cohesive, mineral soil cover was expected to cause a notably uniform distribution of the injected air within the waste layer. Laboratory results also revealed sufficient air permeability of the soil materials (TS-F and SS-Z) placed in lysimeter C. However, at higher compaction density SS-Z became impermeable at 100% WHC. Methane emissions from the reference lysimeter with the smaller substrate cover (12-52 g CH{sub 4}/m{sup 2} d) were significantly higher than fluxes from the other lysimeters (0-19 g CH{sub 4}/m{sup 2} d) during in situ aeration. Regarding water balance, lysimeters covered with compost and compost-sand mixture, showed the lowest leachate rate (18-26% of the precipitation) due to the high water holding capacity and more favourable plant growth conditions compared to the lysimeters with mineral, more cohesive, soil covers (27-45% of the precipitation). On the basis of these results, the authors suggest a layered top cover system using both compost material as well as mineral soil in order to support active low-pressure aeration. Conventional soil materials with lower permeability may be used on top of the landfill body for a more uniform aeration of the waste due to an increased resistance to vertical gas flow. A compost cover may be built on top of the soil cover underlain by a gas distribution layer to improve methane oxidation rates and minimise water infiltration. By planting vegetation with a high transpiration rate, the leachate amount emanating from the landfill could be further minimised. The suggested design may be particularly suitable in combination with intermittent in situ aeration, in the later stage of an aeration measure, or at very small sites and shallow deposits. The top cover system could further regulate water infiltration into the landfill and mitigate residual CH{sub 4} emissions, even beyond the time of active aeration.

  14. Municipal Solid WasteMunicipal Solid Waste Landfills In CitiesLandfills In Cities

    E-print Network

    Columbia University

    -Section of Closure #12;Schedule III ­ Gazette 19 & 21 Specifications for Landfill Cover Daily cover of 10cm of soil;Post Closure Care-Requirements The Post-closure care of landfill site shall be conducted for at leastMunicipal Solid WasteMunicipal Solid Waste Landfills In CitiesLandfills In Cities Arun

  15. Cover Crops Soil Health Forum

    E-print Network

    New Hampshire, University of

    blinking light, onto Silk Farm Road. 4. Entrance to Center and Sanctuary is on the left. See sign. Cover Crops & Soil Health Forum February 18, 2014 NH Audubon Center 84 Silk Farm Road Concord, NH 03301

  16. Field Performance of A Compacted Clay Landfill Final cover At A Humid Site

    SciTech Connect

    Albright, William H.; Benson, Craig H.; Gee, Glendon W.; Abichou, Tarek; Mcdonald, Eric V.; Tyler, Scott W.; Rock, Steven

    2006-11-01

    A study was conducted in southern Georgia, USA to evaluate how the hydraulic properties of the compacted clay barrier layer in a landfill final cover changed over a 4-yr service life. The cover was part of a test section constructed in a large drainage lysimeter that allowed CE Database subject headings: landfill, hydrogeology, compacted soils, lysimeters, desiccation continuous monitoring of the water balance. Patterns in the drainage (i.e., flow from the bottom of the cover) record suggest that preferential flow paths developed in the clay barrier soon after construction, apparently in response to desiccation cracking. After four years, the clay barrier was excavated and examined for changes in soil structure and hydraulic conductivity. Tests were conducted in situ with a sealed double-ring infiltrometer and two-stage borehole permeameters and in the laboratory on hand-carved blocks taken during construction and after four years of service. The in situ and laboratory tests indicated that the hydraulic conductivity increased approximately three orders of magnitude (from ? 10-7 to ? 10-4 cm s-1) during the service life. A dye tracer test and soil structure analysis showed that extensive cracking and root development occurred throughout the entire depth of the barrier layer. Laboratory tests on undisturbed specimens of the clay barrier indicated that the hydraulic conductivity of damaged clay barriers can be under-estimated significantly if small specimens (e.g., tube samples) are used for hydraulic conductivity assessment. The findings also indicate that clay barriers must be protected from desiccation and root intrusion if they are expected to function as intended, even at sites in warm, humid locations.

  17. Geotechnical properties of paper mill sludges for use in landfill covers

    SciTech Connect

    Moo-Young, H.K.; Zimmie, T.F.

    1996-09-01

    This study investigates the geotechnical properties of seven paper mill sludges. Paper mill sludges have a high water content and a high degree of compressibility and behave like a highly organic soil. Consolidation tests reveal a large reduction in void ratio and high strain values that are expected due to the high compressibility. Triaxial shear-strength tests conducted on remolded and undisturbed samples showed variations in the strength parameters resulting from the differences in sludge composition (i.e., water content and organic content). Laboratory permeability tests conducted on in-situ specimens either met the regulatory requirement for the permeability of a landfill cover or were very close. With time, consolidation and dewatering of the paper sludge improved the permeability of cover. Freezing and thawing cycles increased the sludge permeability about one to two orders of magnitude. Maximum permeability changes occurred within 10 freeze and thaw cycles.

  18. Design of top covers supporting aerobic in situ stabilization of old landfills--an experimental simulation in lysimeters.

    PubMed

    Hrad, Marlies; Huber-Humer, Marion; Wimmer, Bernhard; Reichenauer, Thomas G

    2012-12-01

    Landfill aeration by means of low pressure air injection is a promising tool to reduce long term emissions from organic waste fractions through accelerated biological stabilization. Top covers that enhance methane oxidation could provide a simple and economic way to mitigate residual greenhouse gas emissions from in situ aerated landfills, and may replace off-gas extraction and treatment, particularly at smaller and older sites. In this respect the installation of a landfill cover system adjusted to the forced-aerated landfill body is of great significance. Investigations into large scale lysimeters (2 × 2 × 3m) under field conditions have been carried out using different top covers including compost materials and natural soils as a surrogate to gas extraction during active low pressure aeration. In the present study, the emission behaviour as well as the water balance performance of the lysimeters has been investigated, both prior to and during the first months of in situ aeration. Results reveal that mature sewage sludge compost (SSC) placed in one lysimeter exhibits in principle optimal ambient conditions for methanotrophic bacteria to enhance methane oxidation. Under laboratory conditions the mature compost mitigated CH(4) loadings up to 300 lCH(4)/m(2)d. In addition, the compost material provided high air permeability even at 100% water holding capacity (WHC). In contrast, the more cohesive, mineral soil cover was expected to cause a notably uniform distribution of the injected air within the waste layer. Laboratory results also revealed sufficient air permeability of the soil materials (TS-F and SS-Z) placed in lysimeter C. However, at higher compaction density SS-Z became impermeable at 100% WHC. Methane emissions from the reference lysimeter with the smaller substrate cover (12-52 g CH(4)/m(2)d) were significantly higher than fluxes from the other lysimeters (0-19 g CH(4)/m(2)d) during in situ aeration. Regarding water balance, lysimeters covered with compost and compost-sand mixture, showed the lowest leachate rate (18-26% of the precipitation) due to the high water holding capacity and more favourable plant growth conditions compared to the lysimeters with mineral, more cohesive, soil covers (27-45% of the precipitation). On the basis of these results, the authors suggest a layered top cover system using both compost material as well as mineral soil in order to support active low-pressure aeration. Conventional soil materials with lower permeability may be used on top of the landfill body for a more uniform aeration of the waste due to an increased resistance to vertical gas flow. A compost cover may be built on top of the soil cover underlain by a gas distribution layer to improve methane oxidation rates and minimise water infiltration. By planting vegetation with a high transpiration rate, the leachate amount emanating from the landfill could be further minimised. The suggested design may be particularly suitable in combination with intermittent in situ aeration, in the later stage of an aeration measure, or at very small sites and shallow deposits. The top cover system could further regulate water infiltration into the landfill and mitigate residual CH(4) emissions, even beyond the time of active aeration. PMID:22749719

  19. Prediction of long-term erosion from landfill covers in the southwest

    SciTech Connect

    Anderson, C.E.; Stormont, J.C.

    1997-12-31

    Erosion is a primary stressor of landfill covers, especially for climates with high intensity storms and low native plant density. Rills and gullies formed by discrete events can damage barrier layers and induce failure. Geomorphologic, empirical and physical modeling procedures are available to provide estimates of surface erosion, but numerical modeling requires accurate representation of the severe rainfall events that generate erosion. The National Weather Service precipitation frequency data and estimates of 5, 10, 15, 30 and 60-minute intensity can be statistically combined in a numerical model to obtain long-term erosion estimates. Physically based numerical models using the KINEROS and AHYMO programs have been utilized to predict the erosion from a southwestern landfill or waste containment site with 0.03, 0.05 and 0.08 meter per meter surface slopes. Results of AHYMO modeling were within 15 percent of average annual values computed with the empirical Universal Soil Loss Equation. However, the estimation of rill and gully formation that primarily degrades cover systems requires quantifying single events. For Southwestern conditions, a single 10-year storm can produce erosion quantifies equal to three times the average annual erosion and a 100-year storm can produce five times the average annual erosion.

  20. Toxicity Assessment of Contaminated Soils of Solid Domestic Waste Landfill

    NASA Astrophysics Data System (ADS)

    Pasko, O. A.; Mochalova, T. N.

    2014-08-01

    The paper delivers the analysis of an 18-year dynamic pattern of land pollutants concentration in the soils of a solid domestic waste landfill. It also presents the composition of the contaminated soils from different areas of the waste landfill during its operating period. The authors calculate the concentrations of the following pollutants: chrome, nickel, tin, vanadium, lead, cuprum, zinc, cobalt, beryllium, barium, yttrium, cadmium, arsenic, germanium, nitrate ions and petrochemicals and determine a consistent pattern of their spatial distribution within the waste landfill area as well as the dynamic pattern of their concentration. Test-objects are used in experiments to make an integral assessment of the polluted soil's impact on living organisms. It was discovered that the soil samples of an animal burial site are characterized by acute toxicity while the area of open waste dumping is the most dangerous in terms of a number of pollutants. This contradiction can be attributed to the synergetic effect of the polluted soil, which accounts for the regularities described by other researchers.

  1. Deployment of an alternative cover and final closure of the Mixed Waste Landfill, Sandia National Laboratories, Albuquerque, New Mexico.

    SciTech Connect

    Peace, Gerald L.; Goering, Timothy James; McVey, Michael David (GRAM, Inc., Albuquerque, NM); Borns, David James

    2003-06-01

    An alternative cover design consisting of a monolithic layer of native soil is proposed as the closure path for the Mixed Waste Landfill at Sandia National Laboratories, New Mexico. The proposed design would rely upon soil thickness and evapotranspiration to provide long-term performance and stability, and would be inexpensive to build and maintain. The proposed design is a 3-ft-thick, vegetated soil cover. The alternative cover meets the intent of RCRA Subtitle C regulations in that: (a) water migration through the cover is minimized; (b) maintenance is minimized by using a monolithic soil layer; (c) cover erosion is minimized by using erosion control measures; (d) subsidence is accommodated by using a ''soft'' design; and (e) the permeability of the cover is less than or equal to that of natural subsurface soil present. Performance of the proposed cover is integrated with natural site conditions, producing a ''system performance'' that will ensure that the cover is protective of human health and the environment. Natural site conditions that will produce a system performance include: (a) extremely low precipitation and high potential evapotranspiration; (b) negligible recharge to groundwater; (c) an extensive vadose zone; (d) groundwater approximately 500 ft below the surface; and (e) a versatile, native flora that will persist indefinitely as a climax ecological community with little or no maintenance.

  2. Alternative Landfill Cover and Monitoring Systems for Landfills in Arid Environments

    SciTech Connect

    S. E. Rawlinson

    2002-09-01

    In December 2000, a performance monitoring facility was constructed adjacent to the mixed waste disposal unit U-3ax/bl at the Area 3 Radioactive Waste Management Site at the Nevada Test Site. This facility consists of eight drainage lysimeters measuring 10 feet in diameter, 8 feet deep, and backfilled with native soil. The lysimeters have three different surface treatments: two were left bare, two were revegetated with native species, and two were allowed to revegetate with invader species (two are reserved for future studies). The lysimeters are instrumented with an array of soil water content and soil water potential sensors and have sealed bottoms so that any drainage can be measured. All sensors are working properly and indicate that the bare lysimeters are the wettest, as expected. The vegetated lysimeters, both seeded and those allowed to revegetate with invader species, are significantly drier than the bare cover treatments. No drainage has occurred in any of the lysimeters. The Accelerated Site Technology Deployment program under the U.S. Department of Energy's Office of Science and Technology provided the funding for this project with the objective of reducing the uncertainty associated with the performance of monolayer-evapotranspiration waste covers in arid regions such as the one deployed at U-3ax/bl.

  3. Use of the time domain reflectrometry in hydraulic studies of multilayered landfill covers for closure of waste landfills at Los Alamos, New Mexico

    SciTech Connect

    Nyhan, J.W.; Schofield, T.G.; Martin, C.E.

    1994-04-01

    The Los Alamos National Laboratory examined water balance relationships for four different landfill cover designs containing hydraulic and capillary engineered barriers. Seepage is being evaluated as a function of slope length for each plot, as well as interflow, runoff, and precipitation, using an automated water flow datalogging system that routinely collects hourly data. Soil water content within these 16 field plots has been routinely monitored four times a day since November 1991 using time domain reflectrometry techniques with an automated and multiplexed measurement system. Volumetric water content is measured with a pair of 60-cm-long waveguides at each of 212 locations. One set of waveguides was emplaced vertically in four locations in every soil layer to determine soil water inventory in each field plot. A second set of waveguides was emplaced horizontally in several soil layers to provide a more detailed picture of soil water dynamics close to soil layer interfaces. Field data is presented showing pulses of soil water moving through the soil and engineered barriers with high temporal and spatial resolution.

  4. Water balance relationships in four alternative cover designs for radioactive and mixed waste landfills

    SciTech Connect

    Warren, R.W.; Hakonson, T.E.; Trujillo, G.

    1994-08-01

    Preliminary results are presented from a field study to evaluate the relative hydrologic performance of various landfill capping technologies installed by the Los Alamos National Laboratory at Hill Air Force Base, Utah. Four cover designs (two Los Alamos capillary barrier designs, one modified EPA RCRA design, and one conventional design) were installed in large lysimeters instrumented to monitor the fate of natural precipitation between 01 January 1990 and 20 September 1993. After 45 months of study, results showed that the cover designs containing barrier layers were effective in reducing deep percolation as compared to a simple soil cap design. The RCRA cover, incorporating a clay hydraulic barrier, was the most effective of all cover designs in controlling percolation but was not 100% effective. Over 90% of all percolation and barrier lateral flow occurred during the months of February through May of each year, primarily as a result of snow melt, early spring rains and low evapotranspiration. Gravel mulch surface treatments (70--80% coverage) were effective in reducing runoff and erosion. The two plots receiving gravel mulch treatments exhibited equal but enhanced amounts of evapotranspiration despite the fact that one plot was planted with additional shrubs.

  5. Steel slag used in landfill cover liners: laboratory and field tests.

    PubMed

    Herrmann, Inga; Andreas, Lale; Diener, Silvia; Lind, Lotta

    2010-12-01

    Stricter rules for landfilling within the EU have led to the closure of many landfills and a need for large amounts of cover liner materials. Therefore, the potential utilization of mixtures of electric arc furnace slag (EAFS) and ladle slag (LS), which are currently deposited in landfills, as a material for use as landfill liner was investigated. Laboratory analyses showed the mixtures to have similar compression strength to that of high-strength concrete and low hydraulic conductivity (< 10(-11) m s(-1) in some cases). However, both their hydraulic conductivity and compaction properties were strongly affected by the time between adding water to the mixtures and compacting them (tests showed that a delay of 24 h can lead to an increase in hydraulic conductivity, so it should be compacted as soon as possible after mixing the material with water). In addition, the performance of a cover liner constructed using EAFS and LS was studied in a 2-year field trial on a landfill for municipal solid waste, in which the average amount of leachate collected from ten lysimeters was only 27 L m(-2) year(-1), easily meeting Swedish criteria for the permeability of covers on non-hazardous waste landfills (? 50 L m(-2) year(-1)). Thus, the material seems to have promising potential for use in barrier constructions. PMID:20421245

  6. Landfill cover revegetation using organic amendments and cobble mulch in the arid southwest

    SciTech Connect

    AGUILAR,RICHARD; DWYER,STEPHEN F.; REAVIS,BRUCE A.; NEWMAN,GRETCHEN CARR; LOFTIN,SAMUEL R.

    2000-02-01

    Cobble mulch and composted biosolids, greenwaste, and dairy manure were added to arid soil in an attempt to improve plant establishment and production, minimize erosion, increase evapotranspiration, and reduce leaching. Twenty-four plots (10 x 10 m) were established in a completely randomized block design (8 treatments, 3 plots per treatment). Treatments included (1) non-irrigated control, (2) irrigated control, (3) non-irrigated greenwaste compost (2.5 yd{sup 3} per plot), (4) irrigated greenwaste compost (5 yd{sup 3} per plot), (5) non-irrigated biosolids compost (2.5 yd{sup 3} per plot), (6) irrigated biosolids compost (5 yd{sup 3} per plot), (7) cobble-mulch, and (8) non-irrigated dairy manure compost (2.5 yd{sup 3} per plot). Soil samples were collected from each plot for laboratory analyses to assess organic matter contents, macro-nutrient levels and trace metal contents, and nitrogen mineralization potential. All plots were seeded similarly with approximately equal portions of cool and warm season native grasses. The organic composts (greenwaste, biosolids, dairy manure) added to the soils substantially increased soil organic matter and plant nutrients including total nitrogen and phosphorus. However, the results of a laboratory study of the soils' nitrogen mineralization potential after the application of the various composts showed that the soil nitrogen-supplying capability decreased to non-amended soil levels by the start of the second growing season. Thus, from the standpoint of nitrogen fertilizer value, the benefits of the organic compost amendments appear to have been relatively short-lived. The addition of biosolids compost, however, did not produce significant changes in the soils' copper, cadmium, lead, and zinc concentrations and thus did not induce adverse environmental conditions due to excessive heavy metal concentrations. Supplemental irrigation water during the first and second growing seasons did not appear to increase plant biomass production in the irrigated control plots over that produced in the non-irrigated control plots. This surprising result was probably due to the cumulative effects of other factors that influenced the initial establishment and production of plants in the plots (e.g., plant species competition, seed germination delay times, differences in nutrient release and availability). Variation within individual plots, and among the three replicate plots associated with each treatment, rendered many of the recorded differences in vegetation establishment and production statistically insignificant. However, after two complete growing seasons the highest total plant foliar cover and the greatest biomass production and plant species diversity occurred in the cobble-mulched plots. These results suggest that cobble-mulch may be the desired amendment in re-vegetated arid landfill covers if the principal objectives are to quickly establish vegetation cover, stabilize the site from erosion, and increase water usage by plants, thereby reducing the potential for leaching and contaminant movement from the landfill's waste-bearing zone.

  7. A RULE-BASED SYSTEM FOR EVALUATING FINAL COVERS FOR HAZARDOUS WASTE LANDFILLS

    EPA Science Inventory

    This chapter examines how rules are used as a knowledge representation formalism in the domain of hazardous waste management. A specific example from this domain involves performance evaluation of final covers used to close hazardous waste landfills. Final cover design and associ...

  8. Field Performance Of A Compacted Clay Landfill Final Cover At A Humid Site

    EPA Science Inventory

    A study was conducted in southern Georgia, USA, to evalaute how the hydraulic properties of the compacted clay barrier layer in a final landfill cover changed over a 4-year service life. The cover was part of a test section constructed in a large drainage lysimeter that allowed ...

  9. Soil chemistry and pollution study of a closed landfill site at Ampar Tenang, Selangor, Malaysia.

    PubMed

    Mohd Adnan, Siti Nur Syahirah Binti; Yusoff, Sumiani; Piaw, Chua Yan

    2013-06-01

    A total of 20 landfills are located in State of Selangor, Malaysia. This includes the Ampar Tenang landfill site, which was closed on 26 January 2010. It was reported that the landfill has been upgraded to a level I type of sanitary classification. However, the dumpsite area is not being covered according to the classification. In addition, municipal solid waste was dumped directly on top of the unlined natural alluvium formation. This does not only contaminate surface and subsurface soils, but also initiates the potential risk of groundwater pollution. Based on previous studies, the Ampar Tenang soil has been proven to no longer be capable of preventing pollution migration. In this study, metal concentrations of soil samples up to 30 m depth were analyzed based on statistical analysis. It is very significant because research of this type has not been carried out before. The subsurface soils were significantly polluted by arsenic (As), lead (Pb), iron (Fe), copper (Cu) and aluminium (Al). As and Pb exceeded the safe limit values of 5.90 mg/kg and 31.00 mg/kg, respectively, based on Provincial Sediment Quality Guidelines for Metals and the Interim Sediment Quality Values. Furthermore, only Cu concentrations showed a significantly decreasing trend with increasing depth. Most metals were found on clay-type soils based on the cluster analysis method. Moreover, the analysis also differentiates two clusters: cluster I-Pb, As, zinc, Cu, manganese, calcium, sodium, magnesium, potassium and Fe; cluster II-Al. Different clustering may suggest a different contamination source of metals. PMID:23528999

  10. A process-based inventory model for landfill CH4 emissions inclusive of seasonal soil microclimate and CH4 oxidation

    NASA Astrophysics Data System (ADS)

    Spokas, K.; Bogner, J.; Chanton, J.

    2011-12-01

    We have developed and field-validated an annual inventory model for California landfill CH4 emissions that incorporates both site-specific soil properties and soil microclimate modeling coupled to 0.5° scale global climatic models. Based on 1-D diffusion, CALMIM (California Landfill Methane Inventory Model) is a freely available JAVA tool which models a typical annual cycle for CH4 emissions from site-specific daily, intermediate, and final landfill cover designs. Literature over the last decade has emphasized that the major factors controlling emissions in these highly managed soil systems are the presence or absence of engineered gas extraction, gaseous transport rates as affected by the thickness and physical properties of cover soils, and methanotrophic CH4 oxidation in cover materials as a function of seasonal soil microclimate. Moreover, current IPCC national inventory models for landfill CH4 emissions based on theoretical gas generation have high uncertainties and lack comprehensive field validation. This new approach, which is compliant with IPCC "Tier III" criteria, has been field-validated at two California sites (Monterey County; Los Angeles County), with limited field validation at three additional California sites. CALMIM accurately predicts soil temperature and moisture trends with emission predictions within the same order of magnitude as field measurements, indicating an acceptable initial model comparison in the context of published literature on measured CH4 emissions spanning 7 orders of magnitude. In addition to regional defaults for inventory purposes, CALMIM permits user-selectable parameters and boundary conditions for more rigorous site-specific applications where detailed CH4 emissions, meteorological, and soil microclimate data exist.

  11. Two-year performance by evapotranspiration covers for municipal solid waste landfills in northwest Ohio

    SciTech Connect

    Barnswell, Kristopher D.; Dwyer, Daryl F.

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer All ET covers produced rates of percolation less than 32 cm yr{sup -1}, the maximum allowable rate by the Ohio EPA. Black-Right-Pointing-Pointer Dredged sediment provided sufficient water storage and promoted growth by native plant species. Black-Right-Pointing-Pointer Native plant mixtures attained acceptable rates of evapotranspiration throughout the growing season. - Abstract: Evapotranspiration (ET) covers have gained interest as an alternative to conventional covers for the closure of municipal solid waste (MSW) landfills because they are less costly to construct and are expected to have a longer service life. Whereas ET covers have gained acceptance in arid and semi-arid regions (defined by a precipitation (P) to potential evapotranspiration (PET) ratio less than 0.75) by meeting performance standards (e.g. rate of percolation), it remains unclear whether they are suitable for humid regions (P:PET greater than 0.75). The goal of this project is to extend their application to northwest Ohio (P:PET equals 1.29) by designing covers that produce a rate of percolation less than 32 cm yr{sup -1}, the maximum acceptable rate by the Ohio Environmental Protection Agency (OEPA). Test ET covers were constructed in drainage lysimeters (1.52 m diameter, 1.52 m depth) using dredged sediment amended with organic material and consisted of immature (I, plants seeded onto soil) or mature (M, plants transferred from a restored tall-grass prairie) plant mixtures. The water balance for the ET covers was monitored from June 2009 to June 2011, which included measured precipitation and percolation, and estimated soil water storage and evapotranspiration. Precipitation was applied at a rate of 94 cm yr{sup -1} in the first year and at rate of 69 cm yr{sup -1} in the second year. During the first year, covers with the M plant mixture produced noticeably less percolation (4 cm) than covers with the I plant mixture (17 cm). However, during the second year, covers with the M plant mixture produced considerably more percolation (10 cm) than covers with the I plant mixture (3 cm). This is likely due to a decrease in the aboveground biomass for the M plant mixture from year 1 (1008 g m{sup -2}) to year 2 (794 g m{sup -2}) and an increase for the I plant mixture from year 1 (644 g m{sup -2}) to year 2 (1314 g m{sup -2}). Over the 2-year period, the mean annual rates of percolation for the covers with the M and I plant mixtures were 7 and 8 cm yr{sup -1}, which are below the OEPA standard. The results suggest the application of ET covers be extended to northwest Ohio and other humid regions.

  12. Cover crops to enhance soil biological activity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cover crops can be an important component of conservation agricultural systems in the eastern USA. This presentation summarizes some of the benefits derived from cover crops, how cover crops impact soil biological activity, and how soil biological activity can be used to assess the sustainability o...

  13. Reuse of MSWI bottom ash mixed with natural sodium bentonite as landfill cover material.

    PubMed

    Puma, Sara; Marchese, Franco; Dominijanni, Andrea; Manassero, Mario

    2013-06-01

    The research described in this study had the aim of evaluating the reuse of incinerator slag, mixed with sodium bentonite, for landfill capping system components. A characterization was performed on pure bottom ash (BA) samples from an incinerator in the north of Italy. The results show that the BA samples had appropriate properties as covers. The compacted dry unit weight of the studied BA (16.2 kN m(-3)) was lower than the average value that characterizes most conventional fill materials and this can be considered advantageous for landfill cover systems, since the fill has to be placed on low bearing capacity ground or where long-term settlement is possible. Moreover, direct shear tests showed a friction angle of 43°, corresponding to excellent mechanical characteristics that can be considered an advantage against failure. The hydraulic conductivity tests indicated a steady-state value of 8 × 10(-10) m s(-1) for a mixture characterized by a bentonite content by weight of 10%, which was a factor 10 better than required by Italian legislation on landfill covers. The results from a swell index test indicated that fine bentonite swelled, even when divalent cations were released by the BA. The leaching behaviour of the mixture did not show any contamination issues and was far better than obtained for the pure BA. Thus, the BA-bentonite mixture qualified as a suitable material for landfill cover in Italy. Moreover, owing to the low release of toxic compounds, the proposed cover system would have no effect on the leachate quality in the landfill. PMID:23478909

  14. A water balance study of four landfill cover designs varying in slope for semiarid regions

    SciTech Connect

    Nyhan, J.W.; Schofield, T.G.; Salazar, J.A.

    1997-02-01

    The goal of disposing of radioactive and hazardous waste in shallow landfills is to reduce risk to human health and to the environment by isolating contaminants until they no longer pose a hazard. In order to achieve this, the performance of a landfill cover design without an engineered barrier (Conventional Design) was compared with three designs containing either a hydraulic barrier (EPA Design) or a capillary barrier (Loam and Clay Loam Capillary Barrier Designs). Water balance parameters were measured since 1991 at six-hour intervals for four different landfill cover designs in 1.0- by 10.0-m plots with downhill slopes of 5, 10, 15, and 25%. Whereas runoff generally accounted for only 2-3% of the precipitation losses on these designs, similar values for evapotranspiration ranged from 86% to 91%, with increased evapotranspiration occurring with increases in slope. Consequently, interflow and seepage usually decreased with increasing slope for each landfill cover design. Seepage consisted of up to 10% of the precipitation on the Conventional Design, whereas the hydraulic barrier in the EPA Design effectively controlled seepage at all slopes, and both of the capillary designs worked effectively to eliminate seepage at the higher slopes.

  15. Geological and geotechnical characteristics of Metro Manila volcanic soils and their suitability for landfill soil liner

    NASA Astrophysics Data System (ADS)

    Mendoza, Edna Patricia; Catane, Sandra; Pascua, Chelo; Zarco, Mark Albert

    2010-05-01

    Due to the Philippines's island-arc setting, andesitic tuff and volcanic ash constitute two-thirds of the country's agricultural land. In situ weathering of these volcanic sediments produces volcanic soils. Metro Manila volcanic soils were studied to determine their suitability for landfill soil liner. The soils were analyzed using XRD and XRF, and were tested for geotechnical properties. The results show the presence of the smectite group, a swelling variety of clay. The smectite-type clays are weathering products of volcanic glasses which are dominant components of the parental rocks. The high amounts of Al2O3 indicate an Al-rich type of soil. The clay species is either di- or tri-octahedral type, which points to montmorillonite as the main clay species. Swelling clay lowers the permeability of soils and reduces the infiltration and lateral movement of leachates in the ground. Also, geotechnical tests revealed moderate to high plasticity indices and low hydraulic conductivity values. The study shows that the physicochemical characteristics of volcanic soils meet the criteria for a soil liner for future sanitary landfill projects as mandated by RA 9003, a recently ratified solid waste management act of the Philippines. Being widespread, volcanic soils can be viewed as an important resource of the country.

  16. CHEMICAL AND PHYSICAL EFFECTS OF MUNICIPAL LANDFILLS ON UNDERLYING SOILS AND GROUNDWATER

    EPA Science Inventory

    Three municipal landfill sites in the eastern and central United States were studied to determine the effects of the disposal facilities on surrounding soils and groundwater. Borings were made up the groundwater gradient, down the groundwater gradient and through the landfill. So...

  17. Ambient air monitoring of the beneficial use of municipal waste combustor (MWC) ash as daily landfill cover

    SciTech Connect

    Magee, B.H.; Miller, A.C.; Hahn, J.L.; Jones, C.M.

    1997-12-01

    This paper summarizes Human Health Risk Assessments of the proposed use of combined ash from the H-Power municipal waste combustor (MWC) in two beneficial uses: (1) Landfill Daily Cover for the Waimanalo Gulch Sanitary Landfill in Ewa, O`ahu, Hawaii, which is operated by Waste Management of Hawaii, Inc. for the City and County of Honolulu and (2) Landfill Final Cover, a component in the final cover of the Waipahu landfill, in Waipahu, O`ahu, Hawaii. The human health risk assessment represents one phase of a larger project involving the investigation of several potential uses of H-Power MWC ash as alternatives to the current practice of disposal in a lined monofill located at the Waimanalo Gulch Sanitary Landfill. The ash consists of approximately 70% bottom ash and 30% fly ash from the MWC, hereafter referred to as H-Power combined ash. At this time, three alternative uses of H-Power combined ash have been identified: The first option consists of using H-Power combined ash as a component in the final cover in the closure of the Waipahu Landfill; the second option consists of using H-Power combined ash as daily cover at the Waimanalo Gulch Sanitary Landfill; and, the third option consists of mixing H-Power combined ash into aggregate to be used in roadway paving material.

  18. Future landfill emissions and the effect of final cover installation--a case study.

    PubMed

    Laner, David; Fellner, Johann; Brunner, Paul H

    2011-07-01

    Municipal solid waste (MSW) landfills are potential long-term sources of emissions. Hence, they need to be managed after closure until they do not pose a threat to humans or the environment. The case study on the Breitenau MSW landfill was performed to evaluate future emission levels for this site and to illustrate the effect of final cover installation with respect to long-term environmental risks. The methodology was based on a comprehensive assessment of the state of the landfill and included analysis of monitoring data, investigations of landfilled waste, and an evaluation of containment systems. A model to estimate future emission levels was established and site-specific predictions of leachate emissions were presented based on scenario analysis. The results are used to evaluate the future pollution potential of the landfill and to compare different aftercare concepts in view of long-term emissions. As some leachable substances became available for water flow during cover construction due to a change in the water flow pattern of the waste, a substantial increase in leachate concentrations could be observed at the site (e.g. concentrations of chloride increased from 200 to 800 mg/l and of ammonia-nitrogen from 140 to about 500 mg/l). A period of intensive flushing before the final cover installation could have reduced the amount of leachable substances within the landfill body and rapidly decreased the leachate concentrations to 11 mg Cl/l and 79 mg NH(4)-N/l within 50 years. Contrarily, the minimization of water infiltration is associated with leachate concentrations in a high range for centuries (above 400 mg Cl/l and 200 mg NH(4)-N/l) with low concomitant annual emission loads (below 12 kg/year of Cl or 9 kg/year of NH(4)-N, respectively). However, an expected gradual decrease of barrier efficiency over time would be associated with higher emission loads of 50 kg of chloride and 30 kg of ammonia-nitrogen at the maximum, but a faster decrease of leachate concentration levels. PMID:21421299

  19. Methane flux and oxidation at two types of intermediate landfill covers

    SciTech Connect

    Abichou, Tarek . E-mail: abichou@eng.fsu.edu; Chanton, Jeffery; Powelson, David; Fleiger, Jill; Escoriaza, Sharon; Lei, Yuan; Stern, Jennifer

    2006-07-01

    Methane emissions were measured on two areas at a Florida (USA) landfill using the static chamber technique. Because existing literature contains few measurements of methane emissions and oxidation in intermediate cover areas, this study focused on field measurement of emissions at 15-cm-thick non-vegetated intermediate cover overlying 1-year-old waste and a 45-cm-thick vegetated intermediate cover overlying 7-year-old waste. The 45 cm thick cover can also simulate non-engineered covers associated with older closed landfills. Oxidation of the emitted methane was evaluated using stable isotope techniques. The arithmetic means of the measured fluxes were 54 and 22 g CH{sub 4} m{sup -2} d{sup -1} from the thin cover and the thick cover, respectively. The peak flux was 596 g m{sup -2} d{sup -1} for the thin cover and 330 g m{sup -2} d{sup -1} for the thick cover. The mean percent oxidation was significantly greater (25%) at the thick cover relative to the thin cover (14%). This difference only partly accounted for the difference in emissions from the two sites. Inverse distance weighing was used to describe the spatial variation of flux emissions from each cover type. The geospatial mean flux was 21.6 g m{sup -2} d{sup -1} for the thick intermediate cover and 50.0 g m{sup -2} d{sup -1} for the thin intermediate cover. High emission zones in the thick cover were fewer and more isolated, while high emission zones in the thin cover were continuous and covered a larger area. These differences in the emission patterns suggest that different CH{sub 4} mitigation techniques should be applied to the two areas. For the thick intermediate cover, we suggest that effective mitigation of methane emissions could be achieved by placement of individualized compost cells over high emission zones. Emissions from the thin intermediate cover, on the other hand, can be mitigated by placing a compost layer over the entire area.

  20. Site Specific Landfill CH4 Emissions: Shortcomings of National GHG Inventory Guidelines and a New Process-Based Approach Linked to Climate and Soil Microclimate

    NASA Astrophysics Data System (ADS)

    Bogner, J. E.; Spokas, K.; Corcoran, M.

    2012-12-01

    Current (2006) IPCC national GHG inventory guidelines for landfill CH4, which estimate CH4 generation from the mass of waste in place, have high uncertainties, cannot be reliably related to measured emissions at specific sites, and lack comprehensive field validation. Moreover, measured landfill CH4 emissions vary over a wide range from >1000 g/m2/d down to negative values (uptake of atmospheric CH4). Literature over the last decade has emphasized that the major factors controlling emissions in these highly managed soil systems are gaseous transport rates as affected by the thickness and physical properties of cover soils, methanotrophic CH4 oxidation in cover materials as a function of seasonal soil microclimate. and the presence or absence of engineered gas extraction. Thus we developed and field validated a new site specific annual inventory model that incorporates specific soil profile properties and soil microclimate modeling coupled to 0.5° scale global climatic models. Based on 1D diffusion, CALMIM (California Landfill Methane Inventory Model) is a freely available JAVA tool which models a typical annual cycle for CH4 emissions from site specific daily, intermediate, and final landfill cover designs. This new approach, which is compliant with IPCC Tier III criteria, was originally field validated at two California sites (Monterey County; Los Angeles County), with limited field validation at three additional California sites. In addition to regional defaults for inventory purposes, CALMIM permits user selectable parameters and boundary conditions for more rigorous site specific applications where detailed CH4 emissions, meteorological, and soil microclimate data exist. We report here on improvements and expanded international field validation for CALMIM 5.2 in collaboration with research groups in the U.S., Europe, Africa, Asia, and Australia.odeled and measured annual cycle of landfill CH4 emissions for Austrian site. Cover consists of 50 cm sand & gravel overlain by 110 cm loam & sandy loam. No gas recovery. Site 100% vegetated.

  1. Winter cover biomass production and soil penetrability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Winter cover crops can benefit production systems in the southeastern US. Winter cover crops, such as rye (Secale cereale) can reduce weed pressure, increase water infiltration, and improve soil quality over a long period of time. Although several studies have focused on the effects of having a wi...

  2. [Effects of dissolved organic matter in landfill leachate on soil Cd- and Pb bioavailability].

    PubMed

    Fu, Meiyun; Zhou, Lixiang

    2006-07-01

    A pot experiment was conducted to study the effects of dissolved organic matter (DOM) in landfill leachate on ryegrass growth and its uptake of soil Cd and Pb. Fresh sample and Shuige leachate were collected from the municipal waste landfills established 0 and 12 years, respectively. The results showed that after the landfill leachate added, the average concentration of DOM remained in soil was 1.39 (fresh sample) and 1.47 (Shuige) times higher than the control (CK). The bioavailability of Cd and Pb in the soils treated with the two leachates was fluctuated in early period, and then raised. Compared with CK, the bioavailability of soil Cd was increased by 4.81% (fresh sample) and 48.97% (Shuige), and that of soil Pb was enhanced by 7.22% (fresh sample) and 18.99% (Shuige). The total concentrations of plant Cd and Pb in the treatments of fresh sample and Shuige were 19.59% and 104.4%, and 36.03% and 44. 66% higher than CK, respectively, while the total biomass of ryegrass was decreased by 14.03% to approximately 52.24%, in compared with CK. It could be inferred that the dissolved organic matter (DOM) in landfill leachate, especially in that from the landfills established for a longer time, could enhance the bioavailability of soil heavy metals and their accumulation in plant, and thus, suppress the growth of plants. PMID:17044510

  3. PREDICTION/MITIGATION OF SUBSIDENCE DAMAGE TO HAZARDOUS WASTE LANDFILL COVERS

    EPA Science Inventory

    Characteristics of Resource Conservation and Recovery Act hazardous waste landfills and of landfilled hazardous wastes have been described to permit development of models and other analytical techniques for predicting, reducing, and preventing landfill settlement and related cove...

  4. Global climate changes and the soil cover

    NASA Astrophysics Data System (ADS)

    Kudeyarov, V. N.; Demkin, V. A.; Gilichinskii, D. A.; Goryachkin, S. V.; Rozhkov, V. A.

    2009-09-01

    The relationships between climate changes and the soil cover are analyzed. The greenhouse effect induced by the rising concentrations of CO2, CH4, N2O, and many other trace gases in the air has been one of the main factors of the global climate warming in the past 30-40 years. The response of soils to climate changes is considered by the example of factual data on soil evolution in the dry steppe zone of Russia. Probable changes in the carbon cycle under the impact of rising CO2 concentrations are discussed. It is argued that this rise may have an effect of an atmospheric fertilizer and lead to a higher productivity of vegetation, additional input of organic residues into the soils, and activation of soil microflora. Soil temperature and water regimes, composition of soil gases, soil biotic parameters, and other dynamic soil characteristics are most sensitive to climate changes. For the territory of Russia, in which permafrost occupies more than 50% of the territory, the response of this highly sensitive natural phenomenon to climate changes is particularly important. Long-term data on soil temperatures at a depth of 40 cm are analyzed for four large regions of Russia. In all of them, except for the eastern sector of Russian Arctic, a stable trend toward the rise in the mean annual soil temperature. In the eastern sector (the Verkhoyansk weather station), the soil temperature remains stable.

  5. Soils and the soil cover of the Valley of Geysers

    NASA Astrophysics Data System (ADS)

    Kostyuk, D. N.; Gennadiev, A. N.

    2014-06-01

    The results of field studies of the soil cover within the tourist part of the Valley of Geysers in Kamchatka performed in 2010 and 2011 are discussed. The morphology of soils, their genesis, and their dependence on the degree of hydrothermal impact are characterized; the soil cover patterns developing in the valley are analyzed. On the basis of the materials provided by the Kronotskii Biospheric Reserve and original field data, the soil map of the valley has been developed. The maps of vegetation conditions, soil temperature at the depth of 15 cm, and slopes of the surface have been used for this purpose together with satellite imagery and field descriptions of reference soil profiles. The legend to the soil map includes nine soil units and seven units of parent materials and their textures. Soil names are given according to the classification developed by I.L. Goldfarb (2005) for the soils of hydrothermal fields. The designation of soil horizons follows the new Classification and Diagnostic System of Russian Soils (2004). It is suggested that a new horizon—a thermometamorphic horizon TRM—can be introduced into this system by analogy with other metamorphic (transformed in situ) horizons distinguished in this system. This horizon is typical of the soils partly or completely transformed by hydrothermal impacts.

  6. Effects of substrate induced respiration on the stability of bottom ash in landfill cover environment.

    PubMed

    Ilyas, A; Lovat, E; Persson, K M

    2014-12-01

    The municipal solid waste incineration bottom ash is being increasingly used to construct landfill covers in Sweden. In post-closure, owing to increased cover infiltration, the percolating water can add external organic matter to bottom ash. The addition and subsequent degradation of this external organic matter can affect metal mobility through complexation and change in redox conditions. However, the impacts of such external organic matter addition on bottom ash stability have not been fully evaluated yet. Therefore, the objective of this study was to evaluate the impact of external organic matter on bottom ash respiration and metal leaching. The samples of weathered bottom ash were mixed with oven dried and digested wastewater sludge (1%-5% by weight). The aerobic respiration activity (AT4), as well as the leaching of metals, was tested with the help of respiration and batch leaching tests. The respiration and heavy metal leaching increased linearly with the external organic matter addition. Based on the results, it was concluded that the external organic matter addition would negatively affect the quality of landfill cover drainage. PMID:25395160

  7. LEACHATE CLOGGING ASSESSMENT OF GEOTEXTILE AND SOIL LANDFILL FILTERS

    EPA Science Inventory

    The liquids management strategy for any municipal or hazardous waste landfill requires a knowledgeable design strategy for the leachate collection system located at the base of the waste mass. Such leachate collection systems generally consist of sumps, perforated pipes, drainag...

  8. A Water Balance Study of Four Landfill Cover Designs at Material Disposal Area B in Los Alamos, New Mexico

    SciTech Connect

    David D. Breshears; Fairley J. Barnes; John W. Nyhan; Johnny A. Salazar

    1998-09-01

    The goal of disposing of low-level radioactive and hazardous waste in shallow landfills is to reduce risk to human health and the environment by isolating contaminants until they no longer pose an unacceptable hazard. In order to achieve this, the Department of Energy Environmental Restoration Program is comparing the performance of several different surface covers at Material Disposal Area (MDA) B in Los Alamos. Two conventional landfill were compared with an improved cover designed to minimize plant and animal intrusion and to minimize water infiltration into the underlying wastes. The conventional covers varied in depth and both conventional and improved designs had different combinations of vegetation (grass verses shrub) and gravel mulch (no mulch verses mulch). These treatments were applied to each of 12 plots and water balance parameters were measured from March1987 through June 1995. Adding a gravel mulch significantly influenced the plant covered field plots receiving no gravel mulch averaged 21.2% shrub cover, while plots with gravel had a 20% larger percent cover of shrubs. However, the influence of gravel mulch on the grass cover was even larger than the influence on shrub cover, average grass cover on the plots with no gravel was 16.3%, compared with a 42% increase in grass cover due to gravel mulch. These cover relationships are important to reduce runoff on the landfill cover, as shown by a regression model that predicts that as ground cover is increased from 30 to 90%,annual runoff is reduced from 8.8 to 0.98 cm-a nine-fold increase. We also found that decreasing the slope of the landfill cover from 6 to 2% reduced runoff from the landfill cover by 2.7-fold. To minimize the risk of hazardous waste from landfills to humans, runoff and seepage need to be minimized and evapotranspiration maximized on the landfill cover. This has to be accomplished for dry and wet years at MDA B. Seepage consisted of 1.9% and 6.2% of the precipitation in the average and once in ten year events, respectively, whereas corresponding values for runoff were 13% and 16%; these changes were accompanied by corresponding decreases in evapotranspiration, which accounted for 86% and only 78% of the precipitation occurring on the average and once in ten year even~ respectively.

  9. Using fiber optics to detect moisture intrusion into a landfill cap consisting of a vegetative soil barrier.

    PubMed

    Weiss, Jonathan D

    2003-09-01

    The intrusion of moisture into landfills can pose a health hazard because of the possibility that the moisture will carry harmful substances into the groundwater. Early detection of moisture anywhere within these landfills is essential if corrective action is to be taken well before an occurrence of this kind. This paper presents the results of a field-scale simulation test of the use of fiber optics to detect the presence of moisture within landfill covers, using a detection method based on the thermal response of soils as a function of their moisture content. By sending electrical current through an embedded stainless-steel tube, soils of varying moisture content were heated and time-dependent temperature measurements were obtained with a fiber-optic distributed temperature sensor system. The optical fiber itself lay within the tube, but its temperature was a function of how rapidly heat was conducted into the surrounding medium. The results of this experiment, which are in agreement with those obtained using more traditional "point" sampling and laboratory analysis, are presented along with the strengths and limitations of the thermal-response method of detecting moisture. PMID:13678370

  10. Soil contamination by heavy metals in landfills: measurements from an unlined leachate storage basin.

    PubMed

    Bouzayani, Fethi; Aydi, Abdelwaheb; Abichou, Tarek

    2014-08-01

    Landfills are sources of groundwater and soil pollution due to the production of leachate and its migration through refuse. This study was conducted in order to determine the extent of soil pollution within and around the Jebel Chakir landfill, located in the Tunis City, Tunisia. The main objective was to characterize soil samples of an unlined storage basin in relation to heavy metal concentrations in the Jebel Chakir landfill to the southwest of Tunis, Northern Tunisia. Twenty-four soil samples taken from different locations around the storage basin were analyzed by atomic absorption spectrophotometry for Cr, Cu, Ni, Pb, and Zn investigation. Our results indicated high concentrations of Cr (54.4-129.9 mg/kg of DM), Zn (4.1-81.8 mg/kg of DM), Ni (15.1-43.9 mg/kg of DM), Pb (5.6-16.1 mg/kg of DM), and Cu (0.2-1.84 mg/kg of DM). These results suggested that contaminant migration is controlled by an active clay layer acting as an insulating material in the landfill. It is therefore necessary to set a treatment system for the landfill leachates and place a liner under the storage basin to reduce the pollution threat. PMID:24723123

  11. A process-based inventory model for landfill CH4 emissions inclusive of seasonal soil microclimate and CH4 oxidation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have developed and field-validated an annual inventory model for California landfill CH4 emissions that incorporates both site-specific soil properties and soil microclimate modeling coupled to 0.5o scale global climatic models. Based on 1-D diffusion, CALMIM (California Landfill Methane Inventor...

  12. Development of drainage water quality from a landfill cover built with secondary construction materials.

    PubMed

    Travar, Igor; Andreas, Lale; Kumpiene, Jurate; Lagerkvist, Anders

    2015-01-01

    The aim of this study was to evaluate the drainage water quality from a landfill cover built with secondary construction materials (SCM), fly ash (FA), bottom ash (BA) sewage sludge, compost and its changes over time. Column tests, physical simulation models and a full scale field test were conducted. While the laboratory tests showed a clear trend for all studied constituents towards reduced concentrations over time, the concentrations in the field fluctuated considerably. The primary contaminants in the drainage water were Cl(-), N, dissolved organic matter and Cd, Cu, Ni, Zn with initial concentrations one to three orders of magnitude above the discharge values to the local recipient. Using a sludge/FA mixture in the protection layer resulted in less contaminated drainage water compared to a sludge/BA mixture. If the leaching conditions in the landfill cover change from reduced to oxidized, the release of trace elements from ashes is expected to last about one decade longer while the release of N and organic matter from the sludge can be shortened with about two-three decades. The observed concentration levels and their expected development over time require drainage water treatment for at least three to four decades before the water can be discharged directly to the recipient. PMID:25305684

  13. Contamination valuation of soil and groundwater source at anaerobic municipal solid waste landfill site.

    PubMed

    Aziz, Shuokr Qarani; Maulood, Yousif Ismael

    2015-12-01

    The present work aimed to determine the risks that formed landfill leachate from anaerobic Erbil Landfill Site (ELS) poses on groundwater source and to observe the effects of disposed municipal solid waste (MSW) on soil properties. The study further aims to fill the gap in studies on the effects of disposed MSW and produced leachate on the groundwater characteristics and soil quality at ELS, Iraq. Soil, leachate, and groundwater samples were collected from ELS for use as samples in this study. Unpolluted groundwater samples were collected from an area outside of the landfill. Field and laboratory experiments for the soil samples were conducted. Chemical analyses for the soil samples such as organic matter, total salts, and SO4 (=) were also performed. Raw leachate and groundwater samples were analyzed using physical and chemical experiments. The yields for sorptivity, steady-state infiltration rate, and hydraulic conductivity of the soil samples were[Formula: see text], respectively. The soil at ELS was found to be light brown clayey gravel with sand and light brown gravely lean clay layers with low permeability. Unprocessed leachate analysis identified the leachate as stabilized. Findings showed that the soil and groundwater at the anaerobic ELS were contaminated. PMID:26577215

  14. LEACHATE CLOGGING ASSESSMENT OF GEOTEXTILE AND SOIL LANDFILL FILTERS

    EPA Science Inventory

    This project was focused on the performance, design, testing and selection of filters used for leachate collection drains at the base of landfills, waste piles and other solid waste facilities. Geotextiles due to their manufactured uniformity, ease-of placement and savings in lan...

  15. Study of Soil Washing for Remediation of Pb and Zn Contaminated Coastal Landfill

    NASA Astrophysics Data System (ADS)

    Park, S.; Kim, S.; Lee, M.

    2013-12-01

    As a result of analyzing the pre-treatment process of Pb, Zn in contaminated coastal landfill soil presented by Korean Soil Analysis Method, the each concentration was presented 577.00mg/kg, 3894.34mg/kg. This soil was critically contaminated with Pb and Zn because it was exceeded the Standard of soil contamination(2area: Pb-400mg/kg, Zn-600mg/kg). Soil remediation efficiency of the soil washing process for the removal of Pb and Zn was determined to be consistent with the results. The batch experiment on the several washing solutions(HCl, HNO3), washing solutions concentrations(0.1-0.8M) and the ratio of soil vs. solution for soil washing(1:3, 1:5 and 1:10) was performed. The results of experiments, washing time was appropriate in 30 minutes. The removal efficiency of soil washing increased as the ratio of soil vs. washing solution increased. But, in the case of heavy metals, the soil vs. solution for soil washing was determined as the optimal ratio of 1 : 5. Five consecutive soil washing with 0.5M of HCl and HNO3 solutions were performed. Results of experiments, in case of Pb was removed by target removal efficiency from soil on the twice washing. With in case of Zn was over on the first washing by target removal efficiency, but suggesting that twice consecutive soil washing is desirable as stability at field. Results of consecutive soil washing experiments, the removal efficiency maintained lower than 10 % after the 4th washing. From the results, demanding consecutive washing is not recommended. Results about the heavy metal contaminated soil washing experiments of the coastal landfill, in the case of HCl with more than 0.5 M of solution was performed at 1:5 of soil ratio vs. solution, 30 minutes of washing time and 2-3 consecutive soil washing. And in the case of HNO3 with 0.8 M of solution was performed various ratios of soil vs. washing solution, suggesting that 2-3 consecutive soil washing was reached to Pb and Zn target removal efficiency. Key words : landfill soil; washing solution; heavy metal contamination; soil remediation; soil washing; soil contamination

  16. Alishewanella agri sp. nov., isolated from landfill soil Min-Soo Kim,1,2

    E-print Network

    Bae, Jin-Woo

    Alishewanella agri sp. nov., isolated from landfill soil Min-Soo Kim,1,2 3 Seon Kyung Jo,3 3 Seong, named Alishewanella agri sp. nov. The genus Alishewanella was first proposed by Vogel et al. (2000, Alishewanella jeotgali MS1T was isolated from a traditional fermented food in Korea by Kim et al. (2009

  17. Barometric pumping of burial trench soil gases into the atmosphere at the 740-G Sanitary Landfill

    SciTech Connect

    Wyatt, D.E.; Pirkle, R.J.; Masdea, D.J.

    1992-12-01

    In 1991, a soil gas survey was performed at the Savannah River Site Sanitary Landfill as part of the characterization efforts required under the integrated Resource Conservation and Recovery Act (RCRA) Facility Investigation and Comprehensive Environmental Resource Conservation and Recovery Act (CERCLA) Remedial Investigation (RFI/RI) program. This report details the findings of this survey, which identified several areas of the landfill that were releasing volatile organic compounds to the atmosphere at levels exceeding regulatory standards. Knowledge of the rates of VOC outgassing is necessary to protect site workers, provide input into the human health and environmental risk assessment documents and provide input into the remedial design scenario.

  18. Characterization of trichloroethylene adsorption onto waste biocover soil in the presence of landfill gas.

    PubMed

    He, Ruo; Su, Yao; Kong, Jiaoyan

    2015-09-15

    Waste biocover soils (WBS) have been demonstrated to have great potential in mitigating trichloroethylene (TCE) emission from landfills, due to the relatively high TCE-degrading capacity. In this study, the characteristics of TCE adsorption on WBS in the presence of the major landfill gas components (i.e., CH4 and CO2) were investigated in soil microcosms. The adsorption isotherm of TCE onto WBS was fitted well with linear model within the TCE concentrations of 7000 ppmv. The adsorption capacity of TCE onto WBS was affected by temperature, soil moisture content and particle size, of which, temperature was the dominant factor. The adsorption capacity of TCE onto the experimental materials increased with the increasing organic matter content. A significantly positive correlation was observed between the adsorption capacity of TCE and the organic matter content of experimental materials that had relatively higher organic content (r = 0.988, P = 0.044). To better understand WBS application in practice, response surface methodology was developed to predict TCE adsorption capacity and emissions through WBS in different landfills in China. These results indicated that WBS had high adsorption capacity of TCE in LFG and temperature should be paid more attention to manipulate WBS to reduce TCE emissions from landfills. PMID:25909498

  19. DESIGNING AND SPECIFYING LANDFILL By: Timothy D. Stark,1

    E-print Network

    acres. The landfill site is flat, sandy, with groundwater near the surface. The landfill is unlined of a final cover system is important to reduce groundwater contamination. The Code of Maryland Regulations are located along the panhandle as shown in Figure 1. As placement of soil cover was occurring by Somerset

  20. The use of cover crops to manage soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cover crops are used to manage soils for many different reasons. Inserting cover crops into fallow periods and spaces in cropping systems is a beneficial soil management practice. Natural ecosystems typically have some plants growing, covering the soil, transpiring water, taking up nutrients, fixing...

  1. Methane emissions from MBT landfills

    SciTech Connect

    Heyer, K.-U. Hupe, K.; Stegmann, R.

    2013-09-15

    Highlights: • Compilation of methane generation potential of mechanical biological treated (MBT) municipal solid waste. • Impacts and kinetics of landfill gas production of MBT landfills, approach with differentiated half-lives. • Methane oxidation in the waste itself and in soil covers. • Estimation of methane emissions from MBT landfills in Germany. - Abstract: Within the scope of an investigation for the German Federal Environment Agency (“Umweltbundesamt”), the basics for the estimation of the methane emissions from the landfilling of mechanically and biologically treated waste (MBT) were developed. For this purpose, topical research including monitoring results regarding the gas balance at MBT landfills was evaluated. For waste treated to the required German standards, a methane formation potential of approximately 18–24 m{sup 3} CH{sub 4}/t of total dry solids may be expected. Monitoring results from MBT landfills show that a three-phase model with differentiated half-lives describes the degradation kinetics in the best way. This is due to the fact that during the first years of disposal, the anaerobic degradation processes still proceed relatively intensively. In addition in the long term (decades), a residual gas production at a low level is still to be expected. Most of the soils used in recultivation layer systems at German landfills show a relatively high methane oxidation capacity up to 5 l CH{sub 4}/(m{sup 2} h). However, measurements at MBT disposal sites indicate that the majority of the landfill gas (in particular at non-covered areas), leaves the landfill body via preferred gas emission zones (hot spots) without significant methane oxidation. Therefore, rather low methane oxidation factors are recommended for open and temporarily covered MBT landfills. Higher methane oxidation rates can be achieved when the soil/recultivation layer is adequately designed and operated. Based on the elaborated default values, the First Order Decay (FOD) model of the IPCC Guidelines for National Greenhouse Gas Inventories, 2006, was used to estimate the methane emissions from MBT landfills. Due to the calculation made by the authors emissions in the range of 60,000–135,000 t CO{sub 2-eq.}/a for all German MBT landfills can be expected. This wide range shows the uncertainties when the here used procedure and the limited available data are applied. It is therefore necessary to generate more data in the future in order to calculate more precise methane emission rates from MBT landfills. This is important for the overall calculation of the climate gas production in Germany which is required once a year by the German Government.

  2. A comparison of two models for simulating the water balance of soil covers under semi-arid conditions

    SciTech Connect

    Chammas, G.A.; Geddis, M.; McCaulou, D.R.

    1999-07-01

    Numerical water-balance modeling of store-and-release soil covers for hypothetical mine tailings was conducted using the Hydrologic Evaluation of Landfill Performance (HELP) and SoilCover models. The objective of the modeling was to compare the utility of both models in a semi-arid environment. Although values for input parameters were chosen to make simulations as identical as possible between models, differences in model solution methods and discretization led to different water-balance predictions. Specifically, SoilCover predicted less percolation than HELP, because HELP uses simplified water-routing algorithms which may over predict infiltration and under predict subsequent evapotranspiration. Since SoilCover explicitly solves physically based governing equations for heat and water flow, its predictions more accurately represent the water balance in semi-arid regions where evapotranspiration dominates, HELP can only conservatively predict percolation in dry environments.

  3. The release of As, Cr and Cu from contaminated soil stabilized with APC residues under landfill conditions.

    PubMed

    Travar, I; Kihl, A; Kumpiene, J

    2015-03-15

    The aim of this study was to investigate the stability of As, Cr and Cu in contaminated soil treated with air pollution control residues under landfill conditions. The influence of landfill gas and temperature on the release of trace elements from stabilized soil was simulated using a diffusion test. The air pollution control residues immobilized As through the precipitation of Ca-As minerals (calcium arsenate (Ca5H2(AsO4)3 × 5H2O), weilite (CaAsO4) and johnbaumite (Ca5(AsO4)3(OH)), incorporation of As into ettringite (Ca6Al2(SO4)3(OH)12 × 26H2O) and adsorption by calcite (CaCO3). The air pollution control residues generally showed a high resistance to pH reduction, indicating high buffer capacity and stability of immobilized As in a landfill over time. Generation of heat in a landfill might increase the release of trace elements. The release of As from stabilized soil was diffusion-controlled at 60 °C, while surface wash-off, dissolution, and depletion prevailed at 20 °C. The air pollution control residues from the incineration of municipal solid waste immobilized Cr, indicating its stability in a landfill. The treatment of soil with air pollution control residues was not effective in immobilization of Cu. Contaminated soils treated with air pollution control residues will probably have a low impact on overall leachate quality from a landfill. PMID:25528268

  4. Effect of Cover Crops on Soil Fungal Diversity and Biomass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of various cover crops (sordan, mustard, canola, honeysweet, and fallow) to influence soil fungal biomass and diversity were tested in a potato field in the San Luis Valley, Colorado. Soil samples (0-5 cm depth) were randomly selected from each cover crop plot and soil fungal communitie...

  5. THE USE OF ALTERNATIVE MATERIALS FOR DAILY COVER AT MUNICIPAL SOLID WASTE LANDFILLS. A Project Summary (EPA/600/SR-93/172)

    EPA Science Inventory

    This investigation was conducted to assess the applicability of currently available (ca. 1992) alternative materials for use as daily cover at landfills. Information on characteristics, material and equipment requirements, methods of preparation and application, climatic and ope...

  6. About soil cover heterogeneity of agricultural research stations' experimental fields

    NASA Astrophysics Data System (ADS)

    Rannik, Kaire; Kõlli, Raimo; Kukk, Liia

    2013-04-01

    Depending on local pedo-ecological conditions (topography, (geo) diversity of soil parent material, meteorological conditions) the patterns of soil cover and plant cover determined by soils are very diverse. Formed in the course of soil-plant mutual relationship, the natural ecosystems are always influenced to certain extent by the other local soil forming conditions or they are site specific. The agricultural land use or the formation of agro-ecosystems depends foremost on the suitability of soils for the cultivation of feed and food crops. As a rule, the most fertile or the best soils of the area, which do not present any or present as little as possible constraints for agricultural land use, are selected for this purpose. Compared with conventional field soils, the requirements for the experimental fields' soil cover quality are much higher. Experimental area soils and soil cover composition should correspond to local pedo-ecological conditions and, in addition to that, represent the soil types dominating in the region, whereas the fields should be as homogeneous as possible. The soil cover heterogeneity of seven arable land blocks of three research stations (Jõgeva, Kuusiku and Olustvere) was studied 1) by examining the large scale (1:10 000) digital soil map (available via the internet), and 2) by field researches using the transect method. The stages of soils litho-genetic and moisture heterogeneities were estimated by using the Estonian normal soils matrix, however, the heterogeneity of top- and subsoil texture by using the soil texture matrix. The quality and variability of experimental fields' soils humus status, was studied more thoroughly from the aspect of humus concentration (g kg-1), humus cover thickness (cm) and humus stocks (Mg ha-1). The soil cover of Jõgeva experimental area, which presents an accumulative drumlin landscape (formed during the last glacial period), consist from loamy Luvisols and associated to this Cambisols. In Kuusiku area, which landscape is characterized by till and limestone plains with thin Quaternary cover, the soil cover is more heterogeneous than in previous area. Kuusiku soil cover is more variegated by the soil texture and as well as by the genesis of soils. In addition to Cambisols, Leptosols, Gleysols and Luvisols may be found here as well. The dominating soils in Olustvere research area, which is situated on wavy upland plateau, are Albeluvisols.

  7. Design of landfill daily cells.

    PubMed

    Panagiotakopoulos, D; Dokas, I

    2001-08-01

    The objective of this paper is to study the behaviour of the landfill soil-to-refuse (S/R) ratio when size, geometry and operating parameters of the daily cell vary over realistic ranges. A simple procedure is presented (1) for calculating the cell parameters values which minimise the S/R ratio and (2) for studying the sensitivity of this minimum S/R ratio to variations in cell size, final refuse density, working face length, lift height and cover thickness. In countries where daily soil cover is required, savings in landfill space could be realised following this procedure. The sensitivity of minimum S/R to variations in cell dimensions decreases with cell size. Working face length and lift height affect the S/R ratio significantly. This procedure also offers the engineer an additional tool for comparing one large daily cell with two or more smaller ones, at two different working faces within the same landfill. PMID:11720268

  8. Assessment of soil-gas, soil, and water contamination at the former hospital landfill, Fort Gordon, Georgia, 2009-2010

    USGS Publications Warehouse

    Falls, Fred W.; Caldwell, Andral W.; Guimaraes, Wladmir B.; Ratliff, W. Hagan; Wellborn, John B.; Landmeyer, James E.

    2011-01-01

    Soil gas, soil, and water were assessed for organic and inorganic constituents at the former hospital landfill located in a 75-acre study area near the Dwight D. Eisenhower Army Medical Center, Fort Gordon, Georgia, from April to September 2010. Passive soil-gas samplers were analyzed to evaluate organic constituents in the hyporheic zone of a creek adjacent to the landfill and soil gas within the estimated boundaries of the former landfill. Soil and water samples were analyzed to evaluate inorganic constituents in soil samples, and organic and inorganic constituents in the surface water of a creek adjacent to the landfill, respectively. This assessment was conducted to provide environmental constituent data to Fort Gordon pursuant to requirements of the Resource Conservation and Recovery Act Part B Hazardous Waste Permit process. Results from the hyporheic-zone assessment in the unnamed tributary adjacent to the study area indicated that total petroleum hydrocarbons and octane were the most frequently detected organic compounds in groundwater beneath the creek bed. The highest concentrations for these compounds were detected in the upstream samplers of the hyporheic-zone study area. The effort to delineate landfill activity in the study area focused on the western 14 acres of the 75-acre study area where the hyporheic-zone study identified the highest concentrations of organic compounds. This also is the part of the study area where a debris field also was identified in the southern part of the 14 acres. The southern part of this 14-acre study area, including the debris field, is steeper and not as heavily wooded, compared to the central and northern parts. Fifty-two soil-gas samplers were used for the July 2010 soil-gas survey in the 14-acre study area and mostly detected total petroleum hydrocarbons, and gasoline and diesel compounds. The highest soil-gas masses for total petroleum hydrocarbons, diesel compounds, and the only valid detection of perchloroethene were in the southern part of the study area to the west of the debris field. However, all other detections of total petroleum hydrocarbons greater than 10 micrograms and diesel greater than 0.04 micrograms, and all detections of the combined mass of benzene, toluene, ethylbenzene, and xylene were found down slope from the debris field in the central and northern parts of the study area. Five soil-gas samplers were deployed and recovered from September 16 to 22, 2010, and were analyzed for organic compounds classified as chemical agents or explosives. Chloroacetophenones (a tear gas component) were the only compounds detected above a method detection level and were detected at the same location as the highest total petroleum hydrocarbons and diesel detections in the southern part of the 14-acre study area. Composite soil samples collected at five locations were analyzed for 35 inorganic constituents. None of the inorganic constituents exceeded the regional screening levels. One surface-water sample collected in the western end of the hyporheic-zone study area had a trichlorofluoromethane concentration above the laboratory reporting level and estimated concentrations of chloroform, fluoranthene, and isophorone below laboratory reporting levels.

  9. Characterization of landfill gas composition at the Fresh Kills municipal solid-waste landfill

    SciTech Connect

    Eklund, B.; Anderson, E.P.; Walker, B.L.; Burrows, D.B.

    1998-08-01

    The most common disposal method in the US for municipal solid waste (MSW) is burial in landfills. Until recently, air emissions from these landfills were not regulated. Under the New Source Performance Standards and Emission Guidelines for MSW landfills, MSW operators are required to determine the nonmethane organic gas generation rate of their landfill through modeling and/or measurements. This paper summarizes speciated nonmethane organic compound (NMOC) measurement data collected during an intensive, short-term field program. Over 250 separate landfill gas samples were collected from emission sources at the Fresh Kills landfill in New York City and analyzed for approximately 150 different analytes. The average total NMOC value for the landfill was 438 ppmv (as hexane) versus the regulatory default value of 4,000 ppmv (as hexane). Over 70 individual volatile organic compounds (VOCs) were detected and quantified in the landfill gas samples. The typical gas composition for this landfill was determined as well as estimates of the spatial, temporal, and measurement variability in the gas composition. The data for NMOC show that the gas composition within the landfill is equivalent to the composition of the gas exiting the landfill through passive vents and through the soil cover.

  10. Soil changes covered by grass and grazed by cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil properties change with time when exposed to perennial grass cover and subsequently grazed by cattle because of the large input of organic matter that typically occurs at the soil surface from senescent plant residues and animal manure. The accumulation of organic matter at the soil surface res...

  11. Evolution of the soil cover of soccer fields

    NASA Astrophysics Data System (ADS)

    Belobrov, V. P.; Zamotaev, I. V.

    2014-04-01

    A soccer field can be considered a soil-like technogenic formation (STF). According to the theory of soil cover patterns, the artificially constructed (anthropogenic) soil cover of a soccer field is an analogue of a relatively homogeneous elementary soil area. However, the spatial homogeneity of the upper part (50-80 cm) of the STF of soccer fields is unstable and is subjected to gradual transformation under the impact of pedogenetic processes, agrotechnical loads, and mechanical loads during the games. This transformation is favored by the initial heterogeneity of the deep (buried) parts of the STF profile. The technogenic factors and elementary pedogenetic processes specify the dynamic functioning regime of the STF. In 50-75 years, the upper part of the STF is transformed into soil-like bodies with properties close to those in zonal soils. Certain micro- and nanopatterns of the soil cover are developed within the field creating its spatial heterogeneity.

  12. Evaluation of engineering properties for the use of leached brown coal ash in soil covers.

    PubMed

    Mudd, Gavin M; Chakrabarti, Srijib; Kodikara, Jayantha

    2007-01-31

    The need to engineer cover systems for the successful rehabilitation or remediation of a wide variety of solid wastes is increasing. Some common applications include landfills, hazardous waste repositories, or mine tailings dams and waste rock/overburden dumps. The brown coal industry of the Latrobe Valley region of Victoria, Australia, produces significant quantities of coal ash and overburden annually. There are some site-specific acid mine drainage (AMD) issues associated with overburden material. This needs to be addressed both during the operational phase of a project and during rehabilitation. An innovative approach was taken to investigate the potential to use leached brown coal ash in engineered soil covers on this overburden dump. The basis for this is two-fold: first, the ash has favourable physical characteristics for use in cover systems (such as high storage capacity/porosity, moderately low permeability, and an ability to act as a capillary break layer generating minimal leachate or seepage); and second, the leachate from the ash is mildly alkaline (which can help to mitigate and reduce the risk of AMD). This paper will review the engineering issues involved in using leached brown coal ash in designing soil covers for potentially acid-forming overburden dumps. It presents the results of laboratory work investigating the technical feasibility of using leached brown coal ash in engineered solid waste cover systems. PMID:16621267

  13. Assessment of soil-gas and groundwater contamination at the Gibson Road landfill, Fort Gordon, Georgia, 2011

    USGS Publications Warehouse

    Falls, W. Fred; Caldwell, Andral W.; Guimaraes, Wladmir G.; Ratliff, W. Hagan; Wellborn, John B.; Landmeyer, James E.

    2012-01-01

    Soil-gas and groundwater assessments were conducted at the Gibson Road landfill in 201 to provide screening-level environmental contamination data to supplement the data collected during previous environmental studies at the landfill. Passive samplers were used in both assessments to detect volatile and semivolatile organic compounds and polycyclic aromatic hydrocarbons in soil gas and groundwater. A total of 56 passive samplers were deployed in the soil in late July and early August for the soil-gas assessment. Total petroleum hydrocarbons (TPH) were detected at masses greater than the method detection level of 0.02 microgram in all samplers and masses greater than 2.0 micrograms in 13 samplers. Three samplers located between the landfill and a nearby wetland had TPH masses greater than 20 micrograms. Diesel was detected in 28 of the 56 soil-gas samplers. Undecane, tridecane, and pentadecane were detected, but undecane was the most common diesel compound with 23 detections. Only five detections exceeded a combined diesel mass of 0.10 microgram, including the highest mass of 0.27 microgram near the wetland. Toluene was detected in only five passive samplers, including masses of 0.65 microgram near the wetland and 0.85 microgram on the southwestern side of the landfill. The only other gasoline-related compound detected was octane in two samplers. Naphthalene was detected in two samplers in the gully near the landfill and two samplers along the southwestern side of the landfill, but had masses less than or equal to 0.02 microgram. Six samplers located southeast of the landfill had detections of chlorinated compounds, including one perchloroethene detections (0.04 microgram) and five chloroform detections (0.05 to0.08 microgram). Passive samplers were deployed and recovered on August 8, 2011, in nine monitoring wells along the southwestern, southeastern and northeastern sides of the landfill and down gradient from the eastern corner of the landfill. Six of the nine samplers had TPH concentrations greater than 100 micrograms per liter. TPH concentrations declined from 320 micrograms per liter in a sampler near the landfill to 18 micrograms in a sampler near the wetland. Five of the samplers had detections of one or more diesel compounds but detections of individual diesel compounds had concentrations below a method detection level of 0.01 microgram per liter. Benzene was detected in three samplers and exceeded the national primary drinking-water standard of 5 micrograms per liter set by the U.S. Environmental Protection Agency. The concentrations of benzene, and therefore BTEX, were 6.1 micrograms per liter in the sampler near the eastern corner of the landfill, 27 micrograms per liter in the sampler near the wetland, and 37 micrograms per liter in the sampler at the southern corner of the landfill. Nonfuel-related compounds were detected in the four wells that are aligned between the eastern corner of the landfill and the wetland. The sampler deployed nearest the eastern corner of the landfill had the greatest number of detected organic compounds and had the only detections of two trimethylbenzene compounds, naphthalene, 2-methyl naphthalene, and 1,4-dichlorobenzene. The two up gradient samplers had the greatest number of chlorinated compounds with five compounds each, compared to detections of four compounds and one compound in the two down gradient samplers. All four samplers had detections of 1,1-dichloroethane which ranged from 42 to 1,300 micrograms per liter. Other detections of chlorinated compounds included trichloroethene, perchloroethene, cis-1,2-dichloroethene, 1,1,1-trichloroethane and chloroform.

  14. Passive soil venting at the Chemical Waste Landfill Site at Sandia National Laboratories, Albuquerque, New Mexico

    SciTech Connect

    Phelan, J.M.; Reavis, B.; Cheng, W.C.

    1995-05-01

    Passive Soil Vapor Extraction was tested at the Chemical Waste Landfill (CWL) site at Sandia National Laboratories, New Mexico (SNLIW). Data collected included ambient pressures, differential pressures between soil gas and ambient air, gas flow rates into and out of the soil and concentrations of volatile organic compounds (VOCS) in vented soil gas. From the differential pressure and flow rate data, estimates of permeability were arrived at and compared with estimates from other studies. Flow, differential pressure, and ambient pressure data were collected for nearly 30 days. VOC data were collected for two six-hour periods during this time. Total VOC emissions were calculated and found to be under the limit set by the Resource Conservation and Recovery Act (RCRA). Although a complete process evaluation is not possible with the data gathered, some of the necessary information for designing a passive venting process was determined and the important parameters for designing the process were indicated. More study is required to evaluate long-term VOC removal using passive venting and to establish total remediation costs when passive venting is used as a polishing process following active soil vapor extraction.

  15. Assessment of soil-gas contamination at the 17th Street landfill, Fort Gordon, Georgia, 2011

    USGS Publications Warehouse

    Falls, W. Fred; Caldwell, Andral W.; Guimaraes, Wladmir G.; Ratliff, W. Hagan; Wellborn, John B.; Landmeyer, James E.

    2012-01-01

    Assessments of contaminants in soil gas were conducted in two study areas at Fort Gordon, Georgia, in July and August of 2011 to supplement environmental contaminant data for previous studies at the 17th Street landfill. The two study areas include northern and eastern parts of the 17th Street landfill and the adjacent wooded areas to the north and east of the landfill. These study areas were chosen because of their close proximity to the surface water in Wilkerson Lake and McCoys Creek. A total of 48 soil-gas samplers were deployed for the July 28 to August 3, 2011, assessment in the eastern study area. The assessment mostly identified detections of total petroleum hydrocarbons (TPH), and gasoline- and diesel-range compounds, but also identified the presence of chlorinated solvents in six samplers, chloroform in three samplers, 2-methyl naphthalene in one sampler, and trimethylbenzene in one sampler. The TPH masses exceeded 0.02 microgram (?g) in all 48 samplers and exceeded 0.9 ?g in 24 samplers. Undecane, one of the three diesel-range compounds used to calculate the combined mass for diesel-range compounds, was detected in 17 samplers and is the second most commonly detected compound in the eastern study area, exceeded only by the number of TPH detections. Six samplers had detections of toluene, but other gasoline compounds were detected with toluene in three of the samplers, including detections of ethylbenzene, meta- and para-xylene, and octane. All detections of chlorinated organic compounds had soil-gas masses equal to or less than 0.08 ?g, including three detections of trichloroethene, three detections of perchloroethene, three chloroform detections, one 1,4-dichlorobenzene detection, and one 1,1,2-trichloroethane detection. Three methylated compounds were detected in the eastern study area, but were detected at or below method detection levels. A total of 32 soil-gas samplers were deployed for the August 11–24, 2011, assessment in the northern study area. All samplers in the survey had detections of TPH, but only eight of the samplers had detections of TPH greater than 0.9 mg. Four samplers had TPH detections greater than 9 mg; the only other fuel-related compounds detected in these four samplers included toluene in three of the samplers and undecane in the fourth sampler. Three samplers deployed along the western margin of the northern landfill had detections of both diesel-and gasoline-related compounds; however, the diesel-related compounds were detected at or below method detection levels. Seven samplers in the northern study area had detections of chlorinated compounds, including three perchloroethene detections, three chloroform detections, and one 1,4-dichloro-benzene detection. One sampler on the western margin of the landfill had detections of 1,2,4-trimethylbenzene and 1,3,5-tr-methylbenene below method detection levels.

  16. Monitoring the Performance of an Alternative Landfill Cover at the Monticello, Utah, Uranium Mill Tailings Disposal Site

    SciTech Connect

    Waugh, W.J.; Kastens, M.K.; Sheader, L.R.L.; Benson, C.H.; Albright, W.H.; Mushovic, P.S.

    2008-07-01

    The U.S. Department of Energy Office of Legacy Management (DOE) and the U.S. Environmental Protection Agency (EPA) collaborated on the design and monitoring of an alternative cover for the Monticello uranium mill tailings disposal cell, a Superfund site in southeastern Utah. Ground-water recharge is naturally limited at sites like Monticello where thick, fine-textured soils store precipitation until evaporation and plant transpiration seasonally return it to the atmosphere. The cover at Monticello uses local soils and a native plant community to mimic the natural soil water balance. The cover is fundamentally an evapotranspiration (ET) design with a capillary barrier. A 3-hectare drainage lysimeter was embedded in the cover during construction of the disposal cell in 2000. The lysimeter consists of a geo-membrane liner below the capillary barrier that directs percolation water to a monitoring system. Soil water storage is determined by integration of point water content measurements. Meteorological parameters are measured nearby. Plant cover, shrub density, and leaf area index (LAI) are monitored annually. The cover performed well over the 7-year monitoring period (2000-2007). The cumulative percolation was 4.2 mm (0.6 mm yr{sup -1}), satisfying an EPA goal of an average percolation of <3.0 mm yr{sup -1}. Almost all percolation can be attributed to the exceptionally wet winter and spring of 2004-2005 when soil water content slightly exceeded the water storage capacity of the cover. The diversity, percent cover, and LAI of vegetation increased over the monitoring period, although the density of native shrubs that extract water from deeper in the cover has remained less than revegetation targets. DOE and EPA are applying the monitoring results to plan for long-term surveillance and maintenance and to evaluate alternative cover designs for other waste disposal sites. (authors)

  17. Barometric pumping of burial trench soil gases into the atmosphere at the 740-G Sanitary Landfill. Revision 1

    SciTech Connect

    Wyatt, D.E.; Pirkle, R.J.; Masdea, D.J.

    1992-12-01

    In 1991, a soil gas survey was performed at the Savannah River Site Sanitary Landfill as part of the characterization efforts required under the integrated Resource Conservation and Recovery Act (RCRA) Facility Investigation and Comprehensive Environmental Resource Conservation and Recovery Act (CERCLA) Remedial Investigation (RFI/RI) program. This report details the findings of this survey, which identified several areas of the landfill that were releasing volatile organic compounds to the atmosphere at levels exceeding regulatory standards. Knowledge of the rates of VOC outgassing is necessary to protect site workers, provide input into the human health and environmental risk assessment documents and provide input into the remedial design scenario.

  18. Methane emissions from MBT landfills.

    PubMed

    Heyer, K-U; Hupe, K; Stegmann, R

    2013-09-01

    Within the scope of an investigation for the German Federal Environment Agency ("Umweltbundesamt"), the basics for the estimation of the methane emissions from the landfilling of mechanically and biologically treated waste (MBT) were developed. For this purpose, topical research including monitoring results regarding the gas balance at MBT landfills was evaluated. For waste treated to the required German standards, a methane formation potential of approximately 18-24 m(3)CH(4)/t of total dry solids may be expected. Monitoring results from MBT landfills show that a three-phase model with differentiated half-lives describes the degradation kinetics in the best way. This is due to the fact that during the first years of disposal, the anaerobic degradation processes still proceed relatively intensively. In addition in the long term (decades), a residual gas production at a low level is still to be expected. Most of the soils used in recultivation layer systems at German landfills show a relatively high methane oxidation capacity up to 5 l CH(4)/(m(2)h). However, measurements at MBT disposal sites indicate that the majority of the landfill gas (in particular at non-covered areas), leaves the landfill body via preferred gas emission zones (hot spots) without significant methane oxidation. Therefore, rather low methane oxidation factors are recommended for open and temporarily covered MBT landfills. Higher methane oxidation rates can be achieved when the soil/recultivation layer is adequately designed and operated. Based on the elaborated default values, the First Order Decay (FOD) model of the IPCC Guidelines for National Greenhouse Gas Inventories, 2006, was used to estimate the methane emissions from MBT landfills. Due to the calculation made by the authors emissions in the range of 60,000-135,000 t CO(2-eq.)/a for all German MBT landfills can be expected. This wide range shows the uncertainties when the here used procedure and the limited available data are applied. It is therefore necessary to generate more data in the future in order to calculate more precise methane emission rates from MBT landfills. This is important for the overall calculation of the climate gas production in Germany which is required once a year by the German Government. PMID:23756351

  19. Carbon storage in a heavy clay soil landfill site after biosolid application.

    PubMed

    Bolan, N S; Kunhikrishnan, A; Naidu, R

    2013-11-01

    Applying organic amendments including biosolids and composts to agricultural land could increase carbon (C) storage in soils and contribute significantly to the reduction of greenhouse gas emissions. Although a number of studies have examined the potential value of biosolids as a soil conditioner and nutrient source, there has been only limited work on the impact of biosolid application on C sequestration in soils. The objective of this study was to examine the potential value of biosolids in C sequestration in soils. Two types of experiments were conducted to examine the effect of biosolid application on C sequestration. In the first laboratory incubation experiment, the rate of decomposition of a range of biosolid samples was compared with other organic amendments including composts and biochars. In the second field experiment, the effect of biosolids on the growth of two bioenergy crops, Brassica juncea (Indian mustard) and Helianthus annuus (sunflower) on a landfill site was examined in relation to biomass production and C sequestration. The rate of decomposition varied amongst the organic amendments, and followed: composts>biosolids>biochar. There was a hundred fold difference in the rate of decomposition between biochar and other organic amendments. The rate of decomposition of biosolids decreased with increasing iron (Fe) and aluminum (Al) contents of biosolids. Biosolid application increased the dry matter yield of both plant species (by 2-2.5 fold), thereby increasing the biomass C input to soils. The rate of net C sequestration resulting from biosolid application (Mg C ha(-1) yr(-1) Mg(-1) biosolids) was higher for mustard (0.103) than sunflower (0.087). Biosolid application is likely to result in a higher level of C sequestration when compared to other management strategies including fertilizer application and conservation tillage, which is attributed to increased microbial biomass, and Fe and Al oxide-induced immobilization of C. PMID:23380138

  20. INFLUENCE OF COVER CROPS AND SOIL AMENDMENTS ON OKRA (ABELMOSCHUS ESCULENTUS L.) PRODUCTION AND SOIL NEMATODES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A pot experiment to determine the effects of summer cover crops and soil amendments on okra yield and population densities of various soil nematode taxa was conducted in two consecutive growing seasons in a subtropical region. Two cover crops, sunn hemp (Crotalaria juncea) and sorghum sudangrass (So...

  1. Coupled Environmental Processes and Long-term Performance of Landfill Covers in the northern Mojave Desert

    SciTech Connect

    David Shafer; Michael Young; Stephen Zitzer; Eric McDonald; Todd Caldwell

    2004-05-12

    Evapotransiration (ET) covers have gained widespread acceptance as a closure feature for waste disposal sites, particularly in the arid and semi-arid regions of the southwestern U.S. But as landforms, ET covers are subject to change over time because of processes such as pedogenesis, hydrologic processes, vegetation establishment and change, and biological processes. To better understand the effects of coupled process changes to ET covers, a series of four primary analog sites in Yucca Flat on the Nevada Test Site, along with measurements and observations from other locations in the Mojave Desert, were selected to evaluate changes in ET covers over time. The analog sites, of varying ages, were selected to address changes in the early post-institutional control period, the 1,000-year compliance period for disposal of low-level and mixed low-level waste, and the 10,000-year compliance period for transuranic waste sites.

  2. Space monitoring of municipal solid waste landfills in Kazakhstan

    NASA Astrophysics Data System (ADS)

    Skakova, Olga; Shagarova, Lyudmila

    Municipal solid waste (MSW) landfills are special facilities designed for waste isolation and disposal ensuring sanitary and epidemiological safety of population. A solid waste landfill is a complex object with its own specific features. Modern remote-sensing methods are an indispensable source of information for the analysis of space images of solid waste landfills in Kazakhstan. Space monitoring of solid waste landfills includes the following tasks: 1. Identification and mapping of landfill areas according to the data of remote earth sensing. 2. Studying of energy and structural characteristics of landfills based on remote sensing data. 3. Analysis of the state of landfills based on a comparison of current and archive remote sensing data. Space monitoring of territories of municipal solid waste landfills uses modern computer technologies. They include satellite imagery combined with sub-satellite research, as well as other sources of information used for identification and mapping of landfill territories. Investigation of municipal solid waste landfills requires targeted survey of landfill areas, remote sensing using operational and archival data including theoretical foundations of physical optics and statistical data. Processing of digital satellite information uses methods of pattern recognition, automated image processing and correlation analysis. Based on spectral energy and textural characteristics of municipal solid waste landfills obtained by remote sensing methods, the technology of space monitoring of landfill areas, including landfill recognition and characterization of solid waste landfills from remote observations was developed. Monitoring of MSW landfills uses satellite images of ultrahigh and medium spatial resolution. Medium-resolution images are used to determine temperature, vegetation cover and soil degradation. High-resolution images are used to detect landfills, to determine forms of soil degradation, to calculate geometrical parameters, and to evaluate measures of control over the operation of landfill areas. Therefore, the technology of monitoring of landfills, based on reception and processing of multispectral data of different spatial resolution in the specialized software, enables us to detect and to analyze MSW, and to assess their impact on the ecological state of the environment. The introduction of space-based monitoring of MSW will save material and financial resources aimed at identification of solid wastes, assessment of their state and evolution in space and time, especially on vast areas, for example, on the territory of the Republic of Kazakhstan.

  3. Relic components within the soil cover of Mexico: regional variability

    NASA Astrophysics Data System (ADS)

    Solleiro Rebolledo, Elizabeth; Sedov, Sergey

    2015-04-01

    The case of paleosols persisting on the land surface (non-buried paleosols or relict soils) besides paleoecological interest has specific implications for studies of soil geography, ecology and management. In fact these soil bodies form part of the modern soil mantle and provide ecological services for the current (agro)ecosystems but are neither formed nor re-produced by these ecosystems, conforming locally extinct soils (although similar profiles can develop at present under other bioclimatic conditions). In consequence, they are a heritage of past climatic and biotic conditions now extinct, thus presenting a non-restorable component of the present landscape. Mexico has so abundant and diverse paleosols, both surface and buried, that really could be considered to be a "paleopedological paradise". Two groups of factors promote generation of this abundance: Major part of territory of Mexico is occupied by mountainous landscapes with high intensity of tectonic, volcanic and geomorphic processes. These processes create a complex mosaic of geological materials and landforms of different age (like alluvial and lake terraces, eroded slopes, and volcanic deposits of various eruptions). Meanwhile younger landsurfaces are occupied by the recently developed soils, the older ones could bear the relict soil bodies. The same processes produce sedimentary strata (alluvial, colluvial, pyroclastic, etc.) which frequently cover the pre-existing landsurfaces and soils, producing series of buried paleosols. In this work we present three study cases of relict paleosols that are integrated to the modern soil cover of Mexico: the case of reddish-brown soils in the arid landscapes of Sonora (in the north); the pedosediments (tepetates) in central Mexico; and the red soils developed under humid conditions in Yucatan (in the south).

  4. Beneficial uses of recycled asphalt-stabilized products as landfill cover and capping systems

    SciTech Connect

    Camougis, G.

    1996-12-31

    The American Reclamation Corporation (AMREC{reg_sign}) has played a major role in the development of new programs for the recycling of discarded materials from construction, demolition, remediation and manufacturing operations. Excavated petroleum-contaminated soils (oily soils), asphalt paving, concrete rubble, and discarded asphalt roofing shingles have been processed and recycled into beneficially useful construction products. AMREC uses a cold-mix, asphalt-emulsion technology to process many of the recyclables received at its recycling facility in Charlton, MA. Recyclable materials are processed and blended to produce recycled, asphalt-stabilized products. In addition, recycled, asphalt-stabilized products are being investigated and tested for other beneficial uses. This includes their uses as capping materials and as containment materials.

  5. Evaporative losses from soils covered by physical and different types of biological soil crusts

    USGS Publications Warehouse

    Chamizo, S.; Cantón, Y.; Domingo, F.; Belnap, J.

    2013-01-01

    Evaporation of soil moisture is one of the most important processes affecting water availability in semiarid ecosystems. Biological soil crusts, which are widely distributed ground cover in these ecosystems, play a recognized role on water processes. Where they roughen surfaces, water residence time and thus infiltration can be greatly enhanced, whereas their ability to clog soil pores or cap the soil surface when wetted can greatly decrease infiltration rate, thus affecting evaporative losses. In this work, we compared evaporation in soils covered by physical crusts, biological crusts in different developmental stages and in the soils underlying the different biological crust types. Our results show that during the time of the highest evaporation (Day 1), there was no difference among any of the crust types or the soils underlying them. On Day 2, when soil moisture was moderately low (11%), evaporation was slightly higher in well-developed biological soil crusts than in physical or poorly developed biological soil crusts. However, crust removal did not cause significant changes in evaporation compared with the respective soil crust type. These results suggest that the small differences we observed in evaporation among crust types could be caused by differences in the properties of the soil underneath the biological crusts. At low soil moisture (<6%), there was no difference in evaporation among crust types or the underlying soils. Water loss for the complete evaporative cycle (from saturation to dry soil) was similar in both crusted and scraped soils. Therefore, we conclude that for the specific crust and soil types tested, the presence or the type of biological soil crust did not greatly modify evaporation with respect to physical crusts or scraped soils.

  6. Application of ecological risk assessment based on a novel TRIAD-tiered approach to contaminated soil surrounding a closed non-sealed landfill.

    PubMed

    Gutiérrez, Laura; Garbisu, Carlos; Ciprián, Estela; Becerril, José M; Soto, Manu; Etxebarria, Javier; Madariaga, Juan M; Antigüedad, Iñaki; Epelde, Lur

    2015-05-01

    The Ecological Risk Assessment (ERA) is a reliable tool for communicating risk to decision makers in a comprehensive and scientific evidence-based way. In this work, a site-specific ERA methodology based on the TRIAD approach was applied to contaminated soil surrounding a closed non-sealed landfill, as a case study to implement and validate such ERA methodology in the Basque Country (northern Spain). Initially, the procedure consisted of the application of a Parameter Selection Module aimed at selecting the most suitable parameters for the specific characteristics of the landfill contaminated soil, taking into consideration the envisioned land use, intended ecosystem services and nature of contaminants. Afterwards, the selected parameters were determined in soil samples collected from two sampling points located downstream of the abovementioned landfill. The results from these tests were normalized to make them comparable and integrable in a risk index. Then, risk assessment criteria were developed and applied to the two landfill contaminated soil samples. Although the lack of a proper control soil was evidenced, a natural land use was approved by the ERA (at Tier 2) for the two landfill contaminated soils. However, the existence of a potential future risk resulting from a hypothetical soil acidification must be considered. PMID:25659305

  7. Magnetic, geo-electric, and groundwater and soil quality analysis over a landfill from a lead smelter, Cairo, Egypt

    NASA Astrophysics Data System (ADS)

    Khalil, Mohamed H.

    2012-11-01

    A detailed ground magnetic survey, geoelectric vertical electric sounding (VES), and groundwater and soil quality analysis were conducted in the area of the abandoned landfill of the Awadallah lead (Pb) smelter, northeastern Cairo, Egypt. The integration between the applied techniques located successfully the buried solid waste, demarcated the groundwater and its possible contamination, and determined the lead level in soil. Magnetic survey comprised 50 magnetic profiles each 190 m length. Vertical derivatives, wavelength filters, and continuation filters characterized the eastern and central parts of the landfill by high intense magnetic anomalies reflecting metal and lead wastes, whereas the western part was characterized by low intense anomalies indicating change in the landfill composition to non-magnetized material. The geoelectric survey comprised 16 VES with a maximum AB/2 of 100 m. The inverted data demarcated effectively the groundwater aquifer with depth ranged from 11 to 18 m and true resistivities ranged from 96 to 118 ?·m. The second layer (Holocene-Q3) of semi-permeable silty and sandy clay cap (true resistivities 29 ~ 51 ?·m and thickness 9-17 m) constituted a considerable role in limiting the possible contamination from the landfill. The analyzed groundwater parameters pH, Eh, TDS, SEC, and DO indicated a good water quality with homogenous aquifer characteristics, whereas the lead concentration in groundwater (0.033-0.036 mg/L) was slightly exceeding the safe limits identified by the U.S. EPA (? 0.015 mg/L). Lead in soil samples revealed elevated concentrations (3130 mg/L/kg at VES-3) around the Awadallah smelter, whereas a gradual decrease in concentrations was recorded in the northwestern direction.

  8. Transient soil moisture profile of a water-shedding soil cover in north Queensland, Australia

    NASA Astrophysics Data System (ADS)

    Gonzales, Christopher; Baumgartl, Thomas; Scheuermann, Alexander

    2014-05-01

    In current agricultural and industrial applications, soil moisture determination is limited to point-wise measurements and remote sensing technologies. The former has limitations on spatial resolution while the latter, although has greater coverage in three dimensions, but may not be representative of real-time hydrologic conditions of the substrate. This conference paper discusses the use of elongated soil moisture probes to describe the transient soil moisture profile of water-shedding soil cover trial plots in north Queensland, Australia. Three-metre long flat ribbon cables were installed at designed depths across a soil cover with substrate materials from mining activities comprising of waste rocks and blended tailings. The soil moisture measurement is analysed using spatial time domain reflectometry (STDR) (Scheuermann et al., 2009) Calibration of the flat ribbon cable's soil moisture measurement in waste rocks is undertaken in a glasshouse setting. Soil moisture retention and outflows are monitored at specific time interval by mass balance and water potential measurements. These data sets together with the soil hydrologic properties derived from laboratory and field measurements are used as input in the numerical code on unsaturated flow, Hydrus2D. The soil moisture calculations of the glasshouse calibration using this numerical method are compared with results from the STDR soil moisture data sets. In context, the purpose of the soil cover is to isolate sulphide-rich mine wastes from atmospheric interaction as oxidation and leaching of these materials may result to acid and metalliferous drainage. The long term performance of a soil cover will be described in terms of the quantities and physico-chemical characteristics of its outflows. With the soil moisture probes set at automated and pre-determined measurement time intervals, it is expected to distinguish between macropore and soil moisture flows during high intensity rainfall events and, also continuously update data sets on soil moisture retention, especially during long periods of drought. As such, description of the soil cover water balance will be more elaborate as the soil moisture profile will be described in terms of temporal and spatial variability. Moreover, this field data set can lend support on the evaluation of the potential use of mine wastes as cover materials with respect to their hydrologic and geochemical properties.

  9. Interaction effects of climate and land use/land cover change on soil organic carbon sequestration

    E-print Network

    Grunwald, Sabine

    Interaction effects of climate and land use/land cover change on soil organic carbon sequestration carbon sequestration Climate change Soil carbon change Historically, Florida soils stored the largest use/land cover impacted soil C sequestration. · Land use/land cover in FL changed significantly over

  10. Kinetics of biological methane oxidation in the presence of non-methane organic compounds in landfill bio-covers

    SciTech Connect

    Albanna, Muna; Warith, Mostafa; Fernandes, Leta

    2010-02-15

    In this experimental program, the effects of non-methane organic compounds (NMOCs) on the biological methane (CH{sub 4}) oxidation process were examined. The investigation was performed on compost experiments incubated with CH{sub 4} and selected NMOCs under different environmental conditions. The selected NMOCs had different concentrations and their effects were tested as single compounds and mixtures of compounds. The results from all experimental sets showed a decrease in CH{sub 4} oxidation capacity of the landfill bio-cover with the increase in NMOCs concentrations. For example, in the experiment using compost with 100% moisture content at 35 deg. C without any NMOCs the V{sub max} value was 35.0 mug CH{sub 4}h{sup -1}g{sub wetwt}{sup -1}. This value was reduced to 19.1 mug CH{sub 4}h{sup -1}g{sub wetwt}{sup -1} when mixed NMOCs were present in the batch reactors under the same environmental conditions. The experimental oxidation rates of CH{sub 4} in the presence of single and mixed NMOCs were modeled using the uncompetitive inhibition model and kinetic parameters, including the dissociation constants, were obtained. Additionally, the degradation rates of the NMOCs and co-metabolic abilities of methanotrophic bacteria were estimated.

  11. Assessment of soil-gas, soil, and water contamination at the former 19th Street landfill, Fort Gordon, Georgia, 2009-2010

    USGS Publications Warehouse

    Falls, W. Fred; Caldwell, Andral W.; Guimaraes, Wladmir B.; Ratliff, W. Hagan; Wellborn, John B.; Landmeyer, James E.

    2011-01-01

    Soil gas, soil, and water were assessed for organic and inorganic constituents at the former 19th Street landfill at Fort Gordon, Georgia, from February to September 2010. Passive soil-gas samplers were analyzed to evaluate organic constituents in the hyporheic zone and flood plain of a creek and soil gas within the estimated boundaries of the former landfill. Soil and water samples were analyzed to evaluate inorganic constituents in soil samples, and organic and inorganic constituents in the surface water of a creek adjacent to the landfill, respectively. This assessment was conducted to provide environmental constituent data to Fort Gordon pursuant to requirements of the Resource Conservation and Recovery Act Part B Hazardous Waste Permit process. The passive soil-gas samplers deployed in the water-saturated hyporheic zone and flood plain of the creek adjacent to the former landfill indicated the presence of total petroleum hydrocarbon (TPH) and octane above method detection levels in groundwater beneath the creek bed and flood plain at all 12 soil-gas sampler locations. The TPH concentrations ranged from 51.4 to 81.4 micrograms per liter. Octane concentrations ranged from 1.78 to 2.63 micrograms per liter. These detections do not clearly identify specific source areas in the former landfill; moreover, detections of TPH and octane in a soil-gas sampler installed at a seep on the western bank of the creek indicated the potential for these constituents to be derived from source areas outside the estimated boundaries of the former landfill. A passive soil-gas sampler survey was conducted in the former landfill from June 30 to July 5, 2010, and involved 56 soil-gas samplers that were analyzed for petroleum and halogenated compounds not classified as chemical agents or explosives. The TPH soil-gas mass exceeded 2.0 micrograms in 21 samplers. Most noticeable are the two sites with TPH detections which are located in and near the hyporheic zone and are likely to affect the creek. However, most TPH detections were located in and immediately adjacent to a debris field located within the former landfill and in areas where debris was not visible, including the northwestern and southeastern parts of the study area. Two of the four soil-gas samplers installed within a former military training area adjacent to the landfill also had TPH detections above the method detection level. Benzene, toluene, ethylbenzene, and xylene (as combined BTEX mass) were detected at 0.02 microgram or greater in three soil-gas samplers installed at the northwestern boundary and in five samplers installed in the southeastern part of the study area. There was no BTEX mass detected above the method detection level in samplers installed in the debris field. Toluene was the most frequently detected BTEX compound. Compounds indicative of diesel-range organics were detected above 0.04 microgram in 12 soil-gas samplers and had a distribution similar to that of TPH, including being detected in the debris field. Undecane was the most frequently detected diesel compound. Chloroform and naphthalene were detected in eight and two soil-gas samplers, respectively. Five soil-gas samplers deployed during September 2010 were analyzed for organic compounds classified as chemical agents and explosives, but none exceeded the method detection levels. Five composite soil samples collected from within the estimated boundaries of the former landfill were analyzed for 35 inorganic constituents, but none of the constituents detected exceeded regional screening levels for industrial soils. The sample collected in the debris field exceeded background levels for aluminum, barium, calcium, chromium, lead, nickel, potassium, sodium, and zinc. Three surface-water samples were collected in September 2010 from a stormwater outfall culvert that drains to the creek and from the open channel of the creek at upstream and downstream locations relative to the outfall. Toluene was detected at 0.661 mi

  12. Potential for enhanced phytoremediation of landfills using biosolids--a review.

    PubMed

    Kim, Kwon-Rae; Owens, Gary

    2010-01-01

    Despite the use of recyclable materials increasing worldwide, waste disposal to landfill remains the most common method of waste management because it is simple and relatively inexpensive. Although landfill disposal is an effective waste management system, if not managed correctly, a number of potential detrimental environmental impacts have been identified including soil and ground water contamination, leachate generation, and gas emissions. In particular, improper post-closure treatment of landfills or deterioration of the conventional clay landfill capping were shown to result in land degradation which required remediation to secure contaminants within the landfill site. Phytoremediation is an attractive technology for landfill remediation, as it can stabilize soil and simultaneously remediate landfill leachate. In addition, landfill phytoremediation systems can potentially be combined with landfill covers (Phytocapping) for hydrological control of infiltrated rainfall. However, for the successful application of any phytoremediation system, the effective establishment of appropriate, desired vegetation is critical. This is because the typically harsh and sterile nature of landfill capping soil limits the sustainable establishment of vegetation. Therefore, the physicochemical properties of landfill capping soils often need to be improved by incorporating soil amendments. Biosolids are a common soil amendment and will often meet these demanding conditions because they contain a variety of plant nutrients such as nitrogen, phosphate, potassium, as well as a large proportion of organic matter. Such amendment will also ameliorate the physical properties of the capping soils by increasing porosity, moisture content, and soil aggregation. Contaminants which potentially originate from biosolids will also be remediated by activities congruent with the establishment of plants and bacteria. PMID:19939550

  13. Replacing fallow with cover crops in a semiarid soil:Effects on soil properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Replacement of fallow in crop–fallow systems with cover crops (CCs) may improve soil properties. We assessed whether replacing fallow in no-till winter wheat (Triticum aestivum L.)–fallow with winter and spring CCs for 5 years reduced wind and water erosion, increased soil organic carbon (SOC), and ...

  14. Vegetation study in support of the design and optimization of vegetative soil covers, Sandia National Laboratories, Albuquerque, New Mexico.

    SciTech Connect

    Peace, Gerald L.; Goering, Timothy James (GRAM inc., Albuquerque, NM); Knight, Paul J. (Marron and Associates, Albuquerque, NM); Ashton, Thomas S. (Marron and Associates, Albuquerque, NM)

    2004-11-01

    A vegetation study was conducted in Technical Area 3 at Sandia National Laboratories, Albuquerque, New Mexico in 2003 to assist in the design and optimization of vegetative soil covers for hazardous, radioactive, and mixed waste landfills at Sandia National Laboratories/New Mexico and Kirtland Air Force Base. The objective of the study was to obtain site-specific, vegetative input parameters for the one-dimensional code UNSAT-H and to identify suitable, diverse native plant species for use on vegetative soil covers that will persist indefinitely as a climax ecological community with little or no maintenance. The identification and selection of appropriate native plant species is critical to the proper design and long-term performance of vegetative soil covers. Major emphasis was placed on the acquisition of representative, site-specific vegetation data. Vegetative input parameters measured in the field during this study include root depth, root length density, and percent bare area. Site-specific leaf area index was not obtained in the area because there was no suitable platform to measure leaf area during the 2003 growing season due to severe drought that has persisted in New Mexico since 1999. Regional LAI data was obtained from two unique desert biomes in New Mexico, Sevilletta Wildlife Refuge and Jornada Research Station.

  15. Geoelectrical investigation of old/abandoned, covered landfill sites in urban areas: model development with a genetic diagnosis approach

    NASA Astrophysics Data System (ADS)

    Meju, Maxwell A.

    2000-05-01

    Geoelectrical methods have an important, albeit difficult role to play in landfill investigations. In the present economic conditions, with the environmentally sensitive regime, adequate desk-study and model development are essential ingredients for a successful site investigation of landfills. This paper attempts to develop a genetic investigative model for old/abandoned landfill sites where the records of operations are not available. The main elements of the model are the site boundaries, age and nature of anthropogenic deposits, depth and dip of the layers of refuse and sealing materials, the integrity and shape of the capping zones or separating walls and basal floor slopes, the position of concealed access roads in the site, the water table (or perched water bodies within the refuse) and the presence of leachate. The attendant geotechnical, hydrogeological, and bio-geochemical constraints at such sites are also incorporated in the model for consistency of practical solutions to landfill problems. The nature of anthropogenic deposits and the spatial-temporal characteristics of leachates are reviewed in a geoelectrical context. The analogy between waste degradation and leaching, and the well-known weathering processes of supergene mineral enrichment and saprolite formation in crystalline rocks is explored, and used to develop a conceptual resistivity-vs.-depth model for landfill sites. The main tenet of the model is that vertical conductivity profiles will attain maximum values in the zone of mineral enrichment near the water table and tail-off away from it. This conceptual resistivity model is shown to be consistent with non-invasive observations in landfill sites in different geographical environments. Power-law relationships are found to exist between some geoelectrically important hydrochemical parameters (fluid conductivity, chloride content and total dissolved solids) in leachates and leachate-contaminated groundwater from some landfill sites. Since some chemical parameters of fill are known to vary consistently with time, a plausible hydrochemical and age-deductive scheme for saturated fill is proposed for geoelectrical models of landfills without significant amounts of metal. Practical suggestions are made for a consistent approach in geoelectrical investigation and diagnosis of old landfill sites. A few field examples are used to illustrate the diagnosis approach.

  16. Functional and environmental assessment of the urboecosystems designed in the biologically reclamated landfill with industrial wastes (in Ryazan city)

    NASA Astrophysics Data System (ADS)

    Karyakin, Alexey; Vasenev, Ivan; Karyakina, Svetlana

    2015-04-01

    Regional environmental bodies' ability to understand, model and predict their soil cover environmental functions are especially important in case of landfill reclamation. The special attention has to be done to landfills with industrial wastes created earlier in frame of big city - comparatively closed to their residential areas. Dominated in Ryazan region sandy loam gray forest soils with not so high soil organic matter content and soil exchange capacity determine additional problems with landfill biological reclamation and continuous sustainable vegetation cover development. The modern environmental monitoring system has been developed in the big landfill with tanning industrial wastes from the biggest in Europe tannery to develop recommendation on the environmentally friendly reclamation technologies adapted to concrete landscape conditions and functional features of 2 m fresh soil-ground coating the landfill surface. More detailed monitoring system has to be developed to assess the regulatory environmental functions of the regenerated soil cover to minimize the reclamated landfill' negative impacts on the urban ecosystem air, surface and ground water quality. Obtained result will be useful for similar landfills with tanning industrial wastes environmental impact assessment and smart design.

  17. Gully potential in soil-covered uranium waste impoundments

    SciTech Connect

    Abt, S.R. . Dept. of Civil Engineering); Pauley, C.J. ); Hogan, S.A. ); Johnson, T.L. )

    1994-08-01

    Soil covers are routinely considered a design alternative to stabilize uranium waste impoundments. Gully intrusion into the cover is one of the greatest potential threats to the long-term stability of an impoundment. An investigation was conducted to estimate the maximum depth of gully intrusion, the approximate top width of the gully at the point of maximum incision, and the approximate location of the maximum intrusion. A large-scale laboratory study was conducted on seven embankments in which approximately 200 years of rainfall was simulated and the resulting gullies were documented. In addition, 11 gullies occurring in actual reclaimed impoundments were documented. An analysis of the laboratory and field data sets was performed in which the maximum depth of gully incision, top width of the gully, and location of the maximum gully incision were related to the pile height, tributary volume of runoff, and soil composition. These relations provide the designers with a means for assessing the cover design to meet the long-term stability of the waste.

  18. Calculations of radar backscattering coefficient of vegetation-covered soils

    NASA Technical Reports Server (NTRS)

    Mo, T.; Schmugge, T. J.; Jackson, T. J. (principal investigators)

    1983-01-01

    A model for simulating the measured backscattering coefficient of vegetation-covered soil surfaces includes both coherent and incoherent components of the backscattered radar pulses from a rough sil surface. The effect of vegetation canopy scattering is also incorporated into the model by making the radar pulse subject to two-way attenuation and volume scattering when it passes through the vegetation layer. Model results agree well with the measured angular distributions of the radar backscattering coefficient for HH polarization at the 1.6 GHz and 4.75 GHz frequencies over grass-covered fields. It was found that the coherent scattering component is very important at angles near nadir, while the vegetation volume scattering is dominant at incident angles 30 degrees.

  19. Characterization of contaminated soil and groundwater surrounding an illegal landfill (S. Giuliano, Venice, Italy) by principal component analysis and kriging.

    PubMed

    Critto, Andrea; Carlon, Claudio; Marcomini, Antonio

    2003-01-01

    The characterization of a hydrologically complex contaminated site bordering the lagoon of Venice (Italy) was undertaken by investigating soils and groundwaters affected by the chemical contaminants originated by the wastes dumped into an illegal landfill. Statistical tools such as principal components analysis and geostatistical techniques were applied to obtain the spatial distribution of chemical contaminants. Dissolved organic carbon (DOC), SO4(2-) and Cl- were used to trace the migration of the contaminants from the top soil to the underlying groundwaters. The chemical and hydrogeological available information was assembled to obtain the schematic of the conceptual model of the contaminated site capable to support the formulation of major exposure scenarios, which are also provided. PMID:12531312

  20. Comparison of two numerical modelling approaches to a field experiment of unsaturated radon transport in a covered uranium mill tailings soil (Lavaugrasse, France).

    PubMed

    Saâdi, Zakaria; Guillevic, Jérôme

    2016-01-01

    Uncertainties on the mathematical modelling of radon ((222)Rn) transport in an unsaturated covered uranium mill tailings (UMT) soil at field scale can have a great impact on the estimation of the average measured radon exhalation rate to the atmosphere at the landfill cover. These uncertainties are usually attributed to the numerical errors from numerical schemes dealing with soil layering, and to inadequate modelling of physical processes at the soil/plant/atmosphere interface and of the soil hydraulic and transport properties, as well as their parameterization. In this work, we demonstrate how to quantify these uncertainties by comparing simulation results from two different numerical models to experimental data of radon exhalation rate and activity concentration in the soil-gas measured in a covered UMT-soil near the landfill site Lavaugrasse (France). The first approach is based on the finite volume compositional (i.e., water, radon, air) transport model TOUGH2/EOS7Rn (Transport Of Unsaturated Groundwater and Heat version 2/Equation Of State 7 for Radon; Saâdi et al., 2014), while the second one is based on the finite difference one-component (i.e., radon) transport model TRACI (Transport de RAdon dans la Couche Insaturée; Ferry et al., 2001). Transient simulations during six months of variable rainfall and atmospheric air pressure showed that the model TRACI usually overestimates both measured radon exhalation rate and concentration. However, setting effective unsaturated pore diffusivities of water, radon and air components in soil-liquid and gas to their physical values in the model EOS7Rn, allowed us to enhance significantly the modelling of these experimental data. Since soil evaporation has been neglected, none of these two models was able to simulate the high radon peaks observed during the dry periods of summer. However, on average, the radon exhalation rate calculated by EOS7Rn was 34% less than that was calculated by TRACI, and much closer to the measured one for physically-based soil radon diffusion models. Unlike TRACI, EOS7Rn was able to simulate qualitatively seasonal variations of both radon exhalation and concentration. These results show that EOS7Rn produces less numerical errors than TRACI, and can be considered as a promising model for predicting radon transport in the landfill, if soil evaporation is modelled and its numerical inversion for parameter estimation is realized. PMID:25864040

  1. Amending metal contaminated mine soil with biochars to sequester metals and improve plant growth cover

    EPA Science Inventory

    There are numerous mine spoil sites in the U.S. Pacific Northwest that contain highly acidic, heavy metal-laden soils, which limits establishment of a soil-stabilizing plant cover. Biochars may be a suitable soil amendment to reduce toxic metals, improve soil fertility, soil wa...

  2. Estonian soil classification as a tool for recording information on soil cover and its matching with local site types, plant covers and humus forms classifications

    NASA Astrophysics Data System (ADS)

    Kõlli, Raimo; Tõnutare, Tõnu; Rannik, Kaire; Krebstein, Kadri

    2015-04-01

    Estonian soil classification (ESC) has been used successfully during more than half of century in soil survey, teaching of soil science, generalization of soil databases, arrangement of soils sustainable management and others. The Estonian normally developed (postlithogenic) mineral soils (form 72.4% from total area) are characterized by mean of genetic-functional schema, where the pedo-ecological position of soils (ie. location among other soils) is given by means of three scalars: (i) 8 stage lithic-genetic scalar (from rendzina to podzols) separates soils each from other by parent material, lithic properties, calcareousness, character of soil processes and others, (ii) 6 stage moisture and aeration conditions scalar (from aridic or well aerated to permanently wet or reductic conditions), and (iii) 2-3 stage soil development scalar, which characterizes the intensity of soil forming processes (accumulation of humus, podzolization). The organic soils pedo-ecological schema, which links with histic postlithogenic soils, is elaborated for characterizing of peatlands superficial mantle (form 23.7% from whole soil cover). The position each peat soil species among others on this organic (peat) soil matrix schema is determined by mean of 3 scalars: (i) peat thickness, (ii) type of paludification or peat forming peculiarities, and (iii) stage of peat decomposition or peat type. On the matrix of abnormally developed (synlithogenic) soils (all together 3.9%) the soil species are positioned (i) by proceeding in actual time geological processes as erosion, fluvial processes (at vicinity of rivers, lakes or sea) or transforming by anthropogenic and technological processes, and (ii) by 7 stage moisture conditions (from aridic to subaqual) of soils. The most important functions of soil cover are: (i) being a suitable environment for plant productivity; (ii) forming adequate conditions for decomposition, transformation and conversion of falling litter (characterized by humus cover type); (iii) being compartment for deposition of humus, individual organic compounds, plant nutrition elements, air and water, and (iv) forming (bio)chemically variegated active space for soil type specific edaphon. For studying of ESC matching with others ecosystem compartments classifications the comparative analysis of corresponding classification schemas was done. It may be concluded that forest and natural grasslands site types as well the plant associations of forests and grasslands correlate (match) well with ESC and therefore these compartments may be adequately expressed on soil cover matrixes. Special interest merits humus cover (in many countries known as humus form), which is by the issue natural body between plant and soil or plant cover and soil cover. The humus cover, which lied on superficial part of soil cover, has been formed by functional interrelationships of plants and soils, reflects very well the local pedo-ecological conditions (both productivity and decomposition cycles) and, therefore, the humus cover types are good indicators for characterizing of local pedo-ecological conditions. The classification of humus covers (humus forms) should be bound with soil classifications. It is important to develop a pedocentric approach in treating of fabric and functioning of natural and agro-ecosystems. Such, based on soil properties, ecosystem approach to management and protection natural resources is highly recommended at least in temperate climatic regions. The sound matching of soil and plant cover is of decisive importance for sustainable functioning of ecosystem and in attaining a good environmental status of the area.

  3. COVER CROPS ENHANCE SOIL ORGANIC MATTER, CARBON DYNAMICS AND MICROBIOLOGICAL FUNCTION IN A MEDITERRANEAN VINEYARD AGROECOSYSTEM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Impacts of soil tillage and cover crops on soil carbon (C) dynamics and microbiological function were investigated in a vineyard grown in California’s Mediterranean climate. We 1) compared soil organic matter (SOM), C dynamics and microbiological activity of two cover crops [Trios 102 (Triticale x T...

  4. Land Cover Differences in Soil Carbon and Nitrogen at Fort Benning, Georgia

    SciTech Connect

    Garten Jr., C.T.

    2004-02-09

    Land cover characterization might help land managers assess the impacts of management practices and land cover change on attributes linked to the maintenance and/or recovery of soil quality. However, connections between land cover and measures of soil quality are not well established. The objective of this limited investigation was to examine differences in soil carbon and nitrogen among various land cover types at Fort Benning, Georgia. Forty-one sampling sites were classified into five major land cover types: deciduous forest, mixed forest, evergreen forest or plantation, transitional herbaceous vegetation, and barren land. Key measures of soil quality (including mineral soil density, nitrogen availability, soil carbon and nitrogen stocks, as well as properties and chemistry of the O-horizon) were significantly different among the five land covers. In general, barren land had the poorest soil quality. Barren land, created through disturbance by tracked vehicles and/or erosion, had significantly greater soil density and a substantial loss of carbon and nitrogen relative to soils at less disturbed sites. We estimate that recovery of soil carbon under barren land at Fort Benning to current day levels under transitional vegetation or forests would require about 60 years following reestablishment of vegetation. Maps of soil carbon and nitrogen were produced for Fort Benning based on a 1999 land cover map and field measurements of soil carbon and nitrogen stocks under different land cover categories.

  5. Containment and attenuating layers: An affordable strategy that preserves soil and water from landfill pollution.

    PubMed

    Regadío, Mercedes; Ruiz, Ana I; Rodríguez-Rastrero, Manuel; Cuevas, Jaime

    2015-12-01

    The performance of a widely distributed natural clay to attenuate contaminants released from an old landfill was investigated. The objective is to evaluate its potential use as a barrier for waste containment systems. Core samples of the natural clay were collected below the landfill and their parameters distribution with depth was determined. Partition coefficients, retardation factors and percentage values of pollutants concentrations, revealed a rapid decrease of contaminants with depth. The background values of the pollutants were below the maximum limits for drinking and irrigation water and with no need of reactors, collectors, aeration or recirculation systems. Impermeable waste capping is discouraged in order to decrease leachate toxicity, decomposition time and conservative species, and in order to avoid high-reducing conditions that would mobilize redox-sensitive contaminants. A review on leachate-composition evolution and on natural-attenuation processes was undertaken to understand the interactions leachate-substratum, which is essential to properly estimate the leachate transport and implement the attenuation strategy. This strategy complements the traditional containment one regarding (1) the susceptibility of engineering liners to fail, (2) the inevitable diffusion of contaminants through them, (3) the remaining high number of old landfills before the requirements of liner systems and (4) the low-cost and feasibility for developing countries. PMID:26320817

  6. [Nitrous oxide emissions from municipal solid waste landfills and its measuring methodology: a review].

    PubMed

    Jia, Ming-Sheng; Wang, Xiao-Jun; Chen, Shao-Hua

    2014-06-01

    Nitrous oxide (N2O) is one of three major greenhouse gases and the dominant ozone-depleting substance. Landfilling is the major approach for the treatment and disposal of municipal solid waste (MSW), while MSW landfills can be an important anthropogenic source for N2O emissions. Measurements at lab-scale and full-scale landfills have demonstrated that N2O can be emitted in substantial amounts in MSW landfills; however, a large variation in reported emission values exists. Currently, the mechanisms of N2O production and emission in landfills and its contribution to global warming are still lack of sufficient studies. Meanwhile, obtaining reliable N2O fluxes data in landfills remains a question with existing in-situ measurement techniques. This paper summarized relevant literature data on this issue and analyzed the potential production and emission mechanisms of N2O in traditional anaerobic sanitary landfill by dividing it into the MSW buried and the cover soil. The corresponding mechanisms in nitrogen removal bioreactor landfills were analyzed. Finally, the applicability of existing in-situ approaches measuring N2O fluxes in landfills, such as chamber and micrometeorological methods, was discussed and areas in which further research concerning N2O emissions in landfills was urgently required were proposed as well. PMID:25223043

  7. Soil organic carbon and water content effects on remote crop residue cover estimation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conservation tillage (CT) systems help protect the soil and environment, and improve net farm profitability. CT methods leave increased amounts of crop residue cover (CRC) on the soil surface, minimizing soil erosion and evaporation. CT uses less fuel, disturbs soil less, and requires less fertili...

  8. Modeling soil depth from topographic and land cover attributes Teklu K. Tesfa,1

    E-print Network

    Tarboton, David

    Modeling soil depth from topographic and land cover attributes Teklu K. Tesfa,1 David G. Tarboton,1 June 2009; published 29 October 2009. [1] Soil depth is an important input parameter in hydrological and ecological modeling. Presently, the soil depth data available in national soil databases (STATSGO and SSURGO

  9. The effects of different soil cover management practices on plant biodiversity and soil properties in Mediterranean ancient olive orchards

    NASA Astrophysics Data System (ADS)

    Madzaric, Suzana; Aly, Adel; Ladisa, Gaetano; Calabrese, Generosa

    2014-05-01

    The effects of different soil cover management practices on plant biodiversity and soil properties in Mediterranean ancient olive orchards Madzaric S., Aly A., Ladisa G. and Calabrese G. The loss of natural plant cover due to the inappropriate soil cover management is often a decisive factor for soil degradation in Mediterranean area. This accompanied with typical climate, characterized by cool, wet winters and hot and dry summers leads to soil erosion and loss of productivity. Due to simplification of agricultural practice and to the attempt to decrease cost of production, keeping soil bare is a widespread agricultural practice in Mediterranean ancient olive orchards (AOOs). The consequences of this are degradation of soil quality and reduction of plant biodiversity. In last year's some alternative practices are proposed in order to protect soil and biodiversity. One of these practices is the "grassing" i.e. covering the soil by selected autochthonous plant species. Objectives of our study are: (1) to evaluate impact of different soil cover management practices on soil properties and plant biodiversity in AOOs and (2) to define a minimum indicators' set (Minimum Data Set - MDS) to evaluate the effectiveness of different agricultural practices in environmental performance of AOOs. A comparison was carried on considering two management systems (conventional vs. organic) and three agricultural practices: conventional with bare soil (CON), organic with soil covered by selected autochthonous species (MIX) and organic left to the native vegetation (NAT). In general a clear positive influence of organic management system was recognized. Some soil quality indicators (physical, chemical and biological) showed responsiveness in describing the effects of management system and agricultural practices on soil properties. The both approaches with vegetation cover on the soil surface (either sowing of mixture or soil left to the natural plant cover) performed better than conventional one with repeated tillage and bare soil during the whole year. This is peculiarly visible in the case of soil erosion that presents an enormous problem in Mediterranean region. No clear differences resulted between the two organic practices for soil management (natural cover and grassing). Key words: organic agriculture, ecological indicators, agricultural practices, soil quality, olive groves

  10. The role of snow cover and soil freeze/thaw cycles affecting boreal-arctic soil carbon dynamics

    NASA Astrophysics Data System (ADS)

    Yi, Y.; Kimball, J. S.; Rawlins, M. A.; Moghaddam, M.; Euskirchen, E. S.

    2015-07-01

    Northern Hemisphere permafrost affected land areas contain about twice as much carbon as the global atmosphere. This vast carbon pool is vulnerable to accelerated losses through mobilization and decomposition under projected global warming. Satellite data records spanning the past 3 decades indicate widespread reductions (∼ 0.8-1.3 days decade-1) in the mean annual snow cover extent and frozen season duration across the pan-Arctic domain, coincident with regional climate warming trends. How the soil carbon pool responds to these changes will have a large impact on regional and global climate. Here, we developed a coupled terrestrial carbon and hydrology model framework with detailed 1-D soil heat transfer representation to investigate the sensitivity of soil organic carbon stocks and soil decomposition to changes in snow cover and soil freeze/thaw processes in the Pan-Arctic region over the past three decades (1982-2010). Our results indicate widespread soil active layer deepening across the pan-Arctic, with a mean decadal trend of 6.6 ± 12.0 (SD) cm, corresponding with widespread warming and lengthening non-frozen season. Warming promotes vegetation growth and soil heterotrophic respiration, particularly within surface soil layers (? 0.2 m). The model simulations also show that seasonal snow cover has a large impact on soil temperatures, whereby increases in snow cover promote deeper (? 0.5 m) soil layer warming and soil respiration, while inhibiting soil decomposition from surface (? 0.2 m) soil layers, especially in colder climate zones (mean annual T ? -10 °C). Our results demonstrate the important control of snow cover in affecting northern soil freeze/thaw and soil carbon decomposition processes, and the necessity of considering both warming, and changing precipitation and snow cover regimes in characterizing permafrost soil carbon dynamics.

  11. Factors affecting water balance and percolate production for a landfill in operation.

    PubMed

    Poulsen, Tjalfe G; Møoldrup, Per

    2005-02-01

    Percolate production and precipitation data for a full-scale landfill in operation measured over a 13-year period were used to evaluate the impact and importance of the hydrological conditions of landfill sections on the percolate production rates. Both active (open) and closed landfill sections were included in the evaluation. A simple top cover model requiring a minimum of input data was used to simulate the percolate production as a function of precipitation and landfill section hydrology. The results showed that changes over time in the hydrology of individual landfill sections (such as section closure or plantation of trees on top of closed sections) can change total landfill percolate production by more than 100%; thus, percolate production at an active landfill can be very different from percolate production at the same landfill after closure. Furthermore, plantation of willow on top of closed sections can increase the evapotranspiration rate thereby reducing percolate production rates by up to 47% compared to a grass cover. This process, however, depends upon the availability of water in the top layer, and so the evaporation rate will be less than optimal during the summer where soil-water contents in the top cover are low. PMID:15751398

  12. Summer cover crops and soil amendments to improve growth and nutrient uptake of okra

    SciTech Connect

    Wang, Q.R.; Li, Y.C.; Klassen, W.

    2006-04-15

    A pot experiment with summer cover crops and soil amendments was conducted in two consecutive years to elucidate the effects of these cover crops and soil amendments on 'Clemson Spineless 80' okra (Abelmoschus esculentus) yields and biomass production, and the uptake and distribution of soil nutrients and trace elements. The cover crops were sunn hemp (Crotalaria juncea), cowpea (Vigna unguiculata), velvetbean (Mucuna deeringiana), and sorghum sudan-grass (Sorghum bicolor x S. bicolor var. sudanense) with fallow as the control. The organic soil amendments were biosolids (sediment from wastewater plants), N-Viro Soil (a mixture of biosolids and coal ash), coal ash (a combustion by-product from power plants), co-compost (a mixture of 3 biosolids: 7 yard waste), and yard waste compost (mainly from leaves and branches of trees and shrubs, and grass clippings) with a soil-incorporated cover crop as the control. As a subsequent vegetable crop, okra was grown after the cover crops, alone or together with the organic soil amendments, had been incorporated. All of the cover crops, except sorghum sudangrass in 2002-03, significantly improved okra fruit yields and the total biomass production. Both cover crops and soil amendments can substantially improve nutrient uptake and distribution. The results suggest that cover crops and appropriate amounts of soil amendments can be used to improve soil fertility and okra yield without adverse environmental effects or risk of contamination of the fruit. Further field studies will be required to confirm these findings.

  13. What's left? - Investigations on soil cover of conservation tillage methods in Austria

    NASA Astrophysics Data System (ADS)

    Bauer, Thomas; Hösl, Rosemarie; Strauss, Peter

    2014-05-01

    One of the most accepted and a practicable method to prevent soil from erosion is conservation tillage. If conservation tillage practices are performed in a proper way soil is protected from wind and water erosion. This study deals with the effectivity of conservation tillage practices under real field conditions. Therefore we i) carried out rainfall simulation experiments employing conservation tillage practices which had been proposed by farmers to test whether actual conservation tillage practices would be effective, ii) did an observation of mean soil cover on arable land after seeding in Lower and Upper Austria for field sites where conservation tillage was funded. Rainfall simulation experiments were carried out in the years 2011 and 2012 for various conservation tillage treatments consisting of different mulching and no tillage techniques. To evaluate results on surface runoff and erosion we additionally measured soil cover, bulk densities and surface roughness of the experimental plots. Soil cover estimation of the arable land in Lower and Upper Austria which is funded for conservation tillage practices was done in 2012 and 2013. Altogether on 146 randomly chosen field sites soil cover was estimated by using an object-based image analysis method. Results reveal that the effectiveness of conservation tillage was depending on the existence of a sufficient soil cover. However, under conditions of actual farm practices, a sufficient soil cover was not obtained for mulching treatments in 2011 and only partially in 2012. Therefore, mulching treatments partially gained even higher surface runoff and soil loss rates than conventional tillage practices. Due to their high soil cover, soil loss and surface runoff of no tillage treatments were very small as compared to all other tested treatments. The results of the soil cover estimation in Lower and Upper Austria show that under practicable land use a mean soil cover of 12 percent can be reached, what's rather low in a sense of soil erosion prevention compared to the results of our rainfall simulation experiments and literature.

  14. Landfill mining: A critical review of two decades of research

    SciTech Connect

    Krook, Joakim; Svensson, Niclas; Eklund, Mats

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer We analyze two decades of landfill mining research regarding trends and topics. Black-Right-Pointing-Pointer So far landfill mining has mainly been used to solve waste management issues. Black-Right-Pointing-Pointer A new perspective on landfills as resource reservoirs is emerging. Black-Right-Pointing-Pointer The potential of resource extraction from landfills is significant. Black-Right-Pointing-Pointer We outline several key challenges for realization of resource extraction from landfills. - Abstract: Landfills have historically been seen as the ultimate solution for storing waste at minimum cost. It is now a well-known fact that such deposits have related implications such as long-term methane emissions, local pollution concerns, settling issues and limitations on urban development. Landfill mining has been suggested as a strategy to address such problems, and in principle means the excavation, processing, treatment and/or recycling of deposited materials. This study involves a literature review on landfill mining covering a meta-analysis of the main trends, objectives, topics and findings in 39 research papers published during the period 1988-2008. The results show that, so far, landfill mining has primarily been seen as a way to solve traditional management issues related to landfills such as lack of landfill space and local pollution concerns. Although most initiatives have involved some recovery of deposited resources, mainly cover soil and in some cases waste fuel, recycling efforts have often been largely secondary. Typically, simple soil excavation and screening equipment have therefore been applied, often demonstrating moderate performance in obtaining marketable recyclables. Several worldwide changes and recent research findings indicate the emergence of a new perspective on landfills as reservoirs for resource extraction. Although the potential of this approach appears significant, it is argued that facilitating implementation involves a number of research challenges in terms of technology innovation, clarifying the conditions for realization and developing standardized frameworks for evaluating economic and environmental performance from a systems perspective. In order to address these challenges, a combination of applied and theoretical research is required.

  15. Radar backscattering measurement of bare soil and vegetation covered soil using X-band and full polarization

    NASA Astrophysics Data System (ADS)

    Goswami, B.; Kalita, M.

    2014-11-01

    The objective of the study is to measure backscattered power of bare soil and vegetation covered soil using X-band scatterometer system with full polarization and various angles during monsoon season and relate backscattered power to the density of vegetation over soil. The measurement was conducted at an experimental field located in the campus of Assam Engineering College, Guwahati, India. The soil sample consists of Silt and Clay in higher proportions as compared to Sand. The scatterometer system consists of dual-polarimetric square horn antennas, Power meter, Klystron, coaxial cables, isolator and waveguide detector. The polarization of the horn antennas as well as the look angle can be changed in the set-up. The backscattering coefficients were calculated by applying a radar equation for the measured values at incident angles between 30° and 60° for full polarization (HH, VV, HV, VH), respectively, and compared with vegetation cover over soil for each scatterometer measurement simultaneously. The VH polarization and 60° look angle are found to be the most suitable combination of configuration of an X-band scatterometer for distinguishing the land cover targets such as bare soil and vegetation covered soil. From the analysis of the results, polarimetric scatterometer data appear to be promising to distinguish the land cover types such as bare soil and soil completely covered by vegetation. The results of this study will help the scientists working in the field of active microwave remote sensing.

  16. Methanotroph diversity in landfill soil: Isolation of novel type I and type II methanotrophs whose presence was suggested by culture-independent 16S ribosomal DNA analysis

    SciTech Connect

    Wise, M.G.; McArthur, J.V.; Smimkets, L.J.

    1999-11-01

    The diversity of the methanotrophic community in mildly acidic landfill cover soil was assessed by three methods: two culture-independent molecular approaches and a traditional culture-based approach. For the first of the molecular studies, two primer pairs specific for the 16S rRNA gene of validly published type I (including for former type X) and type II methanotrophs were identified and tested. These primers were used to amplify directly extracted soil DNA, and the products were used to construct type I and type II clone libraries. The second molecular approach, based on denaturing gradient gel electrophoresis (DGGE), provided profiles of the methanotrophic community members as distinguished by sequence differences in variable region 3 of the 16S ribosomal DNA. For the culturing studies, an extinction-dilution technique was employed to isolate slow-growing but numerically dominant strains. The key variables of the series of enrichment conditions were initial pH (4.8 versus 6.8), air/CH{sub 4}/CO{sub 2} headspace ratio (50:45:5 versus 90:9:1), and concentration of the medium (1x nitrate minimal salts [NMS] versus 0.2x NMS). Screening of the isolates showed that the nutrient-rich 1x NMS selected for type I methanotrophs, which the nutrient-poor 0.2x NMS tended to enrich for type II methanotrophs. Partial sequencing of the 16S rRNA gene from selected clones and isolates revealed some of the same novel sequence types.

  17. Landfill CH{sub 4}: Rates, fates, and role in global carbon cycle

    SciTech Connect

    Bogner, J.; Spokas, K.

    1991-12-31

    Published estimates for worldwide landfill methane emissions range from 9 to 70 Tg yr{sup {minus}1}. Field and laboratory studies suggest that maximum methane yields from lanfilled refuse are about 0.06 to 0.09 m{sup 3} (dry Kg){sup {minus}1} refuse, depending on moisture content and other variables, such as organic loading, buffering capacity, and nutrients in landfill microevnironments. Methane yields may vary by more than an order of magnitude within a given site. Fates for landfill methane include (1) direct or delayed emission to the atmosphere through landfill cover materials or surface soils; (2) oxidation by methanotrophs in cover soils, with resulting emission of carbon dioxide; or (3) recovery of methane followed by combustion to produce carbon dioxide. The percent methane assigned to each pathway will vary among field sites and, for individual sites, through time. Nevertheless, a general framework for a landfill methane balance can be developed by consideration of landfill age, engineering and management practices, cover soil characteristics, and water balance. Direct measurements of landfill methane emissions are sparse, with rates between 10{sup {minus}6} and 10{sup {minus}8} g cm{sup {minus}2} s{sup {minus}1}; very high rates of 400 kg m{sup {minus}2} yr{sup {minus}1} have been measured at a semiarid unvegetated site. The proportion of landfill carbon that is ultimately converted to methane and carbon dioxide is problematical; the literature suggests that, at best, 25% to 40% of refuse carbon can be converted to biogas carbon. Cellulose contributes the major portion of the methane potential. Routine excavation of nondecomposed cellulosic materials after one or two decades of landfill burial suggests that uniformly high conversion rates are rarely attained at field sites.

  18. Landfill CH sub 4 : Rates, fates, and role in global carbon cycle

    SciTech Connect

    Bogner, J.; Spokas, K.

    1991-01-01

    Published estimates for worldwide landfill methane emissions range from 9 to 70 Tg yr{sup {minus}1}. Field and laboratory studies suggest that maximum methane yields from lanfilled refuse are about 0.06 to 0.09 m{sup 3} (dry Kg){sup {minus}1} refuse, depending on moisture content and other variables, such as organic loading, buffering capacity, and nutrients in landfill microevnironments. Methane yields may vary by more than an order of magnitude within a given site. Fates for landfill methane include (1) direct or delayed emission to the atmosphere through landfill cover materials or surface soils; (2) oxidation by methanotrophs in cover soils, with resulting emission of carbon dioxide; or (3) recovery of methane followed by combustion to produce carbon dioxide. The percent methane assigned to each pathway will vary among field sites and, for individual sites, through time. Nevertheless, a general framework for a landfill methane balance can be developed by consideration of landfill age, engineering and management practices, cover soil characteristics, and water balance. Direct measurements of landfill methane emissions are sparse, with rates between 10{sup {minus}6} and 10{sup {minus}8} g cm{sup {minus}2} s{sup {minus}1}; very high rates of 400 kg m{sup {minus}2} yr{sup {minus}1} have been measured at a semiarid unvegetated site. The proportion of landfill carbon that is ultimately converted to methane and carbon dioxide is problematical; the literature suggests that, at best, 25% to 40% of refuse carbon can be converted to biogas carbon. Cellulose contributes the major portion of the methane potential. Routine excavation of nondecomposed cellulosic materials after one or two decades of landfill burial suggests that uniformly high conversion rates are rarely attained at field sites.

  19. Soil cover patterns and land resources in the south of the Selenga mountainous region

    NASA Astrophysics Data System (ADS)

    Davydova, T. V.; Tsybzhitov, Ts. Kh.; Tsybikdorzhiev, Ts. Ts.; Gonchikov, B.-M. N.

    2009-04-01

    Soil cover patterns within the Kyakhta area of pine stands and the Kudarinsk area of dry steppes in the south of the Selenga mountainous region are characterized. The groups of soil combinations are shown on the map developed on a scale of 1: 500000. The areas of particular soils composing the combinations have been calculated. Thus, this small-scale soil map generally preserves information reflected on large- and medium-scale soil maps.

  20. Final closure cover for a Hanford radioactive mixed waste disposal facility

    SciTech Connect

    Johnson, K.D.

    1996-02-06

    This study provides a preliminary design for a RCRA mixed waste landfill final closure cover. The cover design was developed by a senior class design team from Seattle University. The design incorporates a layered design of indigenous soils and geosynthetics in a layered system to meet final closure cover requirements for a landfill as imposed by the Washington Administrative Code WAC-173-303 implementation of the Resource Conservation and Recovery Act.

  1. Design Rationale for Construction and Monitoring of Unsaturated Soil Covers at the Rocky Mountain Arsenal

    E-print Network

    Zornberg, Jorge G.

    Design Rationale for Construction and Monitoring of Unsaturated Soil Covers at the Rocky Mountain.greg@epa.gov) ABSTRACT: Unsaturated soil covers were designed for contaminated areas of the Rocky Mountain Ar- senal an alternative approach for waste containment within the US regulatory framework. The Rocky Mountain Arsenal (RMA

  2. Ruminant Grazing of Cover Crops: Effects on Soil Properties and Agricultural Production

    ERIC Educational Resources Information Center

    Poffenbarger, Hanna

    2010-01-01

    Integrating livestock into a cropping system by allowing ruminant animals to graze cover crops may yield economic and environmental benefits. The effects of grazing on soil physical properties, soil organic matter, nitrogen cycling and agricultural production are presented in this literature review. The review found that grazing cover crops…

  3. ANALYSES OF THE WATER DIVERSION LENGTH OF INCLINED, LAYERED SOIL COVERS

    E-print Network

    Aubertin, Michel

    designing a layered cover, different soils can be combined to create a capillary barrier effect in order'un recouvrement incliné est toutefois relativement complexe, car il est influencé par plusieurs facteurs. Dans cet, an interesting alternative for cover design is to use a combination of various soils to induce capillary barrier

  4. Importance of moisture transport, snow cover and soil freezing to ground temperature predictions

    E-print Network

    Importance of moisture transport, snow cover and soil freezing to ground temperature predictions freezing SUMMARY: Prediction of undisturbed ground temperature is important to simulation of buildings transport, snow cover, and soil freezing. 1. Introduction Prediction of ground temperature is an important

  5. Rye cover crop effects on soil properties in no-till corn silage/soybean agroecosystems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Farmers in the U.S. Corn Belt are showing increasing interest in winter cover crops. The known benefits of winter cover crops include reduced nitrate leaching, soil erosion, and weed germination, but evidence of improvements in soil productivity would provide further incentive for famers to implemen...

  6. Hydraulic conductivity study of compacted clay soils used as landfill liners for an acidic waste

    SciTech Connect

    Hamdi, Noureddine; Srasra, Ezzeddine

    2013-01-15

    Highlights: Black-Right-Pointing-Pointer Examined the hydraulic conductivity evolution as function of dry density of Tunisian clay soil. Black-Right-Pointing-Pointer Follow the hydraulic conductivity evolution at long-term of three clay materials using the waste solution (pH=2.7). Black-Right-Pointing-Pointer Determined how compaction affects the hydraulic conductivity of clay soils. Black-Right-Pointing-Pointer Analyzed the concentration of F and P and examined the retention of each soil. - Abstract: Three natural clayey soils from Tunisia were studied to assess their suitability for use as a liner for an acid waste disposal site. An investigation of the effect of the mineral composition and mechanical compaction on the hydraulic conductivity and fluoride and phosphate removal of three different soils is presented. The hydraulic conductivity of these three natural soils are 8.5 Multiplication-Sign 10{sup -10}, 2.08 Multiplication-Sign 10{sup -9} and 6.8 Multiplication-Sign 10{sup -10} m/s for soil-1, soil-2 and soil-3, respectively. Soil specimens were compacted under various compaction strains in order to obtain three wet densities (1850, 1950 and 2050 kg/m{sup 3}). In this condition, the hydraulic conductivity (k) was reduced with increasing density of sample for all soils. The test results of hydraulic conductivity at long-term (>200 days) using acidic waste solution (pH = 2.7, charged with fluoride and phosphate ions) shows a decrease in k with time only for natural soil-1 and soil-2. However, the specimens of soil-2 compressed to the two highest densities (1950 and 2050 kg/m{sup 3}) are cracked after 60 and 20 days, respectively, of hydraulic conductivity testing. This damage is the result of a continued increase in the internal stress due to the swelling and to the effect of aggressive wastewater. The analysis of anions shows that the retention of fluoride is higher compared to phosphate and soil-1 has the highest sorption capacity.

  7. The role of snow cover affecting boreal-arctic soil freeze-thaw and carbon dynamics

    NASA Astrophysics Data System (ADS)

    Yi, Y.; Kimball, J. S.; Rawlins, M. A.; Moghaddam, M.; Euskirchen, E. S.

    2015-10-01

    Northern Hemisphere permafrost affected land areas contain about twice as much carbon as the global atmosphere. This vast carbon pool is vulnerable to accelerated losses through mobilization and decomposition under projected global warming. Satellite data records spanning the past 3 decades indicate widespread reductions (~ 0.8-1.3 days decade-1) in the mean annual snow cover extent and frozen-season duration across the pan-Arctic domain, coincident with regional climate warming trends. How the soil carbon pool responds to these changes will have a large impact on regional and global climate. Here, we developed a coupled terrestrial carbon and hydrology model framework with a detailed 1-D soil heat transfer representation to investigate the sensitivity of soil organic carbon stocks and soil decomposition to climate warming and changes in snow cover conditions in the pan-Arctic region over the past 3 decades (1982-2010). Our results indicate widespread soil active layer deepening across the pan-Arctic, with a mean decadal trend of 6.6 ± 12.0 (SD) cm, corresponding to widespread warming. Warming promotes vegetation growth and soil heterotrophic respiration particularly within surface soil layers (? 0.2 m). The model simulations also show that seasonal snow cover has a large impact on soil temperatures, whereby increases in snow cover promote deeper (? 0.5 m) soil layer warming and soil respiration, while inhibiting soil decomposition from surface (? 0.2 m) soil layers, especially in colder climate zones (mean annual T ? -10 °C). Our results demonstrate the important control of snow cover on northern soil freeze-thaw and soil carbon decomposition processes and the necessity of considering both warming and a change in precipitation and snow cover regimes in characterizing permafrost soil carbon dynamics.

  8. Evaluation of Spectral Indices for Estimating Crop Residue Cover and Soil Carbon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Long term use of conservation tillage practices can lead to increased soil organic carbon (SOC) compared to intensively tilled soils. However, monitoring soil tillage intensity over large areas for assessing changes in SOC is difficult. Remote sensing can potentially estimate crop residue cover, a...

  9. TILLAGE, COVER CROPS, AND NITROGEN FERTILIZATION EFFECTS ON SOIL NITROGEN AND COTTON AND SORGHUM YIELDS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sustainable soil and crop management practices that reduce soil erosion and nitrogen (N) leaching, conserve soil organic matter, and optimize cotton and sorghum yields still remain a challenge. We examined the influence of three tillage practices (no-till, strip till, and chisel till ), four cover c...

  10. SOIL PHYSICAL AND BIOLOGICAL RESPONSES TO CATTLE GRAZING OF COVER CROPS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Integration of crops and livestock could be either detrimental or beneficial to soil properties, depending upon timing and intensity of animal traffic and residue cover of the soil surface. We determined surface-soil properties of a Typic Kanhapludult in northeastern Georgia USA during the first thr...

  11. Effects of soil composition and mineralogy on remote sensing of crop residue cover

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The management of crop residues in agricultural fields influences soil erosion and soil carbon sequestration. Remote sensing methods can efficiently assess crop residue cover and tillaje intensity over many fields in a region. Although the reflectance spectra of soils and crop residues are often s...

  12. Accounting for green vegetation and soil spectral properties to improve remote sensing of crop residue cover

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conservation tillage methods are beneficial as they disturb soil less and leaves increased crop residue cover (CRC) after planting on the soil surface. CRC helps reduce soil erosion, evaporation, and the need for tillage operations in fields. Greenhouse gas emissions are reduced to due to less fos...

  13. Subsurface investigation in Sarimukti landfill using DC resistivity

    NASA Astrophysics Data System (ADS)

    Kirana, Kartika Hajar; Susanto, Kusnahadi; Susilawati, Anggie

    2015-09-01

    Layering process in landfill will produce leachate that produced by the entry of a mixture of rain water or ground water into the piles solid waste. In Sarimukti landfill, leachate from landfill channeled through a pipe to the leachate pond that planted beneath the soil surface. If the pipe is leaking, the leachate will contaminate the surrounding soil and may also to contaminate groundwater. Therefore, it is necessary to investigate subsurface conditions. One type of subsurface investigation can be determined by measuring the resistivity by using DC resistivity method. Resistivity measured in Sarimukti landfill with semigriding design including 8 lines perpendicular to each other. The result show there is resistivity contrast of materials, such as the solid waste, soil, water content that is predicted as leachate, and methane gas. The range of resistivity values are from 1 ?m to 500 ?m with variations of depth in according to line lenght. The resistivity values respectively: leachate is 1 to 10 ?m; Wet soil is 10 to 100 ?m; wet waste is 100 to 400 ?m; gas is > 400 ?m. Then, leachate was found at depth of 25 meters and wet soil is predicted as aquifer layer with 70 meters depth. The resistivity of aquifer layer is 1 to 20 ?m and covered by silt clay as clay cap. Thus, it can predicted that leachate not seep into the aquifer layer.

  14. Soil health benefits using cover crops across the Southeast

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soils in the southeastern U.S. are very low in organic matter, which can be attributed to high temperatures, humidity, and rainfall that oxidizes organic residues very quickly. Conventional tillage exacerbates this condition and generally contributes to poor soil health. As a result, soils in the r...

  15. Superfund record of decision (EPA Region 6): Longhorn Army Ammunition Plant, IHAAP 12 and 16 Landfills, Karnack, TX, September 27, 1995

    SciTech Connect

    1996-03-01

    This decision document presents the selected Early Interim Remedial Action for the LHAAP 12 and 16 landfills, Longhorn Army Ammunition Plant (LHAAP), Karnack, Texas. The Record of Decision for the sites addresses an Early Interim Remedial Action. The selected remedy consists of a multilayer landfill cap section which includes the following components: Foundation soil layer, Sodium Bentonite Geocomposite Liner, Geosynthetic Membrane Liner, Final soil cover, and Perimeter berms and drainage swales.

  16. Methane balance of a bioreactor landfill in Latin America.

    PubMed

    Sanderson, Jenny; Hettiaratchi, Patrick; Hunte, Carlos; Hurtado, Omar; Keller, Alejandro

    2008-05-01

    This paper presents results from a methane (CH4) gas emission characterization survey conducted at the Loma Los Colorados landfill located 60 km from Santiago, Chile. The landfill receives approximately 1 million metric tons (t) of waste annually, and is equipped with leachate control systems and landfill gas collection systems. The collected leachate is recirculated to enable operation of the landfill as a bioreactor. For this study, conducted between April and July 2000, a total of 232 surface emission measurements were made over the 23-ha surface area of the landfill. The average surface flux rate of CH4 emissions over the landfill surface was 167 g x m(-2) x day(-1), and the total quantity of surface emissions was 13,320 t/yr. These values do not include the contribution made by "hot spots," originating from leachate pools caused by "daylighting" of leachate, that were identified on the landfill surface and had very high CH4 emission rates. Other point sources of CH4 emissions at this landfill include 20 disconnected gas wells that vent directly to the atmosphere. Additionally, there are 13 gas wells connected to an incinerator responsible for destroying 84 t/yr of CH4. The balance also includes CH4 that is being oxidized on the surface of the landfill by meth-anotrophic bacteria. Including all sources, except leachate pool emissions, the emissions were estimated to be 14,584 t/yr CH4. It was estimated that less than 1% of the gas produced by the decomposition of waste was captured by the gas collection system and 38% of CH4 generated was emitted to the atmosphere through the soil cover. PMID:18512438

  17. Modeling impact of small Kansas landfills on underlying aquifers

    USGS Publications Warehouse

    Sophocleous, M.; Stadnyk, N.G.; Stotts, M.

    1996-01-01

    Small landfills are exempt from compliance with Resource Conservation and Recovery Act Subtitle D standards for liner and leachate collection. We investigate the ramifications of this exemption under western Kansas semiarid environments and explore the conditions under which naturally occurring geologic settings provide sufficient protection against ground-water contamination. The methodology we employed was to run water budget simulations using the Hydrologic Evaluation of Landfill Performance (HELP) model, and fate and transport simulations using the Multimedia Exposure Assessment Model (MULTIMED) for several western Kansas small landfill scenarios in combination with extensive sensitivity analyses. We demonstrate that requiring landfill cover, leachate collection system (LCS), and compacted soil liner will reduce leachate production by 56%, whereas requiring only a cover without LCS and liner will reduce leachate by half as much. The most vulnerable small landfills are shown to be the ones with no vegetative cover underlain by both a relatively thin vadose zone and aquifer and which overlie an aquifer characterized by cool temperatures and low hydraulic gradients. The aquifer-related physical and chemical parameters proved to be more important than vadose zone and biodegradation parameters in controlling leachate concentrations at the point of compliance. ??ASCE.

  18. COVER CROP EFFECTS ON THE FATE OF SWINE MANURE-N APPLIED TO SOIL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cereal grain cover crops increase surface cover, anchor corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] residues, increase infiltration, reduce both rill and interrill erosion, scavenge excess nutrients from the soil, and are easily obtained and inexpensive compared to other cover crop optio...

  19. Characteristics of environmental factors and their effects on CH4 and CO2 emissions from a closed landfill: an ecological case study of Shanghai.

    PubMed

    Xiaoli, Chai; Ziyang, Lou; Shimaoka, Takayuki; Nakayama, Hirofumi; Ying, Zhu; Xiaoyan, Cao; Komiya, Teppei; Ishizaki, Toshio; Youcai, Zhao

    2010-03-01

    To elucidate the influence of landfill gas (LFG) emission on environmental factors, an ecological investigation that was primarily concerned with the characteristics of vegetation, cover soil, and solid waste in the landfill was carried out. Temporal and spatial variations in vegetation diversity and coverage and their effects on reducing the emission of methane in the landfill were investigated. The results showed that both vegetation coverage and diversity increased with elapsed landfill closure time. The transition trend of the vegetation species was from perennial plant (Phragmites australis) to annual plants. Perennial vegetation was the dominant type of vegetation during the early closure period, and annual vegetation coverage increased with closure time. Vegetation preferentially appeared in areas of comparatively high depth of cover soil, which was characterized by high moisture retentiveness that enabled vegetation growth. The concentrations of methane and carbon dioxide in the cover soil significantly decreased with increasing closure time. The concentrations of methane and carbon dioxide from bare cover soil were higher than those from vegetated cover soil whereas the CO(2) flux of bare cover soil was less than that of vegetated cover soil. PMID:19880303

  20. OUTER LOOP LANDFILL CASE STUDY

    EPA Science Inventory

    This presentation will describe the interim data reaulting from a CRADA between USEPA and Waste Management, Inc. at the outer Loop Landfill Bioreactor research project located in Louisville, KY. Recently updated data will be presented covering landfill solids, gas being collecte...

  1. Tracking quicksilver: estimation of mercury waste from consumer products and subsequent verification by analysis of soil, water, sediment, and plant samples from the Cebu City, Philippines, landfill.

    PubMed

    Buagas, Dale Jo B; Megraso, Cristi Cesar F; Namata, John Darwin O; Lim, Patrick John Y; Gatus, Karen P; Cañete, Aloysius M L

    2015-03-01

    Source attribution of mercury (Hg) is critical for policy development to minimize the impact of Hg in wastes. Mercury content of consumer products and its subsequent release into the waste stream of Cebu City, Philippines, is estimated through surveys that employed validated, enumerator-administered questionnaires. Initially, a citywide survey (n?=?1636) indicates that each household annually generates 1.07 ppm Hg (i.e., mg Hg/kg waste) and that linear and compact fluorescent lamps (17.2 %) and thermometers (52.1 %) are the major sources of Hg. A subsequent survey (n?=?372) in the vicinity of the city's municipal solid waste landfill shows that residents in the area annually generate 0.38 ppm Hg per household, which is less than the citywide mean; surprisingly though, less affluent respondents living closer to the landfill site reported more Hg from thermometers and sphygmomanometers. Analysis of collected soil (0.238 ppm), leachate water (6.5 ppb), sediment (0.109 ppm), and three plants (0.393 to 0.695 ppm) shows no significant variation throughout five stations in and around the landfill site, although the period of collection is significant for soil (P?=?0.001) and Cenchrus echinatus (P?=?0.016). Detected Hg in the landfill is considerably less than the annual estimated release, indicating that there is minimal accumulation of Hg in the soil or in plants. As a result of this project, a policy brief has been provided to the Cebu City council in aid of hazardous waste legislation. PMID:25712628

  2. Cover crops and crop residue management under no-till systems improve soils and environmental quality

    NASA Astrophysics Data System (ADS)

    Kumar, Sandeep; Wegner, Brianna; Vahyala, Ibrahim; Osborne, Shannon; Schumacher, Thomas; Lehman, Michael

    2015-04-01

    Crop residue harvest is a common practice in the Midwestern USA for the ethanol production. However, excessive removal of crop residues from the soil surface contributes to the degradation of important soil quality indicators such as soil organic carbon (SOC). Addition of a cover crop may help to mitigate these negative effects. The present study was set up to assess the impacts of corn (Zea mays L.) residue removal and cover crops on various soil quality indicators and surface greenhouse gas (GHG) fluxes. The study was being conducted on plots located at the North Central Agricultural Research Laboratory (NCARL) in Brookings, South Dakota, USA. Three plots of a corn and soybean (Glycine max (L.) Merr.) rotation under a no-till (NT) system are being monitored for soils and surface gas fluxes. Each plot has three residue removal (high residue removal, HRR; medium residue removal, MRR; and low residue removal, LRR) treatments and two cover crops (cover crops and no cover crops) treatments. Both corn and soybean are represented every year. Gas flux measurements were taken weekly using a closed static chamber method. Data show that residue removal significantly impacted soil quality indicators while more time was needed for an affect from cover crop treatments to be noticed. The LRR treatment resulted in higher SOC concentrations, increased aggregate stability, and increased microbial activity. The LRR treatment also increased soil organic matter (SOM) and particulate organic matter (POM) concentrations. Cover crops used in HRR (high corn residue removal) improved SOC (27 g kg-1) by 6% compared to that without cover crops (25.4 g kg-1). Cover crops significantly impacted POM concentration directly after the residue removal treatments were applied in 2012. CO2 fluxes were observed to increase as temperature increased, while N2O fluxes increased as soil moisture increased. CH4 fluxes were responsive to both increases in temperature and moisture. On average, soils under cover crop management had lower N2O fluxes than soils that did not have a cover crop. Results from this study concluded that it is important to allow crop residues to return to the soil as they help to improve soil quality indicators. The presence of cover crops also will contribute to the improvement of these indicators once established and may help mitigate greenhouse gas emissions.

  3. COMPACTED SOIL BARRIERS OF ABANDONED LANDFILL SITES ARE LIKELY TO FAIL IN THE LONG-TERM

    EPA Science Inventory

    Buried wastes are isolated from the environment by barriers constructed entirely or in part of compacted soil. he chief concern in barrier design has been to isolate the waste in the short term by preventing movement of water into and through the waste. owever, in the long term a...

  4. Establishment of five cover crops and total soil nutrient extraction in a humid tropical soil in the Peruvian Amazon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In order to evaluate the establishment of five cover crops and their potential to increase soil fertility through nutrient extraction, an experiment was installed in the Research Station of Choclino, San Martin, Peru. Five cover crops were planted: Arachis pintoi Krapov. & W.C. Greg, Calopogonium m...

  5. Landfill methane oxidation response to vegetation, fertilization, and liming

    SciTech Connect

    Hilger, H.A.; Wollum, A.G.; Barlaz, M.A.

    2000-02-01

    Landfills are the fourth largest global source and the largest US source (USDOE, 1997) of anthropogenic CH{sub 4} emissions. Since gram-for-gram, CH{sub 4} has 21 times the 100-yr global-warming potential of CO{sub 2} (USEPA, 1990). CH{sub 4} release into the atmosphere has important implications for global climate change. This study was conducted to evaluate the effects of vegetation, N fertilizers, and lime addition on landfill CH{sub 4} oxidation. Columns filled with compacted sandy loam and sparged with synthetic landfill gas were used to simulate a landfill cover. Grass-topped and bare-soil columns reduced inlet CH{sub 4} by 47 and 37%, respectively, at peak uptake; but the rate for both treatments was about 18% at steady state. Nitrate and NH{sub 4} amendments induced a more rapid onset of CH{sub 4} oxidation relative to KCl controls. However, at steady state, NH{sub 4} inhibited CH{sub 4} oxidation in bare columns but not in grassed columns. Nitrate addition produced no inhibitory effects. Lime addition to the soil consistently enhanced CH{sub 4} oxidation. In all treatments, CH{sub 4} consumption increased to a peak value, then declined to a lower steady-state value; and all gassed columns developed a pH gradient. Neither nutrient depletion nor protozoan grazing could explain the decline from peak oxidation levels. Ammonium applied to grassed cover soil can cause transient reductions in CH{sub 4} uptake, but there is no evidence that the inhibition persists. The ability of vegetation to mitigate NH{sub 4} inhibition indicates that results from bare-soil tests may not always generalize to vegetated landfill caps.

  6. Size-fractionation and characterization of landfill leachate and the improvement of Cu{sup 2+} adsorption capacity in soil and aged refuse

    SciTech Connect

    Lou Ziyang; Chai Xiaoli; Niu Dongjie; Ou Yuanyang; Zhao Youcai

    2009-01-15

    Leachate was collected from an anaerobic lagoon at Shanghai Laogang refuse landfill, the largest landfill in China, and the sample was separated into six fractions using micro-filtration membranes, followed by ultra-filtration membranes. Several parameters of the samples were measured, including chemical oxygen demand (COD), total organic carbon (TOC), total solids (TS), pH, total phosphate (TP), total nitrogen (TN), fixed solids (FS), NH{sub 4}{sup +}, orthophosphate, color, turbidity, and conductivity. These parameters were then quantitatively correlated with the molecular weight cutoff of the membrane used. Organic matter in the dissolved fraction (MW < 1 kDa) predominated in the leachate, accounting for 65% of TOC. Thermal infrared spectroscopy was used to characterize the filter residues. Asymmetric and symmetric stretching of methyl and methylene groups, and of functional groups containing nitrogen and oxygen atoms, were observed. In addition, the ability of two different samples to adsorb heavy metals was tested. Cu{sup 2+} was chosen as the representative heavy metal in this study, and the samples were soil; aged refuse, which had spent 8 years in a conventional sanitary landfill; and samples of soil and aged refuse treated for 48 h with leachate in the ratio of 5 g of sample per 50 ml of leachate. Cu{sup 2+} uptake by the raw soil was {approx}4.60 {mu}g/g, while uptake by the leachate-contacted soil and leachate-contacted aged refuse were 5.66 and 5.11 {mu}g/g, respectively. These results show that the organic matter in the leachate enhanced the capacity of aqueous solutions to adsorb Cu{sup 2+}.

  7. Impact of cover crops and tillage on porosity of podzolic soil

    NASA Astrophysics Data System (ADS)

    B?a?ewicz-Wo?niak, M.; Konopiñski, M.

    2013-09-01

    The aim of the study was to determine the influence of cover crops biomass, mixed with the soil on different dates and with the use of different tools in field conditions. The cover crop biomass had a beneficial influence on the total porosity of the 0-20 cm layer of the soil after winter. The highest porosity was achievedwith cover crops of buckwheat, phacelia and mustard, the lowest with rye. During the vegetation period the highest porosity of soil was observed in the ridges. Among the remaining non-ploughing cultivations, pre-winter use of stubble cultivator proved to have a beneficial influence on the soil porosity, providing results comparable to those achieved in conventional tillage. The differential porosity of the soil was modified not only by the catch crops and the cultivation methods applied, but also by the sample collection dates, and it did change during the vegetation period. The highest content of macropores after winter was observed for the phacelia cover crop, and the lowest in the case of cultivation without any cover crops. Pre-winter tillage with the use of a stubble cultivator increased the amount of macropores in soil in spring, and caused the biggest participation of mesopores as compared with other non-ploughing cultivation treatments of the soil. The smallest amount of mesopores was found in the ridges.

  8. Soil and crop nitrogen as influenced by tillage, cover crops, and nitrogen fertilization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil and crop management practices may influence soil mineral N, crop N uptake, and N leaching. We evaluated the effects of three tillage practices [no-till (NT), strip till (ST), and chisel till (CT)], four cover crops {legume [hairy vetch (Vicia villosa Roth)], nonlegume [rye (Secale cereale L.)],...

  9. Effects of cover cropping on soil and rhizosphere microbial community structure in tomato production systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Black polyethylene film is frequently used in vegetable farming systems to promote rapid warming of the soil in spring, conserve soil moisture, and suppress weeds. Alternative systems have been developed using cover cropping with legumes to provide a weed-suppressive mulch while also fixing nitrogen...

  10. COVER CROP EFFECT ON SOIL CARBON FRACTIONS UNDER CONSERVATION TILLAGE COTTON

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cover crops may influence soil carbon (C) sequestration and microbial activities by providing additional residue C to soil. We examined the influence of legume [crimson clover (Trifolium incarnatum L.)], nonlegume [rye (Secaele cereale L.)], blend [a mixture of legumes containing balansa clover (Tri...

  11. Improved Remote Crop Residue Cover Estimation by Incorporation of Soil and Residue Information

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Modern agricultural practices are increasingly making use of conservation (reduced- and no-till) methods, in order to minimize soil erosion and increase soil organic carbon (SOC) content. These methods result in increased crop residue cover after planting when compared to conventional tillage metho...

  12. Hyperspectral remote sensing estimation of crop residue cover: Soil mineralogy, surface conditions, and their effects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conservation tillage practices can enhance soil organic carbon content (SOC), improve soil structure, and reduce erosion. However, direct assessment of tillage practice for monitoring SOC change over large regions is difficult. Remote sensing of crop residue cover (CRC) can help assess tillage pra...

  13. Mapping crop Residue Cover and Soil Tillage Intensity Using Remote Sensing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Until recently crop residues were managed primarily to reduce soil erosion and increase soil organic carbon, but demands for biofuels may remove much of the residue. Current methods of measuring crop residue cover are inadequate for characterizing the temporal and spatial variability of crop residu...

  14. Winter Cover Crop Biomass for Biofuel Production, Implications for Soil Coverage and Profitability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High residue winter cover crops are critical for maximizing conservation tillage system benefits, including reductions in soil erosion, improved soil productivity, higher crop yields and greater net returns from crop production. With the increasing demand for biofuel production, the potential to har...

  15. VEGETATIVE COVERS FOR WASTE CONTAINMENT

    EPA Science Inventory

    Disposal of municipal ahd hazardous waste in the United States is primarily accomplished by containment in lined and capped landfills. Evapotranspiration cover systems offer an alternative to conventional landfill cap systems. These covers work on completely different principles ...

  16. Controls of biological soil crust cover and composition shift with succession in sagebrush shrub-steppe

    USGS Publications Warehouse

    Dettweiler-Robinson, E.; Bakker, J.D.; Grace, J.B.

    2013-01-01

    Successional stage may determine strength and causal direction of interactions among abiotic and biotic factors; e.g., species that facilitate the establishment of other species may later compete with them. We evaluated multivariate hypotheses about abiotic and biotic factors shaping biological soil crusts (BSCs) in early and late successional stages. We surveyed vegetation and BSC in the shrub-steppe ecosystem of the Columbia Basin. We analyzed the relationships with bryophyte and lichen covers using structural equation models, and analyzed the relationships with BSC composition using Indicator Species Analysis and distance-based linear models. Cover, indicator species, and composition varied with successional stage. Increasing elevation and bryophyte cover had higher lichen cover early in succession; these relationships were negative in the later successional stage. Lichen cover did not appear to impede B. tectorum cover, but B. tectorum appeared to strongly negatively affect lichen cover in both stages. Biological soil crust composition varied with bunchgrass cover in the early successional stage, but with elevation and B. tectorum cover later in succession. Our findings support the hypotheses that as succession progresses, the strength and direction of certain community interactions shift, and B. tectorum leads to reductions in biological soil crust cover regardless of successional stage.

  17. Improved Remotely-Sensed Estimates of Crop Residue Cover by Incorporating Soils Information

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Remote sensing allows for the rapid determination of crop residue cover. The Cellulose Absorption Index (CAI) has been shown to more accurately estimate residue cover and non-photosynthetic vegetation than other indices. CAI is useful as values are linear areal mixtures of soil and residue spectra...

  18. Integrating choice of variety, soil amendments, and cover crops to optimize organic rice production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have completed our first year of this project to determine the impact of winter cover crops, soil amendments, and rice varieties on organic rice production at Beaumont, TX. Two winter cover crops were established successfully and the amounts of dry biomass produced were 4,690 and 5,157 lb/acre f...

  19. CO2 evolution in highland soils of different land cover types in Iceland

    NASA Astrophysics Data System (ADS)

    Mankasingh, Utra; Gísladóttir, Guðrún; Þórsson, Jóhann; Palomaki, Minna

    2015-04-01

    Soil respiration is a key ecosystem process that releases carbon from soil as CO2. Soil CO2 emission is sensitive to temperature, moisture and disturbance and is influenced by land use and land cover change, especially in the upper soil organic layer. Release of CO2 from soils of the south Icelandic highlands (318 - 356 m above sea level) was studied to observe soil respiration in different land cover types and to quantify soil C lost as CO2. In a laboratory incubation study, exponential release of CO2 from soils was observed (>6 months) for the field moist soils collected from the highlands. Soils were collected at 12 sites from the land cover types (plant communities) in September 2013. The land cover types, categorized by plant communities, were: grasslands (G1-G8), with moss, Carex Bigelowii and dwarf shrubs; a sandy fluvial wetland (S), and unvegetated gravels (M1-M3). Since this experiment was conducted at 25° C whilst the observed annual average temperature was 1.5 ° C (Vatnsfell, 10 year average), this experiment presents an accelerated picture of CO2 released from soils over a much longer time period. For most soils, the rate of release decreased after 5 days. For all land cover types, the CO2 release was greatest in the topspoil and this decreased with depth. Soils with the highest % organic matter (G sites characterized by mosses and few vascular species) appear to release the most CO2. In the top 5 cm, the CO2 emissions follow the trend: grasslands (G1-G8)> sandy fluvial wetland (S) > unvegetated sites (M1-M3). This trend appears to be related to the amount of organic matter present. For all sites, the less than 250 mg CO2 was lost per kg of soil after 75 days, which is equivalent to losing less than 69 mg C per kg soil, and represented less than 0.5% of the total carbon present in any soil; less than 360 mg CO2 was lost after 260 days.

  20. SOIL AND VEGETATIVE COVERS FOR LEAD (PB) MINE WASTE PILES

    EPA Science Inventory

    Conduct vegetation studies that evaluate a variety of seed mixtures and surface amendments (soil, compost, biosolids, yard waste and fertilizers). US Bureau of Reclamation with experts formerly with US Bureau of Mines to contribute to Vegetation Plan for Big River NTCR EE/CA

  1. The litter cover of citrus leaves control soil and water losses in chemically managed orchards

    NASA Astrophysics Data System (ADS)

    Cerdà, A.; Jurgensen, M. F.; González-Peñaloza, F. A.

    2012-04-01

    Soil erosion in chemically managed orchards results in bare soil due to the removal of the weeds and the lack of catch crops. Those conditions results in extremely high erosion rates in citrus orchards (Cerdà et al., 2011) such it has been found in other orchards in the Mediterranean where the soil degradation trigger a change in the soil water properties (Gómez et al., 1999). The Mediterranean climatic and human conditions contribute to very active soil water erosion (Ruiz Sinoga et al., 2010) where rilling and piping are found (Romero-Diaz, 2007). It is widely known that high erosion rates can trigger the soil degradation such it has been found in vineyards (Ramos and Martínez Casasnovas, 2006), Olive (García Orenes et al., 2010) and other crops, which is related to the land management and land use (García Ruiz, 2010). Within the chemically managed citrus orchards, the surface cover is usually bare due to the removal of the pruned branches (usually burned) and the use of herbicides every season. A thin and non-continuous litter layer of leaves from the citrus trees covers the soil surface, which sometimes are removed by the farmers to keep the soil clean. There is no information about the effect of the citrus leaves effects on soil and water losses. The objective of this paper is to quantify the effect of the leaves cover on the surface runoff and soil losses. Experiments were conducted by means of simulated rainfall at 55 mm h-1 during one hour in a small circular plot (0.25 m2) to quantify in the field the effect of different litter cover on soil erosion and water losses. An orchard of orange trees (Navel-lane-late, 10 year old, and planted at 6 x 5m with a 45 % cover) was selected in the Municipality of Montesa. Witin the 2 ha field 35 plots were selected with litter covers from 0 to 100 % cover. The runoff discharge was measured every minute and each 5 minutes a sample for runoff sediment concentration was collected. The sediment concentration was measured by dessication. All the measurements were conducted during the summer (August 2008). The results show that the litter cover control the erosion processes. The orange leaves lying on the floor can reduce the soil losses to negligible values when the cover is higher than 60 %. After 20 % of litter cover the soil losses are dramatically reduced to values lower than 50 % of the soil losses under bare soil conditions. The litter cover also reduces the runoff rates, but the reduction is in 50 % for 80 % litter cover. The 20 % litter cover results only in a small reduction in the runoff discharge. The research conducted demonstrate that the farmers should maintain the leaves on the floor (do not brush them as they use to do) to control the high erosion rates. This research study is being supported by the the research project CGL2008-02879/BTE

  2. RESPONSE OF THE SOIL MICROBIAL COMMUNITY TO SOIL FUMIGATION AND MUSTARD COVER CROPS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil fumigants such as metam-sodium, used in potato production of the Columbia Basin of WA, are very effective for the control of soil borne pathogens, weeds, and nematodes that reduce crop yield and quality. Soil fumigation has been assumed to have minor impacts on the general soil microbial commun...

  3. Salt and N leaching and soil accumulation due to cover cropping practices

    NASA Astrophysics Data System (ADS)

    Gabriel, J. L.; Quemada, M.

    2012-04-01

    Nitrate leaching beyond the root zone can increase water contamination hazards and decrease crop available N. Cover crops used in spite of fallow are an alternative to reduce nitrate contamination in the vadose zone, because reducing drainage and soil mineral N accumulation. Cover crops can improve important characteristics in irrigated land as water retention capacity or soil aggregate stability. However, increasing evapotranspiration and consequent drainage below the root system reduction, could lead to soil salt accumulation. Salinity affects more than 80 million ha of arable land in many areas of the world, and one of the principal causes for yield reduction and even land degradation in the Mediterranean region. Few studies dealt with both problems at the same time. Therefore, it is necessary a long-term evaluation of the potential effect on soil salinity and nitrate leaching, in order to ensure that potential disadvantages that could originate from soil salt accumulation are compensated with all advantages of cover cropping. A study of the soil salinity and nitrate leaching was conducted during 4 years in a semiarid irrigated agricultural area of Central Spain. Three treatments were studied during the intercropping period of maize (Zea mays L.): barley (Hordeum vulgare L.), vetch (Vicia villosa L.) and fallow. Cover crops were killed in March allowing seeding of maize of the entire trial in April, and all treatments were irrigated and fertilised following the same procedure. Before sowing, and after harvesting maize and cover crops, soil salt and nitrate accumulation was determined along the soil profile. Soil analysis was conducted at six depths every 0.20 m in each plot in samples from four 0 to 1.2-m depth holes dug. The electrical conductivity of the saturated paste extract and soil mineral nitrogen was measured in each soil sample. A numerical model based on the Richards water balance equation was applied in order to calculate drainage at 1.2 m depth, using daily soil water content measurements, based on calibrated capacitance probes. Our results showed that drainage during the irrigated period was minimized, because irrigation water was adjusted to crop needs, leading to soil salt and nitrate accumulation on the upper layers after maize harvest. Then, during the intercrop period, most of salt and nitrate leaching occurred. Cover crops use led to shorter drainage period, lower drainage water amount and lower nitrate and salt leaching than treatment with fallow. These effects were related with a larger nitrate accumulation in the upper layers of the soil after cover crop treatments. But there was not soil salt accumulation increase in treatments with cover crops, and even decreased after years with a large cover crop biomass production. Then, adoption of cover crops in this kind of irrigated cropping system reduced water drainage beyond the root zone, salt and nitrate leaching diminished as a consequence but did not lead to salt accumulation in the upper soil layers. Acknowledgements: Financial support by CICYT, Spain (ref. AGL2005-00163 and AGL 2011-24732) and Comunidad de Madrid (project AGRISOST, S2009/AGR-1630).

  4. COVER CROPS AND CULTIVATION: IMPACTS ON SOIL N DYNAMICS, NITROUS OXIDE EFFLUX, AND MICROBIOLOGICAL FUNCTION IN A MEDITERRANEAN VINEYARD AGROECOSYSTEM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Impacts of soil tillage and cover crops on soil nitrogen (N) dynamics and microbiological function were investigated in a vineyard grown in California’s Mediterranean climate. We compared soil N dynamics, N availability and N2O emissions in a vineyard agroecosystem of two cover crops [Trios 102 (Tri...

  5. Emission characteristics and air-surface exchange of gaseous mercury at the largest active landfill in Asia

    NASA Astrophysics Data System (ADS)

    Zhu, Wei; Li, Zhonggen; Chai, Xiaoli; Hao, Yongxia; Lin, Che-Jen; Sommar, Jonas; Feng, Xinbin

    2013-11-01

    The emission characteristics and air-surface exchange of gaseous elemental mercury (GEM) at Laogang landfill in Shanghai, China, the largest active landfill in Asia, has been investigated during two intensive field campaigns in 2011 and 2012. The mercury (Hg) content in municipal solid waste (MSW) varied widely from 0.19 to 1.68 mg kg-1. Over the closed cell in the landfill, the mean ambient air GEM concentration was virtually indistinguishable from the hemispherical background level (1.5-2.0 ng m-3) while the concentration downwind of ongoing landfill operation (e.g. dumping, burying and compacting of MSW) was clearly elevated. GEM emission through landfill gas (LFG) was identified as a significant source. GEM concentrations in LFGs collected from venting pipes installed in different landfill cells varied widely from 3.0 to 1127.8 ng m-3. The GEM concentrations were found negatively correlated to the age of LFG cells, suggesting GEM released through LFG declined readily with time. The GEM emission from this source alone was estimated to be 1.23-1.73 mg h-1. GEM emission from cover soil surfaces was considerably lower and at a scale comparable to that of background soil surfaces. This is in contrast to earlier reports showing enhanced GEM emissions from landfill surfaces in Southern China, probably due to the difference in soil Hg content and gas permeability characteristics of soils at different sites. Vertical concentration profiles of GEM in the interstitial gas of buried MSW were sampled, perhaps for the first time, which exhibited a wide spatial variability (4.9-713.1 ng m-3) in the 3-year-old landfill cell investigated. GEM emission from landfill operation was estimated to be 290-525 mg h-1 using a box model. This suggests that GEM degassing from Laogang landfill is quantitatively largely dominated by emissions from daily landfilling operations with a much smaller contribution from LFG venting and insignificant (bi-directional fluxes near zero) contribution from surfaces capped with a soil layer. This study reveals divergent GEM emission patterns among landfill cells of different ages, and provides essential emission estimates for formulating Hg emission reduction strategies for a large landfill.

  6. Snow Cover Depletion and Soil Moisture Recharge at Three Cold Land Processes Experiment (CLPX) Meteorological Sites

    NASA Astrophysics Data System (ADS)

    Holcombe, J. D.; Elder, K.; Davis, R. E.

    2003-12-01

    With increasing concern regarding water supply in arid and semiarid regions, knowledge of water resources in the Earth's cold regions is critical. Snow-cover depletion and soil moisture recharge are elements used in hydrologic modeling and climate modeling, as well as remote sensing applications. Modeled snow-cover depletion and soil moisture recharge are important parameters in hydrologic forecasting. We evaluate the ability of a one-dimensional mass and energy balance model (SNTHERM.89) to predict snow-cover depletion and to test the accuracy of Fast All season Soil STrength (FASST) in modeling the evolution of soil moisture recharge based on data from three NASA Cold Land Processes Experiment (CLPX) sites. The objective is to evaluate the model's ability to predict observations at three CLPX sites: Buffalo Pass (near Steamboat Springs, CO); St. Louis Creek (in the Fraser Experimental Forest, CO); and Illinois River (located in North Park, CO). The three sites were chosen for their diverse climatic and physiographic differences. The Buffalo Pass site has a deep snowpack with discontinuous forest cover dominated by Englemann spruce (Picea englemannii) and alpine fir (Abies lasiocarpa). The St. Louis site has a moderate snowpack depth and forest cover dominated by lodgepole pine (Pinus contorta). The Illinois River site is irrigated grassland with no forest cover.

  7. Soil moisture and soil loss study under different cover densities in Ultisolsin Pernambuco State semi-arid (Brazil)

    NASA Astrophysics Data System (ADS)

    Borges, T. K. S.; Montenegro, A. A. A.; Santos, T. E. M.; Silva Junior, V. P.; Siqueira, G. M.

    2012-04-01

    Throughout Brazil occurs a large loss of soil and water runoff due to soil erosion especially in rural areas. The soil moisture monitoringhas been a practice increasingly important in agriculture, especially in regions where water scarcity is high and rainfed cropping is adopted. The soil cover is one of the factors that minimize these effects of degradation arising from agricultural land use. To monitor the water content in the soil profile, point measurements were performed using an FDR equipment, which is a capacitance probe, Diviner 2000 ® model, the Sentek Pty Ltd, Australia. The objective of this study was to investigate the dynamics of soil water content under different types of ground cover, using a probe and the Diviner soil loss in the semi-arid Pernambuco. The study was carried out in the Municipality of Pesqueira-PE, located in the State of Pernambuco, in the Alto Ipanema Representative Basin, with average annual rainfall of 730 mm and average annual potential evapotranspiration of 1683 mm. The soil of the study areas is classified as Eutrophic Yellow Ultisol abruptly (Area A) and typical Eutrophic Yellow Ultisol (Area B). For this, study three experimental plots were installed in two different areas, totalling six plots, bounded by brick, with 4.5 m wide and 11 m long in the direction of the slope, under three soil cover conditions. The treatments involved in this study are: bare soil (SD); with cactus (P) and natural cover (CN). The water content in soil was evaluated at 0.10, 0.20 and 0.30 m at the soil profile and sediment sampling were carried out fortnightly between April and July 2011 (rainy season). In this work we used cumulative precipitation for seven and fourteen days before the readings with the Divinerprobe. The highest rainfall is concentrated during the months of May and July of 2011, and May is the month with the highest cumulative rainfall. April received the lowest rainfall, considered the driest. The water content in the soil indicates that in all treatments there was a greater storage of water with increased rainfall and reduced runoff. In area A treatment with CN had a larger increase in moisture at all depths. These results prove that the presence of vegetation is important for the semi-arid region, especially during drought periods. In the area B, at a depth of 0.10 m, the cactus had the highest increase of moisture, while at depths of 0.20 and 0.30 m above the ground there was a lower water storage. This result is related to the fact that in areas with high vegetation density results in a higher water consumption due to the demand of the plants, resulting in less moisture compared to the bare soil plot. The erosion results obtained show that the highest soil losses occurred in the condition without cover and it can be verified that it was influenced by the presence or absence of cover used and demonstrated to be effective (CN and P) to control erosion, providing a greater protective effect in the soil to reduce the area exposed to the raindrops impact.

  8. Soils and the soil cover of the arkaim reserve (Steppe Zone of the Trans-Ural Region)

    NASA Astrophysics Data System (ADS)

    Prikhod'ko, V. E.; Ivanov, I. V.; Manakhov, D. V.; Manakhova, E. V.

    2012-08-01

    Soils of the Arkaim Reserve in the area around a unique settlement-fortress of the Bronze Age in Chelyabinsk oblast have been studied. These soils are generally typical of the entire Trans-Ural Plateau. The soil properties are characterized in detail on the basis of factual data on 170 soil pits and four soil catenas. The soil cover of the reserve is specified into six geomorphic groups: (a) denudational surfaces of the low mountains, (b) accumulative-denudational surfaces of the low mountains, (c) denudational-accumulative plain surfaces, (d) lacustrine-alluvial plain surfaces, (e) floodplain surfaces, and (f) slopes and bottoms of the local ravines and hollows. Chernozems occupy about 50% of the reserve; solonetzes and saline soils, 32%; meadow chernozems, 7%; and forest soils, 1%. The soils of the reserve are relatively thin; they have a distinct tonguing of the humus horizon and are often saline and solonetzic. The latter properties are inherited from the parent materials and are preserved in the soils for a long time under the conditions of a dry continental climate. The genetic features of the soils differ in dependence on the composition and age of the parent materials. With respect to the thickness of the soil profiles and the reserves of soil humus, the soils can be arranged into the following lithogenic sequence: the soils developed from the eluvium of igneous rocks-redeposited kaolin clay-montmorillonite-hydromica nonsaline and saline loams and clays. The content of Corg in the upper 20 cm varies from 2.5 to 5.6%, and the reserves of Corg in the layers of 0-0.5 and 0-1.0 m reach 57-265 and 234-375 t/ha, respectively. The soils of pastures subjected to overgrazing occupy two-thirds of the reserve. Their humus content is 10-16% higher in comparison with that in the analogous plowed soils. Another characteristic feature of the humus in the soils of the pastures is its enrichment in the labile fraction (28-40% of Corg).

  9. Variability in soil CO2 efflux across distinct urban land cover types

    NASA Astrophysics Data System (ADS)

    Weissert, Lena F.; Salmond, Jennifer A.; Schwendenmann, Luitgard

    2015-04-01

    As a main source of greenhouse gases urban areas play an important role in the global carbon cycle. To assess the potential role of urban vegetation in mitigating carbon emissions we need information on the magnitude of biogenic CO2 emissions and its driving factors. We examined how urban land use types (urban forest, parklands, sportsfields) vary in their soil CO2 efflux. We measured soil CO2 efflux and its isotopic signature, soil temperature and soil moisture over a complete growing season in Auckland, New Zealand. Soil physical and chemical properties and vegetation characteristics were also measured. Mean soil CO2 efflux ranged from 4.15 to 12 ?mol m-2 s-1. We did not find significant differences in soil CO2 efflux among land cover types due to high spatial variability in soil CO2 efflux among plots. Soil (soil carbon and nitrogen density, texture, soil carbon:nitrogen ratio) and vegetation characteristics (basal area, litter carbon density, grass biomass) were not significantly correlated with soil CO2 efflux. We found a distinct seasonal pattern with significantly higher soil CO2 efflux in autumn (Apr/May) and spring (Oct). In urban forests and sportsfields over 80% of the temporal variation was explained by soil temperature and soil water content. The ?13C signature of CO2 respired from parklands and sportsfields (-20 permil - -25 permil) were more positive compared to forest plots (-29 permil) indicating that parkland and sportsfields had a considerable proportion of C4 grasses. Despite the large intra-urban variability, our results compare to values reported from other, often climatically different cities, supporting the hypothesis of homogenization across urban areas as a result of human management practices.

  10. Factors influencing the establishment of floristically rich grasslands on a restored landfill site

    SciTech Connect

    Ireland, E.M.

    1991-01-01

    Natural revegetation on landfill sites often results in a species poor sward dominated by Elymus repens (Shaw, 1983; Davis, 1988; Wong, 1988). The aim of this study was primarily to investigate the mechanism by which E.repens achieved such apparent domination and secondly to investigate various methods to establish floristically rich grasslands on a restored landfill site. Low rates of germination and survival were recorded from seeds of Plantago lanceolata, Centaureau nigrand Leucanthemum vulgare sown into a sward of E.repens on a restored landfill site in Essex, even during periods with adequate soil water. Plants of P.lanceolata, C.nigra and L. vulgare were grown in pots and transplanted into the sward of E.repens. Over the following two years a significant decrease in crown cover of these species was recorded. In areas where E.repens had been treated with herbicide or mown, seedlings and introduced plants of P.lanceolata, C.nigra and L.vulgare increased in cover over two years. Stomatal conductance of P.lanceolata, C.nigra and L.vulgare was reduced when these species were growing with E.repens even during periods with adequate soil water. P.lanceolata, C.nigra and L.vulgare growing with E.repens on restored landfill has been shown experimentally to result in reduced cover. It is suggested that this is due to competition in combination potentially, with allelochemical effects of E.repens. Successful establishment of a floristically rich grass mix was achieved by the reduction in cover of E.repens by herbicide or mowing. On newly restored landfill a careful balance between soil treatments, fertilizer levels and subsequent management in the form of mowing must be attained in order to establish floristically rich grasslands. The results from this study show that by utilizing various management techniques a floristically rich grass mix could be established on a restored landfill site.

  11. Ground cover rice production systems increase soil carbon and nitrogen stocks at regional scale

    NASA Astrophysics Data System (ADS)

    Liu, M.; Dannenmann, M.; Lin, S.; Saiz, G.; Yan, G.; Yao, Z.; Pelster, D. E.; Tao, H.; Sippel, S.; Tao, Y.; Zhang, Y.; Zheng, X.; Zuo, Q.; Butterbach-Bahl, K.

    2015-08-01

    Rice production is increasingly limited by water scarcity. Covering paddy rice soils with films (so-called ground cover rice production system: GCRPS) can significantly reduce water demand as well as overcome temperature limitations at the beginning of the growing season, which results in greater grain yields in relatively cold regions and also in those suffering from seasonal water shortages. However, it has been speculated that both increased soil aeration and temperature under GCRPS result in lower soil organic carbon and nitrogen stocks. Here we report on a regional-scale experiment conducted in Shiyan, a typical rice-producing mountainous area of China. We sampled paired adjacent paddy and GCRPS fields at 49 representative sites. Measured parameters included soil carbon (C) and nitrogen (N) stocks (to 1 m depth), soil physical and chemical properties, ?15N composition of plants and soils, potential C mineralization rates, and soil organic carbon (SOC) fractions at all sampling sites. Root biomass was also quantified at one intensively monitored site. The study showed that: (1) GCRPS increased SOC and N stocks 5-20 years following conversion from traditional paddy systems; (2) there were no differences between GCRPS and paddy systems in soil physical and chemical properties for the various soil depths, with the exception of soil bulk density; (3) GCRPS increased above-ground and root biomass in all soil layers down to a 40 cm depth; (4) ?15N values were lower in soils and plant leaves indicating lower NH3 volatilization losses from GCRPS than in paddy systems; and (5) GCRPS had lower C mineralization potential than that observed in paddy systems over a 200-day incubation period. Our results suggest that GCRPS is an innovative production technique that not only increases rice yields using less irrigation water, but that it also increases SOC and N stocks.

  12. Topography Mediates the Influence of Cover Crops on Soil Nitrate Levels in Row Crop Agricultural Systems.

    PubMed

    Ladoni, Moslem; Kravchenko, Alexandra N; Robertson, G Phillip

    2015-01-01

    Supplying adequate amounts of soil N for plant growth during the growing season and across large agricultural fields is a challenge for conservational agricultural systems with cover crops. Knowledge about cover crop effects on N comes mostly from small, flat research plots and performance of cover crops across topographically diverse agricultural land is poorly understood. Our objective was to assess effects of both leguminous (red clover) and non-leguminous (winter rye) cover crops on potentially mineralizable N (PMN) and [Formula: see text] levels across a topographically diverse landscape. We studied conventional, low-input, and organic managements in corn-soybean-wheat rotation. The rotations of low-input and organic managements included rye and red clover cover crops. The managements were implemented in twenty large undulating fields in Southwest Michigan starting from 2006. The data collection and analysis were conducted during three growing seasons of 2011, 2012 and 2013. Observational micro-plots with and without cover crops were laid within each field on three contrasting topographical positions of depression, slope and summit. Soil samples were collected 4-5 times during each growing season and analyzed for [Formula: see text] and PMN. The results showed that all three managements were similar in their temporal and spatial distributions of NO3-N. Red clover cover crop increased [Formula: see text] by 35% on depression, 20% on slope and 32% on summit positions. Rye cover crop had a significant 15% negative effect on [Formula: see text] in topographical depressions but not in slope and summit positions. The magnitude of the cover crop effects on soil mineral nitrogen across topographically diverse fields was associated with the amount of cover crop growth and residue production. The results emphasize the potential environmental and economic benefits that can be generated by implementing site-specific topography-driven cover crop management in row-crop agricultural systems. PMID:26600462

  13. Topography Mediates the Influence of Cover Crops on Soil Nitrate Levels in Row Crop Agricultural Systems

    PubMed Central

    Ladoni, Moslem; Kravchenko, Alexandra N.; Robertson, G. Phillip

    2015-01-01

    Supplying adequate amounts of soil N for plant growth during the growing season and across large agricultural fields is a challenge for conservational agricultural systems with cover crops. Knowledge about cover crop effects on N comes mostly from small, flat research plots and performance of cover crops across topographically diverse agricultural land is poorly understood. Our objective was to assess effects of both leguminous (red clover) and non-leguminous (winter rye) cover crops on potentially mineralizable N (PMN) and NO3--N levels across a topographically diverse landscape. We studied conventional, low-input, and organic managements in corn-soybean-wheat rotation. The rotations of low-input and organic managements included rye and red clover cover crops. The managements were implemented in twenty large undulating fields in Southwest Michigan starting from 2006. The data collection and analysis were conducted during three growing seasons of 2011, 2012 and 2013. Observational micro-plots with and without cover crops were laid within each field on three contrasting topographical positions of depression, slope and summit. Soil samples were collected 4–5 times during each growing season and analyzed for NO3--N and PMN. The results showed that all three managements were similar in their temporal and spatial distributions of NO3—N. Red clover cover crop increased NO3--N by 35% on depression, 20% on slope and 32% on summit positions. Rye cover crop had a significant 15% negative effect on NO3--N in topographical depressions but not in slope and summit positions. The magnitude of the cover crop effects on soil mineral nitrogen across topographically diverse fields was associated with the amount of cover crop growth and residue production. The results emphasize the potential environmental and economic benefits that can be generated by implementing site-specific topography-driven cover crop management in row-crop agricultural systems. PMID:26600462

  14. Considerations over the distribution of the organic matter in the soil cover of Transylvania Plain (Romania)

    NASA Astrophysics Data System (ADS)

    Cacovean, Horia; Man, Titus; Rusu, Teodor

    2010-05-01

    Considerations over the distribution of the organic matter in the soil cover of Transylvania Plain (Romania) Horea Cacovean*, Titus Man**, Teodor Rusu*** *OSPA-Cluj- 1Faglui street, Cluj Napoca, RO-40048, Romania- turda75@yahoo.com ** Faculty of Geographie, University of Babes-Bolyai, 5-7 Clinicilor street, Cluj Napoca, RO-400006, Romania *** Faculty of Agriculture, USAMV, 3-5 Calea Manastur street,Cluj Napoca, RO-400372, Romania Soil degradation has become a major concern in the Transylvania Plain. Erosion, landslides, salinization, gleysation, and loss of humus are the main forms of soil deterioration in that region. This factsheet deals with the role of organic matter in soil productivity and the effects of various management practices and abandonment of the lands on soil organic matter. Soils in Transylvania Plain are analyzed concerning the amount of humus they contain. The influence of soil texture, climatic variables, and soil management on the qualitative soil humus content was studied in the top 20 cm of different managed loess soils of more then 100 profiles along a climosequence in that region. Taken together, soil, landform, land use and vegetation data suggest: (1) summit positions are relatively stable with immobilizing humus environments; (2) the content of humus increase progressively down steep at the contact with the floodplains; 3) without the influx of organic materials, erodible backslopes may become humus depleted as it happen the poor inputs of grassland and forest litter are mixed with surface soil horizon; 4) influx of mixed sediment and organic materials from backslopes maintains concentrations of humus on footslopes and toeslopes. This influence was more pronounced in the heavy clayey soils, suggesting that the accumulation of humus was enhanced by organo-mineral interactions. Entrenchment of drainage ways can circumvent these translocation processes. The results underscore the importance of functional connectivity between upland hillslopes and alluvial soils.

  15. Are biodiversity indices of spontaneous grass covers in olive orchards good indicators of soil degradation?

    NASA Astrophysics Data System (ADS)

    Taguas, E. V.; Arroyo, C.; Lora, A.; Guzmán, G.; Vanderlinden, K.; Gómez, J. A.

    2015-03-01

    Spontaneous grass covers are an inexpensive soil erosion control measure in olive orchards. Olive farmers allow grass to grow on sloping terrain to comply with the basic environmental standards derived from the Common Agricultural Policy (CAP). However, to date there are very few studies assessing the environmental quality and extent of such covers. In this study, we described and compared the biodiversity indicators associated to herbaceous vegetation in two contrasting olive orchards in order to evaluate its relevance and quality. In addition, biodiversity patterns and their relationships with environmental factors such as soil type and properties, precipitation, topography and soil management were analyzed. Different grass cover biodiversity indices were evaluated in two olive orchard catchments under conventional tillage and no tillage with grass cover, during 3 hydrological years (2011-2013). Seasonal samples of vegetal material and pictures in a permanent grid (4 samples ha-1) were taken to characterize the temporal variations of the number of species, frequency, diversity and transformed Shannon's and Pielou's indices. Sorensen's index obtained in the two olive orchard catchments showed notable differences in composition, probably linked with the different site conditions. The catchment with the best site conditions (deeper soil and higher precipitation), with average annual soil losses over 10 t ha-1 and a more intense management, presented the highest biodiversity indices. In absolute terms, the diversity indices were reasonably high in both catchments, despite the fact that agricultural activity usually severely limits the landscape and the variety of species. Finally, a significantly higher content of organic matter in the first 10 cm of soil was found in the catchment with the worst site conditions, average annual soil losses of 2 t ha-1 and the least intense management. Therefore, the biodiversity indicators associated to weeds were not found to be suitable for describing the soil degradation in the study catchments.

  16. Soil Moisture and Snow Cover: Active or Passive Elements of Climate

    NASA Technical Reports Server (NTRS)

    Oglesby, Robert J.; Marshall, Susan; Erickson, David J., III; Robertson, Franklin R.; Roads, John O.; Arnold, James E. (Technical Monitor)

    2002-01-01

    A key question is the extent to which surface effects such as soil moisture and snow cover are simply passive elements or whether they can affect the evolution of climate on seasonal and longer time scales. We have constructed ensembles of predictability studies using the NCAR CCM3 in which we compared the relative roles of initial surface and atmospheric conditions over the central and western U.S. in determining the subsequent evolution of soil moisture and of snow cover. Results from simulations with realistic soil moisture anomalies indicate that internal climate variability may be the strongest factor, with some indication that the initial atmospheric state is also important. Model runs with exaggerated soil moisture reductions (near-desert conditions) showed a much larger effect, with warmer surface temperatures, reduced precipitation, and lower surface pressures; the latter indicating a response of the atmospheric circulation. These results suggest the possibility of a threshold effect in soil moisture, whereby an anomaly must be of a sufficient size before it can have a significant impact on the atmospheric circulation and climate. Results from simulations with realistic snow cover anomalies indicate that the time of year can be crucial. When introduced in late winter, these anomalies strongly affected the subsequent evolution of snow cover. When introduced in early winter, however, little or no effect is seen on the subsequent snow cover. Runs with greatly exaggerated initial snow cover indicate that the high reflectivity of snow is the most important process by which snow cover can impact climate, through lower surface temperatures and increased surface pressures. The results to date were obtained for model runs with present-day conditions. We are currently analyzing runs made with projected forcings for the 21st century to see if these results are modified in any way under likely scenarios of future climate change. An intriguing new statistical technique involving 'clustering' is developed to assist in this analysis.

  17. Bringing new life to old landfills

    SciTech Connect

    Rabasca, L.

    1996-01-01

    On the West Coast, Waste Management, Inc. is bringing new life to old landfills. The Bradley Landfill in Sun Valley, CA, just outside of Los Angeles, is being transformed into a recycling park, while a few hundred miles north, in the San Francisco Bay Area, an old landfill is now home to a transfer station and recycling center. WMI began transforming the landfill in the early 1990s.The first change was to process wood and green waste rather than landfilling it. In 1993, WMI added a sorting facility, and in 1994, after the Jan. 17 Northridge earthquake, the company added a construction and demolition debris (C and D) facility. There also is a landfill gas collection facility on the site. In the future, WMI hopes to add the following facilities: composting, railhaul, alternative fuels production, tire processing, and soil remediation. WMI also hopes several companies that use recycled materials as feedstock will build their plants at the landfill.

  18. Spatial and temporal variability of grass cover in two olive grove catchments on contrasting soil types

    NASA Astrophysics Data System (ADS)

    Aguilera, Laura; Taguas, Encarnación V.; Gimeno, Enrique; Gómez, José A.

    2013-04-01

    Mediterranean climate conditions -characterized by the concentration of the precipitation in the seasons of autumn and spring, the low temperatures in winter and extremely warm and dry summers- determine that ground cover by adventitious (or cover crop) vegetation shows significant seasonal and annual variability. In addition, its spatial variability associates also, partially, to water availability among the landscape. This is especially relevant in olive orchards, an agricultural system under high erosion risk in the region where the establishment of herbaceous cover has proved to improve soil protection reducing erosion risk, as well as the improvement of soil properties (Gómez et al., 2009). All these benefits are based on small scale studies where full ground cover by the cover crop is relatively easy to obtain. However, few information is available about the actual ground cover achieved at farm scale, although preliminary observations suggests that this might be extremely variable (Gómez and Giráldez, 2009). This study presents the preliminary results evaluating the spatial and temporal evolution of ground cover by adventitious vegetation (the preferred option by farmers to achieve a cover crop) in two commercial olive farms during 2 hydrological years (2011-2012). The study was conducted in two farms located in the province of Cordoba, Southern Spain. Both were olive orchards grown under deficit irrigation systems and present a gauge station where rainfall, runoff and sediment loads have been measured from the year 2005. The soil management in "La Conchuela" farm was based in the use of herbicide in the line of olive trees to keep the bare soil all year round, and the application of selective herbicide in the lane between the olive trees to promote the grown of graminaceae grasses . In addition, the grass is mechanically killed in June. In the another farm, "Arroyo Blanco", the grass spontaneous cover is allowed until mid-spring in which is also mechanically killed by several tractor passes. Ground cover was evaluated by a field surveys (4 per year) in which the same areas were measured at an approximate density of 4 samples/ha. In each point, over a 0.25 m2 area ground cover was measured using photographs, then point measurements were interpolated using method of Inverse Distance Weighting methods, to generate continuous distribution maps. The spatial and temporal evolution of ground cover in both farms presented a notably different patterns in both farms. In "La Conchuela", maximum values of cover can be reached in winter (61%, Dec-2011) while in "Arroyo Blanco", the maximum values were observed during the spring (50% May-2011) and are dramatically lower in the seasons of summer and autumn. These differences are justified by the influence of the management, the precipitation regime and the soil qualities such as the depth. On the other hand, the large spatial variability of ground cover measurements in both catchments, with coefficients of variation between 41 and 167%, was mainly led by the topography. In both farms the highest values of ground cover were found in those areas with deeper soils located in also in converging areas where surface runoff is concentrated. In the highest and shallowest area, soil management operations might improve the establishment of the vegetation as well as to address the growing in the most erosive periods. Finally, the impact of grass cover on the hydrological and erosive responses in the catchment is also discussed. References Aguilera, L. 2012. Estudio de cubiertas vegetales para el control de la erosión en olivar. Evaluación espacio-temporal en dos fincas comerciales, y exploración de nuevas opciones de cubiertas. Master Thesis. University of Cordoba. Gómez, J.A., Giráldez, J.V. Erosión y degradación de suelos. In: Sostenibilidad de la producción de olivar en Andalucía. Gómez, J.A. (Editor). Junta de Andalucía. Sevilla, p. 45-86. Gómez, J.A., Sobrinho, T.A., Giráldez, J.V., Fereres, E. 2009. Soil management effects on ru

  19. Comparison of Seasonal Soil Microbial Process in Snow-Covered Temperate Ecosystems of Northern China

    PubMed Central

    Zhang, Xinyue; Wang, Wei; Chen, Weile; Zhang, Naili; Zeng, Hui

    2014-01-01

    More than half of the earth's terrestrial surface currently experiences seasonal snow cover and soil frost. Winter compositional and functional investigations in soil microbial community are frequently conducted in alpine tundra and boreal forest ecosystems. However, little information on winter microbial biogeochemistry is known from seasonally snow-covered temperate ecosystems. As decomposer microbes may differ in their ability/strategy to efficiently use soil organic carbon (SOC) within different phases of the year, understanding seasonal microbial process will increase our knowledge of biogeochemical cycling from the aspect of decomposition rates and corresponding nutrient dynamics. In this study, we measured soil microbial biomass, community composition and potential SOC mineralization rates in winter and summer, from six temperate ecosystems in northern China. Our results showed a clear pattern of increased microbial biomass C to nitrogen (N) ratio in most winter soils. Concurrently, a shift in soil microbial community composition occurred with higher fungal to bacterial biomass ratio and gram negative (G-) to gram positive (G+) bacterial biomass ratio in winter than in summer. Furthermore, potential SOC mineralization rate was higher in winter than in summer. Our study demonstrated a distinct transition of microbial community structure and function from winter to summer in temperate snow-covered ecosystems. Microbial N immobilization in winter may not be the major contributor for plant growth in the following spring. PMID:24667929

  20. Organic farming and cover crops as an alternative to mineral fertilizers to improve soil physical properties

    NASA Astrophysics Data System (ADS)

    Sánchez de Cima, Diego; Luik, Anne; Reintam, Endla

    2015-10-01

    For testing how cover crops and different fertilization managements affect the soil physical properties in a plough based tillage system, a five-year crop rotation experiment (field pea, white potato, common barley undersown with red clover, red clover, and winter wheat) was set. The rotation was managed under four different farming systems: two conventional: with and without mineral fertilizers and two organic, both with winter cover crops (later ploughed and used as green manure) and one where cattle manure was added yearly. The measurements conducted were penetration resistance, soil water content, porosity, water permeability, and organic carbon. Yearly variations were linked to the number of tillage operations, and a cumulative effect of soil organic carbon in the soil as a result of the different fertilization amendments, organic or mineral. All the systems showed similar tendencies along the three years of study and differences were only found between the control and the other systems. Mineral fertilizers enhanced the overall physical soil conditions due to the higher yield in the system. In the organic systems, cover crops and cattle manure did not have a significant effect on soil physical properties in comparison with the conventional ones, which were kept bare during the winter period. The extra organic matter boosted the positive effect of crop rotation, but the higher number of tillage operations in both organic systems counteracted this effect to a greater or lesser extent.

  1. Landfill mining reduces site redevelopment costs

    SciTech Connect

    Weston, K.J.; White, J.R.; Mudhar, T.S.

    1994-12-31

    California-based Clean-Up Technology, Inc. teamed with property owners and agencies to execute one of the largest industrial landfill reclamation projects in the US. Site assessments indicated that the 10 acre site in Commerce, California, was used as an uncontrolled landfill from 1941 to 1953 before it was operated as a trucking terminal until the late 1980`s. Beneath a cover layer of soil and asphalt was 200,000 cubic years of a heterogeneous mixture of soil, concrete, rubber, wood, scrap metal, asphalt and other debris. In addition to the unstable nature of the fill, localized contamination of hydrogen and led made the site unsuitable for redevelopment without remediation. Clean-Up Technology designed, engineered and operated a plant to segregate debris by type, size and contamination level. This reduced the amount of contaminated material by as much as 60% and reduced costs by an estimated $5 million. The semi-automated plant performed multiple screening operations, size reduction of oversize material and separation of wood, metal, concrete and soil. The plant was designed to process the material in one pass at an average of 200 tons per hour.

  2. Factors affecting temporal H2S emission at construction and demolition (C&D) debris landfills.

    PubMed

    Xu, Qiyong; Townsend, Timothy

    2014-02-01

    Odor problems associated with H2S emissions often result in odor complaints from nearby residents of C&D debris landfills, especially in the early morning. As part of a field study conducted on H2S removal ability using different cover materials, daily and seasonal H2S emissions through a soil cover layer were monitored at a C&D debris landfill to investigate factors affecting H2S emissions. H2S emission rates were not a constant, but varied seasonally, with an average emission rate of 4.67×10(-6)mgm(-2)s(-1). During a the 10-month field study, as the H2S concentration increased from 140ppm to about 3500ppm underneath the cover soil in the testing cell, H2S emissions ranged from zero to a maximum emission rate of 1.24×10(-5)mgm(-2)s(-1). Continuous emission monitoring indicated that H2S emissions even changed over time throughout the day, generally increasing from morning to afternoon, and were affected by soil moisture and temperature. Laboratory experiments were also conducted to investigate the effects of H2S concentration and cover soil moisture content on H2S emissions. The results showed that increased soil moisture reduced H2S emissions by retarding H2S migration through cover soil and dissolving H2S into soil water. The field study also indicated that due to atmospheric dispersion, high H2S emissions may not cause odor problems. PMID:23968554

  3. Environmental impact assessment on the construction and operation of municipal solid waste sanitary landfills in developing countries: China case study.

    PubMed

    Yang, Na; Damgaard, Anders; Lü, Fan; Shao, Li-Ming; Brogaard, Line Kai-Sørensen; He, Pin-Jing

    2014-05-01

    An inventory of material and energy consumption during the construction and operation (C&O) of a typical sanitary landfill site in China was calculated based on Chinese industrial standards for landfill management and design reports. The environmental impacts of landfill C&O were evaluated through life cycle assessment (LCA). The amounts of materials and energy used during this type of undertaking in China are comparable to those in developed countries, except that the consumption of concrete and asphalt is significantly higher in China. A comparison of the normalized impact potential between landfill C&O and the total landfilling technology implies that the contribution of C&O to overall landfill emissions is not negligible. The non-toxic impacts induced by C&O can be attributed mainly to the consumption of diesel used for daily operation, while the toxic impacts are primarily due to the use of mineral materials. To test the influences of different landfill C&O approaches on environmental impacts, six baseline alternatives were assessed through sensitivity analysis. If geomembranes and geonets were utilized to replace daily and intermediate soil covers and gravel drainage systems, respectively, the environmental burdens of C&O could be mitigated by between 2% and 27%. During the LCA of landfill C&O, the research scope or system boundary has to be declared when referring to material consumption values taken from the literature; for example, the misapplication of data could lead to an underestimation of diesel consumption by 60-80%. PMID:24656422

  4. Calculation set for design and optimization of vegetative soil covers Sandia National Laboratories, Albuquerque, New Mexico.

    SciTech Connect

    Peace, Gerald L.; Goering, Timothy James

    2005-02-01

    This study demonstrates that containment of municipal and hazardous waste in arid and semiarid environments can be accomplished effectively without traditional, synthetic materials and complex, multi-layer systems. This research demonstrates that closure covers combining layers of natural soil, native plant species, and climatic conditions to form a sustainable, functioning ecosystem will meet the technical equivalency criteria prescribed by the U. S. Environmental Protection Agency. In this study, percolation through a natural analogue and an engineered cover is simulated using the one-dimensional, numerical code UNSAT-H. UNSAT-H is a Richards. equation-based model that simulates soil water infiltration, unsaturated flow, redistribution, evaporation, plant transpiration, and deep percolation. This study incorporates conservative, site-specific soil hydraulic and vegetation parameters. Historical meteorological data are used to simulate percolation through the natural analogue and an engineered cover, with and without vegetation. This study indicates that a 3-foot (ft) cover in arid and semiarid environments is the minimum design thickness necessary to meet the U. S. Environmental Protection Agency-prescribed technical equivalency criteria of 31.5 millimeters/year and 1 x 10{sup -7} centimeters/second for net annual percolation and average flux, respectively. Increasing cover thickness to 4 or 5 ft results in limited additional improvement in cover performance.

  5. A field-validated model for landfill methane emissions inclusive of seasonal methane oxidation

    NASA Astrophysics Data System (ADS)

    Bogner, J. E.; Spokas, K.; Chanton, J.

    2010-12-01

    In addition to natural wetlands, atmospheric methane (CH4) has multiple anthropogenic sources with high uncertainties, including rice production, ruminant animals, natural gas leakages, biomass burning, and landfills. For an improved IPCC Tier III methodology for landfill CH4 emissions in California, we have developed a new science-based, field-validated inventory model which decouples emissions from a historical reliance on a theoretical first order kinetic model for CH4 generation potential. The model (CALMIM, CAlifornia Landfill Methane Inventory Model) is a freely-available JAVA tool which estimates net CH4 emissions to the atmosphere for any landfill cover soil over a typical annual cycle, including (1) the effect of engineered gas extraction; (2) the physical effects of daily, intermediate, and final cover materials to retard emissions; and (3) seasonal soil moisture and temperature effects on both gaseous transport and methanotrophic CH4 oxidation. Linking site-specific data with existing globally-validated USDA models for annual climate and soil microclimate (Global TempSim; Global RainSim; Solarcalc; STM2), this model relies on 1-D diffusion as the major driver for emissions. Importantly, unlike current inventory methods based on modeled generation, the driving force for emissions (e.g., the CH4 concentration gradient) can be directly compared to field data. Methane oxidation is scaled to maximum rates over the full range of moisture and temperature conditions based on extensive supporting laboratory studies using California landfill cover soils. Field validation included meteorological data, soil moisture/temperature measurements, and seasonal (wet/dry) CH4 emissions & oxidation measurements for daily, intermediate, and final cover soils over two annual cycles at a northern (Monterey County) and southern California (Los Angeles County) landfill. The model accurately predicted soil temperature and moisture trends for individual cover materials with acceptable order-of-magnitude predictability for field emissions within the context of published literature spanning 7 orders of magnitude. In addition to regional defaults for inventory purposes, CALMIM permits user-selectable parameters and boundary conditions for more rigorous site-specific applications where detailed CH4 emissions, meteorological, and soil microclimate data exist.

  6. Soil Moisture and Snow Cover: Active or Passive Elements of Climate?

    NASA Technical Reports Server (NTRS)

    Oglesby, Robert J.; Marshall, Susan; Erickson, David J., III; Robertson, Franklin R.; Roads, John O.; Arnold, James E. (Technical Monitor)

    2002-01-01

    A key question in the study of the hydrologic cycle is the extent to which surface effects such as soil moisture and snow cover are simply passive elements or whether they can affect the evolution of climate on seasonal and longer time scales. We have constructed ensembles of predictability studies using the NCAR CCM3 in which we compared the relative roles of initial surface and atmospheric conditions over the central and western U.S. in determining the subsequent evolution of soil moisture and of snow cover. We have also made sensitivity studies with exaggerated soil moisture and snow cover anomalies in order to determine the physical processes that may be important. Results from simulations with realistic soil moisture anomalies indicate that internal climate variability may be the strongest factor, with some indication that the initial atmospheric state is also important. The initial state of soil moisture does not appear important, a result that held whether simulations were started in late winter or late spring. Model runs with exaggerated soil moisture reductions (near-desert conditions) showed a much larger effect, with warmer surface temperatures, reduced precipitation, and lower surface pressures; the latter indicating a response of the atmospheric circulation. These results suggest the possibility of a threshold effect in soil moisture, whereby an anomaly must be of a sufficient size before it can have a significant impact on the atmospheric circulation and hence climate. Results from simulations with realistic snow cover anomalies indicate that the time of year can be crucial. When introduced in late winter, these anomalies strongly affected the subsequent evolution of snow cover. When introduced in early winter, however, little or no effect is seen on the subsequent snow cover. Runs with greatly exaggerated initial snow cover indicate that the high reflectively of snow is the most important process by which snow cover cart impact climate, through lower surface temperatures and increased surface pressures. In early winter, the amount of solar radiation is very small and so this albedo effect is inconsequential while in late winter, with the sun higher in the sky and period of daylight longer, the effect is much stronger.

  7. Soil Moisture and Snow Cover: Active or Passive Elements of Climate?

    NASA Technical Reports Server (NTRS)

    Oglesby, Robert J.; Marshall, Susan; Robertson, Franklin R.; Roads, John O.; Arnold, James E. (Technical Monitor)

    2001-01-01

    A key question in the study of the hydrologic cycle is the extent to which surface effects such as soil moisture and snow cover are simply passive elements or whether they can affect the evolution of climate on seasonal and longer time scales. We have constructed ensembles of predictability studies using the NCAR CCM3 in which we compared the relative roles of initial surface and atmospheric conditions over the central and western U.S. GAPP region in determining the subsequent evolution of soil moisture and of snow cover. We have also made sensitivity studies with exaggerated soil moisture and snow cover anomalies in order to determine the physical processes that may be important. Results from simulations with realistic soil moisture anomalies indicate that internal climate variability may be the strongest factor, with some indication that the initial atmospheric state is also important. The initial state of soil moisture does not appear important, a result that held whether simulations were started in late winter or late spring. Model runs with exaggerated soil moisture reductions (near-desert conditions) showed a much larger effect, with warmer surface temperatures, reduced precipitation, and lower surface pressures; the latter indicating a response of the atmospheric circulation. These results suggest the possibility of a threshold effect in soil moisture, whereby an anomaly must be of a sufficient size before it can have a significant impact on the atmospheric circulation and hence climate. Results from simulations with realistic snow cover anomalies indicate that the time of year can be crucial. When introduced in late winter, these anomalies strongly affected the subsequent evolution of snow cover. When introduced in early winter, however, little or no effect is seen on the subsequent snow cover. Runs with greatly exaggerated initial snow cover indicate that the high reflectivity of snow is the most important process by which snow cover can impact climate, through lower surface temperatures and increased surface pressures. In early winter, the amount of solar radiation is very small and so this albedo, effect is inconsequential while in late winter, with the sun higher in the sky and period of daylight longer, the effect is much stronger. The results to date were obtained for model runs with present-day conditions. We are currently analyzing runs made with projected forcings for the 21st century to see if these results are modified in any way under likely scenarios of future climate change.

  8. Growing trees on completed sanitary landfills. [Nyssa sylvatica, Picea abies, Ginkgo biloba

    SciTech Connect

    Leone, I.A.; Gilman, E.F.; Flower, F.B.

    1983-01-01

    A 10-year old completed landfill in New Jersey consisting of 9 m (depth) of refuse covered with 15-25 cm of soil was cleared of debris and vegetation and covered with 30 cm of subsoil and 15-25 cm of topsoil. Nineteen coniferous and broadleaved species were planted on the landfill and on a control site in 1975, and trees were maintained and growth and condition monitored over 4 years. On the basis of shoot length and stem area increase, the most successful of the surviving trees were Nyssa sylvatica, Picea abies and Ginkgo biloba, in decreasing order of tolerance. Tolerance of landfill conditions appeared to be greatest in those species with low water requirements, a slow growth rate, high acid tolerance and a shallow root system. (Refs. 11).

  9. Influence of Cover Crops in Rotation on Populations of Soil Nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A pot experiment was carried out in south Florida to elucidate suppressive or antagonistic effects of several cover crops grown in rotation on soil nematode populations. The crops were two marigolds, Tagetes patula L. 'Dwarf Double French Mix' (MI), and Tagetes patula L. 'Lemon Drop' (MII), Indian m...

  10. Long-term effects of compost and cover crops on soil phosphorus in two California agroecosystems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Inefficient P use in agriculture results in soil P accumulation and losses to surrounding ecosystems, highlighting the need to reduce external inputs and use them more efficiently. Composts reduce the need for mineral fertilizers by recycling P from wastes at the regional scale, whereas cover crops ...

  11. Tillage and Cover Effects on Soil Microbial Properties and Fluometuron Degradation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field studies were conducted at Stoneville, MS, in 1994 and 1995 to determine the influence of tillage (no tillage [NT] or conventional tillage [CT]) and a ryegrass cover crop in a cotton production system on soil microbial populations and enzyme activity. Fluometuron degradation was evaluated unde...

  12. CONSERVATION TILLAGE AND COVER CROP INFLUENCES ON COTTON PRODUCTION ON SOUTHEASTERN USA COASTAL PLAIN SOILS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A majority of the 2.9 million acres of cotton (Gossypium hirsutum L.) produced in the Southeastern USA is located on Coastal Plain sandy soils that can benefit from conservation cropping systems. An understanding of cover crop and tillage system interactions is needed within specific environments to...

  13. The impact of fall cover crops on soil nitrate and corn growth

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Incorporating cover crops into current production systems can have many beneficial impacts on the current cropping system including decreasing erosion, improving water infiltration, increasing soil organic matter and biological activity but in water limited areas caution should be utilized. A fiel...

  14. TILLAGE, COVER CROP, AND NITROGEN FERTILIZER SOURCE EFFECTS ON SOIL CARBON AND NITROGEN SEQUESTRATION.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The 10-yr effect of combinations of tillage (no-till, mulch till, and conventional till), cover crop (rye vs. none), and N fertilization source and rate (0 and 100 kg N ha-1 from NH4NO3 and 100 and 200 kg N ha-1 from poultry manure) was evaluated on crop residues and soil organic C (SOC) and organic...

  15. Cover crops alter phosphorus soil fractions and organic matter accumulation in a Peruvian cacao agroforestry system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In many tropical soils, excessive weathering of primary minerals confounded by intense agricultural production has resulted in the depletion of organic matter and plant available forms of phosphorus (P). Long-term growth of cover crops in tropical agroforestry systems have been shown to influence nu...

  16. Addition of cover crops enhances no-till potential for improving soil physical properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Interest in the use of cover crops (CC) is growing. Inclusion of CC may be a potential strategy to boost no-till performance by improving soil physical properties. To assess this potential, we utilized a wheat [Triticum aestivum (L.)]-grain sorghum [Sorghum bicolor (L.) Moench] rotation, four N rate...

  17. Effects of multiple rolling cover crops on their termination, soil water and soil strength

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The impact of multiple rolling rye and mixture (rye, crimson clover and hairy vetch) using two rollers (straight bar, and two-stage) on termination rate, soil strength and soil moisture were evaluated in northern Alabama. In 2007 and 2008 growing seasons, both roller types effectively terminated rye...

  18. Modeled Impacts of Cover Crops and Vegetative Barriers on Corn Stover Availability and Soil Quality

    SciTech Connect

    Ian J. Bonner; David J. Muth Jr.; Joshua B. Koch; Douglas L. Karlen

    2014-06-01

    Environmentally benign, economically viable, and socially acceptable agronomic strategies are needed to launch a sustainable lignocellulosic biofuel industry. Our objective was to demonstrate a landscape planning process that can ensure adequate supplies of corn (Zea mays L.) stover feedstock while protecting and improving soil quality. The Landscape Environmental Assessment Framework (LEAF) was used to develop land use strategies that were then scaled up for five U.S. Corn Belt states (Nebraska, Iowa, Illinois, Indiana, and Minnesota) to illustrate the impact that could be achieved. Our results show an annual sustainable stover supply of 194 million Mg without exceeding soil erosion T values or depleting soil organic carbon [i.e., soil conditioning index (SCI)?>?0] when no-till, winter cover crop, and vegetative barriers were incorporated into the landscape. A second, more rigorous conservation target was set to enhance soil quality while sustainably harvesting stover. By requiring erosion to be <1/2 T and the SCI-organic matter (OM) subfactor to be >?0, the annual sustainable quantity of harvestable stover dropped to148 million Mg. Examining removal rates by state and soil resource showed that soil capability class and slope generally determined the effectiveness of the three conservation practices and the resulting sustainable harvest rate. This emphasizes that sustainable biomass harvest must be based on subfield management decisions to ensure soil resources are conserved or enhanced, while providing sufficient biomass feedstock to support the economic growth of bioenergy enterprises.

  19. Restoring the biological crust cover of soils across biomes in arid North America

    NASA Astrophysics Data System (ADS)

    Garcia-Pichel, Ferran; Antoninka, Anita; Bowker, Matthew; Giraldo Silva, Ana; Nelson, Corey; Velasco Ayuso, Sergio; Barger, Nichole; Belnap, Jayne; Reed, Sasha; Duniway, Michael

    2015-04-01

    Biological soil crust communities provide important ecosystem services to arid lands, particularly regarding soil fertility and stability against erosion. In North America, and in many other areas of the globe, increasingly intense human activities, ranging from cattle grazing to military training, have resulted in the significant deterioration of biological soil surface cover of soils. With the intent of attaining sustainable land use practices, we are conducting a 5-year, multi-institutional research effort to develop feasible soil crusts restoration strategies for US military lands. We are including field sites of varying climatic regions (warm and cold deserts, in the Chihuahuan Desert and in the Great Basin, respectively) and varying edaphic characteristics (sandy and silty soils in each). We have multiple aims. First, we aim to establishing effective "biocrust nurseries" that produce viable and pedigreed inoculum, as a supply center for biocrust restoration and for research and development. Second, we aim to develop optimal field application methods of biocrust inoculum in a series of field trials. Currently in our second year of research, we will be reporting on significant advances made on optimizing methodologies for the large-scale supply of inoculum based on a) pedigreed laboratory cultures that match the microbial community structure of the original sites, and b) "in soil" biomass enhancement, whereby small amounts of local crusts are nursed under greenhouse conditions to yield hundred-fold increases in biomass without altering significantly community structure. We will also report on field trials for methodologies in field application, which included shading, watering, application of chemical polymers, and soil surface roughening. In a soon-to-be-initiated effort we also aim to evaluate soil and plant responses to biocrust restoration with respect to plant community structure, soil fertility, and soil stability, in multi-factorial field experiments. An important part of the plan will be to construct effective channels for sharing challenges and solutions in biocrust restoration with military and federal land managers.

  20. Evaluation of Soil Manipulation to Prepare Engineered Earthen Waste Covers for Revegetation.

    PubMed

    Waugh, W Joseph; Benson, Craig H; Albright, William H; Smith, Gregory M; Bush, Richard P

    2015-11-01

    Seven ripping treatments designed to improve soil physical conditions for revegetation were compared on a test pad simulating an earthen cover for a waste disposal cell. The field test was part of study of methods to convert compacted-soil waste covers into evapotranspiration covers. The test pad consisted of a compacted layer of fine-textured soil simulating a barrier protection layer overlain by a gravelly sand bedding layer and a cobble armor layer. Treatments included combinations of soil-ripping implements (conventional shank [CS], wing-tipped shank [WTS], and parabolic oscillating shank with wings [POS]), ripping depths, and number of passes. Dimensions, dry density, moisture content, and particle size distribution of disturbance zones were determined in two trenches excavated across rip rows. The goal was to create a root-zone dry density between 1.2 and 1.6 Mg m and a seedbed soil texture ranging from clay loam to sandy loam with low rock content. All treatments created V-shaped disturbance zones as measured on trench faces. Disturbance zone size was most influenced by ripping depth. Winged implements created larger disturbance zones. All treatments lifted fines into the bedding layer, moved gravel and cobble down into the fine-textured protection layer, and thereby disrupted the capillary barrier at the interface. Changes in dry density within disturbance zones were comparable for the CS and WTS treatments but were highly variable among POS treatments. Water content increased in the bedding layer and decreased in the protection layer after ripping. The POS at 1.2-m depth and two passes created the largest zone with a low dry density (1.24 Mg m) and the most favorable seedbed soil texture (gravely silt loam). However, ripping also created large soil aggregates and voids in the protection layer that may produce preferential flow paths and reduce water storage capacity. PMID:26641343

  1. The Application Of Biofilter System For Reduction Of Methane Emissions From Modern Sanitary Landfills

    NASA Astrophysics Data System (ADS)

    Sung, K.; Park, S.

    2007-12-01

    Increased atmospheric concentrations of greenhouse gases (GHG) caused by anthropogenic activities has been related to global climate change. Methane, the second most important GHG after CO2, is 21 times more effective at trapping heat than CO2. Therefore, methane emission control is of utmost importance for global warming reduction. To minimize leachate production and protect groundwater resources, modern sanitary landfills are equipped with composite covers and gas collection systems. Methane from modern sanitary landfills is vented directly to the atmosphere, except for some of the largest landfills where it is recovered as energy and burned at the site. However, the efficiency of energy recovery systems in larger landfills is reduced as the amount of CH4 generated from landfill begins to decrease. In this study, the performance of a lab-scale model biofilter system was investigated to treat CH4 gas emitted from modern sanitary landfills by conducting batch and column experiments using landfill cover soil amended with earthworm cast as the filter bed medium. From the batch experiments to measure the influence of moisture content and temperature of the filter medium on CH4 removal capacity of a biofilter system, the optimum moisture content and temperature were found to be 10-15% by weight and 25-35°C, respectively. The column experiment was conducted to measure the influence of inlet CH4 concentration and CH4 loading rate on CH4 removal capacity of a biofilter system. As the inlet CH4 concentration decreased, the percentage of CH4 oxidized increased. Up to a CH4 loading rate of 2785 g CH4 m3 h- 1 (EBRT = 7.7 min), the CH4 removal efficiency of the biofilter was able to reach 100%. Based on the results of the study, the installation of a properly managed biofilter system should be capable of achieving a reduction in atmospheric CH4 emissions from modern sanitary landfills at low CH4 generation stage.

  2. High retention of N P nutrients, soil organic carbon, and fine particles by cover crops under tropical climate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cover cropping system has shown a potential to improve soil quality and carbon sequestration but the residue decomposition rates determined by biotic and abiotic factors play a crucial role to reach such objectives. Legume and non-legume cover crop residues were applied to the surface of two soils i...

  3. Spatiotemporal patterns of soil CO2 efflux in drylands are modulated by the type of cover: The role of biocrusts

    NASA Astrophysics Data System (ADS)

    Chamizo, Sonia; Sánchez-Cañete, Enrique P.; Cantón, Yolanda; Rodríguez-Caballero, Emilio; Oyonarte, Cecilio; Domingo, Francisco

    2015-04-01

    Although the quantification of carbon (C) flux dynamics in arid and semiarid ecosystems has acquired relevant interest, it is recognized that C fluxes of drylands have been poorly measured and modeled, despite these regions represent 40% of the Earth land's surface and are known to play a crucial role in the global C cycle. Scarce vegetation and heterogeneity of non vegetated areas contributes to significant uncertainty in evaluating the roles of these ecosystems in C fluxes. In addition, interplant soils in most arid and semiarid areas are covered by biocrusts (communities of cyanobacteria, algae, lichens and mosses in association with soil particles) which strongly affect C uptake and release and also contribute to increasing uncertainty in the assessment of C balance in these ecosystems. A better understanding of CO2 efflux in different soil covers and how they are regulated by environmental factors is necessary for identifying the relationships between C sinks and sources of arid and semiarid ecosystems. Our goal was to analyse temporal dynamics of soil CO2 on representative cover types of semiarid ecosystems (soil under plant, biocrusts and bare soil) and the influence of environmental factors (soil moisture and temperature) on soil CO2 patterns. The study area chosen was a badlands site (El Cautivo, Almería, SE Spain) where biocrusts occupy up to 50% of soil surface. Soil CO2 molar fraction (?c) was continuously monitored using small solid-state CO2 sensors (GM222, Vaisala, Helsinki, Finland) buried at 5 cm under the different covers, during one year. Soil temperature and soil moisture were also measured under these covers. From the CO2 time-series measured, we calculated soil CO2 efflux (Fs) from the 0-5 cm soil profile using Fick's law of diffusion. Our results demonstrate that soil moisture was the main factor driving soil ?c. During summer, when soil was dry, all cover types showed similar soil ?c. Following a rain, there was a rapid increase in soil ?c in all cover types but marked differences were found among them: soil under plant reached the highest values, while in the interplant soil, soils covered by biocrusts showed up to 2 times greater soil ?c than bare soils. Soil ?c also varied depending on the type of biocrust, with higher values under lichen than cyanobacteria biocrusts, attributed to higher organic matter content and higher abundance and diversity of microfauna under more developed than less developed biocrusts. At daily scale, there was a positive relationship between soil ?c and soil temperature. Positive values of Fs (CO2 emissions) were frequently found after rain. Fs was higher in soil under plant (up to 2 µmol m-2 s-1), followed by soil covered by lichens and the lowest in soils covered by cyanobacteria and bare soils (~0.5 µmol m-2 s-1). Our results demonstrate the high spatial variability in CO2 efflux in arid and semiarid areas and the need to consider the contributions of the different representative ground covers to improve C quantification and to make more accurate predictions of the effects of climate change in arid and semiarid regions.

  4. Phytoremediation of landfill leachate.

    PubMed

    Jones, D L; Williamson, K L; Owen, A G

    2006-01-01

    Leachate emissions from landfill sites are of concern, primarily due to their toxic impact when released unchecked into the environment, and the potential for landfill sites to generate leachate for many hundreds of years following closure. Consequently, economically and environmentally sustainable disposal options are a priority in waste management. One potential option is the use of soil-plant based remediation schemes. In many cases, using either trees (including short rotation coppice) or grassland, phytoremediation of leachate has been successful. However, there are a significant number of examples where phytoremediation has failed. Typically, this failure can be ascribed to excessive leachate application and poor management due to a fundamental lack of understanding of the plant-soil system. On balance, with careful management, phytoremediation can be viewed as a sustainable, cost effective and environmentally sound option which is capable of treating 250m(3)ha(-1)yr(-1). However, these schemes have a requirement for large land areas and must be capable of responding to changes in leachate quality and quantity, problems of scheme establishment and maintenance, continual environmental monitoring and seasonal patterns of plant growth. Although the fundamental underpinning science is well understood, further work is required to create long-term predictive remediation models, full environmental impact assessments, a complete life-cycle analysis and economic analyses for a wide range of landfill scenarios. PMID:16168631

  5. Phytoremediation of landfill leachate

    SciTech Connect

    Jones, D.L. . E-mail: d.jones@bangor.ac.uk; Williamson, K.L.; Owen, A.G.

    2006-07-01

    Leachate emissions from landfill sites are of concern, primarily due to their toxic impact when released unchecked into the environment, and the potential for landfill sites to generate leachate for many hundreds of years following closure. Consequently, economically and environmentally sustainable disposal options are a priority in waste management. One potential option is the use of soil-plant based remediation schemes. In many cases, using either trees (including short rotation coppice) or grassland, phytoremediation of leachate has been successful. However, there are a significant number of examples where phytoremediation has failed. Typically, this failure can be ascribed to excessive leachate application and poor management due to a fundamental lack of understanding of the plant-soil system. On balance, with careful management, phytoremediation can be viewed as a sustainable, cost effective and environmentally sound option which is capable of treating 250 m{sup 3} ha{sup -1} yr{sup -1}. However, these schemes have a requirement for large land areas and must be capable of responding to changes in leachate quality and quantity, problems of scheme establishment and maintenance, continual environmental monitoring and seasonal patterns of plant growth. Although the fundamental underpinning science is well understood, further work is required to create long-term predictive remediation models, full environmental impact assessments, a complete life-cycle analysis and economic analyses for a wide range of landfill scenarios.

  6. Prediction of soil properties using imaging spectroscopy: Considering fractional vegetation cover to improve accuracy

    NASA Astrophysics Data System (ADS)

    Franceschini, M. H. D.; Demattê, J. A. M.; da Silva Terra, F.; Vicente, L. E.; Bartholomeus, H.; de Souza Filho, C. R.

    2015-06-01

    Spectroscopic techniques have become attractive to assess soil properties because they are fast, require little labor and may reduce the amount of laboratory waste produced when compared to conventional methods. Imaging spectroscopy (IS) can have further advantages compared to laboratory or field proximal spectroscopic approaches such as providing spatially continuous information with a high density. However, the accuracy of IS derived predictions decreases when the spectral mixture of soil with other targets occurs. This paper evaluates the use of spectral data obtained by an airborne hyperspectral sensor (ProSpecTIR-VS - Aisa dual sensor) for prediction of physical and chemical properties of Brazilian highly weathered soils (i.e., Oxisols). A methodology to assess the soil spectral mixture is adapted and a progressive spectral dataset selection procedure, based on bare soil fractional cover, is proposed and tested. Satisfactory performances are obtained specially for the quantification of clay, sand and CEC using airborne sensor data (R2 of 0.77, 0.79 and 0.54; RPD of 2.14, 2.22 and 1.50, respectively), after spectral data selection is performed; although results obtained for laboratory data are more accurate (R2 of 0.92, 0.85 and 0.75; RPD of 3.52, 2.62 and 2.04, for clay, sand and CEC, respectively). Most importantly, predictions based on airborne-derived spectra for which the bare soil fractional cover is not taken into account show considerable lower accuracy, for example for clay, sand and CEC (RPD of 1.52, 1.64 and 1.16, respectively). Therefore, hyperspectral remotely sensed data can be used to predict topsoil properties of highly weathered soils, although spectral mixture of bare soil with vegetation must be considered in order to achieve an improved prediction accuracy.

  7. Geologic and hydrologic data for the municipal solid waste landfill facility, U.S. Army Air Defense Artillery Center and Fort Bliss, El Paso County, Texas

    USGS Publications Warehouse

    Abeyta, Cynthia G.; Frenzel, P.F.

    1999-01-01

    Geologic and hydrologic data for the Municipal Solid Waste Landfill Facility on the U.S. Army Air Defense Artillery Center and Fort Bliss in El Paso County, Texas, were collected by the U.S. Geological Survey in cooperation with the U.S. Department of the Army. The 106.03-acre landfill has been in operation since January 1974. The landfill contains household refuse, Post solid wastes, bulky items, grass and tree trimmings from family housing, refuse from litter cans, construction debris, classified waste (dry), dead animals, asbestos, and empty oil cans. The depth of the filled areas is about 30 feet and the cover, consisting of locally derived material, is 2 to 3 feet thick. Geologic and hydrologic data were collected at or adjacent to the landfill during (1) drilling of 10 30- to 31-foot boreholes that were completed with gas-monitoring probes, (2) drilling of a 59-foot borehole, (3) drilling of a 355-foot borehole that was completed as a ground-water monitoring well, and (4) in situ measurements made on the landfill cover. After completion, the gas- monitoring probes were monitored on a quarterly basis (1 year total) for gases generated by the landfill. Water samples were collected from the ground-water monitoring well for chemical analysis. Data collection is divided into two elements: geologic data and hydrologic data. Geologic data include lithologic descriptions of cores and cuttings, geophysical logs, soil- gas and ambient-air analyses, and chemical analyses of soil. Hydrologic data include physical properties, total organic carbon, and pH of soil and sediment samples; soil-water chloride and soil-moisture analyses; physical properties of the landfill cover; measurements of depth to ground water; and ground-water chemical analyses. Interpretation of data is not included in this report.

  8. Land agroecological quality assessment in conditions of high spatial soil cover variability at the Pereslavskoye Opolye.

    NASA Astrophysics Data System (ADS)

    Morev, Dmitriy; Vasenev, Ivan

    2015-04-01

    The essential spatial variability is mutual feature for most natural and man-changed soils at the Central region of European territory of Russia. The original spatial heterogeneity of forest soils has been further complicated by a specific land-use history and human impacts. For demand-driven land-use planning and decision making the quantitative analysis and agroecological interpretation of representative soil cover spatial variability is an important and challenging task that receives increasing attention from private companies, governmental and environmental bodies. Pereslavskoye Opolye is traditionally actively used in agriculture due to dominated high-quality cultivated soddy-podzoluvisols which are relatively reached in organic matter (especially for conditions of the North part at the European territory of Russia). However, the soil cover patterns are often very complicated even within the field that significantly influences on crop yield variability and have to be considered in farming system development and land agroecological quality evaluation. The detailed investigations of soil regimes and mapping of the winter rye yield have been carried in conditions of two representative fields with slopes sharply contrasted both in aspects and degrees. Rye biological productivity and weed infestation have been measured in elementary plots of 0.25 m2 with the following analysis the quality of the yield. In the same plot soil temperature and moisture have been measured by portable devices. Soil sampling was provided from three upper layers by drilling. The results of ray yield detailed mapping shown high differences both in average values and within-field variability on different slopes. In case of low-gradient slope (field 1) there is variability of ray yield from 39.4 to 44.8 dt/ha. In case of expressed slope (field 2) the same species of winter rye grown with the same technology has essentially lower yield and within-field variability from 20 to 29.6 dt/ha. The variability in crop yield between two fields is determined by their differences in mesorelief, A-horizon average thickness and slightly changes in soil temperature. The within-field crop yield variability is determined by microrelief and connected differences in soil moisture. Higher soil cover variability reflects in higher variability of winter ray yield and its quality that could be predicted and planed in conditions of concrete field and year according to principal limiting factors evaluation.

  9. Spreading topsoil encourages ecological restoration on embankments: soil fertility, microbial activity and vegetation cover.

    PubMed

    Rivera, Desirée; Mejías, Violeta; Jáuregui, Berta M; Costa-Tenorio, Marga; López-Archilla, Ana Isabel; Peco, Begoña

    2014-01-01

    The construction of linear transport infrastructure has severe effects on ecosystem functions and properties, and the restoration of the associated roadslopes contributes to reduce its impact. This restoration is usually approached from the perspective of plant cover regeneration, ignoring plant-soil interactions and the consequences for plant growth. The addition of a 30 cm layer of topsoil is a common practice in roadslope restoration projects to increase vegetation recovery. However topsoil is a scarce resource. This study assesses the effects of topsoil spreading and its depth (10 to 30 cm) on two surrogates of microbial activity (?-glucosidase and phosphatase enzymes activity and soil respiration), and on plant cover, plant species richness and floristic composition of embankment vegetation. The study also evaluates the differences in selected physic-chemical properties related to soil fertility between topsoil and the original embankment substrate. Topsoil was found to have higher values of organic matter (11%), nitrogen (44%), assimilable phosphorous (50%) and silt content (54%) than the original embankment substrate. The topsoil spreading treatment increased microbial activity, and its application increased ?-glucosidase activity (45%), phosphatase activity (57%) and soil respiration (60%). Depth seemed to affect soil respiration, ?-glucosidase and phosphatase activity. Topsoil application also enhanced the species richness of restored embankments in relation to controls. Nevertheless, the depth of the spread topsoil did not significantly affect the resulting plant cover, species richness or floristic composition, suggesting that both depths could have similar effects on short-term recovery of the vegetation cover. A significant implication of these results is that it permits the application of thinner topsoil layers, with major savings in this scarce resource during the subsequent slope restoration work, but the quality of topsoil relative to the original substrate should be previously assessed on a site by site basis. PMID:24984137

  10. Spreading Topsoil Encourages Ecological Restoration on Embankments: Soil Fertility, Microbial Activity and Vegetation Cover

    PubMed Central

    Rivera, Desirée; Mejías, Violeta; Jáuregui, Berta M.; López-Archilla, Ana Isabel; Peco, Begoña

    2014-01-01

    The construction of linear transport infrastructure has severe effects on ecosystem functions and properties, and the restoration of the associated roadslopes contributes to reduce its impact. This restoration is usually approached from the perspective of plant cover regeneration, ignoring plant-soil interactions and the consequences for plant growth. The addition of a 30 cm layer of topsoil is a common practice in roadslope restoration projects to increase vegetation recovery. However topsoil is a scarce resource. This study assesses the effects of topsoil spreading and its depth (10 to 30 cm) on two surrogates of microbial activity (?-glucosidase and phosphatase enzymes activity and soil respiration), and on plant cover, plant species richness and floristic composition of embankment vegetation. The study also evaluates the differences in selected physic-chemical properties related to soil fertility between topsoil and the original embankment substrate. Topsoil was found to have higher values of organic matter (11%), nitrogen (44%), assimilable phosphorous (50%) and silt content (54%) than the original embankment substrate. The topsoil spreading treatment increased microbial activity, and its application increased ?-glucosidase activity (45%), phosphatase activity (57%) and soil respiration (60%). Depth seemed to affect soil respiration, ?-glucosidase and phosphatase activity. Topsoil application also enhanced the species richness of restored embankments in relation to controls. Nevertheless, the depth of the spread topsoil did not significantly affect the resulting plant cover, species richness or floristic composition, suggesting that both depths could have similar effects on short-term recovery of the vegetation cover. A significant implication of these results is that it permits the application of thinner topsoil layers, with major savings in this scarce resource during the subsequent slope restoration work, but the quality of topsoil relative to the original substrate should be previously assessed on a site by site basis. PMID:24984137

  11. Improvement of remote sensing of crop residue cover by accounting for green vegetation and soil spectral properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conservation tillage methods are beneficial as they disturb soil less and leaves increased crop residue cover (CRC) after planting on the soil surface. CRC helps reduce soil erosion, evaporation, and the need for tillage operations in fields. Greenhouse gas emissions are reduced to due to less fos...

  12. Soil wetting processes at high temporal resolution in a semiarid mediterranean watershed with scattered tree cover

    NASA Astrophysics Data System (ADS)

    Lozano-Parra, Javier; van Schaik, Loes; Schnabel, Susanne; Gómez-Gutiérrez, Álvaro

    2015-04-01

    Soil wetting processes play a key role for the distribution of water and solutes and thereby for the water availability for plants. However, characterization of such processes (from slower to faster flows), frequency of occurrence, and factors that cause them, are still poorly known. This characterization is important in hydrological studies because enables a better understanding of spatio-temporal variability of water resources and allows improving the design of models. Using a method based on the maximal soil water increase registered by a sensor over a minimum given time interval during a rainfall event, types of soil wetting processes were classified and quantified. For this, capacitance sensors which registered the volumetric water content at high temporal resolution (30-min) along of more than two hydrological years (mainly for 2010-2011 and 2011-2012), were installed in soil profiles at 5, 15 cm, and 5 cm above the bedrock and depending on soil depth. This distribution along the soil profile is justified because soils are generally very shallow and most of the roots are concentrated in the upper layer. The sensors were gathered in 9 soil moisture stations characterized by lithology, topographic position, as well as by different vegetation covers: under tree canopy, under shrub, and in open spaces or grasslands. Besides, the data mining technique Multivariate Adaptive Regression Spline (MARS) was used to identify and rank the factors influencing flow types as well as modelling their occurrence. The work was carried out in an experimental catchment of the Spanish region of Extremadura. Results indicated that there is a general behavior or pattern of soil moisture dynamics in the catchment with a dominant occurrence of slower soil wetting processes (>50%), which may be considered as matrix flows, and a low occurrence of those faster processes (<30%), considered as preferential flows. Nevertheless, when the total volume of water is considered then preferential flow becomes the dominant process, so that the ecological role of both flow types becomes prominent in water-limited environments. Statistical multivariate analyses based on data-mining techniques proved that although both flow types depend on variables associated with precipitation and antecedent soil moisture conditions, faster soil wetting processes are mainly related to variables as rainfall intensity and topography, while slower soil wetting processes are related to soils or vegetation.

  13. Role of vegetation cover on soil water balance in two Mediterranean areas: semiarid and dry at southeastern of Spain.

    NASA Astrophysics Data System (ADS)

    Manrique, Àngela; Ruiz, Samantha; Chirino, Esteban; Bellot, Juan

    2014-05-01

    Water is a limited resource in the semiarid areas, which affects both, the population services, the economic growth, like the natural ecosystems stability. In this context, an accurate knowledge of soil water balance and role of the vegetation cover contribute to improve the management of resources water and forest. These studies are increasingly important, if we consider the latest Assessment Reports of the Intergovernmental Panel on Climate Change. In this paper the main objectives were focused on:(1)To determine the soil water balance on two different climatic conditions, semiarid and dry climate and(2) Assess the effect of vegetation (structure and cover) on soil water balance under the studied climatic conditions. For this purpose we used HYDROBAL ecohydrological model, which calculates at a daily resolution the water flows through of the vegetation canopy, estimates daily soil moisture and predicts deep drainage from the unsaturated soil layer into the aquifer. In order to achieve these objectives, we have selected two sites in the south-eastern of Spain, on soils calcareous and different climatic conditions. Ventós site in a semiarid Mediterranean area and Confrides site in a dry Mediterranean area, with 303 and 611 mm of annual precipitation respectively. Both sites, the predominant vegetation are afforestations with Pinus halepensis on dry grasslands with some patches of thorn shrublands and dwarf scrubs; but it show difference on trees density, cover and height of pines.Soil water balance was determined in each site using HYDROBAL ecohydrological model on one hydrological year (October 2012 and September 2013).Model inputs include climatic variables (daily rainfall and temperature), as well as soil and vegetation characteristics (soil field capacity, soil wilting point, initial soil water content and vegetation cover index). Model outputs are interception, net rainfall, runoff, soil water reserves, actual evapotranspiration, direct percolation, and deep percolation (or aquifer recharge). In the last decade, HYDROBAL model has been used successfully in semiarid conditions, to assess the soil water balance on different vegetation cover types, and the effect of different land-use scenarios on water resources and aquifer recharge. Results highlight the role of vegetation cover type and volume of annual rainfall on the soil water balance. Both sites present similar percentage of vegetation cover(>80%), however in Ventós site (semiarid area), a lower pine cover (44%) and lower volume of annual rainfall produced differences in the soil water balance. In Confrides site (dry area), in spite of show the twice of annual rainfall, a higher pine cover (78%) reduced the net precipitation and consequently affected the soil water balance. An understanding the role of vegetation cover on soil water balance is a very useful tool to implement an optimal management of forest and water resources.

  14. Movement of unlined landfill under preloading surcharge.

    PubMed

    Al-Yaqout, Anwar F; Hamoda, Mohamed F

    2007-01-01

    As organic solid waste is decomposed in a landfill and mass is lost due to gas and leachate formation, the landfill settles. Settlement of a landfill interferes with the rehabilitation and subsequent use of the landfill site after closure. This study examined the soil/solid waste movement at the Al-Qurain landfill in Kuwait after 15 years of closure as plans are underway for redevelopment of the landfill site that occupies about a km(2) with an average depth of 8-15m. Field experiments were conducted for 6 mo to measure soil/solid waste movement and water behavior within the landfill using two settlement plates with a level survey access, Casagrande-type piezometers, pneumatic piezometers, and magnetic probe extensometers. Previous results obtained indicated that biological decomposition of refuse continued after closure of the landfill site. The subsurface water rise enhanced the biological activities, which resulted in the production of increasing quantities of landfill gas. The refuse fill materials recorded a high movement rate under the imposed preloading as a result of an increase in the stress state. Up to 55% of the total movement was observed during the first 2 weeks of fill placement and increased to 80% within the first month of the 6-mo preloading test. Pneumatic piezometers showed an increase in water head, which is attributed to the developed pressure of gases escaping during the preloading period. PMID:16574394

  15. A methodology for the determination of fugitive dust emissions from landfill sites.

    PubMed

    Chalvatzaki, Eleftheria; Glytsos, Thodoros; Lazaridis, Mihalis

    2015-01-01

    This study focuses on the development of a methodology for the determination of the contribution of fugitive dust emissions from landfill sites to ambient PM10 concentrations and the subsequent exposure to working personnel. Fugitive dust emissions in landfills mainly originate from resuspension due to truck traffic on paved and unpaved roads and from wind-blown dust from landfill cover soil. The results revealed that exposure to PM10, originating from fugitive dust emissions in the landfill site, was exceeding the health protection standards (50 ?g m(-3)). The higher average daily PM10 concentration (average value) for weekdays was equal to 275 ?g m(-3) and was computed for the areas nearby the unpaved road located inside the landfill facilities that lead to the landfill cell. The percentage contributions of road and wind-blown dust to the PM10 concentrations on weekdays were equal to 76 and 1%, respectively. The influence of the background concentration is estimated close to 23%. PMID:25563337

  16. Remote sensing as a source of land cover information utilized in the universal soil loss equation

    NASA Technical Reports Server (NTRS)

    Morris-Jones, D. R.; Morgan, K. M.; Kiefer, R. W.; Scarpace, F. L.

    1979-01-01

    In this study, methods for gathering the land use/land cover information required by the USLE were investigated with medium altitude, multi-date color and color infrared 70-mm positive transparencies using human and computer-based interpretation techniques. Successful results, which compare favorably with traditional field study methods, were obtained within the test site watershed with airphoto data sources and human airphoto interpretation techniques. Computer-based interpretation techniques were not capable of identifying soil conservation practices but were successful to varying degrees in gathering other types of desired land use/land cover information.

  17. Applications of remote sensing and GIS in surface hydrology: Snow cover, soil moisture and precipitation

    NASA Astrophysics Data System (ADS)

    Wang, Xianwei

    Studies on surface hydrology can generally be classified into two categories, observation for different components of surface water, and modeling their dynamic movements. This study only focuses on observation part of surface water components: snow cover, soil moisture, and precipitation. Moreover, instead of discussion on the detailed algorithm and instrument technique behind each component, this dissertation pours efforts on analysis of the standard remotely sensed products and their applications under different settings. First in Chapter 2, validation of MODIS Terra 8-day maximum snow cover composite (MOD10A2) in the Northern Xinjiang, China, from 2000-2006, shows that the 8-day MODIS/Terra product has high agreements with in situ measurements as the in situ snow depth is larger or equal to 4 cm, while the agreement is low for the patchy snow as the in situ snow depth less than 4 cm. According to the in situ observation, this chapter develops an empirical algorithm to separate the cloud-covered pixels into snow and no snow. Continued long-term production of MODIS-type snow cover product is critical to assess water resources of the study area, as well as other larger scale global environment monitoring. Terra and Aqua satellites carry the same MODIS instrument and provide two parallel MODIS daily snow cover products at different time (local time 10:30 am and 1:30 pm, respectively). Chapter 3 develops an algorithm and automated scripts to combine the daily MODIS Terra (MOD10A1) and Aqua (MYD10A1) snow cover products, and to automatically generate multi-day Terra-Aqua snow cover image composites, with flexible starting and ending dates and a user-defined cloud cover threshold. Chapter 4 systematically compares the difference between MODIS Terra and Aqua snow cover products within a hydrologic year of 2003-2004, validates the MODIS Terra and Aqua snow cover products using in situ measurements in Northern Xinjiang, and compares the accuracy among the standard MODIS Terra and Aqua snow cover products, and the new combined daily and multi-day composite from both MODIS Terra and Aqua daily products. In Chapter 5, utilizing the new cloud-low multi-day composite of MODIS Terra and Aqua snow cover products, several new methods are developed to study the spatiotemporal variation of snow cover conditions from different aspects at the Northern Xinjiang and on the Central Tianshan Mountains, mainly in China, partly covering Kazakhstan and Kyrgyzstan. Secondly, Chapter 6 investigates the feasibility to indirectly map root-zone soil moisture using optical remote sensing techniques and in situ measurements. Specifically, covariation of root-zone soil moisture with the normalized difference of vegetation index (NDVI) from MODIS observation is studied at three sites (New Mexico, Arizona, and Texas). The three sites represent two types of vegetation (shrub and grass) and two types of climate conditions: arid/semi-arid (New Mexico and Arizona) and humid (Texas). Results show that the root-zone soil moisture has significant linear correlation with vegetation (NDVI). Finally, Chapter 7 validates and compares the NEXRAD Stage III and MPE precipitation products using a high density rain gauge network on the Upper Guadalupe River Basin of the Texas Hill Country in 2001 and 2004. (Abstract shortened by UMI.)

  18. Investigation and risk assessment for landfill on US Army installation in Germany

    SciTech Connect

    Strickland, J.A.; Delaney, K.; Luster, T.; Hargrave, R.

    1997-12-31

    Several environmental investigations at a landfill on a US Army installation in Germany focused on determining risk potential and the need for remediation. Risk potential was not related to the determination of the potential for adverse health effects. The determination of risk potential was based on comparison of maximum soil contaminant levels to unenforceable German guidelines based on ground water management principles rather than human exposure. Upon finding that incinerator ash/slag in the landfill was exposed by an eroding landfill cover, a concern for human health risk arose for troops training in the immediate area. During the site visit, the health risk assessment team discovered that slag had also been used as fill material at several places in the training area. The team sampled surface soil in the immediate vicinity of the eroded landfill cap as well as in training areas where slag was used as fill. Surface soil samples were analyzed for dioxins/furans, metals, and polynuclear aromatic hydrocarbons. Analytical results indicated that dioxin/furan contamination was widespread, but that it was probably migrating from the slag fill areas via dust emissions, rather than from the landfill erosion. The risk assessment results for exposed troops, cancer risk of 1E-5 and hazard index of 0.6, would not support remediation of soils based on common Superfund practices. Lessons learned: (1) a site visit by the risk assessment team is crucial (without information on the slag fill, sampling would have concentrated on migration from the landfill); (2) where actual (as opposed to hypothetical) receptors exist, human health risk should be assessed at hazardous waste sites, whether the host country requires it or not; and (3) although Bavarian and US EPA dioxin/furan toxic equivalency factors are somewhat different, they did not produce different risk estimates for dioxins/furans.

  19. Organization of retrospective monitoring of the soil cover in Azov district of Rostov oblast

    NASA Astrophysics Data System (ADS)

    Bryzzhev, A. V.; Rukhovich, D. I.; Koroleva, P. V.; Kalinina, N. V.; Vil'chevskaya, E. V.; Dolinina, E. A.; Rukhovich, S. V.

    2015-10-01

    Retrospective monitoring of the state of soils and lands is based on the principles of actualization of their identification features based on the available materials of remote sensing (RS). The characteristics of RS materials and topographic maps applied for this purpose are discussed. It is argued that temporal changes in the state of soils and lands can be inferred from three types of RS materials covering the entire agricultural territory of Russia. Information about the availability of these materials is given. The methodology of retrospective monitoring of the state of soils and lands is realized with the use of GIS technologies. Classification schemes of the types of land use and their dynamics for the considered region are suggested.

  20. [Radioecological investigation of the soil cover of eastern Urals State radioactive reserve and neighboring areas].

    PubMed

    Mikha?lovskaia, L N; Molchanova, I V; Karavaeva, E N; Pozolotina, V N; Tarasov, O V

    2011-01-01

    The contamination levels and spatial distribution of 90Sr and 137Cs in the soil cover of the Eastern Ural State Radioactive Reserve and neighboring areas have been studied. Situated in the Chelyabinsk region, the Reserve embraces the frontal part of the Eastern Urals Radioactive Trace. This Trace emerged in 1957 as a result of the nuclear accident at the Production Association "Mayak". In the studied areas, the content of radionuclides in soils decreases exponentially as the distance from the source of contamination increases. 90Sr received by the soil cover as a result of the accident in 1957 has remained the main contaminant of the Reserve central part (97% of the total contamination). Its contribution throughout western neighboring areas reduces up to 67%, which decreases the effect of 90Sr on the environment. Within eastern neighboring areas, soil is mainly contaminated by 137Cs received as a result of the wind disseminated dried sediments from the shores of Lake Karachay (1967) that was used for dumping high-level radioactive waste. Also observed was enrichment of forest litters with this radionuclide due to current atmospheric fallout. PMID:21950106

  1. Effects of compaction and wetting of laterite cover soil on development and survival of Musca domestica (Diptera: Muscidae) immatures.

    PubMed

    Abu Tahir, Nurita; Ahmad, Abu Hassan

    2013-09-01

    Effects of laterite cover soil with different characteristics on survival of buried eggs, third instar larvae, and pupae of Musca domestica (L.) were studied experimentally. Soil treatments were loose dry soil, loose wet soil, compacted dry soil, and compacted wet soil (CWS). Eggs, third instar larvae, and pupae were buried under 30 cm of the different soil treatments and placed under field conditions until adults emerged. Rearing medium was provided for eggs and larvae, and control treatments of all stages were unburied immatures placed on soil surface. Egg and pupal survival to adult were significantly affected by the cover soil treatments, but third instars were more resilient. Wet soil treatments (loose wet soil and CWS) resulted in significantly reduced pupal survival, but increased survival of eggs. However, CWS significantly reduced adult emergence from buried eggs. Though emergence of house flies buried as eggs was significantly reduced, some were able to hatch and emerging first instar larvae developed to pupation. Although cover soil does not completely prevent fly emergence, it did limit development and emergence of buried house flies. PMID:24180104

  2. Influence of Snow Cover Duration on Soil Evaporation and Respiration Efflux in Mixed-conifer Ecosystems

    NASA Astrophysics Data System (ADS)

    Nelson, K.; Papuga, S. A.; John, G. P.; Minor, R.; Barron-Gafford, G. A.

    2011-12-01

    Subalpine mixed-conifer ecosystems are sensitive to a warming climate and are dependent on snowfall, which is expected to decrease under projected climate change. These changes in snowpack are likely to have important consequences for water and carbon cycling in these ecosystems and those downstream in the watersheds. Particularly within the semiarid southwest, such transitions to a drier and warmer environment will directly influence localized water and carbon dynamics and indirectly influence regional-scale levels of water availability and carbon sequestration. Therefore, in this study we monitored soil evaporation and respiration to evaluate how snow accumulation and duration of snow cover affected these effluxes. Our study took place within a mixed-conifer ecosystem within the Santa Catalina Mountains about 10 km north of Tucson, Arizona. Here, three understory time-lapse digital cameras have monitored snow cover within the footprint of an eddy covariance tower for nearly two years. Using these cameras, we identified locations with short and long snow duration. We then placed 6 soil collars (3 in short snow duration; 3 in long snow duration) within the field of view of each camera. Since July 2010, evaporation and soil respiration data have been collected regularly from these collars; soil temperature and soil moisture measurements were also collected. Our primary findings include: (1) evaporation fluxes do not vary drastically between long and short snow season sites, (2) evaporation fluxes for both short and long snow seasons have a strong relationship with soil moisture and a poor relationship with soil temperature, (3) CO2 fluxes vary noticeably between long and short snow season sites throughout the year, with short snow season fluxes typically higher than those of long snow season sites, and (4) CO2 fluxes for short and long snow seasons have a strong relationship with soil temperature and a poor relationship with soil moisture. Our findings suggest that rates of evaporative water loss will not be strongly influenced by changes in length of snow season, but that CO2 fluxes will be significantly influenced by these environmental changes such that we might expect greater carbon losses to the atmosphere.

  3. A map of the soil cover patterns in the western part of the Transbaikal region (1: 500000 scale)

    NASA Astrophysics Data System (ADS)

    Gonchikov, B.-M. N.; Tsybzhitov, Ts. Kh.; Tsybikdorzhiev, Ts. Ts.; Davydova, T. V.

    2009-07-01

    The results of soil surveys in the Khorinsk district of the Buryat Republic have been generalized on a map of the soil cover patterns on a scale of 1: 500000. The map reflects the soil cover patterns in the zones of mountainous tundra and taiga, mountainous forest-steppes, sand massifs on piedmonts, and plain steppes and dry steppes. The areas of each component of the soil combinations shown on the map have been calculated. In the course of the generalization of large-scale soil maps, information on the genetic types and subtypes of soils has been preserved. The new map adequately displays the real pattern of the soil distribution in the studied area.

  4. Cover crops impact on excess rainfall and soil erosion rates in orchards and potato fields, Israel

    NASA Astrophysics Data System (ADS)

    Egozi, Roey; Gil, Eshel

    2015-04-01

    Bare soil and high drainage densities are common characteristics of intensive agriculture land. The couplings of these characteristics lead to high runoff and eroded soil volumes leaving the field or the orchard via the local drainage system into the fluvial system. This process increase flood risk due to massive deposition of the coarse fraction of the eroded soil and therefore reduces channel capacity to discharge the increase volumes of concentrated runoff. As a result drainage basin authorities are forced to invest large amount of money in maintaining and enlarging the drainage network. However this approach is un-sustainable. On the other hand, implementing cover crops (CC) and modification to current agricultural practices over the contributing area of the watershed seems to have more benefits and provide sustainable solution. A multi-disciplinary approach applied in commercial potatoes fields and orchards that utilize the benefit of CC shows great success as means of soil and water conservation and weed disinfestation without reduction in the yield, its quality or its profitability. The results indicate that it is possible to grow potatoes and citrus trees under CC with no reduction in yield or nutrient uptake, with more than 95% reduction in soil loss and more than 60% in runoff volumes and peak discharges.

  5. Use of LANDSAT images of vegetation cover to estimate effective hydraulic properties of soils

    NASA Technical Reports Server (NTRS)

    Eagleson, Peter S.; Jasinski, Michael F.

    1988-01-01

    The estimation of the spatially variable surface moisture and heat fluxes of natural, semivegetated landscapes is difficult due to the highly random nature of the vegetation (e.g., plant species, density, and stress) and the soil (e.g., moisture content, and soil hydraulic conductivity). The solution to that problem lies, in part, in the use of satellite remotely sensed data, and in the preparation of those data in terms of the physical properties of the plant and soil. The work was focused on the development and testing of a stochastic geometric canopy-soil reflectance model, which can be applied to the physically-based interpretation of LANDSAT images. The model conceptualizes the landscape as a stochastic surface with bulk plant and soil reflective properties. The model is particularly suited for regional scale investigations where the quantification of the bulk landscape properties, such as fractional vegetation cover, is important on a pixel by pixel basis. A summary of the theoretical analysis and the preliminary testing of the model with actual aerial radiometric data is provided.

  6. A MODELING APPROACH TO ESTIMATING SNOW COVER DEPLETION AND SOIL MOISTURE RECHARGE IN A SEMI-ARID CLIMATE AT TWO NASA CLPX

    E-print Network

    Anderson, Charles W.

    THESIS A MODELING APPROACH TO ESTIMATING SNOW COVER DEPLETION AND SOIL MOISTURE RECHARGE IN A SEMI A MODELING APPROACH TO ESTIMATING SNOW COVER DEPLETION AND SOIL MOISTURE RECHARGE IN A SEMI-ARID CLIMATE ________________________________________ Department Head #12;iii ABSTRACT A MODELING APPROACH TO ESTIMATING SNOW COVER DEPLETION AND SOIL MOISTURE

  7. Conservation tillage, rotations, and cover crop affect soil quality in the Tennessee Valley: Particulate organic matter, organic matter, and microbial biomass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Monocropping cotton (Gossypium hirsutum L.) with conventional tillage provides little carbon input to soil, increases erosion and promotes rapid oxidation of existing soil organic carbon (SOC). Management practices like conservation tillage, crop rotation, and cover cropping can impact soil carbon, ...

  8. Mixed Waste Landfill Integrated Demonstration; Technology summary

    SciTech Connect

    1994-02-01

    The mission of the Mixed Waste Landfill Integrated Demonstration (MWLID) is to demonstrate, in contaminated sites, new technologies for clean-up of chemical and mixed waste landfills that are representative of many sites throughout the DOE Complex and the nation. When implemented, these new technologies promise to characterize and remediate the contaminated landfill sites across the country that resulted from past waste disposal practices. Characterization and remediation technologies are aimed at making clean-up less expensive, safer, and more effective than current techniques. This will be done by emphasizing in-situ technologies. Most important, MWLID`s success will be shared with other Federal, state, and local governments, and private companies that face the important task of waste site remediation. MWLID will demonstrate technologies at two existing landfills. Sandia National Laboratories` Chemical Waste Landfill received hazardous (chemical) waste from the Laboratory from 1962 to 1985, and the Mixed-Waste Landfill received hazardous and radioactive wastes (mixed wastes) over a twenty-nine year period (1959-1988) from various Sandia nuclear research programs. Both landfills are now closed. Originally, however, the sites were selected because of Albuquerque`s and climate and the thick layer of alluvial deposits that overlay groundwater approximately 480 feet below the landfills. This thick layer of ``dry`` soils, gravel, and clays promised to be a natural barrier between the landfills and groundwater.

  9. Effects of Tillage, Rotation and Cover Crop on the Physical Properties of a Silt-Loam Soil

    NASA Astrophysics Data System (ADS)

    Haruna, Samuel Idoko; Nkongolo, Nsalambi Vakanda

    2015-04-01

    Soil and crop management practices can affect the physical properties and have a direct impact on soil sustainability and crop performance. The objective of this study was to investigate how soil physical properties were affected by three years of tillage, cover crop and crop rotation treatments in a corn and soybean field. The study was conducted on a Waldron siltyloam soil at Lincoln University of Missouri. Soil physical properties studied were soil bulk density, volumetric and gravimetric water contents, volumetric air content, total pore space, air-filled and water-filled pore space, gas diffusion coefficient and pore tortuosity factor. Results showed significant interactions (p<0.05) between cover crop and crop rotation for bulk density, gravimetric and total pore space in 2013. In addition, cover crop also significantly interacted (p<0.05) with tillage for bulk density and total pore space. All soil physical properties studied were significantly affected by the depth of sampling (p<0.0001), except for bulk density, the pore tortuosity factor and total pore space in 2012, and gravimetric and volumetric in 2013. Overall, soil physical properties were significantly affected by the treatments, with the effects changing from one year to another. Addition of a cover crop improved soil physical properties better in rotation than in monoculture.

  10. Biogenic NO emission from a spruce forest soil in the Fichtelgebirge (Germany) under the influence of different understorey vegetation cover

    NASA Astrophysics Data System (ADS)

    Bargsten, A.; Andreae, M. O.; Meixner, F. X.

    2009-04-01

    Within the framework of the EGER project (ExchanGE processes in mountainous Regions) soil samples have been taken from the spruce forest site "Weidenbrunnen" (Fichtelgebirge, Germany) in September 2008 to determine the NO exchange in the laboratory and for a series of soil analyses. The soil was sampled below different understorey vegetation covers: young Norway spruce, moss/litter, blueberries and grass. We investigated the net NO release rate from corresponding organic layers as well as from the A horizon of respective soils. Additionally we measured pH, C/N ratio, contents of ammonium, nitrate, and organic C, bulk density, the thickness of the organic layer and the quality of the organic matter. Net NO release rates (as well as the NO production and NO consumption rates) from the soil samples were determined by a fully automated laboratory incubation & fumigation system. Purified dry air passed five dynamic incubation chambers, four containing water saturated soil samples and one reference chamber. By this procedure, the soil samples dried out slowly (within 2-6 days), covering the full range of soil moisture (0-300% gravimetric soil moisture). To quantify NO production and NO consumption rates separately, soil samples were fumigated with zero-air (approx. 0 ppb NO) and air of 133 ppb NO. The chambers were placed in a thermostatted cabinet for incubation at 10 an 20Ë? C. NO and H2O concentrations at the outlet of the five dynamic chambers were measured sequentially by chemiluminescence and IR-absorption based analyzers, switching corresponding valves every two minutes. Net NO release rates were determined from the NO concentration difference between soil containing and reference chambers. Corresponding measurements of H2O mixing ratio yielded the evaporation loss of the soil samples, which (referenced to the gravimetric soil water content before and after the incubation experiment) provided the individual soil moisture contents of each soil samples during the incubation experiment. Our contribution focus net NO release rates, NO production and NO consumption rates of spruce forest soils sampled under different understorey vegetation covers. Generally, organic layers show significant higher NO production and NO consumption rates than the soils from the corresponding A horizons. Soils under the understorey vegetation cover "moos/litter" revealed the lowest NO production and NO consumption rates. Net NO release rates, NO production and NO consumption rates of soil samples obtained below the four different under- storey vegetation covers will be discussed in terms of pH, C/N ratio, contents of ammonium, nitrate, and organic C, bulk density, thickness of organic layer, as well as quality of the organic matter.

  11. Infiltration through layered-soil trench covers: Response to an extended period of rainfall

    USGS Publications Warehouse

    Larson, T.H.; Keefer, D.A.; Albrecht, K.A.; Cartwright, K.

    1988-01-01

    Four experimental waste disposal trench covers were constructed to test the effectiveness of layered-soil cover designs in reducing infiltration. Three covers each consisted of a layer of gravel between an overlying wick layer of compacted fine-grained material (either silt or loam) and a compacted loam base; the fourth consisted of compactd silt over a loam base. Capillary pressures were monitored at various depths within each cover during October through December, 1985, a period of high rainfall following a dry summer. Moisture movement in response to the rainfall was rapid within the upper layers of all four test covers, but was retained within the upper layers of the three wick-system trenches, despite variations in the design thickness and composition of the wick layers. In the wick systems, moisture did not enter the gravel until a threshold level of pressure approaching saturation was established in the wick layer. Once this level was reached, moisture moved into and through the gravel. This experiment demonstrates the functionality of field-scale wick systems. ?? 1988.

  12. The influence of soil type, vegetation cover and soil moisture on spin up behaviour of a land surface model in a monsoonal region

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Anwesha; Mandal, Manabottam

    2015-04-01

    Model spin-up is the process through which the model is adequately equilibrated to ensure balance between the mass fields and velocity fields. In this study, an offline one dimensional Noah land surface model is integrated recursively for three years to assess its spin-up behavior at different sites over the Indian Monsoon domain. Several numerical experiments are performed to investigate the impact of soil category, vegetation cover, initial soil moisture and subsequent dry or wet condition on model spin-up. These include simulations with the dominant soil and vegetation covers of this region, different initial soil moisture content (observed soil moisture; dry soil; moderately wet soil; saturated soil), simulations initialized at different rain conditions (no rain; infrequent rain; continuous rain) and different seasons (Winter, Spring, Summer/Pre-Monsoon, Monsoon and Autumn). It is seen that the spin-up behavior of the model depends on the soil type and vegetation cover with soil characteristics having the larger influence. Over India, the model has the longest spin-up in the case of simulations with loamy soil covered with mixed-shrub. It is noted that the model has a significantly longer spin-up when initialized with very low initial soil moisture content than with higher soil moisture content. It is also seen that in general, simulations initialized just before a continuous rainfall event have the least spin-up time. This observation is reinforced by the results from the simulations initialized in different seasons. It is seen that for monsoonal region, the model spin-up time is least for simulations initialized just before the Monsoon. Model initialized during the Monsoon rain episodes has a longer spin-up than that initialized in any other season. Furthermore, it is seen that the model has a shorter spin-up if it reaches the equilibrium state predominantly via drying process and could be as low as two months under quasi-equilibrium condition depending on the time of initialization.

  13. Land-cover effects on soil organic carbon stocks in a European city.

    PubMed

    Edmondson, Jill L; Davies, Zoe G; McCormack, Sarah A; Gaston, Kevin J; Leake, Jonathan R

    2014-02-15

    Soil is the vital foundation of terrestrial ecosystems storing water, nutrients, and almost three-quarters of the organic carbon stocks of the Earth's biomes. Soil organic carbon (SOC) stocks vary with land-cover and land-use change, with significant losses occurring through disturbance and cultivation. Although urbanisation is a growing contributor to land-use change globally, the effects of urban land-cover types on SOC stocks have not been studied for densely built cities. Additionally, there is a need to resolve the direction and extent to which greenspace management such as tree planting impacts on SOC concentrations. Here, we analyse the effect of land-cover (herbaceous, shrub or tree cover), on SOC stocks in domestic gardens and non-domestic greenspaces across a typical mid-sized U.K. city (Leicester, 73 km(2), 56% greenspace), and map citywide distribution of this ecosystem service. SOC was measured in topsoil and compared to surrounding extra-urban agricultural land. Average SOC storage in the city's greenspace was 9.9 kg m(-2), to 21 cm depth. SOC concentrations under trees and shrubs in domestic gardens were greater than all other land-covers, with total median storage of 13.5 kg m(-2) to 21 cm depth, more than 3 kg m(-2) greater than any other land-cover class in domestic and non-domestic greenspace and 5 kg m(-2) greater than in arable land. Land-cover did not significantly affect SOC concentrations in non-domestic greenspace, but values beneath trees were higher than under both pasture and arable land, whereas concentrations under shrub and herbaceous land-covers were only higher than arable fields. We conclude that although differences in greenspace management affect SOC stocks, trees only marginally increase these stocks in non-domestic greenspaces, but may enhance them in domestic gardens, and greenspace topsoils hold substantial SOC stores that require protection from further expansion of artificial surfaces e.g. patios and driveways. PMID:24309424

  14. Cleaner Landfills

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Osmotek, Inc. developed the Direct Osmosis treatment system through SBIR funding from Ames Research Center. Using technology originally developed for flight aboard the Space Station, the company brought it to their commercial water purification treatment system, Direct Osmosis. This water purification system uses a direct osmosis process followed by a reverse osmosis treatment. Because the product extracts water from a waste product, Osmotek is marketing the unit for use in landfills. The system can treat leachate (toxic chemicals leached into a water source), by filtering the water and leaving behind the leahcate. The leachate then becomes solidified into substance that can not seep into water.

  15. Cover crops influence soil microorganisms and phytoextraction of copper from a moderately contaminated vineyard.

    PubMed

    Mackie, K A; Schmidt, H P; Müller, T; Kandeler, E

    2014-12-01

    We investigated the ability of summer (Avena sativa [oat], Trifolium incarnatum [crimson clover], Chenopodium [goosefoot]) and winter (Vicia villosa [hairy vetch], Secale Cereale L. [Rye], Brassica napus L. partim [rape]) cover crops, including a mixed species treatment, to extract copper from an organic vineyard soil in situ and the microbial communities that may support it. Clover had the highest copper content (14.3mgCukg(-1) DM). However, it was the amount of total biomass production that determined which species was most effective at overall copper removal per hectare. The winter crop rye produced significantly higher amounts of biomass (3532kgDMha(-1)) and, therefore, removed significantly higher amounts of copper (14,920mgCuha(-1)), despite less accumulation of copper in plant shoots. The maximum annual removal rate, a summation of best performing summer and winter crops, would be 0.033kgCuha(-1)y(-1). Due to this low annual extraction efficiency, which is less than the 6kgCuha(-1)y(-1) permitted for application, phytoextraction cannot be recommended as a general method of copper extraction from vineyards. Copper concentration did not influence aboveground or belowground properties, as indicated by sampling at two distances from the grapevine row with different soil copper concentrations. Soil microorganisms may have become tolerant to the copper levels at this site. Microbial biomass and soil enzyme activities (arylsulfatase and phosphatase) were instead driven by seasonal fluxes of resource pools. Gram+ bacteria were associated with high soil moisture, while fungi seemed to be driven by extractable carbon, which was linked to high plant biomass. There was no microbial group associated with the increased phytoextraction of copper. Moreover, treatment did not influence the abundance, activity or community structure of soil microorganisms. PMID:25217742

  16. Cover Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cover crops are a beneficial tool for use in conservation tillage systems. Cover crop residues reduce soil erosion from water and wind, increase soil water availability for subsequent crops, enhance soil organic matter and biological activity, and can decrease labor and energy inputs. Cover crop...

  17. The applicability of ERTS-1 data covering the major landforms of Kenya. [landforms, vegetation, soils, forests

    NASA Technical Reports Server (NTRS)

    Omino, J. H. O. (principal investigator)

    1973-01-01

    The author has identified the following significant results. Five investigators report on the applicability of ERTS-1 data covering the major landforms of Kenya. Deficiencies due to lack of equipment, repetitive coverage and interpretation know-how are also reported on. Revision of lake shorelines is an immediate benefit. Basement system metasediments are rapidly differentiated, but dune areas are not readily distinguishable from sandy soils. Forest, moorland, high altitude grass, tea, and conifer plantations are readily distinguished, with podocarpus forest especially distinguishable from podocarpus/juniperus forest. In the arid areas physiographic features, indicating the major soil types, are readily identified and mapped. Preliminary vegetation type analysis in the Mara Game Reserve indicates that in a typical savannah area about 36% of the vegetation types are distinguishable at a scale of 1:1 million as well as drainage patterns and terrain features.

  18. Spatial Distribution of Iron in Soils and Vegetation Cover Close to an Abandoned Manganese Oxide Ore Mine, Botswana

    NASA Astrophysics Data System (ADS)

    Ekosse, Georges Ivo E.

    This study aimed at establishing the spatial distribution of iron (Fe) in soils and vegetation cover within the periphery of the Kgwakgwe Manganese (Mn) oxides ore abandoned mine in Botswana. Four hundred soil samples and two hundred vegetation samples were obtained from a 4 km2 area close to the mine. Determination of Fe concentrations after acid digestion of samples was performed using an atomic absorption spectrometer equipped with a deuterium background correction. Tests for soil pH and soil colour were complementary to soil chemical analysis. Results were processed using Geographical Information Systems (GIS) and Remote Sensing (RS) techniques with integrated Land and Water Information System (ILWIS), Geosoft Oasis Montaj, ArcGIS and Microsoft Excel software packages. Concentrations of Fe in soils was from 1116.59 to 870766.00 ?g g-1 with a mean of 17593.52 ?g g-1 and for leaves, levels were from 101.2 to 3758.09 ?g g-1 with a mean of 637.07 ?g g-1. Soil pH values ranged from 2.92 to 7.26 and soil colour shades ranged from yellowish red to very dark grey. Gridded soils and vegetation maps show Fe anomalies in different parts of the study area. Values were low in areas located at the mine workings and in the Northwestern part of the study area and high in the north and southern part. Where concentrations of Fe were high in soils, correspondingly high figures were obtained for vegetation cover. Similar trends were obtained for soil pH distribution in the study area. Bedrock geology, topography, Mn mineralization, soil acidity and prevailing oxidizing conditions were governing factors that influenced the concentration and spatial distribution of Fe in the soils and vegetation. The findings further confirm that Fe distribution and its chemistry in the soils and environment around the Kgwakgwe abandoned Mn oxides ore mine have affected the vegetation cover.

  19. ACCUMULATION AND CROP UPTAKE OF SOIL MINERAL NITROGEN AS INFLUEMCED BY TILLAGE, COVER CROPS, AND NITROGEN FERTILIZATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil and crop management practices may influence soil mineral N, crop N uptake, and N leaching. We evaluated the effects of three tillage practices [no-till (NT), strip till (ST), and chisel till (CT)], four cover crops {legume [hairy vetch (Vicia villosa Roth)], nonlegume [rye (Secaele cereale L.)]...

  20. Cover crops tillage and glyphosate effects on chemical and biological properties of a Lower Mississippi Delta soil and soybean yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The adoption of sustainable cropping systems, including cover crops and no-tillage practices can promote soil conservation and improve soil quality. However, the selection of the best management practices to increase crop production is needed. A field study was conducted from 2001 to 2005 at Stone...

  1. Cover crops and sampling date effect on on-farm soil carbon pools under conservation tillage cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cover crops may influence soil C sequestration and microbial activities by providing additional residue C to soil. We examined the influence of legume (crimson clover), nonlegume (rye), blend (a mixture of legumes containing balansa clover, hairy vetch, and crimson clover], and rye + blend mixture c...

  2. Microbial community structure and abundance in the rhizosphere and bulk soil of a tomato cropping system that includes cover crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this report we use Terminal Restriction Fragment Length Polymorphisms (TRFLP) in a tomato production system to “finger printing” the soil microbial community structure with Phylum specific primer sets. Factors influencing the soil microbes are a cover crop of Hairy Vetch (Vicia villosa) or Rye (...

  3. Cover Crops, Tillage, and Glyphosate Effects on Chemical and Biological Properties of a Lower Mississippi Delta Soil and Soybean Yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The adoption of sustainable cropping systems, including cover crops and no-tillage practices can promote soil conservation and improve soil quality. However, the selection of the best management practices to increase crop production is needed. A field study was conducted from 2001 to 2005 at Stone...

  4. Technogenic contaminations of the soil-plant cover in the Primorsky Krai, Russia

    NASA Astrophysics Data System (ADS)

    Molchanova, Inna; Pozolotina, Vera; Mikhailovskaya, Ludmila; Antonova, Elena; Zhuravlev, Yury; Timofeeva, Yana; Burdukovsky, Maxim

    2013-04-01

    All economical development of the countries carries out monitoring as with the aim to estimate impact of the industrial enterprises and nuclear-energetic complexes as consequences of the nuclear accidents. The investigation the region of the Far East due to proximity to epicentre of accident on Fukushima-1 NPP is of a great interest. The aim of this work are radioecological investigations and estimate technogenic load on the ecosystems of tightly populated plots of the shore zone of the Vladivostok region. Eight plots were located on the investigated territory. The tree fall, forest litters and soils were sampling from the profile cuts of layer by layer, up to 20 cm. The artificial radionuclides (Sr-90 and Cs-134,137), as heavy metals and microelements (Co, Cu, Zn, Pb and Mn) content in the prepared samples was determined. The stock of Sr-90 fluctuates from 0.3 to 1.3 kBq/m2 and Cs-137 was from 0.4 to 3.0 kBq/m2 in the examined soils. On the whole, the level of the radionuclides content in the soil cover is within the limits of the background that was formed in the belt between 50° and 60° of northern latitude. The presence in investigated samples of Cs-134 indicates to contribution of accidental fallout of Fukushima-1 into contamination of the components of the natural ecosystems. In a year's time after the accident the stock of this isotope in the soils was 0.01-0.20 kBq/m^2. It is by factor of 10-100 lower than the stock of Cs-137. Taking into account that the ratio Cs-134/Cs-137 on the moment of accident was equal to unity (1:1). It can be estimated the quantity of Cs-137 entering into environment during post - accident period. This quantity was an average 0.03-0.30 kBq/m2 (with correction on radionuclides decay). The observation for the state of the soil cover includes the estimate of the level and peculiarities of distribution in the soils of heavy metals and microelements. Their content in the soils is formed from Clarke number and additional industrial gas-aerosol fallout. The analysis of a large volume data permitted to calculate the maximal level of the elements content in a soil under influence only natural factors. It was established, that maximal content of Co, Zn, Mn in these soils exceed of their Clarke's numbers. Minimal elements content was found for a tree fall. As a rule, this content is by factor of 10-100 lower than the Clarke values. Maximal concentration is in the soil layer. At the same time the additional technogenic fall-out produces the double increasing of the content of Cu and Pb in the soil layer. For the rest elements the concentrations increased on 8-32%. Acknowledgements. This work was supported by the grant for integrative research between the Ural and Far Eastern Branches of the Russian Academy of Sciences (12-C-4-1001).

  5. Use of LANDSAT images of vegetation cover to estimate effective hydraulic properties of soils

    NASA Technical Reports Server (NTRS)

    Eagleson, Peter S.; Jasinski, Michael F.

    1988-01-01

    This work focuses on the characterization of natural, spatially variable, semivegetated landscapes using a linear, stochastic, canopy-soil reflectance model. A first application of the model was the investigation of the effects of subpixel and regional variability of scenes on the shape and structure of red-infrared scattergrams. Additionally, the model was used to investigate the inverse problem, the estimation of subpixel vegetation cover, given only the scattergrams of simulated satellite scale multispectral scenes. The major aspects of that work, including recent field investigations, are summarized.

  6. LANDFILL OPERATION FOR CARBON SEQUESTRATION AND MAXIMUM METHANE EMISSION CONTROL

    SciTech Connect

    Don Augenstein

    1999-01-11

    ''Conventional'' waste landfills emit methane, a potent greenhouse gas, in quantities such that landfill methane is a major factor in global climate change. Controlled landfilling is a novel approach to manage landfills for rapid completion of total gas generation, maximizing gas capture and minimizing emissions of methane to the atmosphere. With controlled landfilling, methane generation is accelerated and brought to much earlier completion by improving conditions for biological processes (principally moisture levels) in the landfill. Gas recovery efficiency approaches 100% through use of surface membrane cover over porous gas recovery layers operated at slight vacuum. A field demonstration project's results at the Yolo County Central Landfill near Davis, California are, to date, highly encouraging. Two major controlled landfilling benefits would be the reduction of landfill methane emissions to minuscule levels, and the recovery of greater amounts of landfill methane energy in much shorter times than with conventional landfill practice. With the large amount of US landfill methane generated, and greenhouse potency of methane, better landfill methane control can play a substantial role in reduction of US greenhouse gas emissions.

  7. Carbon supply and storage in tilled and non-tilled soils as influenced by cover crops and nitrogen fertilization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The influence of four cover crops (hairy vetch, rye, biculture of vetch and rye, and winter weeds)and three N fertilization rates (0, 60 to 65, and 120 to 130 kg N ha-1) was examined on plant C input from cover crops, cotton, and sorghum and soi organic C (SOC) in tilled and non-tilled soils in cent...

  8. Bowen ratio measurements above various vegetation covers and its comparison with actual evapotranspiration estimated by SoilClim model

    NASA Astrophysics Data System (ADS)

    Hlavinka, P.; Trnka, M.; Fischer, M.; Kucera, J.; Mozny, M.; Zalud, Z.

    2010-09-01

    The principle of Bowen ratio is one of the available techniques for measurements of actual evapotranspiration (ETa) as one of essential water balance fractions. The main aims of submitted study were: (i) to compare the water balance of selected crops, (ii) to compare outputs of SoilClim model with observed parameters (including ETa on Bowen ratio basis). The measurements were conducted at two experimental stations in the Czech Republic (Polkovice 49°23´ (N), 17°17´ (E), 205 m a.s.l.; Domanínek 49°32´ (N), 16°15´ (E), 544 m a.s.l.) during the years 2009 and 2010. Together with Bowen ratio the global solar radiation, radiation balance, soil heat flux, volumetric soil moisture and temperature within selected depths, precipitation and wind speed were measured. The measurements were conducted simultaneously above various covers within the same soil conditions: spring barley vs. winter wheat, spring barley vs. winter rape; grass vs. poplars; harvested field after tillage vs. harvested field after cereals without any tillage. The observed parameters from different covers were compared with SoilClim estimates. SoilClim model is modular software for water balance and soil temperature modelling and finally could be used for soil Hydric and Thermic regimes (according to USDA classification) identification. The core of SoilClim is based on modified FAO Penman-Monteith methodology. Submitted study proved the applicability of SoilClim model for ETa, soil moisture within two defined layers and soil temperature (in 0.5 m depth) estimates for various crops, covers, selected soil types and climatic conditions. Acknowledgement: We gratefully acknowledge the support of the Grant Agency of the Czech Republic (no. 521/09/P479) and the project NAZV QI91C054. The study was also supported by Research plan No. MSM6215648905 "Biological and technological aspects of sustainability of controlled ecosystems and their adaptability to climate change".

  9. Subsurface characterization of groundwater contaminated by landfill leachate using microbial community profile

    E-print Network

    Vermont, University of

    from groundwater monitoring wells located within and around an aquifer contaminated with landfillSubsurface characterization of groundwater contaminated by landfill leachate using microbial 15 June 2011. [1] Microbial biodiversity in groundwater and soil presents a unique opportunity

  10. Feasibility of using LANDSAT images of vegetation cover to estimate effective hydraulic properties of soils

    NASA Technical Reports Server (NTRS)

    Eagleson, P. S.

    1985-01-01

    Research activities conducted from February 1, 1985 to July 31, 1985 and preliminary conclusions regarding research objectives are summarized. The objective is to determine the feasibility of using LANDSAT data to estimate effective hydraulic properties of soils. The general approach is to apply the climatic-climax hypothesis (Ealgeson, 1982) to natural water-limited vegetation systems using canopy cover estimated from LANDSAT data. Natural water-limited systems typically consist of inhomogeneous vegetation canopies interspersed with bare soils. The ground resolution associated with one pixel from LANDSAT MSS (or TM) data is generally greater than the scale of the plant canopy or canopy clusters. Thus a method for resolving percent canopy cover at a subpixel level must be established before the Eagleson hypothesis can be tested. Two formulations are proposed which extend existing methods of analyzing mixed pixels to naturally vegetated landscapes. The first method involves use of the normalized vegetation index. The second approach is a physical model based on radiative transfer principles. Both methods are to be analyzed for their feasibility on selected sites.

  11. Elimination of sulphur odours at landfills by bioconversion and the corona discharge plasma technique.

    PubMed

    Xia, Fangfang; Liu, Xin; Kang, Ying; He, Ruo; Wu, Zucheng

    2015-12-01

    Hydrogen sulphide (H2S) contributes a lot to odours at landfills, which is a threat to the environment and the health of the staff therein. To mitigate its emission, the bioconversion within landfill cover soils (LCSs) was introduced. H2S emission and concentration both in the field air above the landfill and in microcosm testing were surveyed. Results indicated that H2S emission and concentration in the landfill varied with landfill seasons and sites. There existed relationship between H2S concentration and fluxes spatially and temporally. To characterize and assess the spatial and temporal diversity of sulphur-oxidizing bacteria (SOB) and sulphate-reducing bacteria (SRB) in the LCSs, the terminal-restriction fragment length polymorphism technique was employed. Using the functional genes of dsrB and soxB, SOB, including Halothiobacillus, Rhodothalassium, Paracocccus, Allochromatium, and Thiobacillus, and SRB, including Desulfovibrio, Syntrophobacter, Desulfomonile and Desulfobacca, were identical and exhibited the dominant role in the LCSs. By employing an alternative available corona reactor, more than 90% removal efficiencies of sulphides were demonstrated, suggesting that the LCSs for eliminating odours in a lower concentration would be feasible. PMID:25244028

  12. Assessing methane oxidation under landfill covers and its contribution to the above atmospheric CO{sub 2} levels: The added value of the isotope ({delta}{sup 13}C and {delta}{sup 18}O CO{sub 2}; {delta}{sup 13}C and {delta}D CH{sub 4}) approach

    SciTech Connect

    Widory, D.; Proust, E.; Bellenfant, G.; Bour, O.

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer Comparison of the isotope and mass balance approaches to evaluate the level of methane oxidation within a landfill. Black-Right-Pointing-Pointer The level of methane oxidation is not homogenous under the landfill cover and is strongly correlated to the methane flux. Black-Right-Pointing-Pointer Isotope tracking of the contribution of the methane oxidation to the CO{sub 2} concentrations in the ambient air. - Abstract: We are presenting here a multi-isotope approach ({delta}{sup 13}C and {delta}{sup 18}O of CO{sub 2}; {delta}{sup 13}C and {delta}D of CH{sub 4}) to assess (i) the level(s) of methane oxidation during waste biodegradation and its migration through a landfill cover in Sonzay (France), and (ii) its contribution to the atmospheric CO{sub 2} levels above the surface. The isotope approach is compared to the more conventional mass balance approach. Results from the two techniques are comparable and show that the CH{sub 4} oxidation under the landfill cover is heterogenous, with low oxidation percentages in samples showing high biogas fluxes, which was expected in clay covers presenting fissures, through which CH{sub 4} is rapidly transported. At shallow depth, more immobile biogas pockets show a higher level of CH{sub 4} oxidation by the methanotrophic bacteria. {delta}{sup 13}C of CO{sub 2} samples taken at different heights (from below the cover up to 8 m above the ground level) were also used to identify and assess the relative contributions of its main sources both under the landfill cover and in the surrounding atmosphere.

  13. Migration of inorganic ions from the leachate of the Rio das Ostras landfill: a comparison of three different configurations of protective barriers.

    PubMed

    Lacerda, Cláudia Virgínia; Ritter, Elisabeth; Pires, João Antônio da Costa; de Castro, José Adilson

    2014-11-01

    Batch tests and diffusion tests were performed to analyze the efficiency of a protective barrier in a landfill consisting of compacted soil with 10% bentonite compared to the results obtained for only compacted soil and for compacted soil covered with a 1-mm-thick HDPE geomembrane; the soil and leachate were collected from the Rio das Ostras Landfill in Rio de Janeiro, Brazil. The diffusion tests were performed for periods of 3, 10 and 60 days. After the test period, the soil pore water was analyzed and the profiles for chloride, potassium and ammonium were determined along a 6-cm soil depth. The results of the batch tests performed to define sorption parameters were used to adjust the profiles obtained in the diffusion cell experiment by applying an ion transfer model between the interstitial solution and the soil particles. The MPHMTP model (Multi Phase Heat and Mass Transfer Program), which is based upon the solution of the transport equations of the ionic contaminants, was used to solve the inverse problem of simultaneously determining the effective diffusion coefficients. The results of the experimental tests and of the model simulation confirmed that the compacted soil with 10% bentonite was moderately efficient in the retention of chloride, potassium and ammonium ions compared to the configurations of compacted soil with a geomembrane and compacted soil alone, representing a solution that is technically feasible and requires potentially lower costs for implementation in landfills. PMID:25042116

  14. Fate and Transport of Pharmaceutical Compounds Applied to Turf-Covered Soil

    NASA Astrophysics Data System (ADS)

    Young, M.; Green, R. L.; Devitt, D.; McCullough, M.; Wright, L.; Vanderford, B. J.; Snyder, S. A.

    2012-12-01

    In arid and semi-arid regions, the use of treated wastewater for landscape irrigation is becoming common practice and a significant asset to conserve potable water supplies. Public interest and lack of field-scale data are leading to a concern that compounds found in reuse water could persist in the environment and contaminate groundwater. As part of a larger study, 2-yr experiments were conducted in CA and NV, where reuse water was the primary source of non-ambient water input. A total of 13 compounds were studied, all originating in irrigation water applied to soil covered in turf or left bare. The target compounds included atenolol, atorvastatin, carbamazepine, diazepam, diclofenac, fluoxetine, gemfibrozil, ibuprofen, meprobamate, naproxen, primidone, sulfamethoxazole, triclosan, and trimethoprim. Analytical protocols for all compounds (detection at ng/L range) were established before the study commenced. The goals of the research were to increase available data on the fate and transport of these target compounds in turfgrass/soil systems, and to use these data to assess long-term risk from using water containing these compounds. Experiments conducted at two scales are discussed here: lysimeter-scale and field-scale. At the lysimeter-scale, 24 drainage lysimeters (120 cm thick) were exposed to treated wastewater as an irrigation source. Lysimeters varied by soil type (two types), soil cover (bare- versus turf-covered) and leaching fraction (5% and 25%). Upper and lower boundary conditions were monitored throughout the study. Water samples were collected periodically after water breakthrough. After the study, soil samples were analyzed for compound mass, allowing compound mass balance and removal to be assessed. At the field-scale, passive drain gages (Decagon Devices) were installed in triplicate in fairways at four operational golf courses, one in NV and three in CA, all with histories of using treated wastewater. The gages measure water fluxes through the 60-cm thick column and store water for subsequent sampling and analysis. Irrigation water was sampled and analyzed for input mass. Using output mass, removal efficiencies could also be assessed. Results of the lysimeter study showed that mass fluxes were reduced to less than 1 g/ha/yr for all compounds (sulfamethoxazole was highest at 0.25 g/ha/yr). Solute breakthrough was concentrated during fall and winter periods when turf was overseeded and sites received winter precipitation. Results of the golf course study were similar, showing scalability. We report more than 100 instances of target compounds detected in water that percolated through the turf and upper 60 cm of soil, but with total mass fluxes of <0.1 g/ha throughout the study. Sulfamethoxazole, meprobamate, and carbamazepine were most commonly found in drainage water, but gemfibrozil, diclofenac, naproxen, and triclosan were also found in more than one sample. The results allowed for a preliminary risk assessment to be conducted. Based on our results, restricting the use of recycled water, based solely on the presence of PPCPs should only be considered at sites where soils are extremely sandy and irrigation regimes are not based on an evapotranspiration feedback approach.

  15. Yolo County's Accelerated Anaerobic and Aerobic Composting (Full-Scale Controlled Landfill Bioreactor) Project

    NASA Astrophysics Data System (ADS)

    Yazdani, R.; Kieffer, J.; Akau, H.; Augenstein, D.

    2002-12-01

    Sanitary landfilling is the dominant method of solid waste disposal in the United States, accounting for about 217 million tons of waste annually (U.S. EPA, 1997) and has more than doubled since 1960. In spite of increasing rates of reuse and recycling, population and economic growth will continue to render landfilling as an important and necessary component of solid waste management. Yolo County Department of Planning and Public Works, Division of Integrated Waste Management is demonstrating a new landfill technology called Bioreactor Landfill to better manage solid waste. In a Bioreactor Landfill, controlled quantities of liquid (leachate, groundwater, gray-water, etc.) are added and recirculated to increase the moisture content of the waste and improve waste decomposition. As demonstrated in a small-scale demonstration project at the Yolo County Central Landfill in 1995, this process significantly increases the biodegradation rate of waste and thus decreases the waste stabilization and composting time (5 to 10 years) relative to what would occur within a conventional landfill (30 to 50 years or more). When waste decomposes anaerobically (in absence of oxygen), it produces landfill gas (biogas). Biogas is primarily a mixture of methane, a potent greenhouse gas, carbon dioxide, and small amounts of Volatile Organic Compounds (VOC's) which can be recovered for electricity or other uses. Other benefits of a bioreactor landfill composting operation include increased landfill waste settlement which increases in landfill capacity and life, improved leachate chemistry, possible reduction of landfill post-closure management time, opportunity to explore decomposed waste for landfill mining, and abatement of greenhouse gases through highly efficient methane capture over a much shorter period of time than is typical of waste management through conventional landfilling. This project also investigates the aerobic decomposition of waste of 13,000 tons of waste (2.5 acre) for elimination of methane production and acceleration of waste decomposition. In the first phase of this project a 12-acre module that contains a 9.5-acre anaerobic cell and a 2.5-acre aerobic cell has been constructed and filled with over 220,000 tons of municipal solid waste. Water and leachate addition began in April 2002 and to date less than 200,000 gallons of liquid has been added to the 3.5-acre anaerobic cell. The waste filling phase of the aerobic cell was completed in June of 2002 and a 12-inches soil cover and 12-inches of greenwaste compost cover was placed on top of the cell. A vacuum will be applied to the piping within the waste to draw air through the landfill. Instrumentations have been installed to monitor the following parameters: waste temperature, moisture, leachate volumes, leachate hydraulic head over the primary liner, leachate composition, gas volumes and composition. A supervisory Control and Data Acquisition (SCADA) system has been installed to monitor and control the operation of the bioreactor cells. Waste samples were taken from each cell for laboratory testing in early June 2002.

  16. Ground penetrating radar characterization of a landfill

    NASA Astrophysics Data System (ADS)

    Yochim, April Theresa

    Ground penetrating radar was investigated in an active landfill to determine if the in-situ water content could be measured. Water content is an important parameter in predicting the generation of landfill gas (LFG), an important renewable energy source. Unfortunately, predicting the quantity of LFG is difficult due to the heterogeneities present in a landfill and the lack of in-situ input parameters. GPR is a non-invasive, near-surface geophysical technique that provides high resolution images of dielectric properties in the earth's subsurface. A transmitter emits high frequency (10 - 1000 MHz) electromagnetic pulses through the subsurface, with the receiver recording the echo. Specialized software is then used to create images of the subsurface. The challenge with using GPR in landfills is the heterogeneity of the subsurface and the clay cap linear covering landfills, both affecting the transmission of the electromagnetic pulses. The use of GPR in a landfill was evaluated at the Region of Waterloo's Waste Management Centre. Measurements were completed using both the surface and the borehole approach. The results indicated that a borehole GPR can be used, with successful measurement of water content a function of borehole separation distance and frequency of the electromagnetic pulses. The developed approach was confirmed at the City of Hamilton's Glanbrook Landfill. The successful comparison of in-situ water content values to laboratory determined values at both landfills shows that GPR can be used to measure in-situ water content.

  17. The Effect of Leaf Litter Cover on Surface Runoff and Soil Erosion in Northern China

    PubMed Central

    Li, Xiang; Niu, Jianzhi; Xie, Baoyuan

    2014-01-01

    The role of leaf litter in hydrological processes and soil erosion of forest ecosystems is poorly understood. A field experiment was conducted under simulated rainfall in runoff plots with a slope of 10%. Two common types of litter in North China (from Quercus variabilis, representing broadleaf litter, and Pinus tabulaeformis, representing needle leaf litter), four amounts of litter, and five rainfall intensities were tested. Results revealed that the litter reduced runoff and delayed the beginning of runoff, but significantly reduced soil loss (p<0.05). Average runoff yield was 29.5% and 31.3% less than bare-soil plot, and for Q. variabilis and P. tabulaeformis, respectively, and average sediment yield was 85.1% and 79.9% lower. Rainfall intensity significantly affected runoff (R?=?0.99, p<0.05), and the efficiency in runoff reduction by litter decreased considerably. Runoff yield and the runoff coefficient increased dramatically by 72.9 and 5.4 times, respectively. The period of time before runoff appeared decreased approximately 96.7% when rainfall intensity increased from 5.7 to 75.6 mm h?1. Broadleaf and needle leaf litter showed similarly relevant effects on runoff and soil erosion control, since no significant differences (p?0.05) were observed in runoff and sediment variables between two litter-covered plots. In contrast, litter mass was probably not a main factor in determining runoff and sediment because a significant correlation was found only with sediment in Q. variabilis litter plot. Finally, runoff yield was significantly correlated (p<0.05) with sediment yield. These results suggest that the protective role of leaf litter in runoff and erosion processes was crucial, and both rainfall intensity and litter characteristics had an impact on these processes. PMID:25232858

  18. The Future Through the Past: The Use of Analog Sites for Design Criteria and Long Term Performance Assessment of Evapotranspiration Landfill Covers

    SciTech Connect

    Shafer, D. S.; Miller, J. J.; Young, M. H.; Edwards, S. C.; Rawlinson, S. E.

    2002-02-26

    There is growing support for using evapotranspiration (ET) covers for closure of low-level waste (LLW) and other types of waste disposal sites, particularly in the lower latitude arid regions of the western United States. At the Nevada Test Site (NTS), monolayer ET covers are the baseline technology for closure of LLW and mixed LLW cells. To better predict the long-term performance of monolayer ET covers, as well as to identify design criteria that will potentially improve their performance, the properties of, and processes occurring on, analog sites for ET covers on the NTS are being studied. The project is funded through the Subsurface Contaminants Focus Area of the U.S. Department of Energy. Four analog sites on the NTS have been selected to predict performance of ET covers over a 1,000-year compliance period. Two sites are relatively recently disturbed (within the last 50 years) and have been selected to evaluate processes and changes on ET covers for the early period after active cover maintenance is discontinued. Two other sites, late to mid-Holocene in age, are intended as analogs for the end of the compliance period (1,000 years or more); both surfaces are abandoned alluvial/colluvial deposits. The history of the early post-institutional control analog sites are being evaluated by an archaeologist to help determine when the sites were last disturbed or modified, and the mode of disturbance to help set baseline conditions. Similar to other ''landforms,'' ET covers will evolve over time because of pedogenic, biotic, and climatic processes. Properties of analog sites that could affect ET water balance performance will be evaluated to help understand ET cover performance over time.

  19. Soil respiration and photosynthetic uptake of carbon dioxide by ground-cover plants in four ages of jack pine forest

    USGS Publications Warehouse

    Striegl, R.G.; Wickland, K.P.

    2001-01-01

    Soil carbon dioxide (CO2) emission (soil respiration), net CO2 exchange after photosynthetic uptake by ground-cover plants, and soil CO2 concentration versus depth below land surface were measured at four ages of jack pine (Pinus banksiana Lamb.) forest in central Saskatchewan. Soil respiration was smallest at a clear-cut site, largest in an 8-year-old stand, and decreased with stand age in 20-year-old and mature (60-75 years old) stands during May-September 1994 (12.1, 34.6, 31.5, and 24.9 mol C??m-2, respectively). Simulations of soil respiration at each stand based on continuously recorded soil temperature were within one standard deviation of measured flux for 48 of 52 measurement periods, but were 10%-30% less than linear interpolations of measured flux for the season. This was probably due to decreased soil respiration at night modeled by the temperature-flux relationships, but not documented by daytime chamber measurements. CO2 uptake by ground-cover plants ranged from 0 at the clear-cut site to 29, 25, and 9% of total growing season soil respiration at the 8-year, 20-year, and mature stands. CO2 concentrations were as great as 7150 ppmv in the upper 1 m of unsaturated zone and were proportional to measured soil respiration.

  20. An experimental investigation to characterise soil macroporosity under different land use and land covers of northeast India

    NASA Astrophysics Data System (ADS)

    Shougrakpam, Sangeeta; Sarkar, Rupak; Dutta, Subashisa

    2010-10-01

    Saturated macropore flow is the dominant hydrological process in tropical and subtropical hilly watersheds of northeast India. The process of infiltration into saturated macroporous soils is primarily controlled by size, network, density, connectivity, saturation of surrounding soil matrix, and depthwise distribution of macropores. To understand the effects of local land use, land cover and management practices on soil macroporosity, colour dye infiltration experiments were conducted with ten soil columns (25 × 25 × 50 cm) collected from different watersheds of the region under similar soil and agro-climatic zones. The sampling sites included two undisturbed forested hillslopes, two conventionally cultivated paddy fields, two forest lands abandoned after Jhum cultivation, and two paddy fields, one pineapple plot and one banana plot presently under active cultivation stage of the Jhum cycle. Digital image analyses of the obtained dye patterns showed that the infiltration patterns differed significantly for different sites with varying land use, land cover, and cultivation practices. Undisturbed forest soils showed high degree of soil macroporosity throughout the soil profile, paddy fields revealed sealing of macropores at the topsoil due to hard pan formation, and Jhum cultivated plots showed disconnected subsoil macropores. The important parameters related to soil macropores such as maximum and average size of macropores, number of active macropores, and depthwise distribution of macropores were estimated to characterise the soil macroporosity for the sites. These experimentally derived quantitative data of soil macroporosity can have wide range of applications in the region such as water quality monitoring and groundwater pollution assessment due to preferential leaching of solutes and pesticides, study of soil structural properties and infiltration behaviour of soils, investigation of flash floods in rivers, and hydrological modelling of the watersheds.

  1. The future through the past: The use of analog sites for design criteria and long-term performance assessment of evapotranspiration landfill covers.

    SciTech Connect

    David Shafer; Julianne Miller; Susan Edwards; Stuart Rawlinson

    2001-10-18

    There is growing support for using evapotranspiration (ET) covers for closure of low-level waste (LLW) and other types of waste disposal sites, particularly in the lower latitude arid regions of the western United States. For the Nevada Test Site (NTS), monolayer ET covers is the baseline technology for closure of LLW and mixed LLW cells. To better predict the long-term performance of monolayer ET covers, as well as to identify design criteria that will potentially improve their performance, the properties of, and processes occurring on, analog sites for ET covers on the NTS are being studied. Four analog sites on the NTS have been selected to predict performance of ET covers over a 1,000-year compliance period. Two are relatively recently disturbed sites (within the last 50 years) and have been selected for the evaluation of processes and changes on ET covers for the early period of post-institutional controls when cover maintenance would be discontinued. Two other sites, late to mid-Holocene in age, are intended as analogs for the end (1,000 years or more) of the compliance period. The late to mid-Holocene surfaces are both abandoned alluvial/colluvial deposits, dated by thermoluminescence analysis. The history of the early post-institutional control analog sites is being evaluated by an archaeologist to help determine when the sites were last disturbed or modified and the mode of disturbance, to help set baseline conditions. Similar to the other ''landforms,'' ET covers will evolve over time because of pedogenic, biotic, and climatic processes. Properties of analog sites that could affect ET water-balance performance will be evaluated to help understand ET cover performance over time. Results of analog site work and resultant modifications to design, monitoring and maintenance of ET covers on the NTS will be compared with results of a similar study being done at Sandia National Laboratories (SNL), where ET cover closures are planned as well. The comparison will help to distinguish potential regional differences needed in ET cover design. Although both sites are at similar latitudes, the NTS is located in a transition zone between the Mojave and southern Great Basin deserts, while SNL is located in the northern Chihuahuan desert. Differences in vegetation and seasonality of precipitation between the sites are significant.

  2. The influence of vegetation covers on soil moisture dynamics at high temporal resolution in scattered tree woodlands of Mediterranean climate

    NASA Astrophysics Data System (ADS)

    Lozano-Parra, Javier; Schnabel, Susanne; Ceballos-Barbancho, Antonio

    2015-04-01

    Soil water is a key factor that controls the organization and functioning of dryland ecosystems. However, in spite of its great importance in ecohydrological processes, most of the studies focus on daily or longer timescales, while its dynamics at shorter timescales are very little known. The main objective of this work was to determine the role of vegetation covers (grassland and tree canopy) in the soil hydrological response using measurements with high temporal resolution in evergreen oak woodland with Mediterranean climate. For this, soil water content was monitored continuously with a temporal resolution of 30 minutes and by means of capacitance sensors, mainly for the hydrological years 2010-2011 and 2011-2012. They were installed at 5, 10 and 15 cm, and 5 cm above the bedrock and depending on soil profile. This distribution along the soil profile is justified because soils are generally very shallow and most of the roots are concentrated in the upper layer. The sensors were gathered in 8 soil moisture stations in two contrasting situations characterized by different vegetation covers: under tree canopy and in open spaces or grasslands. Soil moisture variations were calculated at rainfall event scale at top soil layer and deepest depth by the difference between the final and initial soil moisture registered by a sensor at the finish and the beginning of the rainfall event, respectively. Besides, as soil moisture changes are strongly influenced by antecedent conditions, different antecedent soil moisture conditions or states, from driest to wettest, were also defined. The works were carried out in 3 experimental farms of the Spanish region of Extremadura. Results obtained revealed that rainwater amount bypassing vegetation covers and reaching the soil may temporarily be modified by covers according to precipitation properties and antecedent environmental conditions (from dry to wet) before the rain episode. Rainfall amounts triggering a positive soil hydrological response decreased as initial states became drier, being more accentuated below tree canopies. The frequency of the antecedent states seem to be as important or even more than duration or precipitation amount. The role of vegetation was more decisive under drier environmental conditions, where events lower than 6 mm and 2 mm never caused soil hydrological response either below tree canopy or grassland, respectively. This is important because initial conditions were independent of seasonality and because more than half of all rainfall events registered amounts smaller than 5 mm. If changes on temperature regime or precipitation patterns turn out in drier conditions, dry spells as well as the evaporative demand could increase, causing an increase of interception capacity of vegetation and consequently affecting ecological processes.

  3. Holocene climate evolution, human occupation, soil erosion and vegetation cover change in southeast Spain

    NASA Astrophysics Data System (ADS)

    Bellin, Nicolas; Vanacker, Veerle

    2010-05-01

    The Mediterranean region is commonly reported as the European region that is most affected by soil degradation. The degradation of Mediterranean soils has often been linked to inappropriate agricultural practices during the last decades besides its typical semiarid conditions. The present-day landscape in Southeast Spain is the result of a long occupation history. To have a better understanding of the impact of human societies on soil degradation, the main shifts in vegetation cover, climate and human occupation have to be taken into account. Recently published paleo-environmental data from continental pollen sequences, high-resolution marine cores, and estimations of the past Sea Surface Temperature (SST) of the Alborán Sea provide new insights in the evolution of the Mediterranean climate and vegetation during the Holocene. These data allow overcoming some of the shortcomings of previous studies on the interaction between humans and the landscape that were mainly based on extrapolations of site-specific information from continental deposits and archeological sites and large-scale regional correlations. Our compilation of multi-continental proxies from the Iberic Peninsula indicates that environmental conditions are strongly related to climatic oscillations and strongly correlated with the North Atlantic changes. By use of a vertical approach, several aridification episodes were detected from marine and continental records at 12000-11600 (H), 11100-10800 (G), 10300-9900 (F), 8600-8000 (E), 5500-4600 (D), 4000-3400 (C), 2700-2400 (B), 1800-1300 (A) cal. years BP. The data suggest that those severe aridification phases were most likely climatically induced, not human-driven and well correlated with the Bond events. We observe a clear association between climate, vegetation cover and sediment fluxes for the period from 12000 to 4600 cal. years BP. In contrast, during the last 4600 years, the reconstruction of various eco-historical periods indicated a weak to low association between sediment fluxes and climatic shifts. Periods of improved climatic conditions were associated with both low (end of Post Argaric-Omeya-Nazarene) and high (Chalcolithic-Roman-Early Phoenician I) erosion rates. Various prosperous civilizations (such as Agarics, Phoenicians and Romans) defined by a demographic explosion and associated with an overexploitation of natural resources, are accompanied with higher sediment fluxes. At the moment, we cannot exclude the possibility that the weak association observed between sediment fluxes and human-climatic factors for the last 4600 years is an artifact resulting from the low temporal resolution of soil erosion data from local sites compared to the high-resolution climatic data. It is clear that high-resolution data on sediment fluxes are required to test these hypotheses further.

  4. Evapotranspiration (ET) covers.

    PubMed

    Rock, Steve; Myers, Bill; Fiedler, Linda

    2012-01-01

    Evapotranspiration (ET) cover systems are increasingly being used at municipal solid waste (MSW) landfills, hazardous waste landfills, at industrial monofills, and at mine sites. Conventional cover systems use materials with low hydraulic permeability (barrier layers) to minimize the downward migration of water from the surface to the waste (percolation), ET cover systems use water balance components to minimize percolation. These cover systems rely on soil to capture and store precipitation until it is either transpired through vegetation or evaporated from the soil surface. Compared to conventional membrane or compacted clay cover systems, ET cover systems are expected to cost less to construct. They are often aesthetic because they employ naturalized vegetation, require less maintenance once the vegetative system is established, including eliminating mowing, and may require fewer repairs than a barrier system. All cover systems should consider the goals of the cover in terms of protectiveness, including the pathways of risk from contained material, the lifecycle of the containment system. The containment system needs to be protective of direct contact of people and animals with the waste, prevent surface and groundwater water pollution, and minimize release of airborne contaminants. While most containment strategies have been based on the dry tomb strategy of keeping waste dry, there are some sites where adding or allowing moisture to help decompose organic waste is the current plan. ET covers may work well in places where complete exclusion of precipitation is not needed. The U.S. EPA Alternative Cover Assessment Program (ACAP), USDOE, the Nuclear Regulatory Commission, and others have researched ET cover design and efficacy, including the history of their use, general considerations in their design, performance, monitoring, cost, current status, limitations on their use, and project specific examples. An on-line database has been developed with information about specific projects using ET covers. There are three general approaches for non-conventional cover systems to achieve approval for installation; the first is when equivalent performance to conventional final cover systems can be demonstrated directly on site. This is the approach used by the Sandia study, by most ACAP sites, and the Rocky Mountain Arsenal. A second approach is used when there are data from a site specific study such as an ACAP installation at a site that has analogous soil and climate conditions. Several sites in Colorado and Southern California have achieved approval based on data from similar sites. The third most common approach for regulatory approval is by installation of data collection systems with the agreement that the permanence of the ET cover installation is contingent on success of the cover in meeting certain performance goals. This article is intended as an introduction to the topic and is not intended to serve as guidance for design or construction, nor indicate the appropriateness of using an ET cover systems at a particular site. PMID:22574378

  5. Comment on "Evaluation of evapotranspirative covers for waste containment in arid and semiarid regions in the southwestern USA"

    SciTech Connect

    Gee, Glendon W.; Benson, C H.; Albright, William H.

    2006-05-26

    Landfill covers relying on a balance between soil water storage and evapotranspiration (ET) as the primary means to control drainage have been described in the recent paper by Scanlon et al. (2005) in the Vadose Zone Journal. These so-called "ET Covers" have been receiving considerable interest in the past few years as economically viable cover systems for landfills in arid and semi-arid environments (Hauser et al. 2001, Madalinksi et al. 2003) Scanlon et al. (2005) have provided a summary of their studies in Texas and New Mexico, demonstrating an acceptable performance of ET covers in minimizing drainage under their test conditions. Further, they illustrate with both measurement and modeling that capillary barriers (fine soils over coarse soils) similar in concept to those previously built and tested at Los Alamos, NM and Hanford, WA over the past 20 years, store more water than surface barriers that have uniform profiles.

  6. Effects of continuous cover forestry on soil moisture pattern - Beginning steps of a Hungarian study

    NASA Astrophysics Data System (ADS)

    Kalicz, Péter; Bartha, Dénes; Brolly, Gábor; Csáfordi, Péter; Csiszár, Ágnes; Eredics, Attila; Gribovszki, Zoltán; Király, Géza; Kollár, Tamás; Korda, Márton; Kucsara, Mihály; Nótári, Krisztina; Kornél Szegedi, Balázs; Tiborcz, Viktor; Zagyvai, Gergely; Zagyvai-Kiss, Katalin Anita

    2014-05-01

    Nowadays Hungarian foresters encounter a new challenge. The traditional management practices do not meet anymore with the demand of the civil society. The good old clearcut is no more a supported technology in forest regeneration. The transition to the continuous cover forestry induces much higher spatial variability compared to the even aged, more or less homogeneous, monoculture stands. The gap cutting is one of the proposed key methods in the Hungarian forestry. There is an active discussion among forest professionals how to determine the optimal gap size to maintain ideal conditions for the seedlings. Among other open questions for example how the surrounding trees modify the moisture pattern of the forest floor in the gap? In the early steps of a multidisciplinary project we established four research plots to study the spatial and temporal variability of soil moisture in the forest gap and the surrounding undisturbed stand. Each plot is located in oak (Quercus spp.) stands. Natural regeneration of oak stands is more problematic in our climate compared to the beech (Fagus sylvatica) which is located in the more humid or semi-humid areas of our country. All plots are located in the western part of Hungary: close to Sopron, Bejcgyertyános, Vép and Vajszló settlements. The last plot is an extensive research area, which is located in the riparian zone of a tributary of Feketevíz River. We monitor here the close-to-surface groundwater level fluctuation with pressure transducers. With a diurnal fluctuation based method it is possible to quantify the evapotranspiration differences between the gap and the stand. In two of the remaining stands (Bejcgyertyános and Vép) the gaps were opened in 2010. The monitoring of soil moisture began in 2013. A mobile sensor is used to monitor soil-moisture in a regular grid. The spatial variability of soil-moisture time-series shows a characteristic pattern during the growing-season. The plot in Sopron was established in 2013. Gaps with three different sizes were opened and fenced round to close out wild game. The initial status of the gap was recorded by a terrestrial laser scanner (LIDAR). From the resulting 3D point cloud high-resolution digital terrain and canopy surface model are derived which will help the planned numerical modelling. To prevent the unnecessary disturbance in this plot, two perpendicular transects were selected in each gap. The soil-moisture is monitored along these lines together with additional investigations, for example throughfall, and litter interception, tension disc infiltrometry, plant composition and cover. The microclimatic parameters such as near surface air temperature, relative humidity, radiation, wind speed and soil temperature is continuously recorded along the transects and compared to a nearby reference meteorological station located at an open area. Acknowledgment: The research was financially supported by the TÁMOP-4.2.2.A-11/1/KONV-2012-0004 joint EU-national research project

  7. AgRISTARS: Early warning and crop condition assessment. Plant cover, soil temperature, freeze, water stress, and evapotranspiration conditions

    NASA Technical Reports Server (NTRS)

    Wiegand, C. L. (principal investigator); Nixon, P. R.; Gausman, H. W.; Namken, L. N.; Leamer, R. W.; Richardson, A. J.

    1981-01-01

    Emissive (10.5 to 12.5 microns) and reflective (0.55 to 1.1 microns) data for ten day scenes and infrared data for six night scenes of southern Texas were analyzed for plant cover, soil temperature, freeze, water stress, and evapotranspiration. Heat capacity mapping mission radiometric temperatures were: within 2 C of dewpoint temperatures, significantly correlated with variables important in evapotranspiration, and related to freeze severity and planting depth soil temperatures.

  8. doi:10.1016/j.gca.2004.08.024 Zinc mobility and speciation in soil covered by contaminated dredged sediment

    E-print Network

    was used to quantify the proportion of each Zn species in the soil. In the uncontaminated soil, Zndoi:10.1016/j.gca.2004.08.024 Zinc mobility and speciation in soil covered by contaminated dredged in a pseudogley soil (pH 8.2­8.3) before and after contamination by land-disposition of a dredged sediment ([Zn

  9. Strip-tilled cover cropping for managing nematodes, soil mesoarthropods, and weeds in a bitter melon agroecosystem.

    PubMed

    Marahatta, Sharadchandra P; Wang, Koon-Hui; Sipes, Brent S; Hooks, Cerruti R R

    2010-06-01

    A field trial was conducted to examine whether strip-tilled cover cropping followed by living mulch practice could suppress root-knot nematode (Meloidogyne incognita) and enhance beneficial nematodes and other soil mesofauna, while suppressing weeds throughout two vegetable cropping seasons. Sunn hemp (SH), Crotalaria juncea, and French marigold (MG), Tagetes patula, were grown for three months, strip-tilled, and bitter melon (Momordica charantia) seedlings were transplanted into the tilled strips; the experiment was conducted twice (Season I and II). Strip-tilled cover cropping with SH prolonged M. incognita suppression in Season I but not in Season II where suppression was counteracted with enhanced crop growth. Sunn hemp also consistently enhanced bacterivorous and fungivorous nematode population densities prior to cash crop planting, prolonged enhancement of the Enrichment Index towards the end of both cash crop cycles, and increased numbers of soil mesoarthropods. Strip-tilled cover cropping of SH followed by clipping of the living mulch as surface mulch also reduced broadleaf weed populations up to 3 to 4 weeks after cash crop planting. However, SH failed to reduce soil disturbance as indicated by the Structure Index. Marigold suppressed M. incognita efficiently when planted immediately following a M. incognita-susceptible crop, but did not enhance beneficial soil mesofauna including free-living nematodes and soil mesoarthropods. Strip-tilled cover cropping of MG reduced broadleaf weed populations prior to cash crop planting in Season II, but this weed suppression did not last beyond the initial cash crop cycle. PMID:22736847

  10. Strip-tilled Cover Cropping for Managing Nematodes, Soil Mesoarthropods, and Weeds in a Bitter Melon Agroecosystem

    PubMed Central

    Wang, Koon-Hui; Sipes, Brent S.; Hooks, Cerruti R.R.

    2010-01-01

    A field trial was conducted to examine whether strip-tilled cover cropping followed by living mulch practice could suppress root-knot nematode (Meloidogyne incognita) and enhance beneficial nematodes and other soil mesofauna, while suppressing weeds throughout two vegetable cropping seasons. Sunn hemp (SH), Crotalaria juncea, and French marigold (MG), Tagetes patula, were grown for three months, strip-tilled, and bitter melon (Momordica charantia) seedlings were transplanted into the tilled strips; the experiment was conducted twice (Season I and II). Strip-tilled cover cropping with SH prolonged M. incognita suppression in Season I but not in Season II where suppression was counteracted with enhanced crop growth. Sunn hemp also consistently enhanced bacterivorous and fungivorous nematode population densities prior to cash crop planting, prolonged enhancement of the Enrichment Index towards the end of both cash crop cycles, and increased numbers of soil mesoarthropods. Strip-tilled cover cropping of SH followed by clipping of the living mulch as surface mulch also reduced broadleaf weed populations up to 3 to 4 weeks after cash crop planting. However, SH failed to reduce soil disturbance as indicated by the Structure Index. Marigold suppressed M. incognita efficiently when planted immediately following a M. incognita-susceptible crop, but did not enhance beneficial soil mesofauna including free-living nematodes and soil mesoarthropods. Strip-tilled cover cropping of MG reduced broadleaf weed populations prior to cash crop planting in Season II, but this weed suppression did not last beyond the initial cash crop cycle. PMID:22736847

  11. Reducing Open Cell Landfill Methane Emissions with a Bioactive Alternative Daily

    SciTech Connect

    Helene Hilger; James Oliver; Jean Bogner; David Jones

    2009-03-31

    Methane and carbon dioxide are formed in landfills as wastes degrade. Molecule-for-molecule, methane is about 20 times more potent than carbon dioxide at trapping heat in the earth's atmosphere, and thus, it is the methane emissions from landfills that are scrutinized. For example, if emissions composed of 60% methane and 40% carbon dioxide were changed to a mix that was 40% methane and 60% carbon dioxide, a 30% reduction in the landfill's global warming potential would result. A 10% methane, 90% carbon dioxide ratio will result in a 75% reduction in global warming potential compared to the baseline. Gas collection from a closed landfill can reduce emissions, and it is sometimes combined with a biocover, an engineered system where methane oxidizing bacteria living in a medium such as compost, convert landfill methane to carbon dioxide and water. Although methane oxidizing bacteria merely convert one greenhouse gas (methane) to another (carbon dioxide), this conversion can offer significant reductions in the overall greenhouse gas contribution, or global warming potential, associated with the landfill. What has not been addressed to date is the fact that methane can also escape from a landfill when the active cell is being filled with waste. Federal regulations require that newly deposited solid waste to be covered daily with a 6 in layer of soil or an alternative daily cover (ADC), such as a canvas tarp. The aim of this study was to assess the feasibility of immobilizing methane oxidizing bacteria into a tarp-like matrix that could be used for alternative daily cover at open landfill cells to prevent methane emissions. A unique method of isolating methanotrophs from landfill cover soil was used to create a liquid culture of mixed methanotrophs. A variety of prospective immobilization techniques were used to affix the bacteria in a tarp-like matrix. Both gel encapsulation of methanotrophs and gels with liquid cores containing methanotrophs were readily made but prone to rapid desiccation. Bacterial adsorption onto foam padding, natural sponge, and geotextile was successful. The most important factor for success appeared to be water holding capacity. Prototype biotarps made with geotextiles plus adsorbed methane oxidizing bacteria were tested for their responses to temperature, intermittent starvation, and washing (to simulate rainfall). The prototypes were mesophilic, and methane oxidation activity remained strong after one cycle of starvation but then declined with repeated cycles. Many of the cells detached with vigorous washing, but at least 30% appeared resistant to sloughing. While laboratory landfill simulations showed that four-layer composite biotarps made with two different types of geotextile could remove up to 50% of influent methane introduced at a flux rate of 22 g m{sup -2} d{sup -1}, field experiments did not yield high activity levels. Tests revealed that there were high hour-to-hour flux variations in the field, which, together with frequent rainfall events, confounded the field testing. Overall, the findings suggest that a methanotroph embedded biotarp appears to be a feasible strategy to mitigate methane emission from landfill cells, although the performance of field-tested biotarps was not robust here. Tarps will likely be best suited for spring and summer use, although the methane oxidizer population may be able to shift and adapt to lower temperatures. The starvation cycling of the tarp may require the capacity for intermittent reinoculation of the cells, although it is also possible that a subpopulation will adapt to the cycling and become dominant. Rainfall is not expected to be a major factor, because a baseline biofilm will be present to repopulate the tarp. If strong performance can be achieved and documented, the biotarp concept could be extended to include interception of other compounds beyond methane, such as volatile aromatic hydrocarbons and chlorinated solvents.

  12. Structure and condition of soil-vegetation cover in the Klyazma river basin applying remote sensing data

    NASA Astrophysics Data System (ADS)

    Mishchenko, Natalia; Trifonova, Tatiana; Repkin, Roman

    2015-04-01

    Constant observation of vegetation and soil cover is one of the key issues of river basins ecologic monitoring. It is necessary to consider that observation objects have been continuously changing and these changes are comprehensive and depend on temporal and dimensional parameters. Remote sensing data, embracing vast areas and reflecting various interrelations, allow excluding accidental and short-term changes though concentrating on the transformation of the observed river basin ecosystem environmental condition. The research objective is to assess spatial-temporal peculiarities of soil-vegetation structure formation in the Klyazma basin as a whole and minor river basins within the area. Research objects are located in the centre of European Russia. Data used in our research include both statistic and published data, characterizing soil-vegetation cover of the area, space images Landsat. Research methods: Remote data analysis for assessing land utilization structure and soil-vegetation condition according to NDVI. Laying soil-geobotanic landscape profiles river valleys slopes. Phytomass reserve, phytoproductivity, soil fertility characteristics assessment. NDVI computation for each image pixel helped to map general condition of the Klyazma vegetation cover and to determine geographic ranges without vegetation or with depressed vegetation. For instance high vegetation index geographic range has been defined which corresponded to Vladimir Opolye characterized with the most fertile grey forest soil in the region. Comparative assessment of soil vegetation cover of minor river basins within the Klyazma basin, judging by the terrestrial data, revealed its better condition in the Koloksha basin which is also located in the area of grey forest soil. Besides here the maximum value of vegetation index for all phytocenosis was detected. In the research the most dynamically changing parts of the Klyazma basin have been determined according to NDVI dynamics analysis. Analyzing the reasons for such changes of NDVI the most significant ecologic processes in the region connected to the changes of vegetation cover condition have been revealed. Fields overgrowing and agricultural crops replacement are the most important of them. Soil-geobotanic profiles, laid in minor river basin of the Sudogda, allowed to reveal various vegetation association and to describe the confined soil profile. It is shown that well drained landscape forms correspond to arboreal vegetation type, more humidified elements of the landscape are occupied with gramineous meadow vegetation. There is sand and clay sand under mixed forest humus horizon. In pinewood forests light loam prevails in surface horizons. The results can be used for environmental monitoring of the river basins and for rational agricultural structuring.

  13. Assessing methane oxidation under landfill covers and its contribution to the above atmospheric CO2 levels: The added value of the isotope

    E-print Network

    biogas fluxes, which was expected in clay covers presenting fissures, through which CH4 is rapidly transported. At shallow depth, more immobile biogas pockets show a higher level of CH4 oxidation., 1998). The main com- ponents of biogas are CH4 (50­60%) and carbon dioxide (CO2; 40­50%). A major

  14. Final construction quality assurance report for the Y-12 Industrial Landfill V, Area 2, Oak Ridge, Tennessee

    SciTech Connect

    Bessom, W.H.

    1996-11-01

    Lockheed Martin Energy Systems (LMES) has finished construction of Area 2 of the Y-12 Plant Industrial Landfill (ILF-V), classified as a Class 2 Landfill. This final Construction Quality Assurance (CQA) Report provides documentation that Area 2 was constructed in substantial compliance with the Tennessee Department of Environment and Conservation (TDEC) approved design, as indicated and specified in the permit drawings, approved changes, and specifications. This report applies specifically to the Area 2 excavation, compacted clay soil liner, geomembrane liner, granular leachate collection layer, protective soil cover, and the leachate collection system. An ``As-Built`` survey was performed and is included. The drawings provide horizontal and vertical information for Area 2, the anchor trench, the leachate collection pipe, the temporary access road, and cross-sections of Area 2. This report provides documentation of the following items: the excavation activities of Area 2; the maximum recompacted coefficient of hydraulic conductivity or permeability of the soil is less than 1 {times} 10{sup {minus}7} centimeters per second (cm/sec); the total thickness of the compacted clay soil liner equals a minimum of 2 feet; a 40 mil impermeable geomembrane (polypropylene) flexible membrane liner (FML) and 16 oz. geotextile fabric was placed in direct contact with the compacted clay soil liner; a 12 inch granular leachate collection layer was installed and covered with a 8 oz. geotextile separation fabric; the installation of the leachate collection piping; and the two foot protective clay soil cover.

  15. [Recovery of three tropical forest covers from mid-elevation sites in Costa Rica: oligochaetes, litter and soil analysis].

    PubMed

    Pérez-Molina, Junior Pastor; Cordero Solórzano, Roberto A

    2012-12-01

    In Costa Rica, the region of Rio Macho is a highly fragmented landscape with imminent risk of landslides. This area, which provides important environmental services, has been partially recovered to its original forest through intentional reforestation with exotic species or natural regeneration after abandonment. The aim of this study was to evaluate the bioindicator potential of oligochaete presence as well as some litter and soil characteristics. The ecosystem recovery of the two common restoration modes was measured within three different forest covers. For this, some substrate characteristics were analyzed and compared in a-50 years old secondary forest, a 13 years tacotal, and a 35 years cypress (Cupressus lusitanica) plantation. The three sites studied differed in density, biomass and average mass of oligochaetes, and in some litter (depth, nitrogen, phosphorus and C/N ratio of litter), and soil variables (soil water content (CA), pH, phosphorus, cation exchange capacity, and magnesium). The forest registered the lowest density of earthworms and soil pH, and the highest soil CA and phosphorus. CA was inversely related to the oligochaete density across sites. Besides, there were positive correlations between C/N and C/P ratios from the litter and soil pH, and inverse correlations of litter depth, litter N and P concentrations with soil P. Discriminant Analysis (AD) performed with all soil and litter variables, produced a sharp classification of the three forest cover types. AD suggests that site differences were mostly determined by soil CA and litter nitrogen concentration. Considering all the evaluated parameters, our results suggest in the first place, that oligochaetes are sensitive to changes in some soil and litter characteristics. Secondly, aside from the striking oligochaete differences between the old secondary forest and the other two sites, some soil and litter traits resulted good indicators of the present recovery of the three forest covers. In addition, comparing soil nutrients content (organic carbon, nitrogen, calcium, potassium and sulfur) among the three sites, our findings indicate that the cypress plantation had reached soil nutrient conditions similar to the old secondary forest, presumably by the accumulation of nutrients, as a result of low nutrient recirculation. In conclusion, ecosystem level studies throughout simple evaluation criteria (soils, oligochaetes and ground litter) can be used as rapid indicators of the state of some of the many and complex forest ecosystem compartments. PMID:23342500

  16. On the current state of the Hydrologic Evaluation of Landfill Performance (HELP) model.

    PubMed

    Berger, Klaus U

    2015-04-01

    The Hydrologic Evaluation of Landfill Performance (HELP) model is the most widely applied model to calculate the water balance of cover and bottom liner systems for landfills. The paper summarizes the 30 year history of the model from HELP version 1 to HELP 3.95 D and includes references to the three current and simultaneously available versions (HELP 3.07, Visual HELP 2.2, and HELP 3.95 D). A sufficient validation is an essential precondition for the use of any model in planning. The paper summarizes validation approaches for HELP 3 focused on cover systems in the literature. Furthermore, measurement results are compared to simulation results of HELP 3.95 D for (1) a test field with a compacted clay liner in the final cover of the landfill Hamburg-Georgswerder from 1988 to 1995 and (2) a test field with a 2.3m thick so-called water balance layer on the landfill Deetz near Berlin from 2004 to 2011. On the Georgswerder site actual evapotranspiration was well reproduced by HELP on the yearly average as well as in the seasonal course if precipitation data with 10% systematic measurement errors were used. However, the increase of liner leakage due to the deterioration of the clayey soil liner was not considered by the model. On the landfill Deetz HELP overestimated largely the percolation through the water balance layer resulting from an extremely wet summer due to an underestimation of the water storage in the layer and presumably also due to an underestimation of the actual evapotranspiration. Finally based on validation results and requests from the practice, plans for improving the model to a future version HELP 4 D are described. PMID:25690410

  17. Assessment of soil-gas, seep, and soil contamination at the North Range Road Landfill, Fort Gordon, Georgia, 2008-2009

    USGS Publications Warehouse

    Landmeyer, James E.; Falls, William F.; Ratliff, W. Hagan; Wellborn, John B.

    2011-01-01

    Inorganic concentrations in all four soil samples did not exceed regional screening levels established by the U.S. Environmental Protection Agency. Barium concentrations, however, were two to three times higher than the background concentrations reported in similar Coastal Plain sediments of South Carolina.

  18. LANDFILL GAS MEASUREMENT METHODS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methane from landfills contributes to greenhouse gas emissions. The development of cost-effective methods for measuring diffuse emissions from landfills remains a difficult issue for regulators and landfill operators. Currently, two major options are available: (1) above-ground methods which quantif...

  19. Post-Closure Inspection Report for Corrective Action Unit 424: Area 3 Landfill Complex, Tonopah Test Range, Nevada, Calendar Year 2000

    SciTech Connect

    K. B. Campbell

    2001-06-01

    Corrective Action Unit (CAU) 424, the Area 3 Landfill Complex at Tonopah Test Range, consists of eight landfill sites, Corrective Action Sites (CASS), seven of which are landfill cells that were closed previously by capping. (The eighth CAS, A3-7, was not used as a landfill site and was closed without taking any corrective action.) Figure 1 shows the locations of the landfill cells. CAU 424 closure activities included removing small volumes of soil containing petroleum hydrocarbons, repairing cell covers that were cracked or had subsided, and installing above-grade and at-grade monuments marking the comers of the landfill cells. Post-closure monitoring requirements for CAU 424 are detailed in Section 5.0, Post-Closure Inspection Plan contained, in the Closure Report for Corrective Action Unit 424: Area 3 Landfill Complex, Tonopah Test Range. Nevada, report number DOE/NV--283. The Closure Report (CR) was approved by the Nevada Division of Environmental Protection (NDEP) in July 1999. The CR includes compaction and permeability results of soils that cap the seven landfill cells. Post-closure monitoring consists of the following: (1) Site inspections done twice a year to evaluate the condition of the unit; (2) Verification that the site is secure; (3) Notice of any subsidence or deficiencies that may compromise the integrity of the unit; (4) Remedy of any deficiencies within 90 days of discovery; and (5) Preparation and submittal of an annual report. Site inspections were conducted on June 20, 2000, and November 20, 2000. The inspections were preformed after the NDEP approval of the CR. This report includes copies of the inspection checklist and photographs, and recommendations and conclusions. The Post-Closure Inspection Checklists are found in Attachment A, a copy of the field notes is found in Attachment B, and copies of the inspection photographs are found in Attachment C.

  20. Landuse/Land Cover and Soil Type Co-variation in a Heterogeneous Landscape for Soil Moisture Studies Using Point Data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This research investigates the spatial co-variation of soil and Landuse/land cover (LULC) at the Little River watershed to assess landscape heterogeneity and the spatial extent to which point data from the USDA hydrological network near Tifton, Georgia can be used for regional representations of env...

  1. EFFECTS OF COVER CROPPING AND PLASTICULTURE ON SOIL AND RHIZOSPHERE MICROBIAL COMMUNITY STRUCTURE IN TOMATO PRODUCTION SYSTEMS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In a previous study (Carrera et al., submitted for publication) we found that soil microbial community structure was distinctly different under plasticulture than under hairy vetch cover crops in tomato production systems. In order to determine the major factors affecting microbial communities we se...

  2. EFFECTS OF COVER CROPPING AND PLASTICULTURE ON SOIL AND RHIZOSPHERE MICROBIAL COMMUNITY STRUCTURE IN TOMATO PRODUCTION SYSTEMS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In a previous study (Carrera et al., submitted for publication) we found that soil microbial community structure was distinctly different under black polyethylene film than under hairy vetch cover crops in tomato production systems. In order to determine the major factors affecting microbial communi...

  3. Evaluation of Cover Crops with Potential for Use in Anaerobic Soil Disinfestation (ASD) for Susceptibility to Three Species of Meloidogyne

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several cover crops with potential for use in tropical and subtropical regions were assessed for susceptibility to three common species of root-knot nematode, Meloidogyne arenaria, M. incognita, and M. javanica. Crops were selected based on potential use as organic amendments in anaerobic soil disin...

  4. Effects of seagulls on ecosystem respiration, soil nitrogen and vegetation cover on a pristine volcanic island, Surtsey, Iceland

    NASA Astrophysics Data System (ADS)

    Sigurdsson, B. D.; Magnusson, B.

    2010-03-01

    When Surtsey rose from the North Atlantic Ocean south of Iceland in 1963, it became a unique natural laboratory on how organisms colonize volcanic islands and form ecosystems with contrasting structures and functions. In July, 2004, ecosystem respiration rate (Re), soil properties and surface cover of vascular plants were measured in 21 permanent research plots distributed among the juvenile communities of the island. The plots were divided into two main groups, inside and outside a seagull (Larus spp.) colony established on the island. Vegetation cover of the plots was strongly related to the density of gull nests. Occurrence of nests and increased vegetation cover also coincided with significant increases in Re, soil carbon, nitrogen and C:N ratio, and with significant reductions in soil pH and soil temperatures. Temperature sensitivity (Q10 value) of Re was determined as 5.3. When compared at constant temperature the Re was found to be 59 times higher within the seagull colony, similar to the highest fluxes measured in drained wetlands or agricultural fields in Iceland. The amount of soil nitrogen, mainly brought onto the island by the seagulls, was the critical factor that most influenced ecosystem fluxes and vegetation development on Surtsey. The present study shows how ecosystem activity can be enhanced by colonization of animals that transfer resources from a nearby ecosystem.

  5. Bioreactor Landfill Research and Demonstration Project Northern Oaks Landfill, Harrison, MI

    SciTech Connect

    Zhao, Xiando; Voice, Thomas; and Hashsham, Syed A.

    2006-08-29

    A bioreactor landfill cell with 1.2-acre footprint was constructed, filled, operated, and monitored at Northern Oaks Recycling and Disposal Facility (NORDF) at Harrison, MI. With a filled volume of 74,239 cubic yards, the cell contained approximately 35,317 tons of municipal solid waste (MSW) and 20,777 tons of cover soil. It was laid on the slope of an existing cell but separated by a geosynthetic membrane liner. After the cell reached a design height of 60 feet, it was covered with a geosynthetic membrane cap. A three-dimensional monitoring system to collect data at 48 different locations was designed and installed during the construction phase of the bioreactor cell. Each location had a cluster of monitoring devices consisting of a probe to monitor moisture and temperature, a leachate collection basin, and a gas sampling port. An increase in moisture content of the MSW in the bioreactor cell was achieved by pumping leachate collected on-site from various other cells, as well as recirculation of leachate from the bioreactor landfill cell itself. Three types of leachate injection systems were evaluated in this bioreactor cell for their efficacy to distribute pumped leachate uniformly: a leachate injection pipe buried in a 6-ft wide horizontal stone mound, a 15-ft wide geocomposite drainage layer, and a 60-ft wide geocomposite drainage layer. All leachate injection systems were installed on top of the compacted waste surface. The distribution of water and resulting MSW moisture content throughout the bioreactor cell was found to be similar for the three designs. Water coming into and leaving the cell (leachate pumped in, precipitation, snow, evaporation, and collected leachate) was monitored in order to carry out a water balance. Using a leachate injection rate of 26 – 30 gal/yard3, the average moisture content increased from 25% to 35% (wet based) over the period of this study. One of the key aspects of this bioreactor landfill study was to evaluate bioreactor start up and performance in locations with colder climate. For lifts filled during the summer months, methane generation started within three months after completion of the lift. For lifts filled in winter months, very little methane production occurred even eight months after filling. The temperature data indicated that subzero or slightly above zero (oC) temperatures persisted for unusually long periods (more than six months) in the lifts filled during winter months. This was likely due to the high thermal insulation capability of the MSW and the low level of biological activity during start up. This observation indicates that bioreactor landfills located in cold climate and filled during winter months may require mechanisms to increase temperature and initiate biodegradation. Thus, besides moisture, temperature may be the next important factor controlling the biological decomposition in anaerobic bioreactor landfills. Spatial and temporal characterization of leachate samples indicated the presence of low levels of commonly used volatile organic compounds (including acetone, methyl ethyl ketone, methyl isobutyl ketone, and toluene) and metals (including arsenic, chromium, and zinc). Changes and leachate and gaseous sample characteristics correlated with enhanced biological activity and increase in temperature. Continued monitoring of this bioreactor landfill cell is expected to yield critical data needed for start up, design, and operation of this emerging process.

  6. Methane mass balance at three landfill sites: What is the efficiency of capture by gas collection systems?

    SciTech Connect

    Spokas, K. . E-mail: spokas@morris.ars.usda.gov; Bogner, J.; Chanton, J.P.; Morcet, M.; Aran, C.; Graff, C.; Golvan, Y. Moreau-Le; Hebe, I.

    2006-07-01

    Many developed countries have targeted landfill methane recovery among greenhouse gas mitigation strategies, since methane is the second most important greenhouse gas after carbon dioxide. Major questions remain with respect to actual methane production rates in field settings and the relative mass of methane that is recovered, emitted, oxidized by methanotrophic bacteria, laterally migrated, or temporarily stored within the landfill volume. This paper presents the results of extensive field campaigns at three landfill sites to elucidate the total methane balance and provide field measurements to quantify these pathways. We assessed the overall methane mass balance in field cells with a variety of designs, cover materials, and gas management strategies. Sites included different cell configurations, including temporary clay cover, final clay cover, geosynthetic clay liners, and geomembrane composite covers, and cells with and without gas collection systems. Methane emission rates ranged from -2.2 to >10,000 mg CH{sub 4} m{sup -2} d{sup -1}. Total methane oxidation rates ranged from 4% to 50% of the methane flux through the cover at sites with positive emissions. Oxidation of atmospheric methane was occurring in vegetated soils above a geomembrane. The results of these studies were used as the basis for guidelines by the French environment agency (ADEME) for default values for percent recovery: 35% for an operating cell with an active landfill gas (LFG) recovery system, 65% for a temporary covered cell with an active LFG recovery system, 85% for a cell with clay final cover and active LFG recovery, and 90% for a cell with a geomembrane final cover and active LFG recovery.

  7. Strong dependence of CO2 emissions from anthropogenic land cover change on initial land cover and soil carbon parametrization

    NASA Astrophysics Data System (ADS)

    Goll, Daniel S.; Brovkin, Victor; Liski, Jari; Raddatz, Thomas; Thum, Tea; Todd-Brown, Kathe E. O.

    2015-09-01

    The quantification of sources and sinks of carbon from land use and land cover changes (LULCC) is uncertain. We investigated how the parametrization of LULCC and of organic matter decomposition, as well as initial land cover, affects the historical and future carbon fluxes in an Earth System Model (ESM). Using the land component of the Max Planck Institute ESM, we found that the historical (1750-2010) LULCC flux varied up to 25% depending on the fraction of biomass which enters the atmosphere directly due to burning or is used in short-lived products. The uncertainty in the decadal LULCC fluxes of the recent past due to the parametrization of decomposition and direct emissions was 0.6 Pg C yr-1, which is 3 times larger than the uncertainty previously attributed to model and method in general. Preindustrial natural land cover had a larger effect on decadal LULCC fluxes than the aforementioned parameter sensitivity (1.0 Pg C yr-1). Regional differences between reconstructed and dynamically computed land covers, in particular, at low latitudes, led to differences in historical LULCC emissions of 84-114 Pg C, globally. This effect is larger than the effects of forest regrowth, shifting cultivation, or climate feedbacks and comparable to the effect of differences among studies in the terminology of LULCC. In general, we find that the practice of calibrating the net land carbon balance to provide realistic boundary conditions for the climate component of an ESM hampers the applicability of the land component outside its primary field of application.

  8. Effect of soil spectral properties on remote sensing of crop residue cover

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conservation tillage practices have been shown to improve soil structure, enhance soil organic carbon content (SOC), and reduce soil erosion. Conservation tillage practices include reduced- and no-till methods, which often leave appreciable amounts of crop residues over the soil surfaces after harv...

  9. Influence of conservation tillage and cover crops on soil moisture and cotton leaf temperature

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil compaction can reduce cotton yields by restricting root development necessary for nutrient and water uptake. This condition can be partially avoided by maintaining or improving soil organic matter content. Many soils in central Alabama have hard pans within the top 12 inches of soil, intensifie...

  10. Morphometry and land cover based multi-criteria analysis for assessing the soil erosion susceptibility of the western Himalayan watershed.

    PubMed

    Altaf, Sadaff; Meraj, Gowhar; Romshoo, Shakil Ahmad

    2014-12-01

    Complex mountainous environments such as Himalayas are highly susceptibility to natural hazards particular those that are triggered by the action of water such as floods, soil erosion, mass movements and siltation of the hydro-electric power dams. Among all the natural hazards, soil erosion is the most implicit and the devastating hazard affecting the life and property of the millions of people living in these regions. Hence to review and devise strategies to reduce the adverse impacts of soil erosion is of utmost importance to the planners of watershed management programs in these regions. This paper demonstrates the use of satellite based remote sensing data coupled with the observational field data in a multi-criteria analytical (MCA) framework to estimate the soil erosion susceptibility of the sub-watersheds of the Rembiara basin falling in the western Himalaya, using geographical information system (GIS). In this paper, watershed morphometry and land cover are used as an inputs to the MCA framework to prioritize the sub-watersheds of this basin on the basis of their different susceptibilities to soil erosion. Methodology included the derivation of a set of drainage and land cover parameters that act as the indicators of erosion susceptibility. Further the output from the MCA resulted in the categorization of the sub-watersheds into low, medium, high and very high erosion susceptibility classes. A detailed prioritization map for the susceptible sub-watersheds based on the combined role of land cover and morphometry is finally presented. Besides, maps identifying the susceptible sub-watersheds based on morphometry and land cover only are also presented. The results of this study are part of the watershed management program in the study area and are directed to instigate appropriate measures to alleviate the soil erosion in the study area. PMID:25154685

  11. Large-scale assessment of soil erosion in Africa: satellites help to jointly account for dynamic rainfall and vegetation cover

    NASA Astrophysics Data System (ADS)

    Vrieling, Anton; Hoedjes, Joost C. B.; van der Velde, Marijn

    2015-04-01

    Efforts to map and monitor soil erosion need to account for the erratic nature of the soil erosion process. Soil erosion by water occurs on sloped terrain when erosive rainfall and consequent surface runoff impact soils that are not well-protected by vegetation or other soil protective measures. Both rainfall erosivity and vegetation cover are highly variable through space and time. Due to data paucity and the relative ease of spatially overlaying geographical data layers into existing models like USLE (Universal Soil Loss Equation), many studies and mapping efforts merely use average annual values for erosivity and vegetation cover as input. We first show that rainfall erosivity can be estimated from satellite precipitation data. We obtained average annual erosivity estimates from 15 yr of 3-hourly TRMM Multi-satellite Precipitation Analysis (TMPA) data (1998-2012) using intensity-erosivity relationships. Our estimates showed a positive correlation (r = 0.84) with long-term annual erosivity values of 37 stations obtained from literature. Using these TMPA erosivity retrievals, we demonstrate the large interannual variability, with maximum annual erosivity often exceeding two to three times the mean value, especially in semi-arid areas. We then calculate erosivity at a 10-daily time-step and combine this with vegetation cover development for selected locations in Africa using NDVI - normalized difference vegetation index - time series from SPOT VEGETATION. Although we do not integrate the data at this point, the joint analysis of both variables stresses the need for joint accounting for erosivity and vegetation cover for large-scale erosion assessment and monitoring.

  12. LANDFILL GAS CONSUMPTION IN RHIZOSPHERE OF ALTERNATIVE LANDFILL COVERS

    EPA Science Inventory

    The two identical 12 ft by 12 ft by 12 ft, polished stainless steel, insulated Environmental Chambers, located within the Testing and Evaluation (T&E) Facility, incorporate unique design features. Each chamber is equipped with 16 light fixtures containing a total of 32 light bulb...

  13. USE OF MUNICIPAL SOLID WASTE LANDFILLS AS BIOCHEMICAL REACTORS

    EPA Science Inventory

    Municipal solid waste (MSW) from the nation is managed predominantly in anitary landfills. ue to the physical, chemical and biological makeup f he aste he landfill acts as a biochemical reactor and degrades the organic matter. urrent practices are to use covers and liners as engi...

  14. STANDARDIZED PROCEDURES FOR PLANTING VEGETATION ON COMPLETED SANITARY LANDFILLS

    EPA Science Inventory

    A manual was developed for those charged with establishing a vegetative cover on completed landfills. Special problems associated with growing plants on these sites are discussed, and step-by-step procedures are given for converting a closed landfill to a variety of end uses requ...

  15. Vegetation cover and land use impacts on soil water repellency in an Urban Park located in Vilnius, Lithuania

    NASA Astrophysics Data System (ADS)

    Pereira, Paulo; Cerda, Artemi

    2015-04-01

    It is strongly recognized that vegetation cover, land use have important impacts on the degree of soil water repellency (SWR). Soil water repellency is a natural property of soils, but can be induced by natural and anthropogenic disturbances as fire and soil tillage (Doerr et al., 2000; Urbanek et al., 2007; Mataix-Solera et al., 2014). Urban parks are areas where soils have a strong human impact, with implications on their hydrological properties. The aim of this work is to study the impact of different vegetations cover and urban soils impact on SWR and the relation to other soil variables as pH, Electrical Conductivity (EC) and soil organic matter (SOM) in an urban park. The study area is located in Vilnius city (54°.68' N, 25°.25' E). It was collected 15 soil samples under different vegetation cover as Pine (Pinus Sylvestris), Birch (Alnus glutinosa), Penduculate Oak (Quercus robur), Platanus (Platanus orientalis) and other human disturbed areas as forest trails and soils collected from human planted grass. Soils were taken to the laboratory, air-dried at room temperature and sieved with the <2 mm mesh in order to remove the coarse material. Subsequently were placed in petri dishes and exposed to a controlled laboratory environment (temperature of 20C and 50% of air relative humidity) for one week to avoid potential impacts of the atmospheric conditions on SWR (Doerr, 1998). The persistence of SWR was measured using the water drop penetration time (WDPT) (Wessel, 1998). The classification of WDPT was according to Bisdom et al. (1993) <5 (wettable), 5-60 (slightly water repellent), 60-600 (strongly water repellent), 600-3600 (severely water repellent) and >3600 (extremely water repellent). The results showed significant differences among the different vegetation cover (Kruskal-Wallis H=20.64, p<0.001). The WDPT soil median values collected under Pine, Birch, Penduculate Oak, forest trails and soils from planted grass were significantly higher than Platanus soil. The soils from Pine, Birch, Penduculate Oak, forest trails and planted grass were majorly severely water repellent, while Platanus soils were mostly strong water repellent. Soil water repellency of Pine soils had a significant negative correlation with pH (-0.52, p<0.05) and a significant negative correlation with SOM (0.69, p<0.01) and EC (0.53, p<0.05). In relation to Birch soils, SWR had a significant negative correlation with pH (-0.88, p<0.001) and significant positive correlation with SOM (0.78, p<0.001). In relation to the other species no significant correlations were observed between SWR and pH, EC and SOM. Acknowledgments POSTFIRE (Soil quality, erosion control and plant cover recovery under different post-fire management scenarios, CGL2013-47862-C2-1-R), funded by the Spanish Ministry of Economy and Competitiveness; Fuegored; RECARE (Preventing and Remediating Degradation of Soils in Europe Through Land Care, FP7-ENV-2013-TWO STAGE), funded by the European Commission; and for the COST action ES1306 (Connecting European connectivity research). References Bisdom, E.B.A., Dekker, L., Schoute, J.F.Th. (1993) Water repellency of sieve fractions from sandy soils and relationships with organic material and soil structure. Geoderma, 56, 105-118. Doerr, S.H., Shakesby, R.A., Walsh, R.P.D. (2000) Soil water repellency: Its causes, characteristics and hydro-geomorphological significance. Earth-Science Reviews, 51, 33-65. Doerr, S.H. (1998) On standardising the "Water Drop Penetration Time" and the "Molarity of an Ethanol Droplet" techniques to classify soil hydrophobicity: a case study using medium textured soils. Earth Surface Process and Landforms, 23, 663-668. Mataix-Solera, J., Arcenegui, V., Zavala, L., Perez-Bejarano, A., Jordan, A., Morugan-Coronado, A., Barcenas-Moreno, G., Jimenez-Pinilla, P., Lozano, E., Granjed, A.J.P., Gil-Torres, J. (2014) Small variations of soil properties control fire induced water repellency, Spanish Journal of Soil Science, 4, 51-60. Urbanek., E., Hallet, P., Feeney, D

  16. Soil cover patterns and SOC dynamics impacts on the soil processes, land management and ecosystem services in Central Region of Russia

    NASA Astrophysics Data System (ADS)

    Vasenev, Ivan; Chernikov, Vladimir; Yashin, Ivan; Geraskin, Mikhail; Morev, Dmitriy

    2014-05-01

    In the Central Region of Russia (CRR) the soil cover patterns usually play the very important role in the soil forming and degradation processes (SFP & SDP) potential and current rates, soil organic carbon (SOC) dynamics and pools, greenhouse gases (GHG) emissions and soluble SOC fluxes that we need take into attention for better assessment of the natural and especially man-changed ecosystems' services and for best land-use practices development. Central Region of Russia is the biggest one in RF according to its population and role in the economy. CRR is characterized by high spatial variability of soil cover due to as original landscape heterogeneity as complicated history of land-use practices during last 700 years. Our long-term researches include the wide zonal-provincial set of representative ecosystems and soil cover patterns with different types and history of land-use (forest, meadow-steppe and agricultural ones) from middle-taiga to steppe zones with different level of continentality. The carried out more than 30-years region- and local-scale researches of representative natural and rural landscapes in Tver', Yaroslavl', Kaluga, Moscow, Vladimir, Saransk (Mordovia), Kursk, Orel, Tambov, Voronezh and Saratov oblasts give us the interregional multi-factorial matrix of elementary soil cover patterns (ESCP) with different soil forming and degradation processes rates and soil organic carbon dynamics due to regionally specific soil-geomorphologic features, environmental and dominated microclimate conditions, land-use current practices and history. The validation and ranging of the limiting factors of SFP and SDP develop¬ment, soil carbon dynamics and sequestration potential, ecosystem (agroecosystem) principal services, land functional qualities and agroecological state have been done for dominating and most dynamical components of ESCP regional-typological forms - with application of SOC structure analysis, regional and local GIS, soil spatial patterns detail mapping, traditional regression kriging, correlation tree models and DSS adapted to concrete region and agrolandscape conditions. The outcomes of statistical process modeling show the essential amplification of erosion, dehumification, CO2, CH4 and N2O emission, soluble SOC fluxes, acidification or alkalization, disaggregation and overcompaction processes due to violation of environmentally sound land-use systems and traditional balances of organic matter, nutrients, Ca and Na in agrolandscapes. Due to long-term intensive and out-of-balance land-use practices the most zonal soils and soil cover pattern essentially lost not only their unique natural features (humus horizons depth till 1 m and more in case of Chernozems, 2-6 % of SOC and favorable agrophysical features), but ecosystem services and ecological functions including terrestrial ecosystem carbon balance and the GHG fluxes control. Key-site monitoring results and regional generalized data showed 1-1.5% SOC lost during last 50 years period and active processes of CO2 emission and humus profile eluvial-illuvial redistribution too. A drop of Corg content below threshold "humus limiting content" values (for different soils they vary from 1 to 3-4% of SOC) considerably reduces effectiveness of used fertilizers and possibility of sustai¬nable agronomy here. Forest-steppe Chernozems are usually characterized by higher stability than steppe ones. The ratio between erosive and biological losses in humus supplies can be ten-tatively estimated as fifty-fifty with strong spatial variability due to slope and land-use parameters. These processes have essentially different sets of environmental consequences and ecosystem services that we need to understand in frame of environmental and agroecological problems development prediction.

  17. Cultural Resources Review for Closure of the nonradioactive Dangerous Waste Landfill and Solid Waste Landfill in the 600 Area, Hanford Site, Benton County, Washington, HCRC# 2010-600-018R

    SciTech Connect

    Gutzeit, Jennifer L.; Kennedy, Ellen P.; Bjornstad, Bruce N.; Sackschewsky, Michael R.; Sharpe, James J.; DeMaris, Ranae; Venno, M.; Christensen, James R.

    2011-02-02

    The U.S. Department of Energy Richland Operations Office is proposing to close the Nonradioactive Dangerous Waste Landfill (NRDWL) and Solid Waste Landfill (SWL) located in the 600 Area of the Hanford Site. The closure of the NRDWL/SWL entails the construction of an evapotranspiration cover over the landfill. This cover would consist of a 3-foot (1-meter) engineered layer of fine-grained soil, modified with 15 percent by weight pea gravel to form an erosion-resistant topsoil that will sustain native vegetation. The area targeted for silt-loam borrow soil sits in Area C, located in the northern central portion of the Fitzner/Eberhardt Arid Lands Ecology (ALE) Reserve Unit. The pea gravel used for the mixture will be obtained from both off-site commercial sources and an active gravel pit (Pit #6) located just west of the 300 Area of the Hanford Site. Materials for the cover will be transported along Army Loop Road, which runs from Beloit Avenue (near the Rattlesnake Barricade) east-northeast to the NRDWL/SWL, ending at State Route 4. Upgrades to Army Loop Road are necessary to facilitate safe bidirectional hauling traffic. This report documents a cultural resources review of the proposed activity, conducted according to Section 106 of the National Historic Preservation Act of 1966.

  18. Effects of soil amendments at a heavy loading rate associated with cover crops as green manures on the leaching of nutrients and heavy metals from a calcareous soil.

    PubMed

    Wang, Qing-Ren; Li, Yun-Cong; Klassen, Waldemar

    2003-11-01

    The potential risk of groundwater contamination by the excessive leaching of N, P and heavy metals from soils amended at heavy loading rates of biosolids, coal ash, N-viro soil (1:1 mixture of coal ash and biosolids), yard waste compost and co-compost (3:7 mixture of biosolids to yard wastes), and by soil incorporation of green manures of sunn hemp (Crotalaria juncea) and sorghum sudangrass (Sorghum bicolor x S. bicolor var. sudanense) was studied by collecting and analyzing leachates from pots of Krome very gravelly loam soil subjected to these treatments. The control consisted of Krome soil without any amendment. The loading rate was 205 g pot(-1) for each amendment (equivalent to 50 t ha(-1) of the dry weight), and the amounts of the cover crops incorporated into the soil in the pot were those that had been grown in it. A subtropical vegetable crop, okra (Abelmoschus esculentus L.), was grown after the soil amendments or cover crops had been incorporated into the soil. The results showed that the concentration of NO3-N in leachate from biosolids was significantly higher than in leachate from other treatments. The levels of heavy metals found in the leachates from all amended soils were so low, as to suggest these amendments may be used without risk of leaching dangerous amounts of these toxic elements. Nevertheless the level of heavy metals in leachate from coal ash amended soil was substantially greater than in leachates from the other treatments. The leguminous cover crop, sunn hemp, returned into the soil, increased the leachate NO3-N and inorganic P concentration significantly compared with the non-legume, sorghum sudangrass. The results suggest that at heavy loading rates of soil amendments, leaching of NO3- could be a significant concern by application of biosolids. Leaching of inorganic P can be increased significantly by both co-compost and biosolids, but decreased by coal ash and N-viro soil by virtue of improved adsorption. The leguminous cover crop, sunn hemp, when incorporated into the soil, can cause the concentration of NO3-N to increase by about 7 fold, and that of inorganic P by about 23% over the non-legume. Regarding the metals, biosolids, N-viro soil and coal ash significantly increased Ca and Mg concentrations in leachates. Copper concentration in leachate was increased by application of biosolids, while Fe concentration in leachates was increased by biosolids, coal ash and co-compost. The concentrations of Zn, Mo and Co in leachate were increased by application of coal ash. The concentrations of heavy metals in leachates were very low and unlikely to be harmful, although they were increased significantly by coal ash application. PMID:14649715

  19. Geohydrology of the unsaturated zone and simulated time of arrival of landfill leachate at the water table, municipal solid waste landfill facility, US Army Air Defense Artillery Center and Fort Bliss, El Paso County, Texas

    USGS Publications Warehouse

    Frenzel, Peter F.; Abeyta, Cynthia G.

    1999-01-01

    The U.S. Air Defense Artillery Center and Fort Bliss Municipal Solid Waste Landfill Facility (MSWLF) is located about 10 miles northeast of downtown El Paso, Texas. The landfill is built on the Hueco Bolson, a deposit that yields water to five public-supply wells within 1.1 miles of the landfill boundary on all sides. The bolson deposits consist of lenses and mixtures of sand, clay, silt, gravel, and caliche. The unsaturated zone at the landfill is about 300 feet thick. The Hydrologic Evaluation of Landfill Performance (HELP) and the Multimedia Exposure Assessment Model for Evaluating the Land Disposal of Wastes (MULTIMED) computer models were used to simulate the time of first arrival of landfill leachate at the water table. Site-specific data were collected for model input. At five sites on the landfill cover, hydraulic conductivity was measured by an in situ method; in addition, laboratory values were obtained for porosity, moisture content at field capacity, and moisture content at wilting point. Twenty-seven sediment samples were collected from two adjacent boreholes drilled near the southwest corner of the landfill. Of these, 23 samples were assumed to represent the unsaturated zone beneath the landfill. The core samples were analyzed in the laboratory for various characteristics required for the HELP and MULTIMED models: initial moisture content, dry bulk density, porosity, saturated hydraulic conductivity, moisture retention percentages at various suction values, total organic carbon, and pH. Parameters were calculated for the van Genuchten and Brooks-Corey equations that relate hydraulic conductivity to saturation. A reported recharge value of 0.008 inch per year was estimated on the basis of soil- water chloride concentration. The HELP model was implemented using input values that were based mostly on site-specific data or assumed in a conservative manner. Exceptions were the default values used for waste characteristics. Flow through the landfill was assumed to be at steady state. The HELP-estimated landfill leakage rate was 101.6 millimeters per year, approximately 500 times the estimated recharge rate for the area near the landfill. The MULTIMED model was implemented using input values that were based mainly on site-specific data and some conservatively assumed values. Landfill leakage was assumed to begin when the landfill was established and to continue at a steady-state rate of 101.6 millimeters per year as estimated by the HELP model. By using an assumed solute concentration in the leachate of 1 milligram per liter and assuming no delay or decay of solute, the solute serves as a tracer to indicate the first arrival of landfill leachate. The simulated first arrival of leachate at the water table was 204 to 210 years after the establishment of the landfill.

  20. Post-Closure Inspection Report for Corrective Action Unit 424: Area 3 Landfill Complexes Tonopah Test Range, Nevada Calendar Year 2001

    SciTech Connect

    K. B. Campbell

    2002-02-01

    Corrective Action Unit (CAU) 424, the Area 3 Landfill Complexes at Tonopah Test Range, consists of eight Corrective Action Sites (CASs), seven of which are landfill cells that were closed previously by capping. (The eighth CAS, A3-7, was not used as a landfill site and was closed without taking any corrective action.) Figure 1 shows the general location of the landfill cells. Figure 2 shows in more detail the location of the eight landfill cells. CAU 424 closure activities included removing small volumes of soil containing petroleum hydrocarbons, repairing cell covers that were cracked or had subsided, and installing above-grade and at-grade monuments marking the comers of the landfill cells. Post-closure monitoring requirements for CAU 424 are detailed in Section 5.0, Post-Closure Inspection Plan, contained in the Closure Report for Corrective Action Unit 424: Area 3 Landfill Complexes, Tonopah Test Range, Nevada, report number DOE/NV--283, July 1999. The Closure Report (CR) was approved by the Nevada Division of Environmental Protection (NDEP) in July 1999. The CR includes compaction and permeability results of soils that cap the seven landfill cells. As stated in Section 5.0 of the NDEP-approved CR, post-closure monitoring at CAU 424 consists of the following: (1) Site inspections conducted twice a year to evaluate the condition of the unit. (2) Verification that landfill markers and warning signs are in-place, intact, and readable. (3) Notice of any subsidence, erosion, unauthorized use, or deficiencies that may compromise the integrity of the landfill covers. (4) Remedy of any deficiencies within 90 days of discovery. (5) Preparation and submittal of an annual report. Site inspections were conducted on May 16, 2001, and November 6, 2001. The inspections were preformed after the NDEP approval of the CR. This report includes copies of the inspection checklist, photographs, recommendations, and conclusions. The Post-Closure Inspection Checklists are found in Attachment A, a copy of the field notes is found in Attachment B, and copies of the inspection photographs are found in Attachment C.

  1. Quantifying Spatial and Temporal Variability of Methane Emissions from a Complex Area Source: Case Study of a Central Indiana Landfill

    NASA Astrophysics Data System (ADS)

    Cambaliza, M. O. L.; Bogner, J. E.; Green, R. B.; Shepson, P. B.; Thoma, E. D.; Foster-wittig, T. A.; Spokas, K.

    2014-12-01

    Atmospheric methane is a powerful greenhouse gas that is responsible for about 17% of the total direct radiative forcing from long-lived greenhouse gases (IPCC 2013). While the global emission of methane is relatively well quantified, the temporal and spatial variability of methane emissions from individual area or point sources are still poorly understood. Using 4 field methods (aircraft-based mass balance, tracer correlation, vertical radial plume mapping, and static chambers) and a new field-validated process-based model (California Landfill Methane Inventory Model, CALMIM 5.4), we investigated both the total emissions from a central Indiana landfill as well as the partitioned emissions inclusive of methanotrophic oxidation for the various cover soils. This landfill is an upwind source for the city of Indianapolis, so the resolution of m2 to km2 scale emissions, as well as understanding the temporal variability for this complex area source, contributes to improved regional inventory calculations. Emissions for the site as a whole were measured using both an aircraft-based mass balance approach as well as a ground-based tracer correlation method, permitting direct comparison of the strengths, limitations, and uncertainties of these two approaches. Because US landfills are highly-engineered and composed of daily, intermediate, and final cover areas with differing thicknesses, composition, and implementation of gas recovery, we also expected different emission signatures and strengths from the various cover areas. Thus we also deployed static chambers and vertical radial plume mapping to quantify the spatial variability of emissions from the thinner daily and intermediate cover areas. Understanding the daily, seasonal and annual emission rates from a landfill is not trivial, and usually requires a combination of measurement and modeling approaches. Thus, our unique data set provides an opportunity to gain an improved understanding of the emissions from a complex area source, an essential requirement for developing improved urban-scale greenhouse gas inventories relevant for addressing mitigation strategies. We report on the results here.

  2. Dispersal of Rhagoletis cerasi in Commercial Cherry Orchards: Efficacy of Soil Covering Nets for Cherry Fruit Fly Control

    PubMed Central

    Daniel, Claudia; Baker, Brian

    2013-01-01

    Demand for organic cherries offers producers a premium price to improve their commercial viability. Organic standards require that producers find alternatives to pesticides. Soil treatments to control the European cherry fruit fly Rhagoletis cerasi (L.) (Diptera: Tephrididae) appear to be an attractive option. However, soil treatments can only be effective if the migration of flies is low, because mature flies may migrate from near-by trees for oviposition. To examine the general potential of soil treatments and to understand the dispersal and flight behaviour of R. cerasi within orchards, experiments using netting to cover the soil were conducted in two orchards with different pest pressure during two years. The netting reduced flight activity by 77% and fruit infestation by 91%. The data showed that the flies have a dispersal of less than 5 m within orchards, which is very low. The low thresholds for tolerance for infested fruit in the fresh market creates a strong economic incentive for control, therefore, soil covering is a promising strategy for controlling R. cerasi in commercial orchards. PMID:26466801

  3. Preliminary evaluation of the SIR-B response to soil moisture, surface roughness, and crop canopy cover

    NASA Technical Reports Server (NTRS)

    Dobson, M. C.; Ulaby, F. T.

    1986-01-01

    Two predawn ascending data-takes by the Shuttle Imaging Radar-B (SIR-B) were used to evaluate the effects of surface roughness, crop canopy, and soil moisture on radar backscatter. The two images, separated by three days, were both obtained at 30-deg local angle of incidence, but with opposite azimuth viewing directions. The imagery was externally calibrated with respect to the radar backscattering coefficient sigma(0) via response to arrays of point and area-extended targets of known radar cross section. Three land-cover classes: (1) corn, (2) corn stubble and plowed bare soil, and (3) disked bare soil, soybeans, soybean stubble, alfalfa, and clover could be readily separated for either observation date on the basis of image tone alone. The dependence of sigma(0) on the surface roughness and canopy brightness inhibits the capability of SIR to globally estimate the near-surface soil moisture from the value of sigma(0) for single date observations, unless the surface roughness or canopy cover conditions are accounted for. However, within given ranges of these conditions, the sigma(0) was found to be highly correlated with the soil moisture.

  4. Dispersal of Rhagoletis cerasi in Commercial Cherry Orchards: Efficacy of Soil Covering Nets for Cherry Fruit Fly Control.

    PubMed

    Daniel, Claudia; Baker, Brian

    2013-01-01

    Demand for organic cherries offers producers a premium price to improve their commercial viability. Organic standards require that producers find alternatives to pesticides. Soil treatments to control the European cherry fruit fly Rhagoletis cerasi (L.) (Diptera: Tephrididae) appear to be an attractive option. However, soil treatments can only be effective if the migration of flies is low, because mature flies may migrate from near-by trees for oviposition. To examine the general potential of soil treatments and to understand the dispersal and flight behaviour of R. cerasi within orchards, experiments using netting to cover the soil were conducted in two orchards with different pest pressure during two years. The netting reduced flight activity by 77% and fruit infestation by 91%. The data showed that the flies have a dispersal of less than 5 m within orchards, which is very low. The low thresholds for tolerance for infested fruit in the fresh market creates a strong economic incentive for control, therefore, soil covering is a promising strategy for controlling R. cerasi in commercial orchards. PMID:26466801

  5. LEACHATE COLLECTION IN LANDFILLS: STEADY CASE

    EPA Science Inventory

    This paper analyzes the performance of landfill leachate collection systems with low-permeability soil liners under steady-state conditions. lgebraic equations and graphs are presented for predicting the average and maximum saturated depth on the liner, the location of the maximu...

  6. Estimating photosynthetic vegetation, non-photosynthetic vegetation and bare soil fractions using Landsat and MODIS data: Effects of site heterogeneity, soil properties and land cover

    NASA Astrophysics Data System (ADS)

    Guerschman, J. P.; Scarth, P.; McVicar, T.; Malthus, T. J.; Stewart, J.; Rickards, J.; Trevithick, R.; Renzullo, L. J.

    2013-12-01

    Vegetation fractional cover is a key indicator for land management monitoring, both in pastoral and agricultural settings. Maintaining adequate vegetation cover protects the soil from the effects of water and wind erosion and also ensures that carbon is returned to soil through decomposition. Monitoring vegetation fractional cover across large areas and continuously in time needs good remote sensing techniques underpinned by high quality ground data to calibrate and validate algorithms. In this study we used Landsat and MODIS reflectance data together with field measurements from 1476 observations across Australia to produce estimates of vegetation fractional cover using a linear unmixing technique. Specifically, we aimed at separating fractions of photosynthetic vegetation (PV), non-photosynthetic vegetation (NPV) and bare soil (B). We used Landsat reflectance averaged over a 3x3 pixel window representing the area actually measured on the ground and also a 'degraded' Landsat reflectance 40x40 pixel window to simulate the effect of a coarser sensor. Using these two Landsat reflectances we quantified the heterogeneity of each site. We used data from two MODIS-derived reflectance products: the Nadir BRDF-Adjusted surface Reflectance product (MCD43A4) and the MODIS 8-day surface reflectance (MOD09A1). We derived endmembers from the data and estimated fractional cover using a linear unmixing technique. Log transforms and band interaction terms were added to account for non-linearities in the spectral mixing. For each reflectance source we investigated if the residuals were correlated with site heterogeneity, soil colour, soil moisture and land cover type. As expected, the best model was obtained when Landsat data for a small region around each site was used. We obtained root mean square error (RMSE) values of 0.134, 0.175 and 0.153 for PV, NPV and B respectively. When we degraded the Landsat data to an area of ~1 km2 around each site the model performance decreased to RMSE of 0.142, 0.181 and 0.166 for PV, NPV and B. Using MODIS reflectance data (from the MCD43A4 and MOD09A1 products) we obtained similar results as when using the 'degraded' Landsat reflectance, with no significant differences between them. Model performance decreased (i.e. RMSE increased) with site heterogeneity when coarse resolution reflectance data was used. We did not find any evidence of soil colour or moisture influence on model performance. We speculate that the unmixing models may be insensitive to soil colour and/or that the soil moisture in the top few millimetres of soil, which influence reflectance in optical sensors, is decoupled from the soil moisture in the top layer (i.e. a few cm) as measured by passive microwave sensors or estimated by models. The models tended to overestimate PV in cropping areas, possibly due to a strong red/ near infrared signal in homogeneous crops which do not have a high green cover. This study sets the basis for an operational Landsat/ MODIS combined product which would benefit users with varying requirements of spatial, temporal resolution and latency and could potentially be applied to other regions in the world.

  7. Soil cover characterization at large scale: the example of Perugia Province in central Italy

    NASA Astrophysics Data System (ADS)

    Fanelli, Giulia; Salciarini, Diana; Tamagnini, Claudio

    2015-04-01

    In the last years, physically-based models aimed at predicting the occurrence of landslides have had a large diffusion because the opportunity of having landslide susceptibility maps can be essential to reduce damages and human losses. On one hand physically-based models rationally analyse problems, because mathematically describe the physical processes that actually happen, on the other hand their diffusion is limited by the difficulty of having and managing accurate data over large areas. For this reason, and also because in the Perugia province geotechnical data are partial and not regularly distributed, a data collection campaign has been started in order to have a wide physical-mechanical data set that can be used to apply any physically-based model. The collected data have been derived from mechanical tests and investigations performed to characterize the soil. The data set includes about 3000 points and each record is characterized by the following quantitative information: coordinates, geological description, cohesion, friction angle. Besides, the records contain the results of seismic tests that allow knowing the shear waves velocity in the first 30 meters of soil. The database covers the whole Perugia province territory and it can be used to evaluate the effects of both rainfall-induced and earthquake-induced landslides. The database has been analysed in order to exclude possible outliers; starting from the all data set, 16 lithological units have been isolated, each one with homogeneous geological features and the same mechanical behaviour. It is important to investigate the quality of the data and know how much they are reliable; therefore statistical analyses have been performed to quantify the dispersion of the data - i.e. relative and cumulative frequency - and also geostatistical analyses to know the spatial correlation - i.e. the variogram. The empirical variogram is a common and useful tool in geostatistics because it quantifies the spatial correlation between data. Once the variogram has been calculated, it is possible to use it to forecast the best estimation of a parameter in a generic point where information are missing. One of the most used interpolation techniques is the Kriging, which makes a prediction of a function in a given point as weighted average of known values of such function in the nearest points, deriving the weights from the variogram.

  8. Exploring warm-season cover crops as carbon sources for anaerobic soil disinfestation (ASD)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anaerobic soil disinfestation (ASD) has been shown to be an effective strategy for controlling soilborne plant pathogens and plant parasitic nematodes in vegetable production systems. Soil treatment by ASD relies on the supply of labile carbon (C) to stimulate microbially-driven anaerobic soil condi...

  9. Improved Remotely-Sensed Estimates of Crop Residue Cover by Incorporating Soils Information.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conservation tillage (CT) methods, which include reduced- and no-till methods, leave substantial quantities of crop residues on the soil surface. These crop residues act as a barrier to wind and water to reduce soil erosion and evaporation. Long-term CT also increases soil organic carbon (SOC) cont...

  10. Comparison of algorithms and parameterisations for infiltration into organic-covered permafrost soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Infiltration into frozen and unfrozen soils is critical in hydrology, controlling active layer soil water dynamics and influencing runoff. Few Land Surface Models (LSMs) and Hydrological Models (HMs) have been developed, adapted or tested for frozen conditions and permafrost soils. Considering the v...

  11. EFFECTS OF COVER CROPPING, SOLARIZATION, AND SOIL FUMIGATION ON NEMATODE COMMUNITIES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    While free-living nematodes play important roles in soil nutrient cycling, many pre-plant soil practices act as perturbations to nematode communities. A two-year field experiment was conducted to examine nematode communities in soil treated with methyl bromide (MB) fumigation, solarization (S) for 6...

  12. Soil Carbon and Nitrogen Pools as Influenced by Tillage, Cover Crop, Poultry Manure, and Nitrogen Fertilization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quantification of soil C and N cycling as influenced by management practices is needed for C and N sequestration and soil quality and productivity improvement. We evaluated the 10-yr effects of tillage, cropping system, and N source on soil C and N fractions at 0- to 20-cm depth in Decatur silt loam...

  13. COVER CROP, TILLAGE, AND HERBICIDE EFFECTS ON WEEDS, SOIL PROPERTIES, MICROBIAL POPULATIONS, AND SOYBEAN YIELD

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A field study was conducted during 1997-2001 on a Dundee silt loam soil at Stoneville, MS to examine effects of rye and crimson clover residues on weeds, soil properties, soil microbial populations, and soybean yield under conventional tillage (CT) and no-tillage (NT) systems with preemergence (PRE)...

  14. The role of vegetation covers on soil wetting processes at rainfall event scale in scattered tree woodland of Mediterranean climate

    NASA Astrophysics Data System (ADS)

    Lozano-Parra, Javier; Schnabel, Susanne; Ceballos-Barbancho, Antonio

    2015-10-01

    Soil water is recognized as the key factor that controls the organization and functioning of dryland ecosystems. However, in spite of its great importance in ecohydrological processes as well as in modelling applications, most of the studies focus on daily or longer timescales, while its dynamics at shorter timescales are very little known. The main objective of this work was to determine the role of vegetation covers (grassland and tree canopy) in the soil hydrological response using measurements with high temporal resolution in evergreen oak woodland with Mediterranean climate. For this, soil water content was measured with capacitive sensors installed in the soil profile at different depths registering continuously with a high time resolution. Three study areas were monitored for two and half hydrological years. Results obtained revealed that rainwater amounts reaching the soil may temporarily be modified by covers according to precipitation properties and antecedent conditions (from dry to wet) before the rain episode. Rainfall amounts triggering a positive soil hydrological response decreased as initial states became drier, being more accentuated below tree canopies. The frequency of re-wetting cycles and the antecedent states seem to be as important or even more than either the duration or the precipitation amount. Therefore, the role of vegetation was more decisive under drier environmental conditions, where events lower than 6 mm and 2 mm never caused soil hydrological response either below tree canopy or grassland, respectively. This is important because initial conditions were independent of seasonality and because more than half of all rainfall events registered amounts smaller than 5 mm. If changes on precipitation patterns turn out in drier conditions, the predominance of such situations could have important ecohydrological consequences in semiarid ecosystems.

  15. Hillslope-scale hydrological and snow cover dynamics derived from a wireless soil moisture and temperature monitoring network and time-lapse digital photography

    NASA Astrophysics Data System (ADS)

    Wollschläger, Ute; Vogt, Constantin; Kögler, Simon; Martini, Edoardo

    2015-04-01

    In mountainous catchments, snowmelt may be an important component of the water balance. We apply data from a wireless soil moisture and temperature monitoring network in combination with time-lapse digital photographs from a hillslope in the Schäfertal catchment, Lower Harz Mountains, to investigate interactions between hillslope-scale snow cover, soil moisture and soil temperature. The time series of digital photographs is evaluated using an automatic algorithm that estimates snow height at the position of several snow stakes placed along the hillslope using the green value of the RGB color cube. Inferred snow heights are applied to interpret near-subsurface soil moisture and soil temperature dynamics from the same time period including snow accumulation and melt. The combination of time-lapse digital photography, soil moisture and soil temperature monitoring clearly shows the strong influence of the snow cover on subsurface soil moisture and soil temperature dynamics. The shallow snow cover has a strong insulating effect on near-subsurface soil temperatures keeping the soil unfrozen even at air temperatures reaching down to less than -10 °C. The time-lapse photographs, soil moisture and soil temperature observations also show the different snowmelt behavior of the north- and south-exposed slopes. These observations are important information for future modelling of hillslope and catchment-scale hydrological dynamics.

  16. Landfill disposal systems.

    PubMed

    Slimak, K M

    1978-12-01

    The current status of landfill disposal of hazardous wastes in the United States is indicated by presenting descriptions of six operating landfills. These landfills illustrate the variety of techniques that exist in landfill disposal of hazardous wastes. Although some landfills more effectively isolate hazardous waste than others, all landfills must deal with the following problems. Leachate from hazardous waste landfills is generally highly polluted. Most landfills attempt to contain leachate at the site and prevent its discharge to surface or groundwaters. To retain leachate within a disposal area, subsurface barriers of materials such as concrete, asphalt, butyl rubber, vinyl, and clay are used. It is difficult to assure that these materials can seal a landfill indefinitely. When a subsurface barrier fails, the leachate enters the groundwater in a concentrated, narrow band which may bypass monitoring wells. Once a subsurface barrier has failed, repairs are time-consuming and costly, since the waste above the repair site may have to be removed. The central problem in landfill disposal is leachate control. Recent emphasis has been on developing subsurface barriers to contain the wastes and any leachate. Future emphasis should also be on techniques for removing water from hazardous wastes before they are placed in landfills, and on methods for preventing contact of the wastes with water during and after disposal operations. When leachate is eliminated, the problems of monitoring, and subsurface barrier failure and repair can be addressed, and a waste can be effectively isolated.A surface seal landfill design is recommended for maintaining the dry state of solid hazardous wastes and for controlling leachate. Any impervious liner is utilized over the top of the landfill to prevent surface water from seeping into the waste. The surface barrier is also the site where monitoring and maintenance activities are focused. Barrier failure can be detected by visual inspections and any repairs can be made without disturbing the waste. The surface seal landfill does not employ a subsurface barrier. The surface seal landfill successfully addresses each of the four environmental problems listed above, provided that this landfill design is utilized for dry wastes only and is located at a site which provides protection from groundwater and temporary perched water tables. PMID:738247

  17. Aerobic landfill bioreactor

    DOEpatents

    Hudgins, Mark P (Aiken, SC); Bessette, Bernard J (Aiken, SC); March, John C (Winterville, GA); McComb, Scott T. (Andersonville, SC)

    2002-01-01

    The present invention includes a system of decomposing municipal solid waste (MSW) within a landfill by converting the landfill to aerobic degradation in the following manner: (1) injecting air via the landfill leachate collection system (2) injecting air via vertical air injection wells installed within the waste mass; (3) applying leachate to the waste mass using a pressurized drip irrigation system; (4) allowing landfill gases to vent; and (5) adjusting air injection and recirculated leachate to achieve a 40% to 60% moisture level and a temperature between 120.degree. F. and 140.degree. F. in steady state.

  18. Aerobic landfill bioreactor

    DOEpatents

    Hudgins, Mark P (Aiken, SC); Bessette, Bernard J (Aiken, SC); March, John (Winterville, GA); McComb, Scott T. (Andersonville, SC)

    2000-01-01

    The present invention includes a method of decomposing municipal solid waste (MSW) within a landfill by converting the landfill to aerobic degradation in the following manner: (1) injecting air via the landfill leachate collection system (2) injecting air via vertical air injection wells installed within the waste mass; (3) applying leachate to the waste mass using a pressurized drip irrigation system; (4) allowing landfill gases to vent; and (5) adjusting air injection and recirculated leachate to achieve a 40% to 60% moisture level and a temperature between 120.degree. F. and 140.degree. F. in steady state.

  19. Associations between land cover/use categories and soil concentrations of arsenic, lead and barium, and population race/ethnicity and socioeconomic status

    PubMed Central

    Davis, Harley T.; Aelion, C. Marjorie; Lawson, Andrew B.; Cai, Bo; McDermott, Suzanne

    2015-01-01

    The potential of using land cover/use categories as a proxy for soil metal concentrations was examined by measuring associations between percentages of Anderson land cover categories with soil concentrations of As, Pb, and Ba in ten sampling areas. Land cover category and metal associations with ethnicity and socioeconomic status at the United States Census 2000 block and block group levels also were examined. Arsenic and Pb were highest in urban locations; Ba was a function of geology. Consistent associations were observed between urban/built up land cover, and Pb and poverty. Land cover can be used as proxy for metal concentrations, although associations are metal-dependent. PMID:24914533

  20. REQUIREMENTS FOR HAZARDOUS WASTE LANDFILL DESIGN, CONSTRUCTION AND CLOSURE

    EPA Science Inventory

    This publication contains edited versions of the material presented at ten Technology Transfer seminars conducted in 1988 on this subject. Sections are included on design of clay and flexible membrane liners, leachate collector systems, and landfill covers. Construction quality a...

  1. REVIEW OF LINER AND CAP REGULATIONS FOR LANDFILLS

    EPA Science Inventory

    The U.S. Environmental Protection Agency through its research and field experiences has developed control strategies for hazardous and municipal solid waste landfills and surface impoundments. hese control strategies include liner and cover systems. he liner systems include doubl...

  2. Factors concerned with sanitary landfill site selection: General discussion

    NASA Technical Reports Server (NTRS)

    Graff, W. J.; Stone, L. J.

    1972-01-01

    A general view of factors affecting site selection for sanitary landfill sites is presented. Examinations were made of operational methods, possible environment pollution, types of waste to be disposed, base and cover materials, and the economics involved in the operation.

  3. Use of Landsat imagery to detect land cover changes for monitoring soil sealing; case study: Bologna province (Italy)

    NASA Astrophysics Data System (ADS)

    Casciere, Rossella; Franci, Francesca; Bitelli, Gabriele

    2014-08-01

    Landsat archives (made accessible by USGS at no charge since 2011) have made available to the scientific community a large amount of satellite multispectral images, providing new opportunities for environmental information, such as the analysis of land use/cover changes, which represent important tools for planning and sustainable land management. Processing a time series images, the creation of land cover maps has been improved in order to analyze phenomena such as the soil sealing. The main topic of this work is in fact the detection of roads and buildings construction or everything that involve soil removing. This subject is highly relevant, given the impact of the phenomenon on land use planning, environmental sustainability, agricultural policies and urban runoff. The analysis, still in progress, has been applied to Bologna Province (Emilia-Romagna Region, Italy) that covers 3703 Km2. This area is strongly urbanized: 8,9% of the total surface is sealed against a national value of 6,7%, with the soil sealing rate which has been defined from recent studies as the fourth Italian value in the 2001/2011 period. Other information available for this territory derive from CORINE Land Cover and Copernicus Projects. In the first one, the minimum mapping unit is 25 ha and the one for change is 5 ha; these values are too large for an accurate detection of the soil sealing dynamics. On the other hand, the Copernicus Project provides an imperviousness layer with a better resolution (20x20 m2), but its maps start from 2006. Therefore, the potential of multispectral remote sensing analysis over large areas and the multitemporal Landsat availability have been combined for a better knowledge about land cover changes. For this work, Landsat 5 and Landsat 8 images have been acquired between 1987 and 2013, according to basic requirements as low cloud cover and a common acquisition season (summer). A supervised pixel-based classification has been performed, with maximum likelihood algorithm. Due to landscape heterogeneity, classification has been improved with auxiliary data, such as NDVI. Therefore, the obtained maps have been compared with a post-classification change detection procedure in order to quantify land use changes, with particular attention to the soil sealing increase.

  4. Joint modeling of canopy interception and soil water flow to compare infiltration rates below two land covers (Galápagos Islands)

    NASA Astrophysics Data System (ADS)

    Dominguez, C.; Pryet, A.; Gonzalez, A.; Tournebize, J.; Chaumont, C.; Villacis, M.; D'ozouville, N. I.; Violette, S.

    2014-12-01

    Most volcanic islands face issues due to an imbalance between constantly increasing population and limited freshwater resources. In this context, groundwater exploitation is a valuable strategy and the estimation of recharge rates is crucial for water management planning, specially considering the changes in land use. In the present study we aim to assess the impact of land cover change on the groundwater recharge at the Santa Cruz Island (Galápagos), where a marked vegetation zonation is observed on the windward side. We studied during one year two adjacent land covers that extend on the majority of the island: a secondary forest and a pasture land. We monitored the climatic variables and throughfall over the pasture and under the forest, respectively. At both plots, the soil water suction was measured with automatic tensiometers in a vertical profile at different soil depth. We associate (i) a Rutter-type canopy interception model, with (ii) a 1-D physically-based variably saturated flow model. This allows the estimation of interception losses, cloud water interception, plant transpiration, runoff and deep percolation. The model was calibrated with the throughfall and soil water suction measurements. The model reveals contrasting behaviors in the soil water transfers between the two plots. The difference could be attributed to the reduction of the net precipitation input at the forest, which is caused by higher evaporation losses at the canopy. The approach provides insights about the soil water dynamics under different land covers, and may help to assess the effect of land use change in the groundwater recharge of a vast region of the island.

  5. Effects of a killed-cover crop mulching system on sweetpotato production, soil pests, and insect predators in South Carolina.

    PubMed

    Jackson, D Michael; Harrison, Howard F

    2008-12-01

    Sweetpotatoes, Ipomoea batatas (L.) Lam. (Convolvulaceae), are typically grown on bare soil where weeds and erosion can be serious problems. Conservation tillage systems using cover crop residues as mulch can help reduce these problems, but little is known about how conservation tillage affects yield and quality of sweetpotato or how these systems impact populations of beneficial and pest insects. Therefore, field experiments were conducted at the U.S. Vegetable Laboratory, Charleston, SC, in 2002-2004 to evaluate production of sweetpotatoes in conventional tillage versus a conservation tillage system by using an oat (Avena sativa L. (Poaceae)-crimson clover (Trifolium incarnatum L.) (Fabaceae) killed-cover crop (KCC) mulch. The four main treatments were 1) conventional tillage, hand-weeded; 2) KCC, hand-weeded; 3) conventional tillage, weedy; and 4) KCC, weedy. Each main plot was divided into three subplots, whose treatments were sweetpotato genotypes: 'Ruddy', which is resistant to soil insect pests; and 'SC1149-19' and 'Beauregard', which are susceptible to soil insect pests. For both the KCC and conventional tillage systems, sweetpotato yields were higher in plots that received hand weeding than in weedy plots. Orthogonal contrasts revealed a significant effect of tillage treatment (conventional tillage versus KCC) on yield in two of the 3 yr. Ruddy remained resistant to injury by soil insect pests in both cropping systems; and it consistently had significantly higher percentages of clean roots and less damage by wireworm-Diabrotica-Systena complex, sweetpotato flea beetles, grubs, and sweetpotato weevils than the two susceptible genotypes. In general, injury to sweetpotato roots by soil insect pests was not significantly higher in the KCC plots than in the conventionally tilled plots. Also, more fire ants, rove beetles, and carabid beetle were captured by pitfall traps in the KCC plots than in the conventional tillage plots during at least 1 yr of the study. This study suggests that a sweetpotatoes can be successfully grown under a killed-cover crop production system. PMID:19133469

  6. Weed science and management, in soil sciences, land cover, and land use

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An integral component of conservation agriculture systems in cotton is the use of a high-residue winter cover crop; however, terminating such cover crops is a cost and planting into high-residue is a challenge. Black oat, rye, and wheat winter cover crops were flattened with a straight-blade mechan...

  7. Industrial Waste Landfill IV upgrade package

    SciTech Connect

    1994-10-14

    This document consists of page replacements for the Y-12 industrial waste landfill. The cover page is to replace the old page, and a new set of text pages are to replace the old ones. A replacement design drawing is also included.

  8. Representing the effects of alpine grassland vegetation cover on the simulation of soil thermal dynamics by ecosystem models applied to the Qinghai-Tibetan Plateau

    USGS Publications Warehouse

    Yi, S.; Li, N.; Xiang, B.; Wang, X.; Ye, B.; McGuire, A.D.

    2013-01-01

    Soil surface temperature is a critical boundary condition for the simulation of soil temperature by environmental models. It is influenced by atmospheric and soil conditions and by vegetation cover. In sophisticated land surface models, it is simulated iteratively by solving surface energy budget equations. In ecosystem, permafrost, and hydrology models, the consideration of soil surface temperature is generally simple. In this study, we developed a methodology for representing the effects of vegetation cover and atmospheric factors on the estimation of soil surface temperature for alpine grassland ecosystems on the Qinghai-Tibetan Plateau. Our approach integrated measurements from meteorological stations with simulations from a sophisticated land surface model to develop an equation set for estimating soil surface temperature. After implementing this equation set into an ecosystem model and evaluating the performance of the ecosystem model in simulating soil temperature at different depths in the soil profile, we applied the model to simulate interactions among vegetation cover, freeze-thaw cycles, and soil erosion to demonstrate potential applications made possible through the implementation of the methodology developed in this study. Results showed that (1) to properly estimate daily soil surface temperature, algorithms should use air temperature, downward solar radiation, and vegetation cover as independent variables; (2) the equation set developed in this study performed better than soil surface temperature algorithms used in other models; and (3) the ecosystem model performed well in simulating soil temperature throughout the soil profile using the equation set developed in this study. Our application of the model indicates that the representation in ecosystem models of the effects of vegetation cover on the simulation of soil thermal dynamics has the potential to substantially improve our understanding of the vulnerability of alpine grassland ecosystems to changes in climate and grazing regimes.

  9. Project test plan for runoff and erosion on fine-soil barrier surfaces and rock-covered side slopes

    SciTech Connect

    Walters, W.H.; Hoover, K.A.; Cadwell, L.L.

    1990-06-01

    Pacific Northwest Laboratory (PNL) and Westinghouse Hanford Company are working together to develop protective barriers to isolate near-surface radioactive waste. The purpose of the barriers is to protect defense wastes at the US Department of Energy's (DOE) Hanford Site from infiltration of precipitation, biointrusion, and surficial erosion for up to 10,000 years without the need for long-term monitoring, maintenance, or institutional control. The barriers will be constructed of layered earth and rock material designed to direct surface and groundwater pathways away from the buried waste. To address soil erosion as it applies to barrier design and long-term stability, a task designed to study this problem has been included in the Protective Barriers Program at PNL. The barrier soil-erosion task will investigate the ability of the soil cover and side slopes to resist the erosional and destabilizing processes from externally applied water. The study will include identification and field testing of the dominant processes contributing to erosion and barrier failure. The effects of rock mulches, vegetation cover on the top fine-grained soil surface, as well as the stability of rock armoring on the side slopes, will be evaluated. Some of the testing will include the effects of animal intrusion on barrier erosion, and these will be coordinated with other animal intrusion studies. 6 refs., 4 figs., 1 tab.

  10. The SIR-B observations of microwave backscatter dependence on soil moisture, surface roughness, and vegetation covers

    NASA Technical Reports Server (NTRS)

    Wang, J. R.; Shiue, J. C.; Engman, E. T.; Rusek, M.; Steinmeier, C.

    1986-01-01

    An experiment was conducted from an L-band SAR aboard Space Shuttle Challenger in October 1984 to study the microwave backscatter dependence on soil moisture, surface roughness, and vegetation cover. The results based on the analyses of an image obtained at 21-deg incidence angle show a positive correlatlion between scattering coefficient and soil moisture content, with a sensitivity comparable to that derived from the ground radar measurements reported by Ulaby et al. (1978). The surface roughness strongly affects the microwave backscatter. A factor of two change in the standard deviation of surface roughness height gives a corresponding change of about 8 dB in the scattering coefficient. The microwave backscatter also depends on the vegetation types. Under the dry soil conditions, the scattering coefficient is observed to change from about -24 dB for an alfalfa or lettuce field to about -17 dB for a mature corn field. These results suggest that observations with a SAR system of multiple frequencies and polarizations are required to unravel the effects of soil moisture, surface roughness, and vegetation cover.

  11. Equivalence demonstration of an alternative cover system 307 EQUIVALENCE DEMONSTRATION OF AN ALTERNATIVE COVER SYSTEM

    E-print Network

    Zornberg, Jorge G.

    at the Operating Industries, Inc. (OII) Superfund landfill in southern California. Infiltration control of the closure design show that an evapotranspirative cover is feasible at the site for a wide range engineered components of municipal and hazardous waste landfills is the cover system. The cover system should

  12. Bioreactor landfill technology in municipal solid waste treatment: an overview.

    PubMed

    Kumar, Sunil; Chiemchaisri, Chart; Mudhoo, Ackmez

    2011-03-01

    In recent years, due to an advance in knowledge of landfill behaviour and decomposition processes of municipal solid waste, there has been a strong thrust to upgrade existing landfill technologies for optimizing these degradation processes and thereafter harness a maximum of the useful bioavailable matter in the form of higher landfill gas generation rates. Operating landfills as bioreactors for enhancing the stabilization of wastes is one such technology option that has been recently investigated and has already been in use in many countries. A few full-scale implementations of this novel technology are gaining momentum in landfill research and development activities. The publication of bioreactor landfill research has resulted in a wide pool of knowledge and useful engineering data. This review covers leachate recirculation and stabilization, nitrogen transformation and corresponding extensive laboratory- and pilot-scale research, the bioreactor landfill concept, the benefits to be derived from this bioreactor landfill technology, and the design and operational issues and research trends that form the basis of applied landfill research. PMID:20578971

  13. Effects of Land Cover / Land Use, Soil Texture, and Vegetation on the Water Balance of Lake Chad Basin

    NASA Astrophysics Data System (ADS)

    Babamaaji, R. A.; Lee, J.

    2013-12-01

    Lake Chad Basin (LCB) has experienced drastic changes of land cover and poor water management practices during the last 50 years. The successive droughts in the 1970s and 1980s resulted in the shortage of surface water and groundwater resources. This problem of drought has a devastating implication on the natural resources of the Basin with great consequence on food security, poverty reduction and quality of life of the inhabitants in the LCB. Therefore, understanding the effects of land use / land cover must be a first step to find how they disturb cycle especially the groundwater in the LCB. The abundance of groundwater is affected by the climate change through the interaction with surface water, such as lakes and rivers, and disuse recharge through an infiltration process. Quantifying the impact of climate change on the groundwater resource requires reliable forecasting of changes in the major climatic variables and other spatial variations including the land use/land cover, soil texture, topographic slope, and vegetation. In this study, we employed a spatially distributed water balance model WetSpass to simulate a long-term average change of groundwater recharge in the LCB of Africa. WetSpass is a water balance-based model to estimate seasonal and spatial distribution of surface runoff, interception, evapotranspiration, and groundwater recharge. The model is especially suitable for studying the effect of land use/land cover change on the water regime in the LCB. The present study describes the concept of the model and its application to the development of recharge map of the LCB. The study shows that major role in the water balance of LCB. The mean yearly actual evapotranspiration (ET) from the basin range from 60mm - 400 mm, which is 90 % (69mm - 430) of the annual precipitation from 2003 - 2010. It is striking that about 50 - 60 % of the total runoff is produced on build-up (impervious surfaces), while much smaller contributions are obtained from vegetated, bare soil and open water surfaces. The result of this study also shows that runoff is high in the clay, clay loam and sandy-clay loam due to the lack of infiltration process in clay soil from capping or crusting or sealing of the soil pores, therefore this situation will aid runoff. The application of the WetSpass model shows that precipitation, soil texture and land use / land cover are three controlling factors affecting the water balance in the LCB. Key words: Groundwater recharge, surface runoff, evapotranspiration, water balance, meteorological, draught, Landuse changes, climate changes, WetSpass, GIS.

  14. Cover Crops Can Improve Soil Quality Under No-till Corn Silage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Continuous corn silage production, even with no-till, can degrade soil quality because of nutrient depletion and minimal organic matter (OM) additions. This can reduce productivity and worsen environmental problems such as nutrient runoff and soil erosion. A study was conducted to evaluate effects o...

  15. On the remote measurement of evaporation rates from bare wet soil under variable cloud cover

    NASA Technical Reports Server (NTRS)

    Auer, S.

    1976-01-01

    Evaporation rates from a natural wet soil surface are calculated from an energy balance equation at 0.1-hour intervals. A procedure is developed for calculating the heat flux through the soil surface from a harmonic analysis of the surface temperature curve. The evaporation integrated over an entire 24-hour period is compared with daily evaporation rates obtained from published models.

  16. Simulating runoff from an area covered by soil contour ridges using a hydraulic cascade model

    NASA Astrophysics Data System (ADS)

    Slah, Nasri

    2015-04-01

    Runoff agriculture and rainwater harvesting are well known farming techniques that have guaranteed crop production in the arid zone of Tunisia since ancient times. At present, soil contour ridges (banquettes) are the main water and soil conservation used. Actually about one million ha farming land were protected by this technique. Usually, soil contour ridges are designed for a 10-year return period to reduce runoff and erosion in hill-slope catchments. However, the detailed hydraulic function of this technique is still to a major extent unknown. For this purpose a runoff model was developed to simulate the discharge from an upstream system of several soil contour ridges. The model was validated using experimental runoff. The simulated runoff agreed well with observed discharge. The validated model was used to simulate runoff from a system of one to several soil contour ridges in a cascade from a 10-year rainfall event. Practical conclusions are drawn by discussing the spacing and design of the soil contour ridges. Key words: Soil surface management, soil contour ridge, discharge, hydraulic cascade.

  17. Cover crops and nitrogen fertilization effects of nitrogen conservation in tilled and non-tilled soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Higher cost of N fertilization due to increase in the price of petroleum and increased N leaching from croplands necessitate that soil N be conserved and N fertilization rate be reduced. Proper crop and N management practices may increase soil N conservation and reduce N fertilization rate. We exami...

  18. Nitrogen storage with cover crops and nitrogen fertilization in tilled and non-tilled soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Higher cost of nitrogen (N) fertilization due to increase in the price of gasoline and increased N leaching from croplands necessitate that soil N be conserved and N fertilization rate be reduced. Proper crop and N management practices may increase soil N conservation and reduce N fertilization rate...

  19. Ethylene-orchestrated circuitry coordinates a seedling’s response to soil cover and etiolated growth

    PubMed Central

    Zhong, Shangwei; Shi, Hui; Xue, Chang; Wei, Ning; Guo, Hongwei; Deng, Xing Wang

    2014-01-01

    The early life of terrestrial seed plants often starts under the soil in subterranean darkness. Over time and through adaptation, plants have evolved an elaborate etiolation process that enables seedlings to emerge from soil and acquire autotrophic ability. This process, however, requires seedlings to be able to sense the soil condition and relay this information accordingly to modulate both the seedlings’ growth and the formation of photosynthetic apparatus. The mechanism by which soil overlay drives morphogenetic changes in plants, however, remains poorly understood, particularly with regard to the means by which the cellular processes of different organs are coordinated in response to disparate soil conditions. Here, we illustrate that the soil overlay quantitatively activates seedlings’ ethylene production, and an EIN3/EIN3-like 1–dependent ethylene-response cascade is required for seedlings to successfully emerge from the soil. Under soil, an ERF1 pathway is activated in the hypocotyl to slow down cell elongation, whereas a PIF3 pathway is activated in the cotyledon to control the preassembly of photosynthetic machinery. Moreover, this latter PIF3 pathway appears to be coupled to the ERF1-regulated upward-growth rate. The coupling of these two pathways facilitates the synchronized progression of etioplast maturation and hypocotyl growth, which, in turn, ultimately enables seedlings to maintain the amount of protochlorophyllide required for rapid acquisition of photoautotrophic capacity without suffering from photooxidative damage during the dark-to-light transition. Our findings illustrate the existence of a genetic signaling pathway driving soil-induced plant morphogenesis and define the specific role of ethylene in orchestrating organ-specific soil responses in Arabidopsis seedlings. PMID:24599595

  20. Temporal variation of aqueous-extractable Ca, Mg and K in acidified forest mountainous soils under different vegetation cover

    NASA Astrophysics Data System (ADS)

    Tejnecky, V.; Bradová, M.; Boruvka, L.; Vasat, R.; Nemecek, K.; Ash, C.; Sebek, O.; Rejzek, J.; Drabek, O.

    2012-12-01

    Acidification of forest soils is a natural degradation process which can be significantly enhanced by anthropogenic activities. Inputs of basic cations (BC - Ca, Mg and K) via precipitation, litter and soil organic matter decomposition and also via inter-soil weathering may partially mitigate the consequences of this degradation process. The aim of this study is to assess the temporal variation of aqueous-extractable Ca, Mg and K in acidified forest mountainous soils under different vegetation cover. The Jizera Mountains region (Czech Republic, northern Bohemia) was chosen as a representative soil mountainous ecosystem strongly affected by acidification. Soil and precipitation samples were collected at monthly basis from April till October/ November during the years 2009-2011. Study spots were delimited under two contrasting vegetation covers - beech and spruce monoculture. Prevailing soil types were classified as Alumic Cambisols under beech and Entic Podzols under spruce stands (according to FAO classification). Soil samples were collected from surface fermentation (F) and humified (H) organic horizons and subsurface B horizons (cambic or spodic). The collected soil samples were analyzed immediately under laboratory condition in a "fresh" state. Unsieved fresh samples were extracted by deionised water. The content of main elements (Ca, Mg, K, Al and Fe) was determined by ICP-OES. The content of major anions (SO42-, NO3-, Cl- and F-) was determined by ion-exchange chromatography (IC). Content of major anions and main elements were determined in the precipitation samples (throughfall, stemflow and bulk) as well. Besides computing the basic statistical parameters (mean, median, variance, maximum, minimum, etc.) we also employed other statistical methods such as T-test and ANOVA to assess the differences between beech and spruce vegetation spots. To carry out the temporal variability in the data we used the time series analysis and short-term forecasting by Holt-Winters exponential smoothing and ARIMA models. Our results clearly exhibit differences in the horizontal and spatial distribution of BC. The influences of the study spot, i.e. the influence of stand factors e.g. vegetation covers on BC distribution are well pronounced. The highest amounts of aqueous extractable BC were identified in the F and H organic horizons. The contents of Ca and Mg were significantly higher under beech cover than under spruce cover. The influence of seasonality on BC content and distribution was the strongest in the upper organic horizons. The annual changes are less pronounced in inner mineral B horizons. We have observed a significant influence of the snow melting period - after this event the content of BC was the lowest. In contrast, the BC content rises during the summer period - the time of high biological activity and accelerated organic matter decomposition. This period is again followed by a BC content decrease during the fall period - the time of gradually decreasing biological activity and high precipitation. Generally, we can conclude that the seasonal variations are higher than annual and spatial for both sites.

  1. Podzol development in S Norway - a soil chronosequence of 31 pedons covering soil ages from 85 to 9650 years

    NASA Astrophysics Data System (ADS)

    Sauer, Daniela; Svendgård-Stokke, Siri; Sperstad, Ragnhild; Sørensen, Rolf; Fuchs, Markus; Gebers, Henrik; Schülli-Maurer, Isabelle

    2013-04-01

    The Oslofjord region in SE-Norway has undergone steady glacio-isostatic uplift all over the Holocene. Hence, in the coastal areas land surface age continuously increases with elevation, providing suitable conditions for studying soil development with time. A chronosequence of soils on beach sand and sandy terraces of the Lågen River, showing progressive podzolization with soil age, was studied on the western side of the Oslofjord. 31 pedons with soil ages ranging from 85 years (0.25 m a. s. l.) to ca. 9650 years (62 m a. s. l.) were described and are currently analysed. Soil ages were estimated by relating elevations of the sites to a Holocene relative sea level curve based on twelve AMS 14C-dates of gyttja from the isolation contact (marine / fresh water boundary) and six marine macrofossil 14C-dates (Sørensen et al., 2012). The climate in the study area is comparatively mild, with mean annual temperatures ranging from 5.3°C (Ramnes) to 6.3°C (Sandefjord, Larvik) and a mean annual precipitation of 909 mm (Sandefjord) - 1150 mm (Stokke). The vegetation consists predominantly of mixed forest. In this soil chronosequence, soil organic matter (SOM) accumulation in the A horizons reaches a steady state in less than 2300 years, while SOM in the B horizons continues to accumulate. Soil pH (in water) drops from pH 6.9 in the recent beach sand to pH 4.6 within about 4500 years and stays constant thereafter, which is attributed to sesquioxide buffering. Base saturation shows an exponential decrease with time. Progressive weathering is reflected by increasing Fed and Ald contents, and proceeding podzolization by increasing amounts of pyrophophate- and oxalate-soluble Fe and Al with soil age. Increases of most Fe and Al fractions can be best described by exponential models. Micromorphological analysis reveals accumulation of cloudy, iron-rich, reddish fine material in the Bs horizons that proceeds with soil age, leading to chitonic c/f-related distribution in the Bs horizons. The mineralogical composition of the parent material is dominated by quartz and feldspars, whereby the feldspar grains show features of proceeding weathering with time. In addition to podzolisation features, illuvial clay is observed below the Bs horizons. Apparently, the sand is sufficiently buffered during the first millennia of soil formation so that acidification proceeds slowly enough to allow for clay translocation prior to podzolisation. Reference Sørensen, R., Høeg, H.I., Henningsmoen, K.E., Skog, G., Labowsky, S.F., Stabell, B. (2012): Utviklingen av det senglasiale og tidlig preboreale landskapet og vegetasjonen omkring steinalderboplassene ved Pauler, Larvik kommune, Vestfold. In: Jaksland, L. (Ed.), E18 Brunlaneprospektet. Varia 79. Kulturhistorisk Museum, University of Oslo.

  2. Tracing landfill gas migration using chlorofluorocarbons

    NASA Astrophysics Data System (ADS)

    Archbold, M.; Elliot, T. E.; Redeker, K.; Boshoff, G.

    2003-04-01

    Typical landfill gas (LFG) compositions include a wide range of trace-level Volatile Organic Compounds (VOCs). The most mobile VOCs are chlorofluorocarbons (CFCs), and their presence around landfills may reflect the initial flushing out of VOCs during the early aerobic stage when landfills are most active reaching high temperatures, driving off VOCs, and injecting LFG into the surrounding environment. CFCs are aerobically stable and therefore, may prove a useful means of characterising the environmental impact of landfill gas in the unsaturated zone around landfills. Moreover, as a possible pathfinder environmental tracer of LFG impacts in the environment, any subsequent changes in the CFCs concentrations after injection potentially reflect natural attenuation (NA) processes, which can also affect other VOCs. Thus tracing the CFCs around a landfill may provide an analogue indicator/proxy for other VOCs transport and fate. To assess the feasibility of using chlorofluorocarbons (CFC-11, CFC-12, CFC-113) as proxy tracers, it is imperative to characterise the effects of possible NA processes on both CFC abundances and their overall systematics. In this research, anaerobic biodegradation microcosm studies, which mimic the unsaturated zone of a LFG plume, are conducted using methanogenic soil samples. Results are discussed in terms of the potential effects on CFCs signatures due to anaerobic biodegradation in the unsaturated zone and will also explore ways of characterising NA processes by identifying the effects of diffusion on transport processes, and degradation products of CFCs. The discussion will also include how stable carbon isotopic signatures may be used to enhance our assessments of biodegradation of CFCs in the unsaturated zone around landfills.

  3. Soil depth mapping using seismic surface waves: Evaluation on eroded loess covered hillslopes

    NASA Astrophysics Data System (ADS)

    Bernardie, Severine; Samyn, Kevin; Cerdan, Olivier; Grandjean, Gilles

    2010-05-01

    The purposes of the multidisciplinary DIGISOIL project are the integration and improvement of in situ and proximal technologies for the assessment of soil properties and soil degradation indicators. Foreseen developments concern sensor technologies, data processing and their integration to applications of (digital) soil mapping (DSM). Among available techniques, the seismic one is, in this study, particularly tested for characterising soil vulnerability to erosion. The spectral analysis of surface waves (SASW) method is an in situ seismic technique used for evaluation of the stiffnesses (G) and associated depth in layered systems. A profile of Rayleigh wave velocity versus frequency, i.e., the dispersion curve, is calculated from each recorded seismogram before to be inverted to obtain the vertical profile of shear wave velocity Vs. Then, the soil stiffness can easily be calculated from the shear velocity if the material density is estimated, and the soil stiffness as a function of depth can be obtained. This last information can be a good indicator to identify the soil bedrock limit. SASW measurements adapted to soil characterisation is proposed in the DIGISOIL project, as it produces in an easy and quick way a 2D map of the soil. This system was tested for the digital mapping of the depth of loamy material in a catchment of the European loess belt. The validation of this methodology has been performed with the realisation of several acquisitions along the seismic profiles: - Several boreholes were drilled until the bedrock, permitting to get the geological features of the soil and the depth of the bedrock; - Several laboratory measurements of various parameters were done on samples taken from the boreholes at various depths, such as dry density, solid density, and water content; - Dynamic penetration tests were also conducted along the seismic profile, until the bedrock is attained. Some empirical correlations between the parameters measured with laboratory tests, the qc obtained from the dynamic penetration tests and the Vs acquired from the SASW measurements permit to assess the accuracy of the procedure and to evaluate its limitations. The depth to bedrock determined by this procedure can then be combined with the soil erosion susceptibility to produce a risk map. This methodology will help to target measures within areas that show a reduced soil depth associated with a high soil erosion susceptibility.

  4. SWS 4303/5305 Soil Microbial Ecology Course Description Lectures and laboratory exercises will cover the soil as a

    E-print Network

    Ma, Lena

    or Wednesdays (2 -3 pm), 3196 McCarty Hall B. Textbooks: Paul, Eldor. 2015. Soil Microbiology, Ecology that can be found at: https://catalog.ufl.edu/ugrad/current/regulations/info/attendance.aspx Grading System Current UF grading policies for assigning grade points: https://catalog.ufl.edu/ugrad/current

  5. Quantification of tillage, plant cover, and cumulative rainfall effects on soil surface microrelief by statistical, geostatistical and fractal indices

    NASA Astrophysics Data System (ADS)

    Paz-Ferreiro, J.; Bertol, I.; Vidal Vázquez, E.

    2008-07-01

    Changes in soil surface microrelief with cumulative rainfall under different tillage systems and crop cover conditions were investigated in southern Brazil. Surface cover was none (fallow) or the crop succession maize followed by oats. Tillage treatments were: 1) conventional tillage on bare soil (BS), 2) conventional tillage (CT), 3) minimum tillage (MT) and 4) no tillage (NT) under maize and oats. Measurements were taken with a manual relief meter on small rectangular grids of 0.234 and 0.156 m2, throughout growing season of maize and oats, respectively. Each data set consisted of 200 point height readings, the size of the smallest cells being 3×5 cm during maize and 2×5 cm during oats growth periods. Random Roughness (RR), Limiting Difference (LD), Limiting Slope (LS) and two fractal parameters, fractal dimension (D) and crossover length (l) were estimated from the measured microtopographic data sets. Indices describing the vertical component of soil roughness such as RR, LD and l generally decreased with cumulative rain in the BS treatment, left fallow, and in the CT and MT treatments under maize and oats canopy. However, these indices were not substantially affected by cumulative rain in the NT treatment, whose surface was protected with previous crop residues. Roughness decay from initial values was larger in the BS treatment than in CT and MT treatments. Moreover, roughness decay generally tended to be faster under maize than under oats. The RR and LD indices decreased quadratically, while the l index decreased exponentially in the tilled, BS, CT and MT treatments. Crossover length was sensitive to differences in soil roughness conditions allowing a description of microrelief decay due to rainfall in the tilled treatments, although better correlations between cumulative rainfall and the most commonly used indices RR and LD were obtained. At the studied scale, parameters l and D have been found to be useful in interpreting the configuration properties of the soil surface microrelief.

  6. The influence of cover crops and tillage on actual and potential soil erosion in an olive grove

    NASA Astrophysics Data System (ADS)

    Sastre, Blanca; Bienes, Ramón; García-Díaz, Andrés; Panagopoulos, Thomas; José Marqués, Maria

    2014-05-01

    The study was carried out in an olive grove in central Spain (South of Madrid; Tagus River Basin). In this semi-arid zone, the annual mean temperature is 13.8 ºC and the annual precipitation is 395 mm. Olive groves are planted in an erosion prone area due to steep slopes up to 15%. Soil is classified as Typic Haploxerept with clay loam texture. The land studied was formerly a vineyard, but it was replaced by the studied olive grove in 2004. It covers approximately 3 ha and olive trees are planted every 6 x 7 metres. They were usually managed by tillage to decrease weed competition. This conventional practice results in a wide surface of bare soil prone to erosion processes. In the long term soil degradation may lead to increase the desertification risk in the area. Storms have important consequences in this shallow and vulnerable soil, as more than 90 Mg ha-1 have been measured after one day with 40 mm of rainfall. In order to avoid this situation, cover crops between the olive trees were planted three years ago: sainfoin (Onobrychis viciifolia), barley (Hordeum vulgare), and purple false brome (Brachypodium distachyon), and they were compared with annual spontaneous vegetation after a minimum tillage treatment (ASV). The results regarding erosion control were positive. We observed (Oct. 2012/Sept. 2013) annual soil loss up to 11 Mg ha-1 in ASV, but this figure was reduced in the sown covers, being 8 Mg ha-1 in sainfoin treatment, 3,7 Mg ha-1 in barley treatment, and only 1,5 Mg ha-1 in false brome treatment. Those results are used to predict the risk of erosion in long term. Moreover, soil organic carbon (SOC) increased with treatments, this is significant as it reduces soil erodibility. The increases were found both in topsoil (up to 5 cm) and more in depth, in the root zone (from 5 to 10 cm depth). From higher to lower SOC values we found the false brome (1.05%), barley (0.92%), ASV (0.79%) and sainfoin (0.71%) regarding topsoil. In the root zone (5-10 cm depth) we found 0.76% in false brome and ASV, 0.70% in barley and 0.58% in sainfoin. Other important variable to estimate erosion processes is soil permeability. During the period of study there were no significant differences between treatments. An average of 45±20 mm h-1 was measured. This study addresses the comparison between soil erosion rates measured on the ground with soil erosion risk estimated by models. Mapping soil risk can provide the evidence to demonstrate that economic investments in research, good practices and agri-environment payments are worth to achieve sustainable land management. The use of case studies is usually recommended to help in the dissemination of research. This case also includes the influence of treatments in production and quality of olive oil to respond to the needs of land users.

  7. Effect of summer throughfall exclusion, summer drought, and winter snow cover on methane fluxes in a temperate forest soil

    USGS Publications Warehouse

    Borken, W.; Davidson, E.A.; Savage, K.; Sundquist, E.T.; Steudler, P.

    2006-01-01

    Soil moisture strongly controls the uptake of atmospheric methane by limiting the diffusion of methane into the soil, resulting in a negative correlation between soil moisture and methane uptake rates under most non-drought conditions. However, little is known about the effect of water stress on methane uptake in temperate forests during severe droughts. We simulated extreme summer droughts by exclusion of 168 mm (2001) and 344 mm (2002) throughfall using three translucent roofs in a mixed deciduous forest at the Harvard Forest, Massachusetts, USA. The treatment significantly increased CH4 uptake during the first weeks of throughfall exclusion in 2001 and during most of the 2002 treatment period. Low summertime CH4 uptake rates were found only briefly in both control and exclusion plots during a natural late summer drought, when water contents below 0.15 g cm-3 may have caused water stress of methanotrophs in the A horizon. Because these soils are well drained, the exclusion treatment had little effect on A horizon water content between wetting events, and the effect of water stress was smaller and more brief than was the overall treatment effect on methane diffusion. Methane consumption rates were highest in the A horizon and showed a parabolic relationship between gravimetric water content and CH4 consumption, with maximum rate at 0.23 g H2O g-1 soil. On average, about 74% of atmospheric CH4 was consumed in the top 4-5 cm of the mineral soil. By contrast, little or no CH4 consumption occurred in the O horizon. Snow cover significantly reduced the uptake rate from December to March. Removal of snow enhanced CH4 uptake by about 700-1000%, resulting in uptake rates similar to those measured during the growing season. Soil temperatures had little effect on CH4 uptake as long as the mineral soil was not frozen, indicating strong substrate limitation of methanotrophs throughout the year. Our results suggest that the extension of snow periods may affect the annual rate of CH4 oxidation and that summer droughts may increase the soil CH4 sink of temperate forest soils. ?? 2005 Elsevier Ltd. All rights reserved.

  8. Assessing Vegetation Cover Dynamics Induced by Policy-Driven Ecological Restoration and Implication to Soil Erosion in Southern China

    PubMed Central

    Zhang, Jien; Wang, Tianming; Ge, Jianping

    2015-01-01

    In the aftermath of the severe droughts and floods at the end of the 20th century, the Chinese government launched several ecological restoration projects, including the Natural Forest Protection Program in 1998 and the Grain-for-Green Program in 1999, to promote afforestation and reforestation to reduce surface runoff and consequent soil erosion nationwide. However, it is still unclear how vegetation has changed in southern China since the launch of these programs. In this study, we used the MODIS Enhanced Vegetation Index (EVI) to analyze the vegetation cover dynamics in southern China from 2000 to 2009 and evaluate the resulting effects of controlling soil erosion. Our observations indicate that 5.3% of the study area significantly increased and 0.98% significantly decreased in EVI value (p < 0.05). The spring EVI had largest increase in space. The conversions of croplands on steep slopes to forests resulting from national policies led to significant increases in EVI. The increase in EVI was not driven by annual average temperature and annual precipitation. By referencing ecological restoration statistical data and field observations, we showed that ecological restoration programs significantly improved vegetation cover in southern China. Increase in the area of farmland-converted forestlands has reduced soil erosion based upon monitoring sediment yields at hydrologic stations in the Yangtze River. This study displays the spatial patterns of trend in vegetation growth since the beginning of the 21st century in southern China and highlights the important role of China’s afforestation program. PMID:26115116

  9. Comparison of measurements and theory for backscatter from vegetation-covered soil on the Konza prairie

    NASA Technical Reports Server (NTRS)

    Gogineni, S.; Fung, A. K.; Chen, K. S.; Wang, J.

    1992-01-01

    Radar backscatter measurements over the Konza Prairie were obtained by means of C- and X-band scatterometers as a part of the first ISLSCP Field Experiment (FIFE) to determine soil moisture. Nearly simultaneous radar and radiometer data sets were collected along two transects that coincided with direct soil-moisture measurements. The results show that radars can be used for soil-moisture estimation over the complete transect, whereas radiometer sensitivity to soil moisture is drastically reduced over regions left unburned for many years. A combined rough-surface/volume scatter model was formulated. Calculated and measured scattering data are compared to determine the sensitivity of the scattering coefficient to different surface treatments.

  10. Effects of land cover on water table, soil moisture, evapotranspiration, and groundwater recharge: A Field observation and analysis

    USGS Publications Warehouse

    Zhang, Y.-K.; Schilling, K.E.

    2006-01-01

    The effects of land cover on water table, soil moisture, evapotranspiration, and groundwater recharge were studied with water level measurements collected from two monitoring wells over a period of 122 days. The two wells were installed under similar conditions except that one was drilled on the east side of a creek which was covered with grass, and the other on the west side of the creek which was burned into a bare ground. Substantial differences in water level fluctuations were observed at these two wells. The water level in the east grass (EG) well was generally lower and had much less response to rainfall events than the west no-grass (WNG) well. Grass cover lowered the water table, reduced soil moisture through ET losses, and thus reduced groundwater recharge. The amount of ET by the grass estimated with a water table recession model decreased exponentially from 7.6 mm/day to zero as the water table declined from near the ground surface to 1.42 m below the ground surface in 33 days. More groundwater recharge was received on the WNG side than on the EG side following large rainfall events and by significant slow internal downward drainage which may last many days after rainfall. Because of the decreased ET and increased R, significantly more baseflow and chemical loads may be generated from a bare ground watershed compared to a vegetated watershed. ?? 2005 Elsevier Ltd All rights reserved.

  11. Effects of post-fire salvage logging and a skid trail treatment on ground cover, soils, and sediment production in the interior western United

    E-print Network

    MacDonald, Lee

    Effects of post-fire salvage logging and a skid trail treatment on ground cover, soils 2014 Keywords: Erosion Wildfire Water repellency Soil compaction Salvage logging Mitigation a b s t r a c t Post-fire salvage logging adds another set of environmental effects to recently burned areas

  12. Role of water balance in the long-term stability of hazardous waste site cover treatments

    SciTech Connect

    Barnes, F.J.; Rodgers, J.C.; Trujillo, G.

    1986-01-01

    After the 30-year post-closure maintenance period at hazardous waste landfills, long-term stability must be assured without continued intervention. Understanding water balance in the established vegetative cover system is central to predicting such stability. A Los Alamos National Laboratory research project has established a series of experimental cover treatment plots on a closed waste disposal site which will permit the determination of the effects of such critical parameters as soil cover design, leaf area index, and rooting characteristics on water balance under varied conditions. Data from these experiments are being analyzed by water balance modeling and other means. The results show consistent differences in soil moisture storage between soil profiles and between vegetation cover treatments.

  13. Modelling of environmental impacts of solid waste landfilling within the life-cycle analysis program EASEWASTE

    SciTech Connect

    Kirkeby, Janus T.; Birgisdottir, Harpa; Bhander, Gurbakash Singh; Hauschild, Michael; Christensen, Thomas H.

    2007-07-01

    A new computer-based life-cycle assessment model (EASEWASTE) has been developed to evaluate resource and environmental consequences of solid waste management systems. This paper describes the landfilling sub-model used in the life-cycle assessment program EASEWASTE, and examines some of the implications of this sub-model. All quantities and concentrations of leachate and landfill gas can be modified by the user in order to bring them in agreement with the actual landfill that is assessed by the model. All emissions, except the generation of landfill gas, are process specific. The landfill gas generation is calculated on the basis of organic matter in the landfilled waste. A landfill assessment example is provided. For this example, the normalised environmental effects of landfill gas on global warming and photochemical smog are much greater than the environmental effects for landfill leachate or for landfill construction. A sensitivity analysis for this example indicates that the overall environmental impact is sensitive to the gas collection efficiency and the use of the gas, but not to the amount of leachate generated, or the amount of soil or liner material used in construction. The landfill model can be used for evaluating different technologies with different liners, gas and leachate collection efficiencies, and to compare the environmental consequences of landfilling with alternative waste treatment options such as incineration or anaerobic digestion.

  14. Modelling of environmental impacts of solid waste landfilling within the life-cycle analysis program EASEWASTE.

    PubMed

    Kirkeby, Janus T; Birgisdottir, Harpa; Bhander, Gurbakash Singh; Hauschild, Michael; Christensen, Thomas H

    2007-01-01

    A new computer-based life-cycle assessment model (EASEWASTE) has been developed to evaluate resource and environmental consequences of solid waste management systems. This paper describes the landfilling sub-model used in the life-cycle assessment program EASEWASTE, and examines some of the implications of this sub-model. All quantities and concentrations of leachate and landfill gas can be modified by the user in order to bring them in agreement with the actual landfill that is assessed by the model. All emissions, except the generation of landfill gas, are process specific. The landfill gas generation is calculated on the basis of organic matter in the landfilled waste. A landfill assessment example is provided. For this example, the normalised environmental effects of landfill gas on global warming and photochemical smog are much greater than the environmental effects for landfill leachate or for landfill construction. A sensitivity analysis for this example indicates that the overall environmental impact is sensitive to the gas collection efficiency and the use of the gas, but not to the amount of leachate generated, or the amount of soil or liner material used in construction. The landfill model can be used for evaluating different technologies with different liners, gas and leachate collection efficiencies, and to compare the environmental consequences of landfilling with alternative waste treatment options such as incineration or anaerobic digestion. PMID:17382531

  15. BIOREACTOR LANDFILL DESIGN

    EPA Science Inventory

    Modern landfill design entails many elements including foundations, liner systems, leachate collection systems, stormwater control systems, slope stability considerations, leachate management systems, gas extraction systems, and capping and closure. The use of bioreactor technolo...

  16. Study on the reduction of atmospheric mercury emissions from mine waste enriched soils through native grass cover in the Mt. Amiata region of Italy

    SciTech Connect

    Fantozzi, L.; Dini, F.; Tamburello, L.; Pirrone, N.; Sprovieri, F.

    2013-08-15

    Atmospheric mercury emissions from mine-waste enriched soils were measured in order to compare the mercury fluxes of bare soils with those from other soils covered by native grasses. Our research was conducted near Mt. Amiata in central Italy, an area that was one of the largest and most productive mining centers in Europe up into the 1980s. To determine in situ mercury emissions, we used a Plexiglas flux chamber connected to a portable mercury analyzer (Lumex RA-915+). This allowed us to detect, in real time, the mercury vapor in the air, and to correlate this with the meteorological parameters that we examined (solar radiation, soil temperature, and humidity). The highest mercury flux values (8000 ng m{sup ?2} h{sup ?1}) were observed on bare soils during the hours of maximum insulation, while lower values (250 ng m{sup ?2} h{sup ?1}) were observed on soils covered by native grasses. Our results indicate that two main environmental variables affect mercury emission: solar radiation intensity and soil temperature. The presence of native vegetation, which can shield soil surfaces from incident light, reduced mercury emissions, a result that we attribute to a drop in the efficiency of mercury photoreduction processes rather than to decreases in soil temperature. This finding is consistent with decreases in mercury flux values down to 3500 ng m{sup ?2} h{sup ?1}, which occurred under cloudy conditions despite high soil temperatures. Moreover, when the soil temperature was 28 °C and the vegetation was removed from the experimental site, mercury emissions increased almost four-fold. This increase occurred almost immediately after the grasses were cut, and was approximately eight-fold after 20 h. Thus, this study demonstrates that enhancing wild vegetation cover could be an inexpensive and effective approach in fostering a natural, self-renewing reduction of mercury emissions from mercury-contaminated soils. -- Highlights: ? Mercury air/surface exchange from grass covered soil is different from bare soil. ? Light enhances mercury emissions and is the main parameter driving the process. ? The presence of wild vegetation covering the soil reduces mercury emission. ? Vegetative covers could be a solution to reduce atmospheric mercury pollution.

  17. Field studies of engineered barriers for closure of low level radioactive waste landfills at Los Alamos, New Mexico, USA

    SciTech Connect

    Nyhan, J.W.; Langhorst, G.J.; Martin, C.E.; Martinez, J.L.; Schofield, T.G.

    1993-05-01

    The Los Alamos National Laboratory examined water balance relationships for four different landfill cover designs containing engineered barriers. These field experiments were performed at Los Alamos, New Mexico, USA, in 1.0- by 10.0-m plots with downhill slopes of 5, 10, 15, and 25%. Field measurements of seepage, precipitation, interflow, runoff, and soil water content were collected in each of the 16 plots representing four slopes each with four cover designs: Conventional, EPA, Loam Capillary Barrier and Clay Loam Capillary Barrier. A seepage collection system was installed beneath each cover design to evaluate the influence of slope length on seepage using a series of four metal pans filled with medium gravel that were placed end-to-end in the bottom of each field plot. An automated water flow data logging system was used to collect hourly seepage, interflow and runoff data and consisted of 100 100-liter tanks, each of which was equipped with an ultrasonic liquid-level sensor and a motor-operated ball valve used to drain the tank. Soil water content was routinely monitored every six hours at each of 212 locations throughout the 16 plots with time domain reflectrometry (TDR) techniques using an automated and multiplexed measurement system. Field data is presented to show the effects of slope and slope length on the performance of each landfill cover design for the first 15 months of this field experiment.

  18. LANDFILL OPERATION FOR CARBON SEQUESTRATION AND MAXIMUM METHANE EMISSION CONTROL

    SciTech Connect

    Don Augenstein; Ramin Yazdani; Rick Moore; Michelle Byars; Jeff Kieffer; Professor Morton Barlaz; Rinav Mehta

    2000-02-26

    Controlled landfilling is an approach to manage solid waste landfills, so as to rapidly complete methane generation, while maximizing gas capture and minimizing the usual emissions of methane to the atmosphere. With controlled landfilling, methane generation is accelerated to more rapid and earlier completion to full potential by improving conditions (principally moisture, but also temperature) to optimize biological processes occurring within the landfill. Gas is contained through use of surface membrane cover. Gas is captured via porous layers, under the cover, operated at slight vacuum. A field demonstration project has been ongoing under NETL sponsorship for the past several years near Davis, CA. Results have been extremely encouraging. Two major benefits of the technology are reduction of landfill methane emissions to minuscule levels, and the recovery of greater amounts of landfill methane energy in much shorter times, more predictably, than with conventional landfill practice. With the large amount of US landfill methane generated, and greenhouse potency of methane, better landfill methane control can play a substantial role both in reduction of US greenhouse gas emissions and in US renewable energy. The work described in this report, to demonstrate and advance this technology, has used two demonstration-scale cells of size (8000 metric tons [tonnes]), sufficient to replicate many heat and compaction characteristics of larger ''full-scale'' landfills. An enhanced demonstration cell has received moisture supplementation to field capacity. This is the maximum moisture waste can hold while still limiting liquid drainage rate to minimal and safely manageable levels. The enhanced landfill module was compared to a parallel control landfill module receiving no moisture additions. Gas recovery has continued for a period of over 4 years. It is quite encouraging that the enhanced cell methane recovery has been close to 10-fold that experienced with conventional landfills. This is the highest methane recovery rate per unit waste, and thus progress toward stabilization, documented anywhere for such a large waste mass. This high recovery rate is attributed to moisture, and elevated temperature attained inexpensively during startup. Economic analyses performed under Phase I of this NETL contract indicate ''greenhouse cost effectiveness'' to be excellent. Other benefits include substantial waste volume loss (over 30%) which translates to extended landfill life. Other environmental benefits include rapidly improved quality and stabilization (lowered pollutant levels) in liquid leachate which drains from the waste.

  19. Case study of a full-scale evapotranspiration cover

    USGS Publications Warehouse

    McGuire, P.E.; Andraski, B.J.; Archibald, R.E.

    2009-01-01

    The design, construction, and performance analyses of a 6.1 ha evapotranspiration (ET) landfill cover at the semiarid U.S. Army Fort Carson site, near Colorado Springs, Colo. are presented. Initial water-balance model simulations, using literature reported soil hydraulic data, aided selection of borrow-source soil type(s) that resulted in predictions of negligible annual drainage (???1 mm/year). Final construction design was based on refined water-balance simulations using laboratory determined soil hydraulic values from borrow area natural soil horizons that were described with USDA soil classification methods. Cover design components included a 122 cm thick clay loam (USDA), compaction ???80% of the standard Proctor maximum dry density (dry bulk density ???1.3 Mg/m3), erosion control measures, top soil amended with biosolids, and seeding with native grasses. Favorable hydrologic performance for a 5 year period was documented by lysimeter-measured and Richards'-based calculations of annual drainage that were all <0.4 mm/year. Water potential data suggest that ET removed water that infiltrated the cover and contributed to a persistent driving force for upward flow and removal of water from below the base of the cover. ?? 2009 ASCE.

  20. Exploring cover crops as carbon sources for anaerobic soil disinfestation in a vegetable production system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In a raised-bed plasticulture vegetable production system utilizing anaerobic soil disinfestation (ASD) in Florida field trials, pathogen, weed, and parasitic nematode control was equivalent to or better than the methyl bromide control. Molasses was used as the labile carbon source to stimulate micr...

  1. Thermal remote sensing of surface soil water content with partial vegetation cover for incorporation into climate models

    NASA Technical Reports Server (NTRS)

    Gillies, Robert R.; Carlson, Toby N.

    1995-01-01

    This study outlines a method for the estimation of regional patterns of surface moisture availability (M(sub 0)) and fractional vegetation (Fr) in the presence of spatially variable vegetation cover. The method requires relating variations in satellite-derived (NOAA, Advanced Very High Resolution Radiometer (AVHRR)) surface radiant temperature to a vegetation index (computed from satellite visible and near-infrared data) while coupling this association to an inverse modeling scheme. More than merely furnishing surface soil moisture values, the method constitues a new conceptual and practical approach for combining thermal infrared and vegetation index measurements for incorporating the derived values of M(sub 0) into hydrologic and atmospheric prediction models. Application of the technique is demonstrated for a region in and around the city of Newcastle upon Tyne situated in the northeast of England. A regional estimate of M(sub 0) is derived and is probabbly good for fractional vegetation cover up to 80% before errors in the estimated soil water content become unacceptably large. Moreover, a normalization scheme is suggested from which a nomogram, `universal triangle,' is constructed and is seen to fit the observed data well. The universal triangle also simplifies the inclusion of remotely derived M(sub 0) in hydrology and meteorological models and is perhaps a practicable step toward integrating derived data from satellite measurements in weather forecasting.

  2. Evaluation of Cover Crops with Potential for Use in Anaerobic Soil Disinfestation (ASD) for Susceptibility to Three Species of Meloidogyne

    PubMed Central

    Kokalis-Burelle, Nancy; Butler, David M.; Rosskopf, Erin N.

    2013-01-01

    Several cover crops with potential for use in tropical and subtropical regions were assessed for susceptibility to three common species of root-knot nematode, Meloidogyne arenaria, M. incognita, and M. javanica. Crops were selected based on potential use as organic amendments in anaerobic soil disinfestation (ASD) applications. Nematode juvenile (J2) numbers in soil and roots, egg production, and host plant root galling were evaluated on arugula (Eruca sativa, cv. Nemat), cowpea (Vigna unguiculata, cv. Iron & Clay), jack bean (Canavalia ensiformis, cv. Comum), two commercial mixtures of Indian mustard and white mustard (Brassica juncea & Sinapis alba, mixtures Caliente 61 and Caliente 99), pearl millet (Pennisetum glaucum, cv. Tifleaf III), sorghum-sudangrass hybrid (Sorghum bicolor × S. bicolor var. sudanense, cv. Sugar Grazer II), and three cultivars of sunflower (Helianthus annuus, cvs. 545A, Nusun 660CL, and Nusun 5672). Tomato (Solanum lycopersicum, cv. Rutgers) was included in all trials as a susceptible host to all three nematode species. The majority of cover crops tested were less susceptible than tomato to M. arenaria, with the exception of jack bean. Sunflower cv. Nusun 5672 had fewer M. arenaria J2 isolated from roots than the other sunflower cultivars, less galling than tomato, and fewer eggs than tomato and sunflower cv. 545A. Several cover crops did not support high populations of M. incognita in roots or exhibit significant galling, although high numbers of M. incognita J2 were isolated from the soil. Arugula, cowpea, and mustard mixture Caliente 99 did not support M. incognita in soil or roots. Jack bean and all three cultivars of sunflower were highly susceptible to M. javanica, and all sunflower cultivars had high numbers of eggs isolated from roots. Sunflower, jack bean, and both mustard mixtures exhibited significant galling in response to M. javanica. Arugula, cowpea, and sorghum-sudangrass consistently had low numbers of all three Meloidogyne species associated with roots and are good selections for use in ASD for root-knot nematode control. The remainder of crops tested had significant levels of galling, J2, and eggs associated with roots, which varied among the Meloidogyne species tested. PMID:24379486

  3. Evaluation of Cover Crops with Potential for Use in Anaerobic Soil Disinfestation (ASD) for Susceptibility to Three Species of Meloidogyne.

    PubMed

    Kokalis-Burelle, Nancy; Butler, David M; Rosskopf, Erin N

    2013-12-01

    Several cover crops with potential for use in tropical and subtropical regions were assessed for susceptibility to three common species of root-knot nematode, Meloidogyne arenaria, M. incognita, and M. javanica. Crops were selected based on potential use as organic amendments in anaerobic soil disinfestation (ASD) applications. Nematode juvenile (J2) numbers in soil and roots, egg production, and host plant root galling were evaluated on arugula (Eruca sativa, cv. Nemat), cowpea (Vigna unguiculata, cv. Iron & Clay), jack bean (Canavalia ensiformis, cv. Comum), two commercial mixtures of Indian mustard and white mustard (Brassica juncea & Sinapis alba, mixtures Caliente 61 and Caliente 99), pearl millet (Pennisetum glaucum, cv. Tifleaf III), sorghum-sudangrass hybrid (Sorghum bicolor × S. bicolor var. sudanense, cv. Sugar Grazer II), and three cultivars of sunflower (Helianthus annuus, cvs. 545A, Nusun 660CL, and Nusun 5672). Tomato (Solanum lycopersicum, cv. Rutgers) was included in all trials as a susceptible host to all three nematode species. The majority of cover crops tested were less susceptible than tomato to M. arenaria, with the exception of jack bean. Sunflower cv. Nusun 5672 had fewer M. arenaria J2 isolated from roots than the other sunflower cultivars, less galling than tomato, and fewer eggs than tomato and sunflower cv. 545A. Several cover crops did not support high populations of M. incognita in roots or exhibit significant galling, although high numbers of M. incognita J2 were isolated from the soil. Arugula, cowpea, and mustard mixture Caliente 99 did not support M. incognita in soil or roots. Jack bean and all three cultivars of sunflower were highly susceptible to M. javanica, and all sunflower cultivars had high numbers of eggs isolated from roots. Sunflower, jack bean, and both mustard mixtures exhibited significant galling in response to M. javanica. Arugula, cowpea, and sorghum-sudangrass consistently had low numbers of all three Meloidogyne species associated with roots and are good selections for use in ASD for root-knot nematode control. The remainder of crops tested had significant levels of galling, J2, and eggs associated with roots, which varied among the Meloidogyne species tested. PMID:24379486

  4. Short-Term Impact of Winter Cover Crop Biomass Removal On Soil Physical Properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rye (Secale cereale L.) is often recommended as a winter cover crop for conservation systems in the southeastern United States. Typically, rye is terminated with a glyphosate application 2-3 weeks prior to planting a summer crop. The glyphosate application is followed by a rolling operation to fla...

  5. Cover crop effects on soil microbial communities and enzyme activity in semiarid agroecosystems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to compare a fallow-winter wheat (Triticum aestivum L.) rotation to several cover crop-winter wheat rotations under dryland and irrigated conditions in the semiarid US High Plains. We carried out a study that included two sites (Sidney, NE, and Akron, CO), and three s...

  6. INFLUENCE OF SUMMER COVER CROPS ON SOIL NEMATODES IN A TOMATO FIELD

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A field experiment was conducted to evaluate the effects on populations of nematodes in tomato plots, some on which three legume cover crops (sunn hemp, Crotalaria juncea; velvetbean, Mucuna deeringiana; and cowpea, Vigna unguiculata) had been grown, and some which had been kept as a weed-free fallo...

  7. Impact of Winter Cover Crop Biomass Removal on Soil Properties and Cotton Yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recently, there has been a renewed interest on alternatives sources of energy, especially renewable sources. Numerous materials can be used for this purpose, including crop residues. The use of crop residues would give farmers a new source of income. The use of winter cover crops (WCC) is recommende...

  8. Cover crops alter the soil microbial community and increase potato tuber yield and quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An on-going study at a commercial farm operation in the San Luis Valley, CO is examining the effect of various summer cover crops (mustard, canola, sorghum-sudangrass, and a wet fallow control) on potato tuber yield and quality. In four of the five years, potato tuber yield and quality has shown si...

  9. Soil Persistence of Metarhizium anisopliae Applied to Manage Sugarbeet Root Maggot in a Cover Crop Microenvironment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sugarbeet root maggot, Tetanops myopaeformis (Röder), is a major insect pest of sugarbeet, Beta vulgaris L., in North Dakota, Minnesota, and Idaho. Three field trials using the insect pathogen Metarhizium anisopliae (Metch.) Sorok. ATCC 62176 in conjunction with cover crops were conducted in 200...

  10. Summer cover crop impacts on soil percolation and nitrogen leaching from a winter corn field

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was designed to measure impacts of sweet corn (Zea mays L.) production under South Florida’s subtropical conditions on groundwater quality and to determine the extent to which these impacts may be reduced by use of the leguminous summer cover crop sunn-hemp (Crotalaria juncea) as a potent...

  11. SUGARCANE RESPONSE TO DEPTH OF SOIL COVER AT PLANTING AND HERBICIDE TREATMENT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Research was conducted to evaluate the effects of depth of cover at planting on sugarcane yield and response to preemergence herbicide treatments over a complete three-year sugarcane cycle. Two studies were conducted at the Welcome Plantation in St. James Parish, LA, using LCP 85-384 sugarcane plan...

  12. Sensitivity of the normalized difference vegetation index to subpixel canopy cover, soil albedo, and pixel scale

    NASA Technical Reports Server (NTRS)

    Jasinski, Michael F.

    1990-01-01

    An analytical framework is provided for examining the physically based behavior of the normalized difference vegetation index (NDVI) in terms of the variability in bulk subpixel landscape components and with respect to variations in pixel scales, within the context of the stochastic-geometric canopy reflectance model. Analysis focuses on regional scale variability in horizontal plant density and soil background reflectance distribution. Modeling is generalized to different plant geometries and solar angles through the use of the nondimensional solar-geometric similarity parameter. Results demonstrate that, for Poisson-distributed plants and for one deterministic distribution, NDVI increases with increasing subpixel fractional canopy amount, decreasing soil background reflectance, and increasing shadows, at least within the limitations of the geometric reflectance model. The NDVI of a pecan orchard and a juniper landscape is presented and discussed.

  13. Metal immobilization and soil amendment efficiency at a contaminated sediment landfill site: a field study focusing on plants, springtails, and bacteria.

    PubMed

    Bert, Valérie; Lors, Christine; Ponge, Jean-François; Caron, Lucie; Biaz, Asmaa; Dazy, Marc; Masfaraud, Jean-François

    2012-10-01

    Metal immobilization may contribute to the environmental management strategy of dredged sediment landfill sites contaminated by metals. In a field experiment, amendment effects and efficiency were investigated, focusing on plants, springtails and bacteria colonisation, metal extractability and sediment ecotoxicity. Conversely to hydroxylapatite (HA, 3% DW), the addition of Thomas Basic Slag (TBS, 5% DW) to a 5-yr deposited sediment contaminated with Zn, Cd, Cu, Pb and As resulted in a decrease in the 0.01 M Ca(NO(3))(2)-extractable concentrations of Cd and Zn. Shoot Cd and Zn concentration in Calamagrostis epigejos, the dominant plant species, also decreased in the presence of TBS. The addition of TBS and HA reduced sediment ecotoxicity and improved the growth of the total bacterial population. Hydroxylapatite improved plant species richness and diversity and decreased antioxidant enzymes in C. Epigejos and Urtica dïoica. Collembolan communities did not differ in abundance and diversity between the different treatments. PMID:22647548

  14. Natural variations in snow cover do not affect the annual soil CO2 efflux from a mid-elevation temperate forest

    PubMed Central

    Schindlbacher, Andreas; Jandl, Robert; Schindlbacher, Sabine

    2014-01-01

    Climate change might alter annual snowfall patterns and modify the duration and magnitude of snow cover in temperate regions with resultant impacts on soil microclimate and soil CO2 efflux (Fsoil). We used a 5-year time series of Fsoil measurements from a mid-elevation forest to assess the effects of naturally changing snow cover. Snow cover varied considerably in duration (105–154 days) and depth (mean snow depth 19–59 cm). Periodically shallow snow cover (<10 cm) caused soil freezing or increased variation in soil temperature. This was mostly not reflected in Fsoil which tended to decrease gradually throughout winter. Progressively decreasing C substrate availability (identified by substrate induced respiration) likely over-rid the effects of slowly changing soil temperatures and determined the overall course of Fsoil. Cumulative CO2 efflux from beneath snow cover varied between 0.46 and 0.95 t C ha?1 yr?1 and amounted to between 6 and 12% of the annual efflux. When compared over a fixed interval (the longest period of snow cover during the 5 years), the cumulative CO2 efflux ranged between 0.77 and 1.18 t C ha?1 or between 11 and 15% of the annual soil CO2 efflux. The relative contribution (15%) was highest during the year with the shortest winter. Variations in snow cover were not reflected in the annual CO2 efflux (7.44–8.41 t C ha?1) which did not differ significantly between years and did not correlate with any snow parameter. Regional climate at our site was characterized by relatively high amounts of precipitation. Therefore, snow did not play a role in terms of water supply during the warm season and primarily affected cold season processes. The role of changing snow cover therefore seems rather marginal when compared to potential climate change effects on Fsoil during the warm season. PMID:23966344

  15. Landfill-impact evaluation. Final report

    SciTech Connect

    Not Available

    1985-04-08

    The Army proposes expansion of the building complex and development of the outdoor training area at the Milwaukee USAR Center Complex and Training Area located in Milwaukee, Wisconsin. Land use history indicates that the Milwaukee Sanitation Department disposed of approximately 500,000 cubic yards of solid wastes on the present complex site between 1957 and 1966. In September of 1984 evaluations were conducted to determine the impact of the landfill on the nearby soils and ground water. Monitoring wells were installed to determine the water quality of the groundwater near the surface of the water table and at depth. During soil borings operations, soil samples were analyzed in the field to determine the presence of hydrocarbons. The air in the bore hole was also analyzed to determine the presence of methane or other hydrocarbons. The impact of the existing landfill on groundwater and surface water quality is small. The higher than expected concentrations of hardness, total dissolved solids, chloride, and sulfate in some wells which may be due to the landfill, do not warrant recovery or remedial action to cleanup the ground water.

  16. Improved methodology to assess modification and completion of landfill gas management in the aftercare period.

    PubMed

    Morris, Jeremy W F; Crest, Marion; Barlaz, Morton A; Spokas, Kurt A; Kerman, Anna; Yuan, Lei

    2012-12-01

    Municipal solid waste landfills represent the dominant option for waste disposal in many parts of the world. While some countries have greatly reduced their reliance on landfills, there remain thousands of landfills that require aftercare. The development of cost-effective strategies for landfill aftercare is in society's interest to protect human health and the environment and to prevent the emergence of landfills with exhausted aftercare funding. The Evaluation of Post-Closure Care (EPCC) methodology is a performance-based approach in which landfill performance is assessed in four modules including leachate, gas, groundwater, and final cover. In the methodology, the objective is to evaluate landfill performance to determine when aftercare monitoring and maintenance can be reduced or possibly eliminated. This study presents an improved gas module for the methodology. While the original version of the module focused narrowly on regulatory requirements for control of methane migration, the improved gas module also considers best available control technology for landfill gas in terms of greenhouse gas emissions, air quality, and emissions of odoriferous compounds. The improved module emphasizes the reduction or elimination of fugitive methane by considering the methane oxidation capacity of the cover system. The module also allows for the installation of biologically active covers or other features designed to enhance methane oxidation. A methane emissions model, CALMIM, was used to assist with an assessment of the methane oxidation capacity of landfill covers. PMID:22884579

  17. Municipal landfill leachate management

    SciTech Connect

    Kusterer, T.; Willson, R.; Bruce, S.C.; Tissue, E. Lou, P.J.

    1998-12-31

    From 1995 to 1997, the Montgomery County Leachate Pretreatment Facility (MCLPF) has successfully pretreated in excess of 18,000,000 gallons of leachate generated by the county`s municipal solid waste landfill. The collection system directs leachate from the original landfill. The collection system directs leachate from the original landfill, the new lined section, and the ash cell to the leachate pump station. The leachate, prior to being pumped to the leachate pretreatment system, is equalized in two storage lagoons with a combined capacity of more than 5,000,000 gallons. The innovative leachate treatment system, incorporating a biological reactor system equipped with a submerged fixed-film reactor using a patented Matrix Biological Film (MBF) media, continues to provide excellent pretreatment results for the leachate generated at the Oaks Landfill in Montgomery County, Maryland. In 1995 and 1996, the system responded to the substantial challenges imposed by the changing characteristics of the material being landfilled and by the significant amounts of incinerator ash, received in 1995 from the county`s resource recovery facility (RRF), which influenced the influent leachate characteristics.

  18. Plant cover, soil temperature, freeze, water stress, and evapotranspiration conditions. [south Texas

    NASA Technical Reports Server (NTRS)

    Wiegand, C. L.; Nixon, P. R.; Gausman, H. W.; Namken, L. N.; Leamer, R. W.; Richardson, A. J. (principal investigators)

    1981-01-01

    Emissive and reflective data for 10 days, and IR data for 6 nights in south Texas scenes were analyzed after procedures were developed for removing cloud-affected data. HCMM radiometric temperatures were: within 2 C of dewpoint temperatures on nights when air temperature approached dewpoint temperatures; significantly correlated with variables important in evapotranspiration; and, related to freeze severity and planting depth soil temperatures. Vegetation greenness indexes calculated from visible and reflective IR bands of NOAA-6 to -9 meteorological satellites will be useful in the AgRISTARS program for seasonal crop development, crop condition, and drought applications.

  19. Effects of soil temperature and snow cover on the mortality of overwintering pupae of the cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae)

    NASA Astrophysics Data System (ADS)

    Huang, Jian

    2015-10-01

    Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is one of the most damaging insect pests in the world. However, little is known about the effects of snow cover and soil temperature on the overwintering pupae of H. armigera. A field experiment was conducted from November 2, 2012 to April 24, 2013 at the agrometeorological experimental station in Wulanwusu, China. Overwintering pupae were embedded into the soil at depths of 5, 10, and 15 cm in the following four treatments: without snow cover, snow cover, and increased temperatures from 600 and 1200 W infrared lights. The results showed that snow cover and rising temperatures could all markedly increase soil temperatures, which was helpful in improving the survival of the overwintering pupae of H. armigera. The mortality of overwintering pupae (MOP) at a depth of 15 cm was the highest, and the MOP at a depth of 5 cm followed. The lower accumulated temperature (?0 °C) (AT ? °C) led to the higher MOP, and the lower diurnal soil temperature range (DSTR) likely led to the lower MOP. After snowmelt, the MOPs at the depths of 5 and 10 cm increased as the soil temperature increased, especially in April. The AT of the soil (?0 °C) was the factor with the strongest effect on MOP. The soil moisture content was not a major factor affecting the MOP in this semiarid region because precipitation was 45 mm over the entire experimental period. With climate warming, the MOP will likely decrease, and the overwintering boundary air temperatures of H. armigera should be expanded due to higher soil temperatures and increased snow cover.

  20. Effects of Particle Size and Shape, and Soil Structure on Thermal Properties of Non-aggregated and Aggregated Soils

    NASA Astrophysics Data System (ADS)

    Kamoshida, T.; Hamamoto, S.; Kawamoto, K.; Sakaki, T.; Komatsu, T.; Hu, Q.

    2012-12-01

    Thermal properties including thermal conductivity and heat capacity are very important for understanding heat transport processes in landfill site cover soil to control the microbial processes in the cover soil. Previous studies have shown effects of soil conditions such as moisture content and degree of compaction on the thermal properties for differently-textured soils. However, there are few studies on the relations between the thermal properties and micro-scale soil information such as particle size and shape although the size and shape of soil particles highly affect soil packing configuration. In addition, it is not fully understood that soil structure (i.e., aggregate structure) affects behaviors of thermal properties. In this study, non-aggregated (sandy) and aggregated soils with different size fractions at variably-saturated conditions were used for measuring thermal properties. Micro-scale characterizations of soil-pore structure and soil particle configuration using a X-ray CT device were also performed for sandy soils. For sandy soils, the relation between measured thermal properties and mineral composition (i.e., quartz content), roundness/sphericity of soil particles, and particle size, and solid-phase tortuosity based on X-ray CT images, were investigated. For aggregated soils, the measured thermal conductivities at variably-saturated conditions were discussed based on the water retention characteristics and pore-size distribution in inter- and intra-aggregate pore regions.

  1. Quantification of methane emissions from 15 Danish landfills using the mobile tracer dispersion method.

    PubMed

    Mønster, Jacob; Samuelsson, Jerker; Kjeldsen, Peter; Scheutz, Charlotte

    2015-01-01

    Whole-site methane emissions from 15 Danish landfills were assessed using a mobile tracer dispersion method with either Fourier transform infrared spectroscopy (FTIR), using nitrous oxide as a tracer gas, or cavity ring-down spectrometry (CRDS), using acetylene as a tracer gas. The landfills were chosen to represent the different stages of the lifetime of a landfill, including open, active, and closed covered landfills, as well as those with and without gas extraction for utilisation or flaring. Measurements also included landfills with biocover for oxidizing any fugitive methane. Methane emission rates ranged from 2.6 to 60.8 kg h(-1), corresponding to 0.7-13.2 g m(-2)d(-1), with the largest emission rates per area coming from landfills with malfunctioning gas extraction systems installed, and the smallest emission rates from landfills closed decades ago and landfills with an engineered biocover installed. Landfills with gas collection and recovery systems had a recovery efficiency of 41-81%. Landfills where shredder waste was deposited showed significant methane emissions, with the largest emission from newly deposited shredder waste. The average methane emission from the landfills was 154 tons y(-1). This average was obtained from a few measurement campaigns conducted at each of the 15 landfills and extrapolating to annual emissions requires more measurements. Assuming that these landfills are representative of the average Danish landfill, the total emission from Danish landfills were calculated at 20,600 tons y(-1), which is significantly lower than the 33,300 tons y(-1) estimated for the national greenhouse gas inventory for 2011. PMID:25442105

  2. LANDFILLS EFFLUENT LIMITATIONS GUIDELINES DATABASE

    EPA Science Inventory

    Resource Purpose:This resource served as the main information source for national characteristics of landfills for the landfills effluent guidelines. The database was developed based on responses to the "1994 Waste Treatment Industry Questionnaire: Phase II Landfills" and...

  3. Landfill wall revegetation combined with leachate recirculation: a convenient procedure for management of closed landfills.

    PubMed

    Del Moro, G; Barca, E; Cassano, D; Di Iaconi, C; Mascolo, G; Brunetti, G

    2014-01-01

    There is a need for a reliable sustainable option to effectively manage the landfill leachate generation. This study presents a simple procedure for the revegetation of the walls of closed landfills, employing the leachate as a fertirrigant. The native plants Lepidium sativum, Lactuca sativa, and Atriplex halimus, which suit the local climate, were chosen for this study in Southern Italy. The methodology was structured into three phases (i) early stage toxicity assessment phase (apical root length and germination tests), (ii) adult plant resistance assessment phase, and (iii) soil properties verification phase. The rationale of the proposed approach was first to look at the distinctive qualities and the potential toxicity in landfill leachates for fertigation purposes. Afterwards, through specific tests, the plants used were ranked in terms of resistance to the aqueous solution that contained leachate. Finally, after long-term irrigation, any possible worsening of soil properties was evaluated. The results demonstrated the real possibility of using blended leachate as a fertigant for the revegetation of the walls of closed landfills. In particular, the plants maintained good health when leachate was blended at concentrations of lower than 25 and 5%, respectively for A. halimus and Lepidium sativum. Irrigation tests showed good resistance of the plants, even at dosages of 112 and 133.5 mm m(-2), at maximum concentrations of 25 and 5%, respectively, for A. halimus and Lepidium sativum. The analysis of the total chlorophyll content and of aerial parts dried weight confirmed the results reported above. PMID:24737024

  4. Sustainable sanitary landfills for neglected small cities in developing countries: The semi-mechanized trench method from Villanueva, Honduras

    SciTech Connect

    Oakley, Stewart M.; Jimenez, Ramon

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Open dumping is the most common form of waste disposal in neglected small cities. Black-Right-Pointing-Pointer Semi-mechanized landfills can be a sustainable option for small cities. Black-Right-Pointing-Pointer We present the theory of design and operation of semi-mechanized landfills. Black-Right-Pointing-Pointer Villanueva, Honduras has operated its semi-mechanized landfill for 15 years. Black-Right-Pointing-Pointer The cost of operation is US$4.60/ton with a land requirement of 0.2m{sup 2}/person-year. - Abstract: Open dumping is the most common practice for the disposal of urban solid wastes in the least developed regions of Africa, Asia and Latin America. Sanitary landfill design and operation has traditionally focused on large cities, but cities with fewer than 50,000 in population can comprise from 6% to 45% of a given country's total population. These thousands of small cities cannot afford to operate a sanitary landfill in the way it is proposed for large cities, where heavy equipment is used to spread and compact the waste in daily cells, and then to excavate, transport and apply daily cover, and leachate is managed with collection and treatment systems. This paper presents an alternative approach for small cities, known as the semi-mechanized trench method, which was developed in Villanueva, Honduras. In the semi-mechanized trench method a hydraulic excavator is used for 1-3 days to dig a trench that will last at least a month before it is filled with waste. Trucks can easily unload their wastes into the trench, and the wastes compact naturally due to semi-aerobic biodegradation, after which the trenches are refilled and covered. The exposed surface area is minimal since only the top surface of the wastes is exposed, the remainder being covered by the sides and bottom of the trench. The surplus material from trench excavation can be valorized for use as engineering fill onsite or off. The landfill in Villanueva has operated for 15 years, using a total land area of approximately 11 ha for a population that grew from 23,000 to 48,000, with a land requirement of 0.2 m{sup 2}/person year, a cover to waste ratio of 0.2, and an estimated soil surplus of 298,000 m{sup 3} that is valorized and used onsite. The landfill has been operated solely by the municipality with an operational cost in 2010 estimated at US$4.60 per ton. A modified water balance analysis at Villanueva shows negligible leachate generation from covered trenches and 700 m{sup 3}/yr (60 m{sup 3}/ha yr) from the two open trenches required for daily operation. If the site were an open dump, however, leachate generation is estimated to be 3900 m{sup 3}/ha yr and contaminated runoff 5000 m{sup 3}/ha yr. A simple model used to estimate dilution of generated leachate based on groundwater flow data and aquifer stratigraphy suggests that the leachate will be diluted by a factor of 0.01 in the aquifer. Leachate contaminants will not accumulate because the aquifer discharges to the Ulua River 2 km south of the landfill. While not suitable for all sites, the Villanueva method nevertheless serves as an excellent example of how a small city landfill with natural compaction of waste and attenuation of leachate can be sustainably operated.

  5. The role of land cover change in modulating the soil moisture-temperature land-atmosphere coupling strength over Australia

    NASA Astrophysics Data System (ADS)

    Hirsch, A. L.; Pitman, A. J.; Kala, J.

    2014-08-01

    The severity of recent droughts and heat waves have been linked to land-atmosphere feedbacks. However, investigations of how these feedbacks are influenced by land use and land cover change (LULCC) are limited. Using the Weather and Research Forecasting model with an ensemble framework of planetary boundary layer and cumulus parameterization schemes, we combine the Global Land Atmosphere Coupling Experiment methodology with LULCC to assess how LULCC affects land-atmosphere coupling strength for maximum temperature over Australia. We find a statistically significant decrease in soil moisture-temperature coupling over regions where forest changes to crops, which was consistent across the implemented model physics and background climate. This was associated with a decrease in the ensemble mean variance suggesting that LULCC influences regional climate variability via changes in the regional scale hydrology and surface energy balance. Our results highlight the need to consider land surface changes and coupling strength in combination, rather than in isolation.

  6. Post-closure care of engineered municipal solid waste landfills.

    PubMed

    Bagchi, Amalendu; Bhattacharya, Abhik

    2015-03-01

    Post-closure care is divided into perpetual care (PPC) and long-term care (LTC). Guidelines for post-closure care and associated costs are important for engineered municipal solid waste (MSW) landfills. In many states in the USA, landfill owners are required to set aside funds for 30-40 years of LTC. Currently there are no guidelines for PPC, which is also required. We undertook a pilot study, using two landfills (note: average landfill capacity 2.5 million MT MSW waste) in Wisconsin, to establish an approach for estimating the LTC period using field data and PPC funding need. Statistical analysis of time versus concentration data of selected leachate parameters showed that the concentration of most parameters is expected to be at or below the preventive action limit of groundwater and leachate volume will be very low, within 40 years of the LTC period. The gas extraction system may need to be continued for more than 100 years. Due to lack of data no conclusion could be made regarding adequacy of the LTC period for the groundwater monitoring system. The final cover must be maintained for perpetuity. The pilot study shows that although technology is available, the financial liability of maintaining a 'Dry Tomb' design for landfills is significantly higher than commonly perceived. The paper will help landfill professionals to estimate realistic post-closure funding and to develop field-based policies for LTC and PPC of engineered MSW landfills. PMID:25687915

  7. HYDROLOGIC EVALUATION OF LANDFILL PERFORMANCE (HELP) MODEL: USER'S GUIDE FOR VERSION 3

    EPA Science Inventory

    The Hydrologic Evaluation of Landfill Performance (HELP) computer program is a quasi-two-dimensional hydrologic model of water movement across, into, through and out of landfills. he model accepts weather, soil and design data. andfill systems including various combinations of ve...

  8. Mixed waste landfill cell construction at energy solutions LLC: a regulator's perspective

    SciTech Connect

    Lukes, G.C.; Willoughby, O.H.

    2007-07-01

    A small percentage of the property that EnergySolutions' (formerly Envirocare) operates at Clive, Utah is permitted by the State of Utah as a treatment, storage and disposal facility for mixed waste. Mixed Waste is defined as a hazardous waste (Title 40 Code of Federal Regulations Part 261.3) that also has a radioactive component. Typically, the waste EnergySolutions receives at its mixed waste facility is contaminated with heavy metals and organic compounds while also contaminated with radioactivity. For EnergySolutions, the largest generator of mixed waste is the United States Department of Energy. However, EnergySolutions also accepts a wide variety of mixed waste from other generators. For many wastes, EnergySolutions goes through the process of characterization and acceptance (if appropriate) of the waste, treating the waste (if necessary), confirmation that the waste meets Land Disposal Restriction, and disposal of the waste in its mixed waste landfill cell (MWLC). EnergySolutions originally received its State-issued Part B (RCRA) permit in 1990. The Permit allows a mixed waste landfill cell footprint that covers roughly 10 hectares and includes 20 individual 'sumps'. EnergySolutions chose to build small segments of the landfill cell as waste receipts dictated. Nearly 16 years later, EnergySolutions has just completed its Phase V construction project. 18 of the 20 sumps in the original design have been constructed. The last two sumps are anticipated to be its Phase VI construction project. Further expansion of its mixed waste disposal landfill capacity beyond the current design would require a permit modification request and approval by the Executive Secretary of the Utah Solid and Hazardous Waste Control Board. Construction of the landfill cell is governed by the Construction Quality Assurance/Quality Control manual of its State-issued Permit. The construction of each sump is made up of (from the bottom up): a foundation; three feet of engineered clay; primary and secondary geo-synthetics (60 mil HDPE, geo-fabric and geo-textile); a two foot soil protective cover; tertiary geo-synthetics (80 mil HDPE, geo-fabric and geo-textile); and a final two foot soil protective cover. The Utah Department of Environmental Quality Division of Solid and Hazardous Waste (UDEQ/DSHW) oversees the construction process and reviews the documentation after the construction is complete. If all aspects of the construction process are met, the Executive Secretary of the Utah Solid and Hazardous Waste Control Board approves the landfill cell for disposal. It is the role of the regulator to ensure to the stakeholders that the landfill cell has been constructed in accordance with the State-issued permit and that the cell is protective of human health and the environment. A final determination may require conflict resolution between the agency and the facility. (authors)

  9. The use of olive-mill waste compost to promote the plant vegetation cover in a trace-element-contaminated soil.

    PubMed

    Pardo, Tania; Martínez-Fernández, Domingo; Clemente, Rafael; Walker, David J; Bernal, M Pilar

    2014-01-01

    The applicability of a mature compost as a soil amendment to promote the growth of native species for the phytorestoration of a mine-affected soil from a semi-arid area (SE Spain), contaminated with trace elements (As, Cd, Cu, Mn, Pb and Zn), was evaluated in a 2-year field experiment. The effects of an inorganic fertiliser were also determined for comparison. Bituminaria bituminosa was the selected native plant since it is a leguminous species adapted to the particular local pedoclimatic conditions. Compost addition increased total organic-C concentrations in soil with respect to the control and fertiliser treatments, maintained elevated available P concentrations throughout the duration of the experiment and stimulated soil microbial biomass, while trace elements extractability in the soil was rather low due to the calcareous nature of the soil and almost unaltered in the different treatments. Tissue concentrations of P and K in B. bituminosa increased after the addition of compost, associated with growth stimulation. Leaf Cu concentration was also increased by the amendments, although overall the trace elements concentrations can be considered non-toxic. In addition, the spontaneous colonisation of the plots by a total of 29 species of 15 different families at the end of the experiment produced a greater vegetation cover, especially in plots amended with compost. Therefore, the use of compost as a soil amendment appears to be useful for the promotion of a vegetation cover and the phytostabilisation of moderately contaminated soils under semi-arid conditions. PMID:23868726

  10. Soil cover patterns in the northern part of the area of aspen-fir taiga in the southeast of Western Siberia

    NASA Astrophysics Data System (ADS)

    Loiko, S. V.; Geras'ko, L. I.; Kulizhskii, S. P.; Amelin, I. I.; Istigechev, G. I.

    2015-04-01

    Soil cover patterns in the northern part of the area of aspen-fir taiga on the Tom'-Yaya interfluve at 170-270 m a.s.l. are analyzed. Landscapes of the subtaiga piedmont province are found at somewhat lower heights. The three major forms of the local mesotopography include virtually flat interfluve surfaces, slopes (that predominate in area), and the network of ravines and small river valleys. Modal soil combinations on the slopes consist of the typical soddy-podzolic soils with very deep bleached eluvial horizons and dark gray (or gray) residual-humus gleyic soils with dark humus coatings. With an increase in the degree of drainage of the territory (toward the local erosional network), the portion of gleyic soil subtypes decreases from nearly 100% on the flat interfluves to 10-15% on the slopes; the portion of soils with residual humus features decreases from 80-90 to 10-15%, respectively. These two soil subtypes can be considered intergrades between typical soils of the aspen-fir taiga (soddy-podzolic soils with very deep bleached horizons) and dark gray and gray residual-humus soils characteristic of the subtaiga zone in the south of Western Siberia.

  11. Hydrologic Evaluation of Landfill Performance (HELP) Model: B (Set Includes, A- User's Guide for Version 3 w/disks, B-Engineering Documentation for Version 3

    EPA Science Inventory

    The Hydrologic Evaluation of Landfill Performance (HELP) computer program is a quasi-two-dimensional hydrologic model of water movement across, into, through and out of landfills. The model accepts weather, soil and design data. Landfill systems including various combinations o...

  12. Superfund record of decision (EPA Region 3): Bush Valley Landfill Superfund Site, Harford County, Abingdon, MD, (final remedial action), September 26, 1995

    SciTech Connect

    1995-10-01

    This Record of Decision (`ROD`) presents the final remedial action selected for the Bush Valley Landfill Superfund Site (`Site`), located near the town of Abingdon in Hardford County, Maryland. The remedial action selected for this Site is a final remedy which will address the wastes buried in the landfill, contaminated soils, leachate, landfill gas, the adjacent wetlands and streams, and contaminated ground water.

  13. Effects of nitrogen deposition and soil fertility on cover and physiology of Cladonia foliacea (Huds.) Willd., a lichen of biological soil crusts from Mediterranean Spain.

    PubMed

    Ochoa-Hueso, Raúl; Manrique, Esteban

    2011-02-01

    We are fertilizing a thicket with 0, 10, 20 and 50 kg nitrogen (N) ha(-1) yr(-1) in central Spain. Here we report changes in cover, pigments, pigment ratios and FvFm of the N-tolerant, terricolous, lichen Cladonia foliacea after 1-2 y adding N in order to study its potential as biomarker of atmospheric pollution. Cover tended to increase. Pigments increased with fertilization independently of the dose supplied but only significantly with soil nitrate as covariate. ?-carotene/chlorophylls increased with 20-50 kg N ha(-1) yr(-1) (over the background) and neoxanthin/chlorophylls also increased with N. (Neoxanthin+lutein)/carotene decreased with N when nitrate and pH seasonalities were used as covariates. Between 26 and 56 kg N ha(-1) yr(-1).Pinho et al. (2012) suggested that the critical Nload for Mediterranean epiphytic lichens (based on responses of functional groups) was lower than 26 kg N ha(-1) yr(-1) [corrected]. Water-stress, iron and copper also explained variables of lichen physiology. We conclude that this tolerant lichen could be used as biomarker and that responses to N are complex in heterogeneous Mediterranean-type landscapes. PMID:21071125

  14. Improved methodology to assess modification and completion of landfill gas management in the aftercare period

    SciTech Connect

    Morris, Jeremy W.F.; Crest, Marion; Barlaz, Morton A.; Spokas, Kurt A.; Akerman, Anna; Yuan, Lei

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Performance-based evaluation of landfill gas control system. Black-Right-Pointing-Pointer Analytical framework to evaluate transition from active to passive gas control. Black-Right-Pointing-Pointer Focus on cover oxidation as an alternative means of passive gas control. Black-Right-Pointing-Pointer Integrates research on long-term landfill behavior with practical guidance. - Abstract: Municipal solid waste landfills represent the dominant option for waste disposal in many parts of the world. While some countries have greatly reduced their reliance on landfills, there remain thousands of landfills that require aftercare. The development of cost-effective strategies for landfill aftercare is in society's interest to protect human health and the environment and to prevent the emergence of landfills with exhausted aftercare funding. The Evaluation of Post-Closure Care (EPCC) methodology is a performance-based approach in which landfill performance is assessed in four modules including leachate, gas, groundwater, and final cover. In the methodology, the objective is to evaluate landfill performance to determine when aftercare monitoring and maintenance can be reduced or possibly eliminated. This study presents an improved gas module for the methodology. While the original version of the module focused narrowly on regulatory requirements for control of methane migration, the improved gas module also considers best available control technology for landfill gas in terms of greenhouse gas emissions, air quality, and emissions of odoriferous compounds. The improved module emphasizes the reduction or elimination of fugitive methane by considering the methane oxidation capacity of the cover system. The module also allows for the installation of biologically active covers or other features designed to enhance methane oxidation. A methane emissions model, CALMIM, was used to assist with an assessment of the methane oxidation capacity of landfill covers.

  15. Characterization of fine fraction mined from two Finnish landfills.

    PubMed

    Mönkäre, Tiina J; Palmroth, Marja R T; Rintala, Jukka A

    2016-01-01

    A fine fraction (FF) was mined from two Finnish municipal solid waste (MSW) landfills in Kuopio (1- to 10-year-old, referred as new landfill) and Lohja (24- to 40-year-old, referred as old landfill) in order to characterize FF. In Kuopio the FF (<20mm) was on average 45±7% of the content of landfill and in Lohja 58±11%. Sieving showed that 86.5±5.7% of the FF was smaller than 11.2mm and the fraction resembled soil. The total solids (TS) content was 46-82%, being lower in the bottom layers compared to the middle layers. The organic matter content (measured as volatile solids, VS) and the biochemical methane potential (BMP) of FF were lower in the old landfill (VS/TS 12.8±7.1% and BMP 5.8±3.4m(3)CH4/t TS) than in the new landfill (VS/TS 21.3±4.3% and BMP 14.4±9.9m(3)CH4/t TS), and both were lower compared with fresh MSW. In the Kuopio landfill materials were also mechanically sieved in the full scale plant in two size fraction <30mm (VS/TS 31.1% and 32.9m(3)CH4/t TS) and 30-70mm (VS/TS 50.8% and BMP 78.5m(3)CH4/t TS). The nitrogen (3.5±2.0g/kg TS), phosphorus (<1.0-1.5g/kg TS) and soluble chemical oxygen demand (COD) (2.77±1.77kg/t TS) contents were low in all samples. Since FF is major fraction of the content of landfill, the characterization of FF is important to find possible methods for using or disposing FF mined from landfills. PMID:25817722

  16. Exploring the linkage between spontaneous grass cover biodiversity and soil degradation in two olive orchard microcatchments with contrasting environmental and management conditions

    NASA Astrophysics Data System (ADS)

    Taguas, E. V.; Arroyo, C.; Lora, A.; Guzmán, G.; Vanderlinden, K.; Gómez, J. A.

    2015-11-01

    Spontaneous grass covers are an inexpensive soil erosion control measure in olive orchards. Olive farmers allow grass to grow on sloping terrain to comply with the basic environmental standards derived from the Common Agricultural Policy (CAP, European Commission). However, to date there are few studies assessing the environmental quality considering such covers. In this study, we measured biodiversity indices for spontaneous grass cover in two olive orchards with contrasting site conditions and management regimes in order to evaluate the potential for biodiversity metrics to serve as an indicator of soil degradation. In addition, the differences and temporal variability of biodiversity indicators and their relationships with environmental factors such as soil type and properties, precipitation, topography and soil management were analysed. Different grass cover biodiversity indices were evaluated in two olive orchard catchments under conventional tillage and no tillage with grass cover, during 3 hydrological years (2011-2013). Seasonal samples of vegetal material and photographs in a permanent grid (4 samples ha-1) were taken to characterize the temporal variations of the number of species, frequency of life forms, diversity and modified Shannon and Pielou indices. Sorensen's index showed strong differences in species composition for the grass covers in the two olive orchard catchments, which are probably linked to the different site conditions. The catchment (CN) with the best site conditions (deeper soil and higher precipitation) and most intense management presented the highest biodiversity indices as well as the highest soil losses (over 10 t ha-1). In absolute terms, the diversity indices of vegetation were reasonably high for agricultural systems in both catchments, despite the fact that management activities usually severely limit the landscape and the variety of species. Finally, a significantly higher content of organic matter in the first 10 cm of soil was found in the catchment with worse site conditions in terms of water deficit, average annual soil losses of 2 t ha-1 and the least intense management. Therefore, the biodiversity indices considered in this study to evaluate spontaneous grass cover were not found to be suitable for describing the soil degradation in the study catchments.

  17. Effects of Cover Crops to Offset Soil Carbon Changes Under No-till on an Ohio farm when Biomass is Harvested

    NASA Astrophysics Data System (ADS)

    Kimble, J. M.; Everett, L. R.; Richards, W.

    2003-12-01

    The results of a long term experiment to look at the use of cover crops and there effect on soil organic carbon. No-till has been shown to increase SOC and improve the overall soil quality under conditions where the biomass has been returned to the field. However, biomass may be removed as silage or for use in biofuels. The removal will reduce the inputs to the field so to overcome the amount of biomass not returned to the soil different cover crops were used. This experiment was done on a working farm where the corn biomass was being removed as silage. Four cover crops were planted in early September of 2002: rye, oats, clover, and canola with two controls, one with no cover crop and one where corn stubble was left on the field. The soils were sampled soon after the crops were planted and again in the spring of 2003 before the cover crops were killed just prior to planting. The first results indicate that the most root biomass was produced by the rye followed by oats then canola and then clover.

  18. COVER CROP SYSTEM EFFECTS ON CARBON/NITROGEN SEQUESTRATION AND THE PHYSICAL PROPERTIES OF COASTAL PLAIN SOILS UNDER CONSERVATION TILLAGE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crop growth and water/solute movement are affected by soil properties. Crop growth is affected by soil moisture retention, which relates to soil structure (particle and pore size distribution), which is greatly affected by soil C levels. Soil hydraulic conductivity depends on particle size distrib...

  19. Effects of land use and land cover on selected soil quality indicators in the headwater area of the Blue Nile basin of Ethiopia.

    PubMed

    Teferi, Ermias; Bewket, Woldeamlak; Simane, Belay

    2016-02-01

    Understanding changes in soil quality resulting from land use and land management changes is important to design sustainable land management plans or interventions. This study evaluated the influence of land use and land cover (LULC) on key soil quality indicators (SQIs) within a small watershed (Jedeb) in the Blue Nile Basin of Ethiopia. Factor analysis based on principal component analysis (PCA) was used to determine different SQIs. Surface (0-15 cm) soil samples with four replications were collected from five main LULC types in the watershed (i.e., natural woody vegetation, plantation forest, grassland, cultivated land, and barren land) and at two elevation classes (upland and midland), and 13 soil properties were measured for each replicate. A factorial (2?×?5) multivariate analysis of variance (MANOVA) showed that LULC and altitude together significantly affected organic matter (OM) levels. However, LULC alone significantly affected bulk density and altitude alone significantly affected bulk density, soil acidity, and silt content. Afforestation of barren land with eucalypt trees can significantly increase the soil OM in the midland part but not in the upland part. Soils under grassland had a significantly higher bulk density than did soils under natural woody vegetation indicating that de-vegetation and conversion to grassland could lead to soil compaction. Thus, the historical LULC change in the Jedeb watershed has resulted in the loss of soil OM and increased soil compaction. The study shows that a land use and management system can be monitored if it degrades or maintains or improves the soil using key soil quality indicators. PMID:26744135

  20. Air emissions assessment and air quality permitting for a municipal waste landfill treating municipal sewage sludge

    SciTech Connect

    Koehler, J.

    1998-12-31

    This paper presents a case study into the air quality permitting of a municipal solid waste (MSW) landfill in the San Francisco Bay Area undergoing a proposed expansion in operations to increase the life of the landfill. The operations of this facility include MSW landfilling, the treatment and disposal of municipal sewage sludge, the aeration of petroleum-contaminated soils, the construction of a new on-site plant to manufacture soil amendment products from waste wood and other organic material diverted from the landfill, and the installation of a vaporator to create steam from leachate for injection into the landfill gas flare. The emissions assessment for each project component relied upon interpretation of source tests from similar operations, incorporation of on-site measurements into emissions models and mass balances, and use of AP-42 procedures for emissions sources such as wind-blown dust, material handling and transfer operations, and fugitive landfill gas. Air permitting issues included best available control technology (BACT), emission offset thresholds, new source performance standards (NSPS), potential air toxics health risk impacts, and compliance with federal Title V operating permit requirements. With the increasing difficulties of siting new landfills, increasing pressures to reduce the rate of waste placement into existing landfills, and expanding regulatory requirements on landfill operations, experiences similar to those described in this paper are likely to increase in the future as permitting scenarios become more complex.

  1. GEOtop: Simulating the combined energy and water balance at and below the land surface accounting for soil freezing, snow cover and terrain effects (Invited)

    NASA Astrophysics Data System (ADS)

    Endrizzi, S.; Dall'Amico, M.; Gruber, S.; Rigon, R.

    2013-12-01

    One of the most interesting characteristics of the GEOtop distributed model is the way that it treats soil freezing. The theory behind soil freezing in GEOtop is here reviewed by means of a neat thermodynamical treatment that includes a discussion of the Clausius-Clapeyron relation. Effects of soil freezing on the production of subsurface fluxes and surface runoff are presented through some simple "virtual" case study, which constitutes a possible benchmark for comparing soil freezing models. Effects of freezing and thawing is also presented in a real case study. Effects of snow-cover on the thermal evolution of soil is also presented and discussed. Eventually ways to improve GEOtop are presented and discussed.

  2. Characterization of post-fire surface cover, soils, and burn severity at the Cerro Grande Fire, New Mexico, using hyperspectral and multispectral remote sensing

    USGS Publications Warehouse

    Kokaly, R.F.; Rockwell, B.W.; Haire, S.L.; King, T.V.V.

    2007-01-01

    Forest fires leave behind a changed ecosystem with a patchwork of surface cover that includes ash, charred organic matter, soils and soil minerals, and dead, damaged, and living vegetation. The distributions of these materials affect post-fire processes of erosion, nutrient cycling, and vegetation regrowth. We analyzed high spatial resolution (2.4??m pixel size) Airborne Visible and Infrared Imaging Spectrometer (AVIRIS) data collected over the Cerro Grande fire, to map post-fire surface cover into 10 classes, including ash, soil minerals, scorched conifer trees, and green vegetation. The Cerro Grande fire occurred near Los Alamos, New Mexico, in May 2000. The AVIRIS data were collected September 3, 2000. The surface cover map revealed complex patterns of ash, iron oxide minerals, and clay minerals in areas of complete combustion. Scorched conifer trees, which retained dry needles heated by the fire but not fully combusted by the flames, were found to cover much of the post-fire landscape. These scorched trees were found in narrow zones at the edges of completely burned areas. A surface cover map was also made using Landsat Enhanced Thematic Mapper plus (ETM+) data, collected September 5, 2000, and a maximum likelihood, supervised classification. When compared to AVIRIS, the Landsat classification grossly overestimated cover by dry conifer and ash classes and severely underestimated soil and green vegetation cover. In a comparison of AVIRIS surface cover to the Burned Area Emergency Rehabilitation (BAER) map of burn severity, the BAER high burn severity areas did not capture the variable patterns of post-fire surface cover by ash, soil, and scorched conifer trees seen in the AVIRIS map. The BAER map, derived from air photos, also did not capture the distribution of scorched trees that were observed in the AVIRIS map. Similarly, the moderate severity class of Landsat-derived burn severity maps generated from the differenced Normalized Burn Ratio (dNBR) calculation had low agreement with the AVIRIS classes of scorched conifer trees. Burn severity and surface cover images were found to contain complementary information, with the dNBR map presenting an image of degree of change caused by fire and the AVIRIS-derived map showing specific surface cover resulting from fire.

  3. Assessment of groundwater contamination by landfill leachate: a case in México.

    PubMed

    Reyes-López, Jaime A; Ramírez-Hernández, Jorge; Lázaro-Mancilla, Octavio; Carreón-Diazconti, Concepción; Garrido, Miguel Martín-Loeches

    2008-01-01

    In México, uncontrolled landfills or open-dumps are regularly used as "sanitary landfills". Interactions between landfills/open-dumps and shallow unconfined aquifers have been widely documented. Therefore, evidence showing the occurrence of aquifer contamination may encourage Mexican decision makers to enforce environmental regulations. Traditional methods such as chemical analysis of groundwater, hydrological descriptions, and geophysical studies including vertical electrical sounding (VES) and ground penetrating radar (GPR) were used for the identification and delineation of a contaminant plume in a shallow aquifer. The Guadalupe Victoria landfill located in Mexicali is used as a model study site. This landfill has a shallow aquifer of approximately 1m deep and constituted by silty sandy soil that may favor the transport of landfill leachate. Geophysical studies show a landfill leachate contaminant plume that extends for 20 and 40 m from the SE and NW edges of the landfill, respectively. However, the zone of the leachate's influence stretches for approximately 80 m on both sides of the landfill. Geochemical data corroborates the effects of landfill leachate on groundwater. PMID:18595685

  4. Using multi-approaches to investigate the effects of land cover on runoff and soil erosion in the Loess Plateau of China

    NASA Astrophysics Data System (ADS)

    Gao, G.; Fu, B.; Liu, Y.; Wang, Y.

    2012-12-01

    This study used the in-situ measurement, model simulation and radioisotope tracing methods to investigate the effects of land cover on runoff and soil erosion at plot and hillslope scales in the Loess Plateau of China. Three runoff plot groups covered by sparse young trees (Group 1), native shrubs (Group 2) and dense tussock (Group 3) with different revegetation time were established in the Yangjuangou catchment of Loess Plateau. Greater runoff was produced in plot groups (Group 2 and Group 3) with higher vegetation cover and longer restoration time as a result of soil compaction processes. Both of the runoff coefficient and soil loss rate decreased with increasing plot length in Group 2 and Group 3 plots. The runoff coefficient increased with plot length in Group 1 plots located at the early stage of revegetation, and the soil loss rates increased over an area threshold. Therefore, the effect of scale on runoff and soil erosion was dependent on restoration extent. The antecedent moisture condition (AMC) was explicitly incorporated in runoff production and initial abstraction of the SCS-CN model, and the direct effect of runoff on event soil loss was considered in the RUSLE model by adopting a rainfall-runoff erosivity factor. The modified SCS-CN and RUSLE models were coupled to link rainfall-runoff-erosion modeling. The modified SCS-CN model was accurate in predicting event runoff from the three plot groups with Nash-Sutcliffe model efficiency (EF) over 0.85, and the prediction accuracy of the modified RUSLE model was satisfactory with EF values being over 0.70. The 137Cs tracing technique was used to examine soil erosion under different land uses and land-use combinations. The results show that the order of erosion rate in different land uses increases sequentially from mature forest to grass to young forest to orchard to terrace crop. The land-use combinations of 'grass (6 years old) + mature forest (25 years old) + grass (25 years old)' and 'grass (6 years old) + young forest (6 years old) + mature forest (25 years old) + grass (25 years old)' are better for soil erosion control, lowering soil erosion amount by 42% compared with a mixtures of 'grass (6 years old) and shrub (6 years old)'. This study indicates that land cover type/pattern, vegetation cover, soil property, restoration time and scale effect as well as stand condition all contribute to the complex hydrological effects of restoring vegetation in the Loess Plateau. Each approach has its own advantages and limitations. Appropriate method should be chosen for specific purpose and study scale. It is better that the results from different approach can be checked with each other.

  5. FIELD STUDIES OF LINER INSTALLATION METHODS AT LANDFILLS AND SURFACE IMPOUNDMENTS

    EPA Science Inventory

    This study investigates procedures for subgrade preparation and liner placement during the construction of lined surface impoundments and landfills. Lining materials studied include admixes, soils and clays, sprayed-on membranes, and polymeric membranes. Objectives of the study w...

  6. Environmental risks and problems of the optimal management of an oil shale semi-coke and ash landfill in Kohtla-Järve, Estonia.

    PubMed

    Vallner, Leo; Gavrilova, Olga; Vilu, Raivo

    2015-08-15

    The main wastes of the Estonian shale oil industry - oil shale semi-coke and ashes - are deposited in landfills. The Kohtla-Järve oil shale semi-coke and ash landfill, which is likely the largest of its kind in the World, was started in 1938. The environmental risks connected with the landfill were assessed and prioritized. The most significant hazard to human health is emission of harmful landfill gases and the water contamination in the local river network is harmful for aqueous organisms. The spatial expansion of subsurface contamination predicted by the groundwater transport model completed is practically insignificant from the viewpoint of health services. The landfill's leachates must be captured and purified, and the closed part of the landfill should be covered by greenery. The partial landfill capping recently executed is useless. The EU Landfill Directive requirements imposed on the hydraulic resistance of geological barriers cannot prevent the leakage of contaminants from a landfill. PMID:25930241

  7. Geosynthetics in Landfills Prepared by M. Bouazza and J. Zornberg

    E-print Network

    Zornberg, Jorge G.

    in the figure and provides protection against sheet and gully erosion. The use of geotextiles as filters of the vegetative cover soil. A geocomposite erosion control system above the vegetative cover soil is indicated

  8. Reutilization of industrial sedimentation plants as a domestic landfill

    SciTech Connect

    Viehweg, M.; Duetsch, M.; Wagner, J.; Edelmann, F.

    1995-12-31

    The methods and the investigation results for evalu