Kinetic modelling of chlorination of nitrided ilmenite using MATLAB

Energy Technology Data Exchange (ETDEWEB)

Ramakrishnan, Sivakumar, E-mail: srsivakumar@usm.my; Kwok, Teong Chen, E-mail: ctck@live.com; Hamid, Sheikh Abdul Rezan Sheikh Abdul, E-mail: rezanshk@gmail.com [School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, 14300, Nibong Tebal, Penang (Malaysia)

2016-07-19

In the present study, chlorination of nitride ilmenite using 2{sup k} factorial design was investigated. The reduction experiments were carried out in a temperature range of 400°C to 500°C, chlorination duration from 1 hour to 3 hours and using different type of carbon reactant. Phases of raw materials and reduced samples were analyzed by X-ray diffraction (XRD). Ilmenite was reduced to TiO{sub x}C{sub y}N{sub z} through carbothermal and nitridation for further chlorination into titanium tetrachloride. The Design of Experiment analysis suggested that the types of carbon reactant contribute most influence to the extent of chlorination of nitride ilmenite. The extent of chlorination was highest at 500°C with 3 hours chlorination time and carbon nanotube as carbon reactant.

Selective depression of titanaugite in the ilmenite flotation with carboxymethyl starch

Science.gov (United States)

Meng, Qingyou; Yuan, Zhitao; Yu, Li; Xu, Yuankai; Du, Yusheng; Zhang, Chen

2018-05-01

In order to intensify the flotation separation of ilmenite from titanaugite, surface modification of mineral particles was carried out using carboxymethyl starch (CMS) by microflotation experiments, zeta potential measurements, Fourier transform infrared (FTIR) and atomic force microscopy (AFM) analysis. Microflotation results showed that CMS was a selective depressant, and it effectively enhanced the floatability difference between ilmenite and titanaugite in the pH range from 6.0 to 10.0. As it was revealed by the zeta potential, FTIR and AFM analysis, the CMS adsorption occurred onto mineral surfaces through chemisorption and hydrogen bonding, while CMS exhibited a stronger interaction with titanaugite than ilmenite. After that, the CMS adsorption impeded the adsorption of sodium oleate collector on titanaugite surfaces, giving rise to a concomitant decrease in the floatability of titanaugite. These findings exhibit great potential for CMS application in the selective flotation of ilmenite.

Thermogravimetry studies on ilmenite nitridation

Directory of Open Access Journals (Sweden)

Sanjay Kumar

2014-12-01

Full Text Available The present study is based on the possibility of beneficiation of Indian-ilmenite by carbonitrothermic process. The investigations were carried out in two parts. In the first part, thermogravimetric-differential thermogravimetric (TG-DTG experiments were conducted using cold pressed pellets of blended mixtures TiO2-C and FeTiO3-C. The TG experiments were carried out up to 1500 °C at the rate of 10 °C/min under flowing nitrogen gas. The formations of TiN in case of TiO2-C mixture and TiN along with Fe in case of FeTiO3-C mixture were observed. In the second part, the experiments were conducted using similar pellets, prepared under identical conditions, in a resistance heating furnace at 1500 °C. By simple operations of crushing and sieving, the products obtained from the ilmenite-carbon mixture were separated into a fraction enriched in titanium and a fraction depleted in titanium.

A novel collector 2-ethyl-2-hexenoic hydroxamic acid: Flotation performance and adsorption mechanism to ilmenite

International Nuclear Information System (INIS)

Xu, Haifeng; Zhong, Hong; Tang, Qing; Wang, Shuai; Zhao, Gang; Liu, Guangyi

2015-01-01

Graphical abstract: EHHA's synthesis route, flotation performance and coadsorption molecule–ion mechanism to ilmenite. - Highlights: • 2-Ethyl-2-hexenoic hydroxamic acid (EHHA) was synthesized and characterized. • EHHA showed stronger affinity to ilmenite. • EHHA might chemisorb onto ilmenite surfaces by form of five-membered chelates. • EHHA might adsorb onto ilmenite surfaces through molecule–ion coadsorption model. - Abstract: In this paper, a novel collector, 2-ethyl-2-hexenoic hydroxamic acid (EHHA) was prepared and characterized by elemental analysis, infrared, "1H NMR, "1"3C NMR and mass spectra. The flotation performance and adsorption mechanism of EHHA to ilmenite were investigated by micro-flotation tests, density functional theory (DFT) calculations, FTIR spectra, zeta potential and solution chemistry analyses. The micro-flotation results indicated that EHHA exhibited superior flotation performance compared to isooctyl hydroximic acid (IOHA) and octyl hydroxamic acid (OHA), and floated out 84.03% ilmenite at pH 8.0 with 250 mg/L dosage. The analyses of FTIR spectra and zeta potential demonstrated that EHHA might chemisorb onto ilmenite surfaces by form of five-membered chelates. The solution chemistry analyses further inferred that at pH 6.3–10.5, both Fe and Ti species on ilmenite surfaces could chelate EHHA. DFT calculation results implied EHHA owned the strongest affinity to ilmenite among the three C_8 hydroximic acids. To discern the sharply improving floatability of ilmenite at pH 8–10, a schematic co-adsorption molecule–ion model of EHHA on ilmenite surfaces was suggested.

Electrochemistry and dissolution kinetics of magnetite and ilmenite

Science.gov (United States)

White, A.F.; Peterson, M.L.; Hochella, M.F.

1994-01-01

Natural samples of magnetite and ilmenite were experimentally weathered in pH 1-7 anoxic solutions at temperatures of 2-65 ??C. Reaction of magnetite is described as [Fe2+Fe23+]O4(magnetite) + 2H+ ??? ??[Fe23+]O3(maghemite) + Fe2+ + H2O. Dynamic polarization experiments using magnetite electrodes confirmed that this reaction is controlled by two electrochemical half cells, 3[Fe2+Fe23+]O4(magnetite) ??? 4??[Fe23+]O3(maghemite) + Fe2+ + 2e- and [Fe2+Fe23+]O4(magnetite) + 8 H+ + 2e- ??? 3Fe2+ + 4H2O, which result in solid state Fe3+ reduction, formation of an oxidized layer and release of Fe(II) to solution. XPS data revealed that iron is present in the ferric state in the surfaces of reacted magnetite and ilmenite and that the Ti Fe ratio increased with reaction pH for ilmenite. Short-term (<36 h) release rates of Fe(II) were linear with time. Between pH 1 and 7, rates varied between 0.3 and 13 ?? 10-14 mol ?? cm-2 ?? s-1 for magnetite and 0.05 and 12.3 ?? 10-14 mol ?? cm-2 ?? s-1 for ilmenite. These rates are two orders of magnitude slower than electrochemical rates determined by Tafel and polarization resistance measurements. Discrepancies are due to both differences in geometric and BET surface area estimates and in the oxidation state of the mineral surface. In long-term closed-system experiments (<120 days), Fe(II) release slowed with time due to the passivation of the surfaces by increasing thicknesses of oxide surface layers. A shrinking core model, coupling surface reaction and diffusion transport, predicted that at neutral pH, the mean residence time for sand-size grains of magnetite and ilmenite will exceed 107 years. This agrees with long-term stability of these oxides in the geologic record. ?? 1994.

Studies Involving Immobilization Of Hazardous Wastes In Cement-ilmenite Matrix

International Nuclear Information System (INIS)

El-Dakrory, A.M.; Sayed, M.S.; Adham, K.

1999-01-01

Ilmenite was added to Ordinary Portland Cement to Modify the characteristic properties of the matrix as density, compressive strength and thermal stability . Coal tar and radiocesium were solidified as hazardous waste in cement-ilmenite matrix. The physical properties as density, sitting times and porosity were studied. The mechanical properties as compressive strength values and the chemical properties as leaching were measured

The kinetics of titanium leaching of ilmenite using HCl

International Nuclear Information System (INIS)

MV Purwani; Herry Poernomo

2015-01-01

The research of ilmenite leaching of tailings processing zircon sand has been done. Tailings of processing zircon sand contain Zr, Ti, Nb and Fe. Determination of leaching kinetics of Ti on ilmenite using HCl was done on this research. Determination of reaction rate consist the influence of weight ratio of HCl to ilmenite, HCl molarity and temperature reaction. The experiment of kinetics was done by varying the temperature reaction from 70°C to 108°C and time parameter range 0 to 200 minutes. From data of research can be concluded that the greater of weight ratio of HCl with ilmenite, M HCl and reaction temperature, the faster rate of reaction. On weight ratio of HCl with ilmenite varied 4 - 20, average reaction rate along 50 minutes and instantaneous reaction rate in the first 50 minutes ranged from 0.0021 to 0.0032 gmol/(l.minute). Average reaction rate along 250 minutes ranged from 0.0005 to 0.0007 gmol/(l.minute) and instantaneous reaction rate at 50 minutes latest ranged from 0.0000 to 0.0001 gmol/(l.minute). For M HCl = 8 to 12.23 M, average reaction rate and instantaneous reaction rate in the first 50 minutes ranged from 0.0012 to 0.0026 gmol/(l.minute). Average reaction rate along 250 minutes ranged from 0.0004 to 0.0006 gmol/(l.minute) and instantaneous reaction rate at 50 minutes latest ranged from 0.0000 to 0.0001 gmol/(l.minute). On reaction temperature = 70 - 108°C, average reaction rate along 50 minutes and instantaneous reaction rate in the first 50 minutes ranged from 0.0012 to 0.0032 gmol/(l.minute). Average reaction rate along 250 minutes ranged from 0.0002 to 0.0006 gmol/(l.minute) and instantaneous reaction rate at 50 minutes latest ranged from 0.0000 to 0.0001 gmol/(l.minute). The leaching reaction of Ti in ilmenite was second order reaction. The relationship between temperature (T) with the reaction rate constant (k) are - ln k = 3333.2/T - 1.3685 or k = 1.3685. e-3333,2/T , frequency factor A = 1446 and activation energy E = 27.712 k

Thermal modification of hematite-ilmenite intergrowths in the Ecstall pluton, British Columbia, Canada

DEFF Research Database (Denmark)

Brownlee, S.J.; Feinberg, J.M.; Harrison, R.J.

2010-01-01

In this study, we examine the effects of reheating on finely exsolved hematite-ilmenite intergrowths from the similar to 91 Ma Ecstall pluton using reflected light microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). As a result of the emplacement of the you......In this study, we examine the effects of reheating on finely exsolved hematite-ilmenite intergrowths from the similar to 91 Ma Ecstall pluton using reflected light microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). As a result of the emplacement...... of the younger adjacent similar to 52 Ma Quottoon pluton, samples closer to a thermal boundary have experienced greater degrees of thermal alteration. Five main microstructural features characterize hematite-ilmenite intergrowths from the Ecstall: (I) exsolution lamellae of hematite and ilmenite; (II) oxidation....... Higher temperatures also enhanced oxidation in ilmenite. The formation of magnetite altered the bulk magnetic properties of these samples, increasing NRM intensity. This study underscores the need to consider a pluton's post-emplacement thermal history before making tectonic interpretations based...

Identification of minority compounds in natural ilmenites by X-ray absorption spectroscopy

International Nuclear Information System (INIS)

Klepka, M.T.; Lawniczak-Jablonska, K.; Wolska, A.; Jablonski, M.

2010-01-01

Research highlights: → White pigment TiO 2 production process. → The principal component analysis using XANES. → Ilmenite accompanying chemical compounds identification. → Chemical binding of Mg in ilmenite depends on the climatic and geological conditions. -- Abstract: Natural ilmenites are used all over the world as raw materials in white pigment (TiO 2 ) production. Besides the FeTiO 3 in the raw material many other compounds are present. The chemical compounds based on the minority elements influence quality of the final product and are difficult to identify. The knowledge about chemical bonding of the minor elements enables to properly adjust chemical reactions during production processes and to improve quality of the final product. In this paper the X-ray absorption spectroscopy (XAS) identification of the chemical compounds formed by Mg, Mn and Cr in natural ilmenites originating from different places is presented.

A shrinking particle model at leaching of titanium in ilmenite use HCl

International Nuclear Information System (INIS)

MV Purwani; Suyanti

2016-01-01

The research of ilmenite leaching has conducted. Ilmenite was tailings of zircon sand processing. Zircon sand processing tailings containing Zr, Ti, Nb and Fe. This research will be conducted to determine the kinetic leaching of Ti in HCl based shrinking core models. From the research results ilmenite leaching of Ti in HCl wear, it can be concluded that the 50 grams of ilmenite leaching wear 11 M HCl leaching, the higher temperature was conducted the greater of the Ti conversion. The mechanism of the leaching process was controlled by Sphere Reaction with formula equation 1- (1-α)1/3 = "k"."C"/"r"_o"ρ t = klt, the relationship between temperature (T) with the reaction rate constant (k), k = 61.744.e- 4553.3 / T or ln k = - 4553.3 / T + 4.123, the frequency factor A = 61.744, the activation energy E = 37.856 kJ/mol. (author)

Flotability Improvement of Ilmenite Using Attrition-Scrubbing as a Pretreatment Method

Directory of Open Access Journals (Sweden)

Jihua Zhai

2017-01-01

Full Text Available Flotation technology of the recovery and utilization of ilmenite from tailings of iron beneficiated in Panzhihua was investigated based on mineralogical study. The results of mineralogical study show that the main occurrence of the valuable mineral are liberated grains of ilmenite. Experimental results of flotation conditions show that attrition-scrubbing raw ores exhibit good flotability with higher recoveries and a slight decrease in grade compared to ores without attrition-scrubbing. Further, open-circuit experiments also prove the superiority of attrition-scrubbing raw ores. The results of closed-circuit experiments show that qualified ilmenite concentrate can be obtained and the yield, grade, and recovery are 22.26%, 47.06%, and 60.73%, respectively. Theoretical study and analysis show that there are two contributions to superior flotability for attrition-scrubbing samples. The first is that the attrition-scrubbing samples can uncover more ferrous ions on the newly-produced fresh ilmenite surface, resulting in the increase in active sites. The other is that in the process of attrition-scrubbing, the transformation of ferrous ions to ferric ions can be promoted.

Fast neutron fluxes distribution in Egyptian ilmenite concrete

International Nuclear Information System (INIS)

Megahed, R.M.; Abou El-Nasr, T.Z.; Bashter, I.I.

1978-01-01

This work is concerned with the study of the distribution of fast neutron fluxes in a new type of heavy concrete made from Egyptian ilmenite ores. The neutron source used was a collimated beam of reactor neutrons emitted from one of the horizontal channels of the ET-RR-1 reactor. Measurements were carried-out using phosphorous activation detectors. Iso-flux curves were represented which give directly the shape and thickness required to attenuate the emitted fast neutron flux to a certain value. The relaxation lengths were also evaluated from the measured data for both disc monodirectional source and infinite plane monodirectional source. The obtained values were compared with that calculated using the derived values of relative number densities and microscopic removal cross-sections of the different constituents. The obtained data show that ilmenite concrete attenuates fast neutron flux more strongly than ordinary concrete. A semiemperical formula was derived to calculate the fast neutron flux at different thicknesses along the beam axis. Another semiemperical formula was also derived to calculate the fast neutron flux in ordinary concrete along the beam axis using the corresponding value in ilmenite concrete

The thermal equation of state of FeTiO3 ilmenite based on in situ X-ray diffraction at high pressures and temperatures

International Nuclear Information System (INIS)

Tronche, E.J.; Van Kan Parker, M.; De Vries, J.; Wang, Y.; Sanehire, T.; Li, J.; Chen, B.; Gao, L.; Klemme, S.; McCammon, C.A.; Van Westerenen, W.

2010-01-01

We present in situ measurements of the unit-cell volume of a natural terrestrial ilmenite (Jagersfontein mine, South Africa) and a synthetic reduced ilmenite (FeTiO 3 ) at simultaneous high pressure and high temperature up to 16 GPa and 1273 K. Unit-cell volumes were determined using energy-dispersive synchrotron X-ray diffraction in a multi-anvil press. Moessbauer analyses show that the synthetic sample contained insignificant amounts of Fe 3+ both before and after the experiment. Results were fit to Birch-Murnaghan thermal equations of state, which reproduce the experimental data to within 0.5 and 0.7 GPa for the synthetic and natural samples, respectively. At ambient conditions, the unit-cell volume of the natural sample (V 0 = 314.75 ± 0.23 (1σ) (angstrom) 3 ) is significantly smaller than that of the synthetic sample (V 0 = 319.12 ± 0.26 (angstrom) 3 ). The difference can be attributed to the presence of impurities and Fe 3+ in the natural sample. The 1 bar isothermal bulk moduli K T0 for the reduced ilmenite is slightly larger than for the natural ilmenite (181 ± 7 and 165 ± 6 GPa, respectively), with pressure derivatives K(prime) 0 = 3 ± 1. Our results, combined with literature data, suggest that the unit-cell volume of reduced ilmenite is significantly larger than that of oxidized ilmenite, whereas their thermoelastic parameters are similar. Our data provide more appropriate input parameters for thermo-chemical models of lunar interior evolution, in which reduced ilmenite plays a critical role.

Synthesis of TiO2 Nanoparticles from Ilmenite Through the Mechanism of Vapor-Phase Reaction Process by Thermal Plasma Technology

Science.gov (United States)

Samal, Sneha

2017-11-01

Synthesis of nanoparticles of TiO2 was carried out by non-transferred arc thermal plasma reactor using ilmenite as the precursor material. The powder ilmenite was vaporized at high temperature in plasma flame and converted to a gaseous state of ions in the metastable phase. On cooling, chamber condensation process takes place on recombination of ions for the formation of nanoparticles. The top-to-bottom approach induces the disintegration of complex ilmenite phases into simpler compounds of iron oxide and titanium dioxide phases. The vapor-phase reaction mechanism was carried out in thermal plasma zone for the synthesis of nanoparticles from ilmenite compound in a plasma reactor. The easy separation of iron particles from TiO2 was taken place in the plasma chamber with deposition of light TiO2 particles at the top of the cooling chamber and iron particles at the bottom. The dissociation and combination process of mechanism and synthesis are studied briefly in this article. The product TiO2 nanoparticle shows the purity with a major phase of rutile content. TiO2 nanoparticles produced in vapor-phase reaction process shows more photo-induced capacity.

Experimental evidence for lamellar magnetism in hemo-ilmenite by polarized neutron scattering

DEFF Research Database (Denmark)

Brok, Erik; Sales, Morten; Lefmann, Kim

2014-01-01

Large local anomalies in the Earth's magnetic field have been observed in Norway, Sweden, and Canada. These anomalies have been attributed to the unusual magnetic properties of naturally occurring hemo-ilmenite, consisting of a paramagnetic ilmenite host (alpha-Fe2O3-bearing FeTiO3) with exsoluti...

Effect of Pb2+ ions on ilmenite flotation and adsorption of benzohydroxamic acid as a collector

Science.gov (United States)

Xu, Longhua; Tian, Jia; Wu, Houqin; Lu, Zhongyuan; Yang, Yaohui; Sun, Wei; Hu, Yuehua

2017-12-01

The effects of Pb2+ ions on ilmenite flotation and adsorption of benzohydroxamic acid (BHA) as a collector were investigated using microflotation tests, zeta potential measurements, adsorption analysis, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The microflotation results indicate that the addition of Pb2+ significantly improves the recovery of ilmenite using BHA as a collector. A maximum recovery of 88.46% is obtained at pH 8.12 in the presence of Pb2+; a maximum recovery of 45% is obtained at the same pH using BHA alone. At pHs below 8.0, lead nitrate are mainly present in the solution as Pb2+ and PbOH+, while at pHs above 8.0, the predominant components are Pb(OH)2(s) and Pb(OH)3-. The adsorption of these lead species influences the zeta potential of ilmenite and the number of activated sites on the ilmenite surface. FTIR and XPS analyses reveal that lead species and BHA react with the metal sites on the ilmenite surface. The lead species in solution are either adsorbed onto the ilmenite surface, which increases the surface activity of ilmenite, or react with BHA in solution to form complexes of lead and BHA.

Nano-ilmenite FeTiO3 : synthesis and characterization

OpenAIRE

Raghavender, A. T.; Hoa Hong, Nguyen; Lee, Kyu Joon; Jung, Myung-Hwa; Skoko, Z.; Vasilevskiy, Mikhail; Cerqueira, M. F.; Samantilleke, A. P.

2013-01-01

In general, ilmenite FeTiO3 is synthesized by solid-state reaction at very high pressure and high temperature. Synthesis of FeTiO3 is not an easy task as the Fe2+ ions are not stable. Therefore, it is really challenging to prepare this material. In this work nano-ilmenite FeTiO3 was synthesized by the sol-gel method. Structural, optical and magnetic characterizations were performed. The bandgap of FeTiO3 was determined to be 2.8 eV showing FeTiO3 as suitable wide bandgap material for technolo...

Valorisation of waste ilmenite mud in the manufacture of sulphur polymer cement.

Science.gov (United States)

Contreras, Manuel; Gázquez, Manuel Jesús; García-Díaz, Irene; Alguacil, Francisco J; López, Félix A; Bolívar, Juan Pedro

2013-10-15

This paper reports the preparation of sulphur polymer cements (SPCs) incorporating waste ilmenite mud for use in concrete construction works. The ilmenite mud raw material and the mud-containing SPCs (IMC-SPCs) were characterised physico-chemically and radiologically. The optimal IMC-SPC mixture had a sulphur/mud ratio (w/w) of 1.05 (mud dose 20 wt%); this cement showed the greatest compressive strength (64 MPa) and the lowest water absorption coefficient (0.4 g cm(-2) at 28 days). Since ilmenite mud is enriched in natural radionuclides, such as radium isotopes (2.0·10(3) Bq kg(-1)(228)Ra and 5.0·10(2) Bq kg(-1)(226)Ra), the IMC-SPCs were subjected to leaching experiments, which showed their environmental impact to be negligible. The activity concentration indices for the different radionuclides in the IMC-SPCs containing 10% and 20% ilmenite mud met the demands of international standards for materials used in the construction of non-residential buildings. Copyright © 2013 Elsevier Ltd. All rights reserved.

Leachability of nitrided ilmenite in hydrochloric acid

CSIR Research Space (South Africa)

Swanepoel, JJ

2010-10-01

Full Text Available Titanium nitride in upgraded nitrided ilmenite (bulk of iron removed) can selectively be chlorinated to produce titanium tetrachloride. Except for iron, most other components present during this low temperature (ca. 200 °C) chlorination reaction...

Fabrication of mesoporus TiO_2 from TiOSO_4 from leached ilmenite

International Nuclear Information System (INIS)

Wahyuningsih S; Ramelan AH; Rinawati L; Munifa RMI; Saputri LNMZ; Hanif QA; Pranata HP; Ismoyo YA

2016-01-01

The fabrication of mesoporous TiO_2 from TiOSO_4 precursor through roasted process, leaching, and homogeneous hydrolysis of ilmenite had been done. Analysis of X-ray Diffraction (XRD) showed the characteristics of ilmenite, hematite and rutile. After roasting the mineral ilmenite with the addition of Na_2S at a temperature of 800°C the XRD characterization showed peaks characteristic for hematite, TiO_2 anatase, TiO_2 rutile, Na_2SO_4, NaFeS_2, and NaFeO_2. Leaching processes of roasted ilmenite which maintained with an addition of strong acid H_2SO_4 6; 7.2; 9; 12, and 18 N were obtained TiOSO_4 filtrate. The results indicated that the more concentration of H_2SO_4 the more solubility of ilmenite, where optimum solubility was achieved when H_2SO_4 concentration was 12 N. The fabrication of mesoporous TiO_2 from TiOSO_4 was conducted with homogeneous hydrolysis method used urea and surfactant template F-127. XRD characterization results indicated the dominant peak of TiO_2 anatase. Crystallite size of 3.2 nm was obtained and the results of Scanning Electron Microscopy (SEM) showed that the presence of urea and surfactant be able to arrange porosity. (author)

Titanium Analysis of Ilmenite Bangka by Spectrophotometric Method Using Perhidrol

International Nuclear Information System (INIS)

Rusydi-S

2004-01-01

Determination of titanium by spectrofotometric method using perhydrol has been done. The purpose of experiment is to find out the condition of titanium analysis of ilmenite by spectrophotometric method. The experiment parameter e c. analysis condition include the Ti-perhydrol complex spectrum, acidity of complex, perhydrol concentration, linearity, influence of anion, limit detection, interfere elements, application of the method using 40 SRM Standard and analysis for ilmenite samples. Result of experiments are spectrum of Ti-perhydrol complex at 410 nm, acidity of complex is the H 2 SO 4 2 M, perhydrol concentration is 0,24 %, the curve calibration is linier at 1-80 ppm, anion of PO 4 , NO 3 , Cl, CO 3 not be influence until 2000 ppm, limit detection is 0,30 ppm and Mo, V is interfere. The method which was aplicated to 40 SRM standard, shown that the content of Ti is 1580 ppm while the standard is 1600 ppm, and the content of Ti from ilmenite high grade samples is 31,46 % and low grade is 13,55 %. (author)

Characterizing Surfaces of the Wide Bandgap Semiconductor Ilmenite with Scanning Probe Microcopies

Science.gov (United States)

Wilkins, R.; Powell, Kirk St. A.

1997-01-01

Ilmenite (FeTiO3) is a wide bandgap semiconductor with an energy gap of about 2.5eV. Initial radiation studies indicate that ilmenite has properties suited for radiation tolerant applications, as well as a variety of other electronic applications. Two scanning probe microscopy methods have been used to characterize the surface of samples taken from Czochralski grown single crystals. The two methods, atomic force microscopy (AFM) and scanning tunneling microscopy (STM), are based on different physical principles and therefore provide different information about the samples. AFM provides a direct, three-dimensional image of the surface of the samples, while STM give a convolution of topographic and electronic properties of the surface. We will discuss the differences between the methods and present preliminary data of each method for ilmenite samples.

The effect of ilmenite viscosity on the dynamics and evolution of an overturned lunar cumulate mantle

Science.gov (United States)

Zhang, Nan; Dygert, Nick; Liang, Yan; Parmentier, E. M.

2017-07-01

Lunar cumulate mantle overturn and the subsequent upwelling of overturned mantle cumulates provide a potential framework for understanding the first-order thermochemical evolution of the Moon. Upwelling of ilmenite-bearing cumulates (IBCs) after the overturn has a dominant influence on the dynamics and long-term thermal evolution of the lunar mantle. An important parameter determining the stability and convective behavior of the IBC is its viscosity, which was recently constrained through rock deformation experiments. To examine the effect of IBC viscosity on the upwelling of overturned lunar cumulate mantle, here we conduct three-dimensional mantle convection models with an evolving core superposed by an IBC-rich layer, which resulted from mantle overturn after magma ocean solidification. Our modeling shows that a reduction of mantle viscosity by 1 order of magnitude, due to the presence of ilmenite, can dramatically change convective planform and long-term lunar mantle evolution. Our model results suggest a relatively stable partially molten IBC layer that has surrounded the lunar core to the present day.Plain Language SummaryThe Moon's mantle is locally ilmenite rich. Previous models exploring the convective evolution of the lunar mantle did not consider the effects of ilmenite viscosity. Recent rock deformation experiments demonstrate that Fe-Ti oxide (ilmenite) is a low viscosity phase compared to olivine and other silicate minerals. Our modeling shows that ilmenite changes the lunar mantle plume process. An ilmenite-rich layer around the lunar core would be highly stable throughout geologic time, consistent with a partially molten, low viscosity layer around the core inferred from seismic attenuation and tidal dissipation.

Soft x-ray absorption spectra of ilmenite family.

Science.gov (United States)

Agui, A; Mizumaki, M; Saitoh, Y; Matsushita, T; Nakatani, T; Fukaya, A; Torikai, E

2001-03-01

We have carried out soft x-ray absorption spectroscopy to study the electronic structure of ilmenite family, such as MnTiO3, FeTiO3, and CoTiO3 at the soft x-ray beamline, BL23SU, at the SPring-8. The Ti and M L2,3 absorption spectra of MTiO3 (M=Mn, Fe, and Co) show spectra of Ti4+ and M2+ electron configurations, respectively. Except the Fe L2,3 spectrum, those spectra were understood within the O(h) symmetry around the transition metal ions. The Fe L3-edge spectrum clearly shows a doublet peak at the L3 edge, which is attributed to Fe2+ state, moreover the very high-resolution the L-edge spectra of transition metals show fine structures. The spectra of those ilmenites are compared.

Ferrian Ilmenites: Investigating the Magnetic Phase Diagram

Science.gov (United States)

Lagroix, F.

2007-12-01

The main objective of this study is to investigate the magnetic phase changes within the hematite-ilmenite solid solution, yFeTiO3·(1-y)·Fe2O3. Two sets of synthetic ferrian ilmenites of y-values equal to 0.7, 0.8, 0.9, and 1.0 were available for this study. As currently drawn, the magnetic phase diagram, proposed by Ishikawa et al. [1985, J. Phys. Soc. Jpn. v.54, 312-325], predicts for increasing y values (0.5Ilmenite, y=1.0, is antiferromagnetic. Various low tempreature experiments including temperature dependance of remanence and induced magnetizations and AC susceptibility were conducted in order to characterize the magnetic behaviour and changes of magnetic states. In general, the data confirms the predicted phase changes for the different compositions investigated. The y=1.0 sample, pure ilmenite, is antiferromagnetic below 57K, the measured Néel temperature. The y=0.9 sample magnetically orders at about 100K in a superparamagnetic state. Hysteresis loops remain effectively closed down to 60K below which an antiferromagnetic order prior to reaching the spin glass state is ambiguous. The y=0.8 sample magnetically orders at about 270K in an initially superparamagnetic states before entering a ferrimagnetic state below about 250K. Lastly, as previously demonstrated in Lagroix et al. [2004, JGR-B, v.109, doi:10.1029/2004JB003076], the y=0.7 samples order ferrimagnetically at 380K. However, like the y=0.7 samples which also demonstrated an antiferromagnetic state at temperature above the Curie temperature, hysteresis loops for y=0.9 and y=0.8 only achieve perfect linearity at 190K and 340K respectively. All samples (except y=1.0) show a frequency dependent amplitude non

Geological and geophysical exploration for offshore ilmenite placers off the Konkan coast, Maharashtra, India

Digital Repository Service at National Institute of Oceanography (India)

Siddiquie, H.N.; Rajamanickam, G.V.; Gujar, A.R.; Ramana, M.V.

total area of 436 km2. The offshore reserves and ilmenite are estimated to be about 12.5 million tons whereas estimates based on the 2 to 10 m thickness and spread of ilmenite bearing sands over an area of 436 km2, total reserves appears to be very large...

Electrochemical reactivity of ilmenite FeTiO3, its nanostructures and oxide-carbon nanocomposites with lithium

International Nuclear Information System (INIS)

Tao, Tao; Glushenkov, Alexey M.; Rahman, Md Mokhlesur; Chen, Ying

2013-01-01

The electrochemical reactivity of the ball-milled ilmenite FeTiO 3 and ilmenite nanoflowers with lithium has been investigated. The electrode assembled with the ilmenite nanoflowers delivers better electrochemical performance than that of the milled material during charging and discharging in the potential range of 0.01 and 3 V vs. Li/Li + . The ilmenite nanoflowers demonstrate the capacity of ca. 650 mAh g −1 during the first discharge, and a reversible capacity of approximately 200 mAh g −1 in the course of the first 50 cycles. The possible reaction mechanism between ilmenite and lithium was studied using cyclic voltammetry and transmission electron microscopy. The first discharge involves the formation of an irreversible phase, which is either LiTiO 2 or LiFeO 2 . Subsequently, the extraction–insertion of lithium happens in a reversible manner. It was also observed that the lithium storage might be significantly improved if the electrode was prepared in the form of a nanocomposite of FeTiO 3 with carbon

XPS studies of water and oxygen on iron-sputtered natural ilmenite

Science.gov (United States)

Schulze, P. D.; Neil, T. E.; Shaffer, S. L.; Smith, R. W.; Mckay, D. S.

1985-01-01

The adsorption of D2O and O2 on polycrystalline FeTiO3 (natural ilmenite) has been studied by X-ray photoelectron spectroscopy. Oxygen was found to absorb reactively with Fe(0) on Ar(+)-sputtered surfaces at and above 150 K while D2O was found to adsorb molecularly or in ice layers below 170 K on both Ar(+) and O2(+) ion-bombarded ilmenite. The D2O desorbs at 170 K with either the formation of an OD complex or a strongly bound molecular layer of water.

Synthesis of high purity rutile nanoparticles from medium-grade Egyptian natural ilmenite

Directory of Open Access Journals (Sweden)

Mohamed G. Shahien

2015-09-01

Full Text Available The Egyptian magmatic ilmenite is classified as a medium-grade ore. The present work is an attempt to produce a high-quality TiO2 that can be used in several industries from this medium-grade raw material using the mechanical activation, carbothermic reduction, hydrochloric acid leaching and calcination. A mixture from the ilmenite (FeTiO3 and activated carbon was milled for 30 h. This mixture was annealed at 1200 °C for one hour and the product was leached by hydrochloric acid and calcined at 600 °C for two hours. The role of the ball milling was to grind the raw ilmenite to obtain the nano size, and the carbothermic reduction was to reduce all the Fe-Ti phases to a mixture from Fe metal and TiO2. Leaching procedure was carried out to remove all the Fe metal and obtain a high-grade TiO2. After leaching and calcination of the milled and annealed mixture of FeTiO3/C under the optimal conditions, TiO2 nanoparticles with a size of 10–100 nm and purity more than 95% were obtained. The qualifications of the synthesized high purity rutile nanoparticles from the Egyptian natural ilmenite match the conditions of many industrial applications.

Ilmenite Nanotubes for High Stability and High Rate Sodium-Ion Battery Anodes.

Science.gov (United States)

Yu, Litao; Liu, Jun; Xu, Xijun; Zhang, Liguo; Hu, Renzong; Liu, Jiangwen; Ouyang, Liuzhang; Yang, Lichun; Zhu, Min

2017-05-23

To solve the problem of large volume change and low electronic conductivity of earth-abundant ilmenite used in rechargeable Na-ion batteries (SIBs), an anode of tiny ilmenite FeTiO 3 nanoparticle embedded carbon nanotubes (FTO⊂CNTs) has been successfully proposed. By introducing a TiO 2 shell on metal-organic framework (Fe-MOF) nanorods by sol-gel deposition and subsequent solid-state annealing treatment of these core-shell Fe-MOF@TiO 2 , such well-defined FTO⊂CNTs are obtained. The achieved FTO⊂CNT electrode has several distinct advantages including a hollow interior in the hybrid nanostructure, fully encapsulated ultrasmall electroactive units, flexible conductive carbon matrix, and stable solid electrolyte interface (SEI) of FTO in cycles. FTO⊂CNT electrodes present an excellent cycle stability (358.8 mA h g -1 after 200 cycles at 100 mA g -1 ) and remarkable rate capability (201.8 mA h g -1 at 5000 mA g -1 ) with a high Coulombic efficiency of approximately 99%. In addition, combined with the typical Na 3 V 2 (PO 4 ) 3 cathode to constitute full SIBs, the assembled FTO⊂CNT//Na 3 V 2 (PO 4 ) 3 batteries are also demonstrated with superior rate capability and a long cycle life.

Phase Evolution During the Carbothermic Reduction Process of Ilmenite Concentrate

Science.gov (United States)

Gou, Hai-Peng; Zhang, Guo-Hua; Chou, Kuo-Chih

2015-02-01

The phase evolution during the carbothermic reduction process of Panzhihua ilmenite concentrate was investigated under argon atmosphere. The Panzhihua ilmenite concentrate briquette with graphite powder was reduced at 1473 K, 1573 K, 1673 K, and 1773 K (1200 °C, 1300 °C, 1400 °C, and 1500 °C) respectively, with the molar ratios of C to FeTiO3 being 4:1 and 5:1. The phase transformation of the briquette reduced at different temperatures was investigated by X-ray diffraction and scanning electron microscope. During the carbothermic reduction process from 1473 K to 1773 K (1200 °C to 1500 °C), it was found that main phases were Fe, Ti3O5, Ti2O3, and TiC x O y . The lowest temperature for the generation of TiC x O y was 1573 K (1300 °C) for both kinds of briquettes with different C contents. The rate controlling step for the carbothermic reduction above 1573 K (1300 °C) obeyed the diffusion model. The reduction degree of the ilmenite was increased by increasing the temperature. With the increase of reaction temperature and reaction time, TiC x O y phase would be reduced to TiC phase.

Synthesis of anatase and rutile TiO{sub 2} nanostructures from natural ilmenite

Energy Technology Data Exchange (ETDEWEB)

Wahyuingsih, Sayekti, E-mail: sayekti@mipa.uns.ac.id; Ramelan, Ari Handono; Pramono, Edi; Sulistya, Ariantama Djati; Argawan, Panji Rofa; Dharmawan, Frenandha Dwi; Rinawati, Ludfiaastu; Hanif, Qonita Awliya [Inorganic Materials Research Group, Faculty of Mathematic and Natural Science, Sebelas Maret University (Indonesia); Sulistiyono, Eko; Firdiyono, Florentinus [Metallurgy Extraction Laboratory, Central of Metallurgy Research LIPI, Serpong (Indonesia)

2016-02-08

Nanostructure anatase and rutile type TiO{sub 2} were synthesized from dissolution roasted ilmenite from natural ilmenite sand as the starting materials. Anatase TiO{sub 2} and rutile TiO{sub 2} (high crystallinity) with the diameters of 20–100 nm were obtained by calcined soluble ilmenite sand produced by leaching process. Calcinations of the xerogel TiO{sub 2} from liquor products were conducted for 4 hours at temperature of 450 °C. The samples were characterized by XRD (X-ray diffraction), STA (simultant thermal analysis), TEM (Transmission Electron Microscopy), and BET surface area. Titania Anatase-Rutile form as a mixture were produced by titania slag with the hydrolysis product. While, in another route, complete titania anatase phase was produced through hydrolysis and condensation steps of leach liquors. This synthesis methods provide a simple route to fabricate nanostructure TiO{sub 2} from low cost material.

Application of microscopy methods to the understanding of mechanisms involved in ilmenite reduction by hydrogen

International Nuclear Information System (INIS)

De Vries, M.; Grey, I.; Fitzgerald, J.

2003-01-01

faster along grain boundaries than laterally into the grains leaving each grain as a single topochemical reaction. Bands of iron metal are observed in each grain indicating preferential reaction along crystal planes, confirmed from TEM results to be normal to the c-axis of ilmenite. At the surface there is a confused array of crystallinity arrangements of the products, whereas inwards from the surface there is a definite correlation of crystallinity alignment of the product rutile to the parent ilmenite indicating diffusion mechanisms taking place. These include any one of or a combination of many diffusion mechanisms possible such as gaseous diffusion of the product water through the microporous iron metal leading to Knudsen diffusion, chemical or self diffusion of iron through the rutile to nucleate away from the parent ilmenite. From the TEM results the reaction products, iron metal and rutile, showed dense formation in their individual crystals. The reduced sample overall did not reduce in size. The theoretical volume decrease of 18 % for equation, hence leading to an increase in porosity, is incorporated in the original porosity or by forming new pores along grain boundaries as the reaction front proceeds. From the microscopy analysis of reduced ilmenite samples, it appears strongly that chemical reaction is not the main driving force except initially at the surface. As reaction proceeds inwards diffusion mechanisms are increasing their control. Copyright (2003) Australian Microbeam Analysis Society

Characterization and photocatalytic activity of Barkin-Ladi ilmenite ...

African Journals Online (AJOL)

Photocatalysis is an advanced oxidation process that can be carried out at room temperature under atmospheric pressure using atmospheric oxygen as the oxidant and the sun as the source of energy. This work focuses on the composition and photocatalytic activity of the raw and calcined samples of ilmenite ore obtained ...

IMPROVEMENT OF FATIGUE STRENGTH OF TIN BABBITT BY REINFORCING WITH NANO ILMENITE

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M. V. S. BABU

2017-08-01

Full Text Available Tin Babbitt is an idle journal bearing material, its fatigue strength limits and its usage. To enhance its fatigue strength, in this paper a Tin Babbitt metal matrix is reinforced with nano Ilmenite. The metal matrix nanocomposite was fabricated by using ultrasonic assisted stir casting technique. ASTM standards in statistical planning for fatigue testing were employed in planning the fatigue tests. Fatigue tests were conducted at three stress levels, i.e., 0.9 UTS, 0.7 UTS and 0.5 UTS. Tests were conducted on a rotating-beam type fatigue testing machine. It was observed that the nano Ilmenite reinforcement enhanced the fatigue strength of Tin Babbitt.

The heat-capacity of ilmenite and phase equilibria in the system Fe-T-O

Science.gov (United States)

Anovitz, Lawrence M.; Treiman, A.H.; Essene, E.J.; Hemingway, B.S.; Westrum, E.F.; Wall, V.J.; Burriel, R.; Bohlen, S.R.

1985-01-01

Low temperature adiabatic calorimetry and high temperature differential scanning calorimetry have been used to measure the heat-capacity of ilmenite (FeTiO3) from 5 to 1000 K. These measurements yield S2980 = 108.9 J/(mol ?? K). Calculations from published experimental data on the reduction of ilmenite yield ??2980(I1) = -1153.9 kJ/(mol ?? K). These new data, combined with available experimental and thermodynamic data for other phases, have been used to calculate phase equilibria in the system Fe-Ti-O. Calculations for the subsystem Ti-O show that extremely low values of f{hook}O2 are necessary to stabilize TiO, the mineral hongquiite reported from the Tao district in China. This mineral may not be TiO, and it should be re-examined for substitution of other elements such as N or C. Consideration of solid-solution models for phases in the system Fe-Ti-O allows derivation of a new thermometer/oxybarometer for assemblages of ferropseudobrookite-pseudobrookitess and hematite-ilmenitess. Preliminary application of this new thermometer/oxybarometer to lunar and terrestrial lavas gives reasonable estimates of oxygen fugacities, but generally yields subsolidus temperatures, suggesting re-equilibration of one or more phases during cooling. ?? 1985.

Kinetics of acid leaching of ilmenite decomposed by KOH part 1: decomposition by KOH and leaching by HCl

International Nuclear Information System (INIS)

Nayl, A.A; Aly, H.F.

2010-01-01

Decomposition of ilmenite by KOH solutions, to convert titanium to potassium titanate, was first studied . This was followed by leaching titanium from the ilmenite paste using HCl solutions in the temperature range 50-150 degree C for different periods up to 3 hr. The significant factors affecting the leaching process were studied. The experimental data of the decomposition rate of ilmenite by KOH and of the formed KOH paste by HCl under the relevant operating variables were interpreted with the shrinking core model under chemically controlled process. The apparent activation energy for leaching of titanium in both cases bas been evaluated and discussed.

Ion bombardment and adsorption studies on ilmenite (FeTiO3) by X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Schulze, P.D.

1983-01-01

The effects of 5 KeV argon and oxygen ion bombardment on FeTiO3 (ilmenite) at low temperatures have been studied using x-ray photoelectron spectroscopy (XPS). Also, using this same technique, the adsorption of O 2 , NO, N 2 O, and CO at 300 K and the adsorption of O 2 and D 2 O at 150K have been studied. Argon and oxygen ion bombardment of ilmenite have confirmed earlier studies on metal oxides that argon ions generally reduce the anion species while oxygen ions generally oxidize the anion species. The two iron states involved were Fe sup +2 and Fe sup O. The reduction of Ti sup +4 was not verified although a significant shift in the Ti(2p1,3) binding energies toward the metallic state was observed after oxygen ion bombardment at low temperatures. At temperatures above 150K, O 2 adsorbs dissociatively on ilmenite while D 2 O adsorbs molecularly below 170K. Above 300 K NO, N 2 O, and CO do not appear to adsorb dissociatively. Low temperature adsorption of D 2 O was found to be inhibited by predosing the ilmenite with O 2

Ion bombardment and adsorption studies on ilmenite (FeTiO3) by X-ray photoelectron spectroscopy

Science.gov (United States)

Schulze, P. D.

1983-01-01

The effects of 5 KeV argon and oxygen ion bombardment on FeTiO3 (ilmenite) at low temperatures have been studied using X-ray photoelectron spectroscopy (XPS). Also, using this same technique, the adsorption of O2, NO, N2O, and CO at 300 K and the adsorption of O2 and D2O at 150K have been studied. Argon and oxygen ion bombardment of ilmenite have confirmed earlier studies on metal oxides that argon ions generally reduce the anion species while oxygen ions generally oxidize the anion species. The two iron states involved were Fe sup +2 and Fe sup O. The reduction of Ti sup +4 was not verified although a significant shift in the Ti(2p1,3) binding energies toward the metallic state was observed after oxygen ion bombardment at low temperatures. At temperatures above 150K, O2 adsorbs dissociatively on ilmenite while D2O adsorbs molecularly below 170K. Above 300 K No, N2O, and CO do not appear to adsorb dissociatively. Low temperature adsorption of D2O was found to be inhibited by predosing the ilmenite with O2.

Iron released from ilmenite mineral sustains a phytoplankton community in microcosms

Digital Repository Service at National Institute of Oceanography (India)

Fernandes, C.E.G.; Velip, D.; Mourya, B.S.; Shaikh, S.; Das, A.; LokaBharathi, P.A.

Natural biotic communities from Kalbadevi Bay were monitored in microcosms (1-l glass flasks) to test the hypothesis that iron released from ilmenite through microbial action contributes to proliferation of phytoplankton. Microcosms containing...

Influence of cation disorder on the magnetic properties of ball-milled ilmenite (FeTiO₃)

DEFF Research Database (Denmark)

Mørup, Steen; Rasmussen, Helge Kildahl; Brok, Erik

2012-01-01

We have investigated the evolution of crystal structure, cation disorder and magnetic properties of ilmenite (FeTiO3) after increasing time of high-energy ball-milling in an inert atmosphere. Refinement of X-ray diffraction data show that the hexagonal crystal structure of ilmenite is maintained...

Combination of soil classification and some selected soil properties ...

African Journals Online (AJOL)

The advantage in the combined use of soil classification and top soil analysis for explaining crop yield variation was examined. Soil properties and yields of maize (Zea mays L) on different soil types were measured on farmers' fields for 2 years. Yield prediction improved from 2 per cent at the Order and Association levels to ...

Sustainable carbothermal reduction and nitridation of Malaysian ilmenite by polyethylene terephthalate and coal

Science.gov (United States)

Ahmadi, Eltefat; Hamid, Sheikh Abdul Rezan Sheikh Abdul; Hussin, Hashim; Baharun, Norlia; Ariffin, Kamar Shah; Ramakrishnan, Sivakumar; Fauzi, M. N. Ahmad; Ismail, Hanafi

2017-07-01

In this paper, the carbothermal reduction and nitridation (CTRN) of Malaysian ilmenite has been studied as a part of crucial steps involved in reduction and subsequent chlorination processes for synthesizing titanium tetrachloride (TiCl4) from nitrided Malaysian ilmenite concentrates. In CTRN, waste plastics such as polyethylene terephthalate (PET) could be utilized as an alternative source of carbon reductant. In this study, titanium oxycarbonitride (TiOxCyNz) separated from iron (Fe) phase was synthesized by non-isothermal CTRN of Malaysian ilmenite under H2-N2 atmosphere by utilizing a mixture of Sarawak Mukah-Balingan coal and PET as reducing agents in a horizontal tube furnace. Experiments have been carried out in the temperature range of 1150-1250°C for 3 hours with various ratios of PET to coal (25 wt.% PET, 50 wt.% PET, and 75 wt.% PET). X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) methods of analysis were conducted to assess the microstructures and chemical compositions of the unreduced and reduced samples. The results indicated that utilizing PET had a significant effect on iron separation from titanium oxycarbonitride (TiO0.02C0.13N0.85) at 1250°C with a mixture of 75 wt.% PET. Furthermore, XRD and SEM studies demonstrated that with increasing PET weight ratio in the mixtures, the rate of conversion increased and a low-carbon TiOxCyNz with minimal intermediate titanium sub-oxides was synthesized. The method of applying PET as potential reductant for CTRN of ilmenite has beneficial side effects in sustainable recycling of waste PET.

Geophysical studies of ilmenite and monazite placers in Itaparica island - Bahia State

International Nuclear Information System (INIS)

Cerqueira Neto, J.X.

1976-01-01

A ground scintillometric survey along the southern shores of the island of Itaparica, Bahia, Brazil, discovered numerous anomalies. Detailed geophysical and sedimentological studies proved that the major anomaly is due to an ilmenite placer deposit. A comparison of the field geophysical measurements (ground scintillometry, magnetics and induced polarization) with the laboratory samples suggests the following: i) Ground scintillometry is suitable for locating and delineating such placer deposits. ii) Induced polarization is useful to investigate the deposit at depth. iii) Magnetic surveys were not particularly useful in spite of the high ilmenite concentration, thus they do not appear to be a helpful survey tool in this case. A more extensive prospecting program in the Brazilian coastal areas particularly in the State of Bahia are also proposed. (author)

Combined Application of QEM-SEM and Hard X-ray Microscopy to Determine Mineralogical Associations and Chemcial Speciation of Trace Metals

Energy Technology Data Exchange (ETDEWEB)

M Grafe; M Landers; R Tappero; P Austin; B Gan; A Grabsch; C Klauber

2011-12-31

We describe the application of quantitative evaluation of mineralogy by scanning electron microscopy in combination with techniques commonly available at hard X-ray microprobes to define the mineralogical environment of a bauxite residue core segment with the more specific aim of determining the speciation of trace metals (e.g., Ti, V, Cr, and Mn) within the mineral matrix. Successful trace metal speciation in heterogeneous matrices, such as those encountered in soils or mineral residues, relies on a combination of techniques including spectroscopy, microscopy, diffraction, and wet chemical and physical experiments. Of substantial interest is the ability to define the mineralogy of a sample to infer redox behavior, pH buffering, and mineral-water interfaces that are likely to interact with trace metals through adsorption, coprecipitation, dissolution, or electron transfer reactions. Quantitative evaluation of mineralogy by scanning electron microscopy coupled with micro-focused X-ray diffraction, micro-X-ray fluorescence, and micro-X-ray absorption near edge structure (mXANES) spectroscopy provided detailed insights into the composition of mineral assemblages and their effect on trace metal speciation during this investigation. In the sample investigated, titanium occurs as poorly ordered ilmenite, as rutile, and is substituted in iron oxides. Manganese's spatial correlation to Ti is closely linked to ilmenite, where it appears to substitute for Fe and Ti in the ilmenite structure based on its mXANES signature. Vanadium is associated with ilmenite and goethite but always assumes the +4 oxidation state, whereas chromium is predominantly in the +3 oxidation state and solely associated with iron oxides (goethite and hematite) and appears to substitute for Fe in the goethite structure.

Syntheses of Fe–TiC nanocomposite from ilmenite concentrate via ...

Indian Academy of Sciences (India)

Administrator

Abstract. In this paper, the possibility of production of Fe–TiC nanocomposite as a useful ceramic, from ilmenite concentrate, aluminum powder and carbon black has been investigated. ... The Fe–TiC composite is one of the special composites that was first ..... many applications such as master alloys, coating and sin-.

The Effects of Leaching Process to the TiO2 Synthesis from Bangka Ilmenite

Science.gov (United States)

Wahyuningsih, S.; Ramelan, A. H.; Pramono, E.; Argawan, P.; Djatisulistya, A.; Firdiyono, F.; Sulistiyono, E.; Sari, P. P.

2018-03-01

Ilmenite mineral is a naturally occurring iron titanate (FeTiO3) and is abundant in nature. The separation of components into TiO2 and Fe2O3 must be expand. The purpose of this research is to synthesis TiO2 nanoparticles from the filtrate of Bangka ilmenite leaching process. Leaching of ilmenite was done with H2SO4 and HCl at various concentrations. The formation of TiO2 crystal determined by hydrolysis conditions and condensation reaction. TiO2 synthesized from the filtrate of sulfuric acid leaching that produced from TiO2 anatase phase when hydrolyzed in an aquaregia solvent and low concentrations of HCl (0.1M). Hydrolysis conditions at higher concentrations of HCl (1M) was produced TiO2 anatase-rutile phase. The synthesis of TiO2 from the filtrate of hydrochloric acid leaching was produced anatase phase. While the condition under the alcoholic solvent (2-propanol: H2O (v/v) = 9: 1) anatase phase crystallites grow in the temperature range up to 550 °C, above this temperature, TiO2 transform into rutile phase.

High-resolution EELS investigation of the electronic structure of ilmenites

NARCIS (Netherlands)

Radtke, G.; Lazar, S.; Botton, G.A.

2006-01-01

The electronic structure of a series of compounds belonging to the ilmenite family is investigated using high resolution electron energy loss spectroscopy (EELS). The energy loss near edge structure (ELNES) of the O-K, Ti-L23 and transition metal L23 edges have been recorded in MnTiO3, FeTiO3,

Remediation of soils combining soil vapor extraction and bioremediation: benzene.

Science.gov (United States)

Soares, António Alves; Albergaria, José Tomás; Domingues, Valentina Fernandes; Alvim-Ferraz, Maria da Conceição M; Delerue-Matos, Cristina

2010-08-01

This work reports the study of the combination of soil vapor extraction (SVE) with bioremediation (BR) to remediate soils contaminated with benzene. Soils contaminated with benzene with different water and natural organic matter contents were studied. The main goals were: (i) evaluate the performance of SVE regarding the remediation time and the process efficiency; (ii) study the combination of both technologies in order to identify the best option capable to achieve the legal clean up goals; and (iii) evaluate the influence of soil water content (SWC) and natural organic matter (NOM) on SVE and BR. The remediation experiments performed in soils contaminated with benzene allowed concluding that: (i) SVE presented (a) efficiencies above 92% for sandy soils and above 78% for humic soils; (b) and remediation times from 2 to 45 h, depending on the soil; (ii) BR showed to be an efficient technology to complement SVE; (iii) (a) SWC showed minimum impact on SVE when high airflow rates were used and led to higher remediation times for lower flow rates; (b) NOM as source of microorganisms and nutrients enhanced BR but hindered the SVE due the limitation on the mass transfer of benzene from the soil to the gas phase. (c) 2010 Elsevier Ltd. All rights reserved.

Measurement of 238U and 232Th radionuclides in ilmenite and synthetic rutile

Science.gov (United States)

Idris, M. I.; Siong, K. K.; Fadzil, S. M.

2018-01-01

The only factory that currently processes ilmenite to produce synthetic rutile is Tor Minerals in Ipoh, Perak, Malaysia. These two minerals contain radioactive elements such as uranium and thorium. Furthermore, this factory was built close to the residential areas. Thus, the primary issues are radiation exposure attributed to the decay of the radionuclides. Hence, the objectives of this study are to measure the dose and to evaluate activity levels of uranium and thorium. Dose rates from surrounding area of factory indicate the normal range for both on the surface and 1 meter above the ground (0.3-0.7 μSv/hr) lower than the global range of 0.5-1.3 μSv/hr set by UNSCEAR. The mean activity levels of uranium and thorium for ilmenite are 235 Bq/kg and 503 Bq/kg while for synthetic rutile are 980 Bq/kg and 401 Bq/kg, respectively. The result shows that uranium activity levels of synthetic rutile is 4 times higher than ilmenite but it is still lower than the regulatory exemption limit of 1000 Bq/kg set by IAEA Basic Safety Standards. Even though the dose rates at the factory and the activity levels are within safe limits, safety precautions must be followed by the factory management to prevent any unwanted accident to occur.

Thermal, epithermal and thermalized neutron attenuation properties of ilmenite-serpentine heat resistant concrete shield

International Nuclear Information System (INIS)

Kany, A.M.I.; El-Gohary, M.I.; Kamal, S.M.

1994-01-01

Experimental measurements were carried out to study the attenuation properties of low-energy neutrons transmitted through unheated and preheated barriers of heavy-weight, highly hydrated and heat-resistant concrete shields. The concrete shields under investigation have been prepared from naturally occurring ilmenite and serpentine Egyptian ores. A collimated beam obtained from an Am-Be source was used as a source of neutrons, while the measurements of total thermal, epithermal, and thermalized neutron fluxes were performed using a BF-3 detector, multichannel analyzer and Cd filter. Results show that the ilmenite-serpentine concrete proved to be a better thermal, epithermal and thermalized neutron attenuator than the ordinary concrete especially at a high temperature of concrete exposure. (Author)

Production of titanium carbide from ilmenite

Directory of Open Access Journals (Sweden)

Sutham Niyomwas

2008-03-01

Full Text Available The production of titanium carbide (TiC powders from ilmenite ore (FeTiO3 powder by means of carbothermal reduction synthesis coupled with hydrochloric acid (HCl leaching process was investigated. A mixture of FeTiO3 and carbon powders was reacted at 1500oC for 1 hr under flowing argon gas. Subsequently, synthesized product of Fe-TiC powders were leached by 10% HCl solutions for 24 hrs to get final product of TiC powders. The powders were characterized using X-ray diffraction, scanning electron and transmission electron microscopy. The product particles were agglomerated in the stage after the leaching process, and the size of this agglomerate was 12.8 μm with a crystallite size of 28.8 nm..

Reducibility study of Rossetta ilmenite ore briquettes and powder with coke breeze at 800-1100°C

Directory of Open Access Journals (Sweden)

Abd el Gawad Hala H.

2013-01-01

Full Text Available Ilmenite ore fine and coke breeze as reduced material were briquetted with different amounts of organic materials such as molasses or pitch were studied in this investigation. The produced briquettes at reasonable condition were reduced in nitrogen atmosphere at temperature range 800 - 1100oC to determine the factors controlling the reduction and to determine the controlling mechanism. Also ilmenite ore fine with coke breeze were reduced at the same temperature range in nitrogen atmosphere without briquetting process, for the sake of comparison.

Numerical simulation of temperature distribution in cylindrical ilmenite (FeTiO3) due to microwave heating

Science.gov (United States)

Hidayat, Mas Irfan P.; Fellicia, Dian Mughni; Rafandi, Ferdiansyah Iqbal

2018-04-01

Microwave assisted heating has been extensively used in materials processing particularly in extraction of TiO2 from Ilmenite (FeTiO3) minerals. Nevertheless, this method could generate non-uniform temperature distribution during the heating process. The observation of this phenomena in cylindrical ilmenite has been conducted by numerical simulation using finite element method according to the Poynthing's theorem. Four different cylinders with variation on its height were simulated in ANSYS 17 with input microwave power of 5.5 Kw. The results indicated that height of heated object could vigorously influence the uniformity of temperature inside the body.

Alkali roasting of bomar ilmenite: rare earths recovery and physico-chemical changes

Directory of Open Access Journals (Sweden)

Sanchez-Segado Sergio

2014-11-01

(FeTiO3 is presented as a process route for integrated beneficiation of the mineral for rutile-rich phase and rare earth oxides; the latter is released as a consequence of physical changes in the ilmenite matrix, during the water leaching after roasting. The oxidative alkali roasting transforms ilmenite mineral into water-insoluble alkali titanate and water-soluble ferrite. After roasting the insoluble alkali titanate is separated from rare-earth oxide mixture in colloidal form and water-soluble ferrite. Further leaching of alkali titanate is carried out with oxalic (0.3M and ascorbic (0.01M acid solution which removes the remaining Fe2+ ions into the leachate and allows precipitation of high-purity synthetic rutile containing more than 95% TiO2. Iron is removed as iron oxalate. The physico-chemical changes occurred during the roasting and leaching processes are reported by comparing the role of alkali on the roasting process and product morphologies formed.

SEP-Kr and SEP-Xe in Lunar Ilmenite and the Ar/Kr/Xe Ratio in the Solar Wind

Science.gov (United States)

Wieler, R.; Baur, H.; Signer, P.

1992-07-01

We analyzed all five noble gases in an ilmenite sample from lunar soil 71501 by closed system stepped etching (CSSE), thus extending our CSSE studies of solar noble gases (Wieler et al., 1986; Benkert et al., 1988) to Kr and Xe. He, Ne, Ar isotopes: We observe the familiar presence of two solar noble gas components: step 1 shows ^4He/^3He = 2250, ^20Ne/^22Ne = 13.8, and ^36Ar/^38Ar=5.46. The first two ratios are essentially identical to modern solar wind values (SWC; Geiss, 1973), indicating an isotopically unfractionated SW noble gas reservoir in lunar ilmenite. The Ne data-points of later steps fall on a straight line and reach the SEP-Ne point (^20Ne/^22Ne = 11.3). The slope of this line indicates mass dependent fractionation between SW-Ne and SEP-Ne. SEP-He (^4He/^3He = 4650 +-100) and SEP-Ar (^36Ar/^38Ar = 4.89+-0.05) are also observed (latter two numbers slightly revised compared to Wieler et al., 1992). Kr, Xe isotopes: Kr in those two steps that release pure SW-Ne is very slightly lighter than atmospheric Kr (^86Kr/^84Kr = 0.3041; see also Wieler et al., 1992). We interpret this to be SW-Kr in soil 71501. Steps containing (isotopically heavier) SEP-Ne likewise release heavier Kr, interpreted accordingly as SEP-Kr (^86Kr/^84Kr = 0.323). Similarly, a light Xe component is released first (SW-Xe, ^136Xe/^132Xe = 0.3003), followed by heavier SEP-Xe (^136Xe/^132Xe = 0.319). The data are consistent with both Kr and Xe in SW and SEP components to be related by mass fractionation. The relation first proposed by Benkert et al. (1988) between a ratio R(m(sub)2,m(sub)1) of two isotopes with masses m(sub)2>m(sub)1 in SW and SEP now holds for all five noble gases: (R(sub)SW-R(sub)SEP)/R(sub)SW = (2+-0.13)*(m(sub)2- m(sub)1)/m(sub)2. Since m(sub)2~m(sub)1, this relation may also be written as: R(sub)SEP/R(sub)SW ~ (m(sub)1/m(sub)2)^2 (Geiss and Bochsler, 1991). Element ratios: ^4He/^36Ar and ^20Ne/^36Ar rise from values several times below SWC to essentially SWC ratios in

Overturn of magma ocean ilmenite cumulate layer: Implications for lunar magmatic evolution and formation of a lunar core

Science.gov (United States)

Hess, P. C.; Parmentier, E. M.

1993-01-01

We explore a model for the chemical evolution of the lunar interior that explains the origin and evolution of lunar magmatism and possibly the existence of a lunar core. A magma ocean formed during accretion differentiates into the anorthositic crust and chemically stratified cumulate mantle. The cumulative mantle is gravitationally unstable with dense ilmenite cumulate layers overlying olivine-orthopyroxene cumulates with Fe/Mg that decreases with depth. The dense ilmenite layer sinks to the center of the moon forming the core. The remainder of the gravitationally unstable cumulate pile also overturns. Any remaining primitive lunar mantle rises to its level of neutral buoyancy in the cumulate pile. Perhaps melting of primitive lunar mantle due to this decompression results in early lunar Mg-rich magmatism. Because of its high concentration of incompatible heat producing elements, the ilmenite core heats the overlying orthopyroxene-bearing cumulates. As a conductively thickening thermal boundary layer becomes unstable, the resulting mantle plumes rise, decompress, and partially melt to generate the mare basalts. This model explains both the timing and chemical characteristics of lunar magmatism.

Ilmenit z dvojslídných granitů klenovského plutonu

Czech Academy of Sciences Publication Activity Database

René, Miloš

2013-01-01

Roč. 46, Prosinec (2013), s. 224-227 ISSN 0514-8057 R&D Projects: GA MŠk ME10083 Institutional support: RVO:67985891 Keywords : ilmenite * two-mica granite * Moldanubian Zone * Bohemian Massif Subject RIV: DB - Geology ; Mineralogy http://www.geology.cz/zpravy/obsah/2012/Zpravy_2012-45.pdf

Formation and evolution of a lunar core from ilmenite-rich magma ocean cumulates

NARCIS (Netherlands)

de Vries, J.; van den Berg, A.P.; van Westrenen, W.

2010-01-01

In the absence of comprehensive seismic data coverage, the size, composition and physical state of the lunar core are still debated. It has been suggested that a dense ilmenite-rich layer, which originally crystallised near the top of the lunar magma ocean, may have sunk to the centre of the Moon to

Environmental and geochemical assessment of surface sediments on irshansk ilmenite deposit area

Directory of Open Access Journals (Sweden)

Наталия Олеговна Крюченко

2015-03-01

Full Text Available It is revealed the problem of pollution of surface sediments of Irshansk ilmenite deposit area of various chemical elements hazard class (Mn, V, Ba, Ni, Co, Cr, Mo, Cu, Pb, Zn. It is determined its average content in surface sediments of various functional areas (forest and agricultural land, flood deposits, reclaimed land, calculated geochemical criteria, so given ecological and geochemical assessment of area

Modelling trends in soil solution concentrations under five forest-soil combinations in the Netherlands

NARCIS (Netherlands)

Salm, van der C.; Vries, de W.; Kros, J.

1996-01-01

The influence of forest and soil properties on changes in soil solution concentration upon a reduction deposition was examined for five forest-soil combinations with the dynamic RESAM model. Predicted concentrations decreased in the direction Douglas fir - Scotch pine - oak, due to decreased

Effect of CaO addition on preparation of ferrotitanium from ilmenite by electrochemical reduction in CaCl_2−NaCl molten salt

International Nuclear Information System (INIS)

Xiong, Li; Hua, Yixin; Xu, Cunying; Li, Jian; Li, Yan; Zhang, Qibo; Zhou, Zhongren; Zhang, Yadong; Ru, Juanjian

2016-01-01

Ferro-titanium (FeTi) alloy was prepared successfully from synthesized ilmenite through electrochemical reduction method in equal-molar CaCl_2−NaCl molten salt at 973 K and a cell voltage of 3.2 V under inert atmosphere, where molybdenum rod and graphite were used as cathode and anode respectively. It is indicated that the CaO content in the molten salt has an appreciable effect on the phase transformation of reactants occurring in the electrolytic process. The optimized CaO content in the molten salt is 1 mol% and this suitable content of CaO can significantly improve the reduction rate of ilmenite. The micromorphology of the ferrotitanium product is porous with the amount of 1 mol%CaO addition. It is observed that the particles of ferrotitanium had a uniform size in the initial period of time. Along with the electrolysis time extension, however, the particles connected with each other to generate strips and then form a honeycomb structure. These findings provide a basis for scientifically discussion on the optimization of CaO addition amount during the electrochemical reduction of ilmenite and other oxides in molten salts. - Highlights: • Ferro-titanium was prepared from synthesized ilmenite in CaCl_2−NaCl molten salt. • CaO content has appreciable effect on the phase transformation of ilmenite reactant. • The optimized CaO content is 1 mol% which can significantly improve reaction rate. • The products are connected with each other to form strips as electrolysis time.

Remediation of multiple heavy metal-contaminated soil through the combination of soil washing and in situ immobilization.

Science.gov (United States)

Zhai, Xiuqing; Li, Zhongwu; Huang, Bin; Luo, Ninglin; Huang, Mei; Zhang, Qiu; Zeng, Guangming

2018-09-01

The remediation of heavy metal-contaminated soils is a great challenge for global environmental sciences and engineering. To control the ecological risks of heavy metal-contaminated soil more effectively, the present study focused on the combination of soil washing (with FeCl 3 ) and in situ immobilization (with lime, biochar, and black carbon). The results showed that the removal rate of Cd, Pb, Zn, and Cu was 62.9%, 52.1%, 30.0%, and 16.7%, respectively, when washed with FeCl 3 . After the combined remediation (immobilization with 1% (w/w) lime), the contaminated soils showed 36.5%, 73.6%, 70.9%, and 53.4% reductions in the bioavailability of Cd, Cu, Pb, and Zn (extracted with 0.11M acetic acid), respectively, than those of the soils washed with FeCl 3 only. However, the immobilization with 1% (w/w) biochar or 1% (w/w) carbon black after washing exhibited low effects on stabilizing the metals. The differences in effects between the immobilization with lime, biochar, and carbon black indicated that the soil pH had a significant influence on the lability of heavy metals during the combined remediation process. The activity of the soil enzymes (urease, sucrase, and catalase) showed that the addition of all the materials, including lime, biochar, and carbon black, exhibited positive effects on microbial remediation after soil washing. Furthermore, lime was the most effective material, indicating that low soil pH and high acid-soluble metal concentrations might restrain the activity of soil enzymes. Soil pH and nutrition were the major considerations for microbial remediation during the combined remediation. These findings suggest that the combination of soil washing and in situ immobilization is an effective method to amend the soils contaminated with multiple heavy metals. Copyright © 2018 Elsevier B.V. All rights reserved.

Biopiles and biofilters combined for soil cleanup

International Nuclear Information System (INIS)

Lei, J.; Sansregret, J.L.; Cyr, B.

1994-01-01

Bioremediation of hydrocarbon-contaminated soils can be completed using a combination of biopile and biofiltration technologies. Target contaminants, such as gasoline, jet fuel, diesel fuel and other petroleum-derived products are removed from the soil by biodegradation and volatilization in the biopile. Air emissions from the biopile containing volatile hydrocarbons are treated subsequently in a biofilter, where the pollutants are degraded and mineralized by heterotrophic aerobic microorganisms. In the biopile process, contaminated soil is excavated and stockpiled in a treatment area. Remediation of the soil relies on microbial degradation and volatilization of hydrocarbons under controlled treatment conditions

First-principles investigation of Fe-doped MgSiO3-ilmenite

International Nuclear Information System (INIS)

Stashans, Arvids; Rivera, Krupskaya; Pinto, Henry P.

2012-01-01

First principles density functional theory and generalised gradient approximation (GGA) have been exploited to investigate Fe-doped ilmenite-type MgSiO 3 mineral. Strong electron correlation effects not included in a density-functional formalism are described by a Hubbard-type on-site Coulomb repulsion (the DFT+U approach). Microstructure of equilibrium geometries, electronic band structures as well as magnetic properties are computed and discussed in detail. Hartree-Fock methodology is used as an extra tool to study optical properties of the same system. For equilibrium state of the doped mineral we find zigzag-type atomic rearrangements around the Fe impurity. The inclusion of correlation effects leads to an improved description of the electronic properties. In particular, it is discovered that Fe incorporation produces local energy levels within the band-gap of the material. Using ΔSCF method optical absorption energies are found to be equal to 2.2 and 2.6 eV leading to light absorption at longer wavelengths compared to the undoped MgSiO 3 . Our results provide evidence on the occurrence of local magnetic moment in the region surrounding iron dopant. According to the outcomes, the Fe⇒Mg reaction can be described as substitutionally labile with Fe 2+ complex being found in the high-spin state at low pressure MgSiO 3 -ilmenite conditions.

Effect of CaO addition on preparation of ferrotitanium from ilmenite by electrochemical reduction in CaCl{sub 2}−NaCl molten salt

Energy Technology Data Exchange (ETDEWEB)

Xiong, Li [Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093 (China); State Key Lab of Complex Nonferrous Metal Resources Clean Utilization, Kunming 650093 (China); Hua, Yixin, E-mail: yxhua@kmust.edu.cn [Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093 (China); State Key Lab of Complex Nonferrous Metal Resources Clean Utilization, Kunming 650093 (China); Xu, Cunying; Li, Jian; Li, Yan; Zhang, Qibo; Zhou, Zhongren; Zhang, Yadong [Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093 (China); State Key Lab of Complex Nonferrous Metal Resources Clean Utilization, Kunming 650093 (China); Ru, Juanjian [Faculty of Material Science and Engineering, Kunming University of Science and Technology, Kunming 650093 (China)

2016-08-15

Ferro-titanium (FeTi) alloy was prepared successfully from synthesized ilmenite through electrochemical reduction method in equal-molar CaCl{sub 2}−NaCl molten salt at 973 K and a cell voltage of 3.2 V under inert atmosphere, where molybdenum rod and graphite were used as cathode and anode respectively. It is indicated that the CaO content in the molten salt has an appreciable effect on the phase transformation of reactants occurring in the electrolytic process. The optimized CaO content in the molten salt is 1 mol% and this suitable content of CaO can significantly improve the reduction rate of ilmenite. The micromorphology of the ferrotitanium product is porous with the amount of 1 mol%CaO addition. It is observed that the particles of ferrotitanium had a uniform size in the initial period of time. Along with the electrolysis time extension, however, the particles connected with each other to generate strips and then form a honeycomb structure. These findings provide a basis for scientifically discussion on the optimization of CaO addition amount during the electrochemical reduction of ilmenite and other oxides in molten salts. - Highlights: • Ferro-titanium was prepared from synthesized ilmenite in CaCl{sub 2}−NaCl molten salt. • CaO content has appreciable effect on the phase transformation of ilmenite reactant. • The optimized CaO content is 1 mol% which can significantly improve reaction rate. • The products are connected with each other to form strips as electrolysis time.

Spin orientation in solid solution hematite-ilmenite

DEFF Research Database (Denmark)

Brok, Erik; Frandsen, Cathrine; Lefmann, Kim

2017-01-01

temperature range below the Néel temperature and does not depend systematically on Ti-content. The results indicate that the out-of-plane spin component is an intrinsic feature of hematite itself, with an origin not yet fully understood, but consistent with group theory. This represents a major shift...... spectroscopy. The usually assumed magnetic structure of hematite within this temperature range is antiferromagnetic with the spins confined to the basal plane of the hexagonal structure; however, an out-of-plane spin component is allowed by the symmetry of the system and has been observed in recent studies......The spin orientation in synthetic hematite-ilmenite samples and in a sample of natural hematite was studied from room temperature to above the antiferromagnetic-paramagnetic phase transition (the Néel temperature; TN ≈ 600–950 K) by neutron powder diffraction and at room temperature by Mössbauer...

Parameter estimation of a two-horizon soil profile by combining crop canopy and surface soil moisture observations using GLUE

Science.gov (United States)

Sreelash, K.; Sekhar, M.; Ruiz, L.; Tomer, S. K.; Guérif, M.; Buis, S.; Durand, P.; Gascuel-Odoux, C.

2012-08-01

SummaryEstimation of soil parameters by inverse modeling using observations on either surface soil moisture or crop variables has been successfully attempted in many studies, but difficulties to estimate root zone properties arise when heterogeneous layered soils are considered. The objective of this study was to explore the potential of combining observations on surface soil moisture and crop variables - leaf area index (LAI) and above-ground biomass for estimating soil parameters (water holding capacity and soil depth) in a two-layered soil system using inversion of the crop model STICS. This was performed using GLUE method on a synthetic data set on varying soil types and on a data set from a field experiment carried out in two maize plots in South India. The main results were (i) combination of surface soil moisture and above-ground biomass provided consistently good estimates with small uncertainity of soil properties for the two soil layers, for a wide range of soil paramater values, both in the synthetic and the field experiment, (ii) above-ground biomass was found to give relatively better estimates and lower uncertainty than LAI when combined with surface soil moisture, especially for estimation of soil depth, (iii) surface soil moisture data, either alone or combined with crop variables, provided a very good estimate of the water holding capacity of the upper soil layer with very small uncertainty whereas using the surface soil moisture alone gave very poor estimates of the soil properties of the deeper layer, and (iv) using crop variables alone (else above-ground biomass or LAI) provided reasonable estimates of the deeper layer properties depending on the soil type but provided poor estimates of the first layer properties. The robustness of combining observations of the surface soil moisture and the above-ground biomass for estimating two layer soil properties, which was demonstrated using both synthetic and field experiments in this study, needs now to

Kajian Konsep Teknologi Pengolahan Pasir Zirkon Lokal yang Mengandung Monasit, Senotim dan Ilmenit

Directory of Open Access Journals (Sweden)

Herry Poernomo

2016-11-01

Full Text Available The existence of zircon (ZrSiO4 in the nature is mostly associated with some of the valuable oxide compounds (VOC, such as TiO2 and rare earth oxides (REO. The existence of natural minerals in Indonesia containing zirconium (Zr and REO lies in 13 regions, ranging from Aceh to West Papua province. Based on those aforementioned aspects, the goal of this research is to conduct the study of integrated technology of local zircon sand processing containing TiO2 and REO. The study was conducted by analyzing the content of VOC in zircon sand samples from the areas of Landak and Tumbang Titi West Kalimantan and Bangka by using XRF. Based on the content of VOC in this zircon sand, it can be predicted that the zircon sand from the area of Landak and Tumbang Titi West Kalimantan and Bangka contains mineral zircon (ZrSiO4, ilmenite (FeTiO3, monazite (LREE, ThPO4, and xenotime (HREE, ThPO4. Based on these types of mineral, the flow chart of beneficiation technology process to increase the concentration of each mineral and the flow chart of zircon concentrate process into ZrO2(zirconia and ZrOCl2.8H2O (zirconium oxychloride industrial grade and zirconia and zirconium chemicals nuclear grade, ilmenite into TiO2, monazite into Nd2O3, and Th(OH4 concentrate, xenotime into Y2O3, Gd2O3, and Th(OH4 concentrate are obtained in one area of pilot plant or an integrated factory. The results of the study concluded that the concept of local processing of zircon sands containing monazite, xenotime, and ilmenite can be either integrated in the region with the results of multi-product plant. If it can be realized in Indonesia with the addition of an integrated waste water treatment system, then in addition to safe for the environment can also save on production costs and give economic added value for shareholders zircon mining permit

Electroremediation of PCB contaminated soil combined with iron nanoparticles: Effect of the soil type.

Science.gov (United States)

Gomes, Helena I; Dias-Ferreira, Celia; Ottosen, Lisbeth M; Ribeiro, Alexandra B

2015-07-01

Polychlorinated biphenyls (PCB) are carcinogenic and persistent organic pollutants that accumulate in soils and sediments. Currently, there is no cost-effective and sustainable remediation technology for these contaminants. In this work, a new combination of electrodialytic remediation and zero valent iron particles in a two-compartment cell is tested and compared to a more conventional combination of electrokinetic remediation and nZVI in a three-compartment cell. In the new two-compartment cell, the soil is suspended and stirred simultaneously with the addition of zero valent iron nanoparticles. Remediation experiments are made with two different historically PCB contaminated soils, which differ in both soil composition and contamination source. Soil 1 is a mix of soils with spills of transformer oils, while Soil 2 is a superficial soil from a decommissioned school where PCB were used as windows sealants. Saponin, a natural surfactant, was also tested to increase the PCB desorption from soils and enhance dechlorination. Remediation of Soil 1 (with highest pH, carbonate content, organic matter and PCB concentrations) obtained the maximum 83% and 60% PCB removal with the two-compartment and the three-compartment cell, respectively. The highest removal with Soil 2 were 58% and 45%, in the two-compartment and the three-compartment cell, respectively, in the experiments without direct current. The pH of the soil suspension in the two-compartment treatment appears to be a determining factor for the PCB dechlorination, and this cell allowed a uniform distribution of the nanoparticles in the soil, while there was iron accumulation in the injection reservoir in the three-compartment cell. Copyright © 2015 Elsevier Ltd. All rights reserved.

Electroremediation of PCB contaminated soil combined with iron nanoparticles: Effect of the soil type

DEFF Research Database (Denmark)

Gomes, Helena I.; Dias-Ferreira, Celia; Ottosen, Lisbeth M.

2015-01-01

Polychlorinated biphenyls (PCB) are carcinogenic and persistent organic pollutants that accumulate in soils and sediments. Currently, there is no cost-effective and sustainable remediation technology for these contaminants. In this work, a new combination of electrodialytic remediation and zero...... nanoparticles. Remediation experiments are made with two different historically PCB contaminated soils, which differ in both soil composition and contamination source. Soil 1 is a mix of soils with spills of transformer oils, while Soil 2 is a superficial soil from a decommissioned school where PCB were used...... as windows sealants. Saponin, a natural surfactant, was also tested to increase the PCB desorption from soils and enhance dechlorination. Remediation of Soil 1 (with highest pH, carbonate content, organic matter and PCB concentrations) obtained the maximum 83% and 60% PCB removal with the two...

First-principles investigation of Fe-doped MgSiO{sub 3}-ilmenite

Energy Technology Data Exchange (ETDEWEB)

Stashans, Arvids, E-mail: arvids@utpl.edu.ec [Grupo de Fisicoquimica de Materiales, Universidad Tecnica Particular de Loja, Apartado 11-01-608, Loja (Ecuador); Rivera, Krupskaya [Grupo de Fisicoquimica de Materiales, Universidad Tecnica Particular de Loja, Apartado 11-01-608, Loja (Ecuador); Escuela de Geologia y Minas, Universidad Tecnica Particular de Loja, Apartado 11-01-608, Loja (Ecuador); Pinto, Henry P. [Interdisciplinary Center for Nanotoxicity, Department of Chemistry, Jackson State University, Jackson, Mississippi 39217-0510 (United States)

2012-06-15

First principles density functional theory and generalised gradient approximation (GGA) have been exploited to investigate Fe-doped ilmenite-type MgSiO{sub 3} mineral. Strong electron correlation effects not included in a density-functional formalism are described by a Hubbard-type on-site Coulomb repulsion (the DFT+U approach). Microstructure of equilibrium geometries, electronic band structures as well as magnetic properties are computed and discussed in detail. Hartree-Fock methodology is used as an extra tool to study optical properties of the same system. For equilibrium state of the doped mineral we find zigzag-type atomic rearrangements around the Fe impurity. The inclusion of correlation effects leads to an improved description of the electronic properties. In particular, it is discovered that Fe incorporation produces local energy levels within the band-gap of the material. Using {Delta}SCF method optical absorption energies are found to be equal to 2.2 and 2.6 eV leading to light absorption at longer wavelengths compared to the undoped MgSiO{sub 3}. Our results provide evidence on the occurrence of local magnetic moment in the region surrounding iron dopant. According to the outcomes, the Fe Rightwards-Double-Arrow Mg reaction can be described as substitutionally labile with Fe{sup 2+} complex being found in the high-spin state at low pressure MgSiO{sub 3}-ilmenite conditions.

Preparation of Ferrotitanium Alloys by Electrolysis-Assisted Calciothermic Reduction of Ilmenite in Equimolar CaCl2-NaCl Electrolyte: Effect of Calcium Oxide

Science.gov (United States)

Zhou, Zhongren; Zhang, Yingjie; Hua, Yixin; Xu, Cunying; Dong, Peng; Zhang, Qibo; Wang, Ding

2018-04-01

The effect of CaO content on the preparation of ferrotitanium alloys from ilmenite with the method of the electrolysis-assisted calciothermic reduction has been investigated by use of ilmenite powders as raw materials that positions them next to the cathodic molybdenum plate, equimolar CaCl2-NaCl molten salt with 2-7 mol.% CaO as electrolyte and graphite as anode at 700°C with cell voltage of 2.8 V under argon atmosphere. It is demonstrated that increasing the reactant CaO content is beneficial to the calciothermic reduction of ilmenite and the intermediate CaTiO3. Experimental results also show that after 14 h of calciothermic reduction process, the products are ferrotitanium alloys and the specific energy consumption is only about 10.21 kWh kg-1 when adding 5 mol.% CaO into equimolar CaCl2-NaCl molten salt and approximately 14.40 kWh kg-1 when CaO content is increased to 7 mol.%.

Quenching ilmenite with a high-temperature and high-pressure phase using super-high-energy ball milling.

Science.gov (United States)

Hashishin, Takeshi; Tan, Zhenquan; Yamamoto, Kazuhiro; Qiu, Nan; Kim, Jungeum; Numako, Chiya; Naka, Takashi; Valmalette, Jean Christophe; Ohara, Satoshi

2014-04-25

The mass production of highly dense oxides with high-temperature and high-pressure phases allows us to discover functional properties that have never been developed. To date, the quenching of highly dense materials at the gramme-level at ambient atmosphere has never been achieved. Here, we provide evidence of the formation of orthorhombic Fe2TiO4 from trigonal FeTiO3 as a result of the high-temperature (>1250 K) and high-pressure (>23 GPa) condition induced by the high collision energy of 150 gravity generated between steel balls. Ilmenite was steeply quenched by the surrounding atmosphere, when iron-rich ilmenite (Fe2TiO4) with a high-temperature and high-pressure phase was formed by planetary collisions and was released from the collision points between the balls. Our finding allows us to infer that such intense planetary collisions induced by high-energy ball milling contribute to the mass production of a high-temperature and high-pressure phase.

Anaerobic Soil Disinfestation (ASD) Combined with Soil Solarization for Root-Knot Nematode Control in Vegetable and Ornamental Crops in Florida

Science.gov (United States)

Anaerobic soil disinfestation (ASD) combined with soil solarization continues to be evaluated for management of plant-parasitic nematodes in vegetable and ornamental crops in Florida. ASD combines organic amendments and soil saturation to stimulate microbial activity and create anaerobic conditions...

Combined Radar-Radiometer Surface Soil Moisture and Roughness Estimation

Science.gov (United States)

Akbar, Ruzbeh; Cosh, Michael H.; O'Neill, Peggy E.; Entekhabi, Dara; Moghaddam, Mahta

2017-01-01

A robust physics-based combined radar-radiometer, or Active-Passive, surface soil moisture and roughness estimation methodology is presented. Soil moisture and roughness retrieval is performed via optimization, i.e., minimization, of a joint objective function which constrains similar resolution radar and radiometer observations simultaneously. A data-driven and noise-dependent regularization term has also been developed to automatically regularize and balance corresponding radar and radiometer contributions to achieve optimal soil moisture retrievals. It is shown that in order to compensate for measurement and observation noise, as well as forward model inaccuracies, in combined radar-radiometer estimation surface roughness can be considered a free parameter. Extensive Monte-Carlo numerical simulations and assessment using field data have been performed to both evaluate the algorithms performance and to demonstrate soil moisture estimation. Unbiased root mean squared errors (RMSE) range from 0.18 to 0.03 cm3cm3 for two different land cover types of corn and soybean. In summary, in the context of soil moisture retrieval, the importance of consistent forward emission and scattering development is discussed and presented.

Combined soil washing and CDEO for the removal of atrazine from soils

Energy Technology Data Exchange (ETDEWEB)

Vieira dos Santos, Elisama [Institute of Chemistry, Federal University of Rio Grande do Norte, Lagoa Nova CEP 59078-970, Natal, RN (Brazil); Sáez, Cristina [Department of Chemical Engineering, Universidad de Castilla – La Mancha, Enrique Costa Building, Campus Universitario s/n, 13071 Ciudad Real (Spain); Martínez-Huitle, Carlos Alberto [Institute of Chemistry, Federal University of Rio Grande do Norte, Lagoa Nova CEP 59078-970, Natal, RN (Brazil); Cañizares, Pablo; Rodrigo, Manuel Andres [Department of Chemical Engineering, Universidad de Castilla – La Mancha, Enrique Costa Building, Campus Universitario s/n, 13071 Ciudad Real (Spain)

2015-12-30

Highlights: • Sequential soil washing-waste electrolysis is an efficient treatment for removing atrazine. • Ratio surfactant/soil influences on the size of micelles and organic load. • Electrolysis with diamond anodes oxidizes pollutants from soils washing wastes. • Electrolysis of soil washing fluids promotes the reduction in size of micelles. • Sulphate ions release from the oxidation of SDS participates in the oxidation process. - Abstract: In this work, it is studied the removal of atrazine from spiked soils by soil washing using surfactant fluids, followed by the treatment of the resulting washing waste by electrolysis with boron doped diamond (BDD) anode. Results confirm that combination of both technologies is efficient for the removal and total mineralization of atrazine. Ratio surfactant/soil is a key parameter for the removal of atrazine from soil and influences significantly in the characteristic of the wastewater produced, affecting not only to the total organic load but also to the mean size of micelles. The higher the ratio surfactant soil, the lower is the size of the particles. Electrolyses of this type of waste attain the complete mineralization. TOC and COD are removed from the start of the treatment but the key of the treatment is the reduction in size of the micelles, which lead to a higher negative charge in the surface and to the faster depletion of the surfactant as compared with the pesticide.

Ion irradiation damage in ilmenite at 100 K

International Nuclear Information System (INIS)

Mitchell, J.N.; Yu, N.; Devanathan, R.; Sickafus, K.E.; Nastasi, M.A.

1997-01-01

A natural single crystal of ilmenite (FeTiO 3 ) was irradiated at 100 K with 200 keV Ar 2+ . Rutherford backscattering spectroscopy and ion channeling with MeV He + ions were used to monitor damage accumulation in the surface region of the implanted crystal. At an irradiation fluence of 1 x 10 15 Ar 2+ cm -2 , considerable near-surface He + ion dechanneling was observed, to the extent that ion yield from a portion of the aligned crystal spectrum reached the yield level of a random spectrum. This observation suggests that the near-surface region of the crystal was amorphized by the implantation. Cross-sectional transmission electron microscopy and electron diffraction on this sample confirmed the presence of a 150 nm thick amorphous layer. These results are compared to similar investigations on geikielite (MgTiO 3 ) and spinel (MgAl 2 O 4 ) to explore factors that may influence radiation damage response in oxides

Ion irradiation damage in ilmenite under cryogenic conditions

International Nuclear Information System (INIS)

Mitchell, J.N.; Yu, N.; Devanathan, R.; Sickafus, K.E.; Nastasi, M.A.

1996-01-01

A natural single crystal of ilmenite was irradiated at 100 K with 200 keV Ar 2+ . Rutherford backscattering spectroscopy and ion channeling with 2 MeV He + ions were used to monitor damage accumulation in the surface region of the implanted crystal. At an irradiation fluence of 1 x 10 15 Ar 2+ cm -2 , considerable near-surface He + ion dechanneling was observed, to the extent that ion yield from a portion of the aligned crystal spectrum reached the yield level of a random spectrum. This observation suggests that the near-surface region of the crystal was amorphized by the implantation. Cross-sectional transmission electron microscopy and electron diffraction on this sample confirmed the presence of a 150 mm thick amorphous layer. These results are compared to similar investigations on geikielite (MgTiO 3 ) and spinel (MgAl 2 O 4 ) to explore factors that may influence radiation damage response in oxides

Ion irradiation damage in ilmenite at 100 K

Science.gov (United States)

Mitchell, J.N.; Yu, N.; Devanathan, R.; Sickafus, K.E.; Nastasi, M.A.; Nord, G.L.

1997-01-01

A natural single crystal of ilmenite (FeTiO3) was irradiated at 100 K with 200 keV Ar2+. Rutherford backscattering spectroscopy and ion channeling with 2 MeV He+ ions were used to monitor damage accumulation in the surface region of the implanted crystal. At an irradiation fluence of 1 ?? 1015 Ar2+/cm2, considerable near-surface He+ ion dechanneling was observed, to the extent that ion yield from a portion of the aligned crystal spectrum reached the yield level of a random spectrum. This observation suggests that the near-surface region of the crystal was amorphized by the implantation. Cross-sectional transmission electron microscopy and electron diffraction on this sample confirmed the presence of a 150 nm thick amorphous layer. These results are compared to similar investigations on geikielite (MgTiO3) and spinel (MgAl2O4) to explore factors that may influence radiation damage response in oxides.

Use of a combined penetrometer-TDR moisture probe for soil compaction studies

International Nuclear Information System (INIS)

Pedro Vaz, C.M.

2004-01-01

measurement technique, we have developed a combined cone penetrometer-TDR moisture probe by wrapping two TDR wires around the penetrometer rod (combined rod TDR) as a double helix, so that both soil water content and penetration resistance can be measured simultaneously and at approximately the same location within the soil profile. The main advantage of the coiled design is that relative long travel times can be obtained, allowing accurate water content measurements for small-sized TDR probes. The objective of this lecture is to present the combined penetrometer-TDR probe as a new tool to study soil compaction. The presentation will cover the following topics: Theory of the dynamic cone penetrometer; Laboratory calibration of a coiled TDR moisture probe and application of the mixing model; Field calibration and use of the combined penetrometer-coiled TDR moisture probe; Penetration resistance, bulk density, water content and potential relationships; Practical applications of the combined penetrometer-coiled TDR moisture probe

Combined Effects of Biochar and Fertilizer on Cadmium Contaminated Soil Remediation

Directory of Open Access Journals (Sweden)

WANG Qi-kai

2015-12-01

Full Text Available The field experiment was employed to study on the combined effects of biochar and chicken manure and N, P and K compound chemical fertilizer on cadmium contaminated soil remediation, and the immobilization mechanism was elucidated through fractionation of cadmium in the tested soil. Results showed that the addition of these ammendments could significantly reduce the edible Cd accumulation in Lactuca sativa L., decreased from 32.6% to 54.8% compared with the control. The application of these additives could also significantly decrease extractable Cd concentration by 7.04%~21.85%. Biochar could significantly improve soil pH value, promote the inactivation of Cd contaminated soil, while the application of chicken manure significantly decreased soil pH value, which showed the effect of activating Cd in soil. Soil pH value had significant positive correlation with root Cd concentration of tested cultivars, but did not reach the significant effect level with the shoot Cd concentration. The research can provide a theoretical basis for the application of biochar combined with chicken manure and N, P and K compound chemical fertilizer on remediation of sewage irrigated Cd contaminated soil.

Electronic structure and magnetism of new ilmenite compounds for spintronic devices: FeBO{sub 3} (B = Ti, Hf, Zr, Si, Ge, Sn)

Energy Technology Data Exchange (ETDEWEB)

Ribeiro, R.A.P. [Department of Chemistry, State University of Ponta Grossa, Av. General Carlos Cavalcanti, 4748, 84030-900 Ponta Grossa, PR (Brazil); Camilo, A. [Department of Physics, State University of Ponta Grossa, Av. General Carlos Cavalcanti, 4748, 84030-900 Ponta Grossa, PR (Brazil); Lazaro, S.R. de, E-mail: srlazaro@uepg.br [Department of Chemistry, State University of Ponta Grossa, Av. General Carlos Cavalcanti, 4748, 84030-900 Ponta Grossa, PR (Brazil)

2015-11-15

First-principles calculations were performed in the framework of Density Functional Theory (DFT) within hybrid functional (B3LYP) to study the electronic structure and magnetic properties of new ilmenite FeBO{sub 3} (B=Ti, Hf, Zr, Si, Ge, Sn) materials. In particular, the magnetic exchange interaction between Fe{sup 2+} layers is dependent on the interlayer distance and it can be controlled by ionic radius of B-site cation. Thus, Fe(Ti, Si, Ge)O{sub 3} are antiferromagnetic materials, while Fe(Zr, Hf, Sn)O{sub 3} are ferromagnetic. We also argue that antiferromagnetic materials and FeZrO{sub 3} are convectional semiconductors, whereas FeHfO{sub 3} and FeSnO{sub 3} exhibit intrinsic half-metallic behavior, making them promising candidates for spintronic devices. - Highlights: • We study electronic structure and magnetism of new FeBO{sub 3} (B=Ti, Hf, Zr, Si, Ge, Sn) ilmenite materials. • We found that magnetic ordering of Fe-based ilmenite materials can be controlled by size of B-site cation. • Fe(Ti, Zr, Si, Ge)O{sub 3} are convectional semiconductors. • FeHfO{sub 3} and FeSnO{sub 3} exhibit intrinsic half-metallic behavior with potential application for spintronic devices.

Study of temperature effect on the physical properties of ilmenite-serpentine heat resistant concrete radiation shields

International Nuclear Information System (INIS)

Kany, A.M.I.; EL-Fouly, M.M.; EL-Gohary, M.I.; Makatious, A.S.; Kamal, S.M.

1990-01-01

A series of experimental studies have been carried out to determine the change in unit weigh, compressive strength, water content and neutron macroscopic cross section of a new type of concrete shields made from egyptian ilmenite and serpentine ores when heated for long period at temperatures up to 600 degree C. Results show that the unit weight of the cure concrete has a value of 2.98 Ton/M 3 and decreases with increasing temperature, while the compressive strength reaches a maximum value of 19 Ton/M 2 at 100 degree C. The differential thermal analysis (D.T.A.) of this concrete shows three endothermic peaks at 100 degree C, 48 degree C and 740 degree C. Also, the thermogravimetry analysis (T.G.A.) shows that the cure concrete retains about 11% water content of the total sample weigh and still retains 4.5% of its initial value when heated for long period at 600 degree C. Results also show that the neutron macroscopic cross section (for neutrons of energies < 1 MeV) of the ilmenite-serpentine heat resistant concrete decreases to 18.6% of its initial value after heating to 600 degree C

Remediation of Nitrobenzene Contaminated Soil by Combining Surfactant Enhanced Soil Washing and Effluent Oxidation with Persulfate

Science.gov (United States)

Yan, Jingchun; Gao, Weiguo; Qian, Linbo; Han, Lu; Chen, Yun; Chen, Mengfang

2015-01-01

The combination of surfactant enhanced soil washing and degradation of nitrobenzene (NB) in effluent with persulfate was investigated to remediate NB contaminated soil. Aqueous solution of sodium dodecylbenzenesulfonate (SDBS, 24.0 mmol L-1) was used at a given mass ratio of solution to soil (20:1) to extract NB contaminated soil (47.3 mg kg-1), resulting in NB desorption removal efficient of 76.8%. The washing effluent was treated in Fe2+/persulfate and Fe2+/H2O2 systems successively. The degradation removal of NB was 97.9%, being much higher than that of SDBS (51.6%) with addition of 40.0 mmol L-1 Fe2+ and 40.0 mmol L-1 persulfate after 15 min reaction. The preferential degradation was related to the lone pair electron of generated SO4•−, which preferably removes electrons from aromatic parts of NB over long alkyl chains of SDBS through hydrogen abstraction reactions. No preferential degradation was observed in •OH based oxidation because of its hydrogen abstraction or addition mechanism. The sustained SDBS could be reused for washing the contaminated soil. The combination of the effective surfactant-enhanced washing and the preferential degradation of NB with Fe2+/persulfate provide a useful option to remediate NB contaminated soil. PMID:26266532

Monitoring Soil Microbial Activities in Different Cropping Systems Using Combined Methods

Institute of Scientific and Technical Information of China (English)

YUAN Zhimin; LIU Haijun; HAN Jun; SUN Jingjing; WU Xiaoying; YAO Jun

2017-01-01

Cropping activities may affect soil microbial activities and biomass,which would affect C and N cycling in soil and thus the crop yields and quality.In the present study,a combination of microcalorimetric,enzyme activity (sucrase,urease,catalase,and fluorescein diacetate hydrolysis),and real-time polymerase chain reaction (RT-PCR) analyses was used to investigate microbial status of farmland soils,collected from 5 different sites in Huazhong Agriculture University,China.Our results showed that among the 5 sites,both positive and negative impacts of cropping activities on soil microbial activity were observed.Enzyme activity analysis showed that cropping activities reduced soil sucrase and urease activities,which would influence the C and N cycles in soil.Much more attentions should be given to microbial status affected by cropping activities in future.According to the correlation analysis,fluorescein diacetate hydrolysis showed a significantly (P ＜ 0.05) negative correlation with the time to reach the maximum power output (R =--0.898),but a significantly (P ＜ 0.05) positive correlation with bacterial gene copy number (R =0.817).Soil catalase activity also showed a significantly (P ＜ 0.05) positive correlation with bacterial gene copy number (R =0.965).Using combined methods would provide virtual information of soil microbial status.

Phase-dependent space weathering effects and spectroscopic identification of retained helium in a lunar soil grain

Science.gov (United States)

Burgess, K. D.; Stroud, R. M.

2018-03-01

The solar wind is an important driver of space weathering on airless bodies. Over time, solar wind exposure alters the physical, chemical, and optical properties of exposed materials and can also impart a significant amount of helium into the surfaces of these bodies. However, common materials on the surface of the Moon, such as glass, crystalline silicates, and oxides, have highly variable responses to solar wind irradiation. We used scanning transmission electron microscopy (STEM) with electron energy loss spectroscopy (EELS) to examine the morphology and chemistry of a single grain of lunar soil that includes silicate glass, chromite and ilmenite, all present and exposed along the same surface. The exposure of the silicate glass and oxides to the same space weathering conditions allows for direct comparisons of the responses of natural materials to the complex lunar surface environment. The silicate glass shows minimal effects of solar wind irradiation, whereas both the chromite and ilmenite exhibit defect-rich rims that currently contain trapped helium. Only the weathered rim in ilmenite is rich in nanophase metallic iron (npFe0) and larger vesicles that retain helium at a range of internal pressures. The multiple exposed surfaces of the single grain of ilmenite demonstrate strong crystallographic controls of planar defects and non-spherical npFe0. The direct spectroscopic identification of helium in the vesicles and planar defects in the oxides provides additional evidence of the central role of solar wind irradiation in the formation of some common space weathering features.

Concentration of metals in surface soil around Orissa Sands Complex (OSCOM), IREL, Orissa

International Nuclear Information System (INIS)

Sahoo, S.K.; Raghunath, R.; Tripathi, R.M.; Vidya Sagar, D.; Khan, A.H.

2004-01-01

Indian Rare Earth Limited (IREL) has been carrying beach-sand mineral separation (Monazite, Ilmenite, Zircon etc.) in Bay of Bengal. Since last decade thorium plant at OSCOM processes thorium oxalate to produce mantle grade thorium nitrate and nuclear grade thorium oxide by solvent extraction process. A study has been initiated to check the environmental impact of the operating plants on the soil contamination in the surrounding areas. The results of preliminary survey are discussed

Immobilization of soil cadmium using combined amendments of illite/smectite clay with bone chars.

Science.gov (United States)

Li, Hong; Ou, Jieyong; Wang, Xuedong; Yan, Zengguang; Zhou, Youya

2018-05-12

The widespread use of cadmium (Cd)-containing organic fertilizers is a source of heavy metal inputs to agricultural soils in suburban areas. Therefore, the research and development of new materials and technologies for the remediation of Cd-contaminated soil is of great significance and has the potential to guarantee the safety of agricultural products and the protection of human health. We performed pot experiments to determine the potential of combined amendments of illite/smectite (I/S) clay with bone chars for the remediation of Cd-contaminated agricultural soils in a suburban area of Beijing, China. The results showed that both diethylene triamine pentaacetic acid (DTPA)-extractable Cd in soil and the Cd in Brassica chinensis were significantly decreased by the application of 1, 2, or 5% combined amendments with various I/S and bone char (BC) ratios. The higher proportions of BC used in the combined amendments resulted in a better immobilization of soil Cd. The application of the 5% amendment that combined I/S with either pig or cattle BC resulted in the best immobilization. All of the combined amendments, regardless of the composition and ratio of the components, had no negative effects on the growth of B. chinensis. Therefore, it was concluded that combined amendments of I/S and BC have a good potential for remediating Cd-contaminated soils.

Pyrene removal from contaminated soil using electrokinetic process combined with surfactant

Directory of Open Access Journals (Sweden)

Seyed Enayat Hashemi

2015-07-01

Full Text Available Background: Pyrene is one of the stable polycyclic aromatic hydrocarbons that is considered as an important pollutants, because of extensive distribution in the environment and carcinogenic and mutagenic properties. Among the various treatment techniques, electrokinetic method is an environmental- friendly process for organic and mineral pollutants adsorbed to soil with fine pore size the same as clay and low hydraulic conductivity soils. For improving the efficiency of pyrene removal from soil, soulobilization of pyrene from soil could be used by surfactants. Materials and Methods : In this study, clay soil was selected as model because of the specific properties. Combined method using surfactant and electrokinetic was applied for pyrene removal from soil. Experiments were designed using response surface methodology (RSM, and effect of three variables includes surfactant concentration, voltage and surfactant type were evaluated for pyrene removal from contaminated soil. Results: Pyrene removal using anionic surfactants(SDS and nonionic surfactants(TX100 as a solubilizing agents has high removal efficiency. In the optimum condition with 95% confidence coefficient, utilizing mixed surfactants of sodium dodecyl sulfate and triton X-100 with the same volume, induced of 18.54 volt and 6.53 percent surfactant concentration have 94.6% pyrene removal efficiency. Conclusion:: Results of this study shows that electrokinetic process combined with surfactant as solubilizing agent could be applied as an efficient method for treating the pyrene-contaminated soils.

Ilmenite exploration on the Senegal continental shelf. Methods and results

International Nuclear Information System (INIS)

Horn, R.; Le Lann, F.; Scolari, G.; Tixeront, M.

1975-01-01

From the results of a study based on geomorphology, geophysics and sedimentology, it has been possible to point out, South of Dakar, the existence of a fossil lagoon (peat dated 8400 years BP) partly isolated from the open sea by a littoral sand bar at -25m and strongly eroded. To the North of Dakar, the unconsolidated sediments, with a thickness over 40m, are thinning out seawards and from North of Dakar, the unconsolidated sediments, with a thickness over 40m, are thinning out seawards and from North to South. This pattern reflect the action of the longshore current which overstates the drainage effect to the Cayar canyon. The distribution of ilmenites in the sediments is studied in terms of a possible exploitation however, the grades are too low in the present economic conditions [fr

A Combination of Biochar-Mineral Complexes and Compost Improves Soil Bacterial Processes, Soil Quality, and Plant Properties.

Science.gov (United States)

Ye, Jun; Zhang, Rui; Nielsen, Shaun; Joseph, Stephen D; Huang, Danfeng; Thomas, Torsten

2016-01-01

Organic farming avoids the use of synthetic fertilizers and promises food production with minimal environmental impact, however this farming practice does not often result in the same productivity as conventional farming. In recent years, biochar has received increasing attention as an agricultural amendment and by coating it with minerals to form biochar-mineral complex (BMC) carbon retention and nutrient availability can be improved. However, little is known about the potential of BMC in improving organic farming. We therefore investigated here how soil, bacterial and plant properties respond to a combined treatment of BMC and an organic fertilizer, i.e., a compost based on poultry manure. In a pakchoi pot trial, BMC and compost showed synergistic effects on soil properties, and specifically by increasing nitrate content. Soil nitrate has been previously observed to increase leaf size and we correspondingly saw an increase in the surface area of pakchoi leaves under the combined treatment of BMC and composted chicken manure. The increase in soil nitrate was also correlated with an enrichment of bacterial nitrifiers due to BMC. Additionally, we observed that the bacteria present in the compost treatment had a high turnover, which likely facilitated organic matter degradation and a reduction of potential pathogens derived from the manure. Overall our results demonstrate that a combination of BMC and compost can stimulate microbial process in organic farming that result in better vegetable production and improved soil properties for sustainable farming.

A combination of biochar-mineral complexes and compost improves soil bacterial processes, soil quality and plant properties

Directory of Open Access Journals (Sweden)

JUN eYE

2016-04-01

Full Text Available Organic farming avoids the use of synthetic fertilizers and promises food production with minimal environmental impact, however this farming practice does not often result in the same productivity as conventional farming. In recent years, biochar has received increasing attention as an agricultural amendment and by coating it with minerals to form biochar-mineral complex (BMC carbon retention and nutrient availability can be improved. However, little is known about the potential of BMC in improving organic farming. We therefore investigated here how soil, bacterial and plant properties respond to a combined treatment of BMC and an organic fertilizer, i.e. a compost based on poultry manure. In a pakchoi pot trial, BMC and compost showed synergistic effects on soil properties, and specifically by increasing nitrate content. Soil nitrate has been previously observed to increase leaf size and we correspondingly saw an increase in the surface area of pakchoi leaves under the combined treatment of BMC and chicken manure. The increase in soil nitrate was also correlated with an enrichment of bacterial nitrifiers due to BMC. Additionally, we observed that the bacteria present in the compost treatment had a high turnover, which likely facilitated organic matter degradation and a reduction of potential pathogens derived from the manure. Overall our results demonstrate that a combination of BMC and compost can stimulate microbial process in organic farming that result in better vegetable production and improved soil properties for sustainable farming.

Studies on Thorium Adsorption Characteristics upon Activated Titanium Hydroxide Prepared from Rosetta Ilmenite Concentrate

International Nuclear Information System (INIS)

Gado, M; Zaki, S

2016-01-01

The titanium hydroxide prepared from Rosetta ilmenite concentrate has been applied for Th (IV) adsorption from its acid aqueous solutions. The prepared hydroxide is first characterized by both Fourier transform infrared (FT-IR) spectrum and thermogravimetric analysis. The relevant factors affecting the adsorption process have been studied. The obtained equilibrium data fits well with the Langmuir isotherm rather than Freundlich isotherm, while the adsorption kinetic data follow the pseudo-second order model. The different thermodynamic parameters have also been calculated and indicate that the adsorption process is spontaneous

The Effects of Biochar and Its Combination with Compost on Lettuce (Lactuca sativa L. Growth, Soil Properties, and Soil Microbial Activity and Abundance

Directory of Open Access Journals (Sweden)

Dalila Trupiano

2017-01-01

Full Text Available Impacts of biochar application in combination with organic fertilizer, such as compost, are not fully understood. In this study, we tested the effects of biochar amendment, compost addition, and their combination on lettuce plants grown in a soil poor in nutrients; soil microbiological, chemical, and physical characteristics were analyzed, together with plant growth and physiology. An initial screening was also done to evaluate the effect of biochar and compost toxicity, using cress plants and earthworms. Results showed that compost amendment had clear and positive effects on plant growth and yield and on soil chemical characteristics. However, we demonstrated that also the biochar alone stimulated lettuce leaves number and total biomass, improving soil total nitrogen and phosphorus contents, as well as total carbon, and enhancing related microbial communities. Nevertheless, combining biochar and compost, no positive synergic and summative effects were observed. Our results thus demonstrate that in a soil poor in nutrients the biochar alone could be effectively used to enhance soil fertility and plant growth and biomass yield. However, we can speculate that the combination of compost and biochar may enhance and sustain soil biophysical and chemical characteristics and improve crop productivity over time.

Pilot tests of microbe-soil combined treatment of waste drilling sludge

OpenAIRE

Lirong Chen; Min Huang; Xuebin Jiang; Hui Li; Qiang Chen; Min Zhang; Shenglin Li

2015-01-01

Microbe-soil combined treatment is a newly developed technology in view of the defects of the curing process and waste drilling mud slag properties. In particular, 0.3%–0.5% bioremediation reagents were fully mixed with the waste drilling sludge according to its wet and dry degree, and 1.5 folds to twice weight of more finely ground soil was added in the mix, which was covered by soil of 5–15 cm thick and thereby grasses or greeneries were planted on the soil. The process was successfully app...

Trace element partitioning between ilmenite, armalcolite and anhydrous silicate melt: Implications for the formation of lunar high-Ti mare basalts

NARCIS (Netherlands)

Kan Parker, M. van; Mason, P.R.D.; Westrenen, W. van

2011-01-01

We performed a series of experiments at high pressures and temperatures to determine the partitioning of a wide range of trace elements between ilmenite (Ilm), armalcolite (Arm) and anhydrous lunar silicate melt, to constrain geochemical models of the formation of titanium-rich melts in the Moon.

Ilmenit z dvojslídných granitů šumavské větve moldanubického batolitu

Czech Academy of Sciences Publication Activity Database

René, Miloš

2012-01-01

Roč. 2011, podzim (2012), s. 193-196 ISSN 0514-8057 R&D Projects: GA MŠk ME10083 Institutional research plan: CEZ:AV0Z30460519 Keywords : ilmenite * two-mica granite * Moldanubian Zone * Bohemian Massif Subject RIV: DB - Geology ; Mineralogy http://www.geology.cz/zpravy/obsah/2011/zpravy_2011-44.pdf

Découverte et signification d'une paragenèse à ilménite zincifère dans les métapélites des Jebilet centrales (Maroc)Occurrence and significance of zincian ilmenite in low-pressure metapelites from central Jebilet (Morocco)

Science.gov (United States)

Essaifi, Abderrahim; Ballèvre, Michel; Marignac, Christian; Capdevila, Ramon

2001-10-01

A zincian ilmenite paragenesis is found in metapelites from a contact metamorphic zone (central Jebilet, Morocco) induced by the emplacement of microgranitic intrusions. The zincian ilmenite is mainly preserved in syntectonic andalusite porphyroblasts. The growth of zincian ilmenite is related either to sphalerite breakdown during prograde metamorphism, or to the pervasive flow of a mineralizing fluid within the metapelites. The chlorine-rich fluid carried zinc and other metals leached in the microgranites, during its flow to discharge zones which were probably the Jebilet sulfide deposits.

Remote sensing of potential lunar resources. I - Near-side compositional properties

Science.gov (United States)

Johnson, Jeffrey R.; Larson, Stephen M.; Singer, Robert B.

1991-01-01

Using telescopic CCD multispectral images of the lunar near side and the results of 330-870 nm spectroscopy of selected regions, the compositional differences relevant to the locations of potential lunar resources (such as ilmenite, FeTiO3, and solar-wind-implanted He-3 and H) are estimated. The 400/560 nm CCD ratio images were converted to weight percent TiO2, and the values were used to construct a new TiO2 abundance map which can be used to estimate the areas potentially rich in ilmenite. A 950/560 nm CCD ratio mosaic of the full moon provides estimates of relative surface maturity. Since high He-3 concentrations correlate with mature ilmenite-rich soils, a combination of relative surface maturity maps and the TiO2 abundance maps can be used to estimate distributions of He-3 (and possibly H) on local scales.

Degradation of 2,4-D in soils by Fe₃O₄ nanoparticles combined with stimulating indigenous microbes.

Science.gov (United States)

Fang, Guodong; Si, Youbin; Tian, Chao; Zhang, Gangya; Zhou, Dongmei

2012-03-01

Degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) in soils by Fe₃O₄ nanoparticles combined with soil indigenous microbes was investigated, and the effects of Fe₃O₄ nanoparticles on soil microbial populations and enzyme activities were also studied. The soils contaminated with 2,4-D were treated with Fe₃O₄ nanoparticles. The microbial populations and enzyme activities were analyzed by dilution plate method and chemical assay, respectively, and the concentration of 2,4-D in soil was determined by high-performance liquid chromatography (HPLC). The results indicated that Fe₃O₄ nanoparticles combined with soil indigenous microbes led to a higher degradation efficiency of 2,4-D than the treatments with Fe₃O₄ nanoparticles or indigenous microbes alone. The degradation of 2,4-D in soils followed the pseudo first-order kinetic. The half-lives of 2,4-D degradation (DT₅₀) of the combined treatments were 0.9, 1.9 and 3.1 days in a Red soil, Vertisol and Alfisol, respectively, which implied that the DT₅₀ of the combination treatments were significantly shorter than that of the treatments Fe₃O₄ nanoparticles or indigenous microbes alone. The effects of Fe₃O₄ nanoparticles on soil microbial populations and enzyme activities were also investigated and compared with the α-Fe₂O₃ nanoparticles. The results suggested that the α-Fe₂O₃ nanoparticles had only comparatively small effects on degradation of 2,4-D in soils, while the Fe₃O₄ nanoparticles not only degraded 2,4-D in soils but also increased the soil microbial populations and enzyme activities; the maximum increase in enzyme activities were 67.8% (amylase), 53.8% (acid phosphatase), 26.5% (catalase) and 38.0% (urease), compared with the untreated soil. Moreover, the introduction of Fe₃O₄ nanoparticles at the different dosage resulted in a variable degradation efficiency of 2,4-D in soil. The method of combining Fe₃O₄ nanoparticles with indigenous soil microbes may

Assessment of combined electro–nanoremediation of molinate contaminated soil

Energy Technology Data Exchange (ETDEWEB)

Gomes, Helena I., E-mail: hrg@campus.fct.unl.pt [CENSE, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); CERNAS — Research Center for Natural Resources, Environment and Society, Escola Superior Agraria de Coimbra, Instituto Politecnico de Coimbra, Bencanta, 3045-601 Coimbra (Portugal); Fan, Guangping [CENSE, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences (ISSCAS), East Beijing Road, Nanjing 210008 (China); Mateus, Eduardo P. [CENSE, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Dias-Ferreira, Celia [CERNAS — Research Center for Natural Resources, Environment and Society, Escola Superior Agraria de Coimbra, Instituto Politecnico de Coimbra, Bencanta, 3045-601 Coimbra (Portugal); Ribeiro, Alexandra B. [CENSE, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal)

2014-09-15

Molinate is a pesticide widely used, both in space and time, for weed control in rice paddies. Due to its water solubility and affinity to organic matter, it is a contaminant of concern in ground and surface waters, soils and sediments. Previous works have showed that molinate can be removed from soils through electrokinetic (EK) remediation. In this work, molinate degradation by zero valent iron nanoparticles (nZVI) was tested in soils for the first time. Soil is a highly complex matrix, and pollutant partitioning between soil and water and its degradation rates in different matrices is quite challenging. A system combining nZVI and EK was also set up in order to study the nanoparticles and molinate transport, as well as molinate degradation. Results showed that molinate could be degraded by nZVI in soils, even though the process is more time demanding and degradation percentages are lower than in an aqueous solution. This shows the importance of testing contaminant degradation, not only in aqueous solutions, but also in the soil-sorbed fraction. It was also found that soil type was the most significant factor influencing iron and molinate transport. The main advantage of the simultaneous use of both methods is the molinate degradation instead of its accumulation in the catholyte. - Highlights: • Molinate is degraded in soil by zero valent iron nanoparticles (nZVI). • Higher contact time of nZVI with soil facilitates molinate degradation. • Soil type was the most significant factor influencing iron and molinate transport. • When using nZVI and EK molinate is not only transported to catholyte, but also degraded.

Combining land use data acquired from Landsat with soil map data

Science.gov (United States)

Westin, F. C.; Brandner, T. M.

1981-01-01

A method currently used to derive agrophysical units (APUs), i.e., geographical areas having definable/comparable agronomic and physical parameters which reflect a range in agricultural use and management, is discussed with reference to results obtained for South Dakota and an area in China. The method consists of combining agricultural land use data acquired from Landsat with soil map data. The resulting map units are soil associations characterized by cropland use intensity, and they can be used to identify major cropland areas and to develop a rating reflecting the relative potential of the soils in the delineated area for crop production, as well as to update small-scale soil maps.

Combined effects of leaf litter and soil microsite on decomposition process in arid rangelands.

Science.gov (United States)

Carrera, Analía Lorena; Bertiller, Mónica Beatriz

2013-01-15

The objective of this study was to analyze the combined effects of leaf litter quality and soil properties on litter decomposition and soil nitrogen (N) mineralization at conserved (C) and disturbed by sheep grazing (D) vegetation states in arid rangelands of the Patagonian Monte. It was hypothesized that spatial differences in soil inorganic-N levels have larger impact on decomposition processes of non-recalcitrant than recalcitrant leaf litter (low and high concentration of secondary compounds, respectively). Leaf litter and upper soil were extracted from modal size plant patches (patch microsite) and the associated inter-patch area (inter-patch microsite) in C and D. Leaf litter was pooled per vegetation state and soil was pooled combining vegetation state and microsite. Concentrations of N and secondary compounds in leaf litter and total and inorganic-N in soil were assessed at each pooled sample. Leaf litter decay and soil N mineralization at microsites of C and D were estimated in 160 microcosms incubated at field capacity (16 month). C soils had higher total N than D soils (0.58 and 0.41 mg/g, respectively). Patch soil of C and inter-patch soil of D exhibited the highest values of inorganic-N (8.8 and 8.4 μg/g, respectively). Leaf litter of C was less recalcitrant and decomposed faster than that of D. Non-recalcitrant leaf litter decay and induced soil N mineralization had larger variation among microsites (coefficients of variation = 25 and 41%, respectively) than recalcitrant leaf litter (coefficients of variation = 12 and 32%, respectively). Changes in the canopy structure induced by grazing disturbance increased leaf litter recalcitrance, and reduced litter decay and soil N mineralization, independently of soil N levels. This highlights the importance of the combined effects of soil and leaf litter properties on N cycling probably with consequences for vegetation reestablishment and dynamics, rangeland resistance and resilience with implications

Remediation of metal polluted soils by phytorremediation combined with biochar addition

Science.gov (United States)

Méndez, Ana; Paz-Ferreiro, Jorge; Gómez-Limón, Dulce; César Arranz, Julio; Saa, Antonio; Gascó, Gabriel

2016-04-01

The main objective of this work is to optimize and quantify the treatment of metal polluted soils through phytoremediation techniques combined with the addition of biochar. Biochar is a carbon rich material obtained by thermal treatment of biomass in inert atmosphere. In recent years, it has been attracted considerable interest due to their positive effect after soil addition. The use of biochar also seems appropriate for the treatment of metal-contaminated soils decreasing their mobility. Biochar properties highly depend on the raw material composition and manufacturing conditions. This paper is based on the use of manure wastes, rich in nutrients and therefore interesting raw materials for biochar production, especially when combined with phytoremediation techniques since the biochar act as conditioner and slow release fertilizer. We are very grateful to Ministerio de Economia y Competitividad (Spain) for financial support under Project CGL2014-58322-R.

Ecotoxicological effects of copper and selenium combined pollution on soil enzyme activities in planted and unplanted soils.

Science.gov (United States)

Hu, Bin; Liang, Dongli; Liu, Juanjuan; Xie, Junyu

2013-04-01

The present study explored the joint effects of Cu and Se pollution mechanisms on soil enzymes to provide references for the phytoremediation of contaminated areas and agricultural environmental protection. Pot experiments and laboratory analyses were carried out to study the individual and combined influences of Cu and Se on soil enzyme activities. The activities of four soil enzymes (urease, catalase, alkaline phosphatase, and nitrate reductase) were chosen. All soil enzyme activities tested were inhibited by Cu and Se pollution, either individually or combined, in varying degrees, following the order nitrate reductase>urease>catalase>alkaline phosphatase. Growing plants stimulated soil enzyme activity in a similar trend compared with treatments without plants. The joint effects of Cu and Se on catalase activity showed synergism at low concentrations and antagonism at high concentrations, whereas the opposite was observed for urease activity. However, nitrate reductase activity showed synergism both with and without plant treatments. The half maximal effective concentration (EC50) of exchangeable fractions had a similar trend with the EC50 of total content and was lower than that of total content. The EC50 values of nitrate reductase and urease activities were significantly lower for both Se and Cu (p<0.05), which indicated that they were more sensitive than the other two enzymes. Copyright © 2013 SETAC.

Combinational effects of sulfomethoxazole and copper on soil microbial community and function.

Science.gov (United States)

Liu, Aiju; Cao, Huansheng; Yang, Yan; Ma, Xiaoxuan; Liu, Xiao

2016-03-01

Sulfonamides and Cu are largely used feed additives in poultry farm. Subsequently, they are spread onto agricultural soils together with contaminated manure used as fertilizer. Both sulfonamides and Cu affect the soil microbial community. However, an interactive effect of sulfonamides and Cu on soil microorganisms is not well understood. Therefore, a short-time microcosm experiment was conducted to investigate the interaction of veterinary antibiotic sulfomethoxazole (SMX) and Cu on soil microbial structure composition and functions. To this end, selected concentrations of SMX (0, 5, and 50 mg kg(-1)) and Cu (0, 300, and 500 mg kg(-1)) were combined, respectively. Clear dose-dependent effects of SMX on microbial biomass and basal respiration were determined, and these effects were amplified in the presence of additional Cu. For activities of soil enzymes including β-glucosidase, urease, and protease, clear reducing effects were determined in soil samples containing 5 or 50 mg kg(-1) of SMX, and the interaction of SMX and Cu was significant, particularly in soil samples containing 50 mg kg(-1) SMX or 500 mg kg(-1) Cu. SMX amendments, particularly in combination with Cu, significantly reduced amounts of the total, bacterial, and fungal phospholipid fatty acids (PLFAs) in soil. Moreover, the derived ratio of bacteria to fungi decreased significantly with incremental SMX and Cu, and principal component analysis of the PLFAs showed that soil microbial composition was significantly affected by SMX interacted with Cu at 500 mg kg(-1). All of these results indicated that the interaction of SMX and Cu was synergistic to amplify the negative effect of SMX on soil microbial biomass, structural composition, and even the enzymatic function.

A combined process coupling phytoremediation and in situ flushing for removal of arsenic in contaminated soil.

Science.gov (United States)

Yan, Xiulan; Liu, Qiuxin; Wang, Jianyi; Liao, Xiaoyong

2017-07-01

Phytoremediation and soil washing are both potentially useful for remediating arsenic (As)-contaminated soils. We evaluated the effectiveness of a combined process coupling phytoremediation and in situ soil flushing for removal of As in contaminated soil through a pilot study. The results showed that growing Pteris vittata L. (P.v.) accompanied by soil flushing of phosphate (P.v./Flushing treatment) could significantly decrease the total As concentration of soil over a 37day flushing period compared with the single flushing (Flushing treatment). The P.v./Flushing treatment removed 54.04% of soil As from contaminated soil compared to 47.16% in Flushing treatment, suggesting that the growth of P. vittata was beneficial for promoting the removal efficiency. We analyzed the As fractionation in soil and As concentration in soil solution to reveal the mechanism behind this combined process. Results showed that comparing with the control treatment, the percent of labile arsenate fraction significantly increased by 17% under P.v./Flushing treatment. As concentration in soil solution remained a high lever during the middle and later periods (51.26-56.22mg/L), which was significantly higher than the Flushing treatment. Although soil flushing of phosphate for more than a month, P. vittata still had good accumulation and transfer capacity of As of the soil. The results of the research revealed that combination of phytoremediation and in situ soil flushing is available to remediate As-contaminated soils. Copyright © 2016. Published by Elsevier B.V.

Combination of microbial oxidation and biogenic schwertmannite immobilization: A potential remediation for highly arsenic-contaminated soil.

Science.gov (United States)

Yang, Zhihui; Wu, Zijian; Liao, Yingping; Liao, Qi; Yang, Weichun; Chai, Liyuan

2017-08-01

Here, a novel strategy that combines microbial oxidation by As(III)-oxidizing bacterium and biogenic schwertmannite (Bio-SCH) immobilization was first proposed and applied for treating the highly arsenic-contaminated soil. Brevibacterium sp. YZ-1 isolated from a highly As-contaminated soil was used to oxidize As(III) in contaminated soils. Under optimum culture condition for microbial oxidation, 92.3% of water-soluble As(III) and 84.4% of NaHCO 3 -extractable As(III) in soils were removed. Bio-SCH synthesized through the oxidation of ferrous sulfate by Acidithiobacillus ferrooxidans immobilize As(V) in the contaminated soil effectively. Consequently, the combination of microbial oxidation and Bio-SCH immobilization performed better in treating the highly As-contaminated soil with immobilization efficiencies of 99.3% and 82.6% for water-soluble and NaHCO 3 -extractable total As, respectively. Thus, the combination can be considered as a green remediation strategy for developing a novel and valuable solution for As-contaminated soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

Combination of surfactant enhanced soil washing and electro-Fenton process for the treatment of soils contaminated by petroleum hydrocarbons.

Science.gov (United States)

Huguenot, David; Mousset, Emmanuel; van Hullebusch, Eric D; Oturan, Mehmet A

2015-04-15

In order to improve the efficiency of soil washing treatment of hydrocarbon contaminated soils, an innovative combination of this soil treatment technique with an electrochemical advanced oxidation process (i.e. electro-Fenton (EF)) has been proposed. An ex situ soil column washing experiment was performed on a genuinely diesel-contaminated soil. The washing solution was enriched with surfactant Tween 80 at different concentrations, higher than the critical micellar concentration (CMC). The impact of soil washing was evaluated on the hydrocarbons concentration in the leachates collected at the bottom of the soil columns. These eluates were then studied for their degradation potential by EF treatment. Results showed that a concentration of 5% of Tween 80 was required to enhance hydrocarbons extraction from the soil. Even with this Tween 80 concentration, the efficiency of the treatment remained very low (only 1% after 24 h of washing). Electrochemical treatments performed thereafter with EF on the collected eluates revealed that the quasi-complete mineralization (>99.5%) of the hydrocarbons was achieved within 32 h according to a linear kinetic trend. Toxicity was higher than in the initial solution and reached 95% of inhibition of Vibrio fischeri bacteria measured by Microtox method, demonstrating the presence of remaining toxic compounds even after the complete degradation. Finally, the biodegradability (BOD₅/COD ratio) reached a maximum of 20% after 20 h of EF treatment, which is not enough to implement a combined treatment with a biological treatment process. Copyright © 2015 Elsevier Ltd. All rights reserved.

Paramagnetic resonance and susceptibility of ilmenite, FeTiO3 crystal

Science.gov (United States)

Mcdonald, P. F.; Parasiris, A.; Pandey, R. K.; Gries, B. L.; Kirk, W. P.

1991-01-01

Large high-purity single crystals of FeTiO3 with ilmenite structure have been grown from a stoichiometric melt of Fe2O3 and TiO2 under an inert atmosphere using the modified Czochralski technique. Susceptibility and X-band paramagnetic resonance studies have been performed. Susceptibility measurements indicate a Neel temperature of about 59 K. The paramagnetic resonance spectrum for magnetic field perpendicular to the crystal c axis consists of a portion of a single, very intense approximately Lorentzian absorption line with its peak at about 600 G and half width at half maximum almost 1200 G. The absorption extends to zero magnetic field. For magnetic field approximately parallel to the c axis, the paramagnetic absorption is much smaller and may be considered a superposition of two approximately Lorentzian line shapes. The magnetic resonance measurements indicate a weak temperature dependence and large angular anisotropy.

Studying of the combined salts effect on the engineering properties of clayey soil

Directory of Open Access Journals (Sweden)

Al-Obaidi Anwar

2018-01-01

Full Text Available In recent years, a number of studies had been performed to investigate the effect of pore water chemistry on the strength and compressibility characteristics of soil. Although the effect of chloride and sulfates salts separately in pore fluids on the geotechnical properties of soil seems to be well understood, but the influence of combined effect of sulfates and chlorides in pore water on the behavior of soil is still unclear mostly due to the limited numbers of studies as well as the complexity of processes that may occur in soil (with the presence of salts in pore water-soil interaction. Southern regions of Iraq, especially Basra suffers from low water levels in the summer season in addition to the lack of rain water, which causes a significant increase of salt in the Shatt al Arab. Water salinity continues to increase with time. To investigate the combined impacts of water salinity on the behavior of clayey soils, the basic characteristics of the soil brought from Al-Nahrawan site was studied. Chemical methods were done with three types of water (distilled, water of highly saline as Shatt Al-Arab water and water of Tarmiya as moderate saline water. The effect of water salinity on the geotechnical properties of fine grain soil was investigated. Different laboratory tests such as Atterberg limits, standard compaction, consolidation and shear strength of soil .Results showed that the presence of perceptible amounts of dissolved salts in water can lead to changes in the engineering properties of the soil.

The application of Lorentz transmission electron microscopy to the study of lamellar magnetism in hematite-ilmenite

DEFF Research Database (Denmark)

Kasama, Takeshi; Dunin-Borkowski, Rafal E.; Asaka, T

2009-01-01

. However, the magnitude of the experimental contrast is higher than that in the simulations, suggesting that an alternative origin for the observed asymmetry cannot be ruled out. Electron tomography was used to show that the lamellae have lens-like shapes and that (001) planes make up a significant...... in hematite. The likelihood that lamellar magnetism may be responsible for this contrast is assessed using simulations that incorporate interfacial magnetic moments on the (001) basal planes of hematite and ilmenite. The simulations suggest qualitatively that the asymmetric contrast is magnetic in origin...

The Distribution of Titanium in Lunar Soils on the Basis of Sensor and In Situ Data Fusion

Science.gov (United States)

Clark, P. E.; Evans, L.

1999-01-01

A variety of remote-sensing measurements have been used to map the distribution of elements on the Moon as a means of providing constraints on the processes from which its crust and major terranes originated. Discussed here is Ti, which is incorporated into refractory minerals such as ilmenite during the latter stages of differentiation, and is thus a most useful element for understanding mare basalt petrogenesis. One of the earliest Ti maps showed Ti variations in nearside maria on the basis of groundbased spectral reflectance measurements. A map of Ti derived from gamma-ray measurements on Apollo 15 and 16 was produced at about the same time, and was improved upon considerably by Davis and coworkers, who effectively removed sources of spurious variation from Fe and Al or REE (e.g., Th) interference, and calibrated Ti on the bases of landing-site soil averages. In recent years, spectral reflectance measurements from Clementine have been used by Lucey and coworkers to produce global Ti distribution maps as well. As we indicated previously, the Lucey and Davis maps agree to first order. Meanwhile, we are using the concept of sensor data fusion to combine measurements from the AGR (Apollo gamma-ray) and CSR (Clementine Spectral Reflectance) techniques with ground truth from lunar soils to utilize the differences between the two maps to understand the distribution of Ti within lunar soil components, as we have done with Fe. This technique should be verified and applied on Lunar Prospector gamma-ray measurements of Ti, as the calibrated data become available within the next couple of years. Lunar Ti is found principally in the mineral ilmenite, and is associated with certain components of lunar soil: crystalline Ilmenite mineral fragments and high Ti-bearing glass. All data indicate that Ti is associated with maria and mafic minerals. In AGR and CSR datasets, Ti is highest on the nearside and in the maria, particularly in southern Serenitatis/northern Tranquillitatis

Combined Amendments of Nano-hydroxyapatite Immobilized Cadmium in Contaminated Soil-Potato (Solanum tuberosum L.) System.

Science.gov (United States)

Liu, Chang; Wang, Lei; Yin, Jiang; Qi, Lipan; Feng, Yan

2018-04-01

The toxicity of cadmium (Cd) has posed major public health concern in crops grown in the Cd-contaminated soils. The effects of five amendments, nano-hydroxyapatite (n-HA) and it combined with lime, zeolite, bone mill and fly ash on Cd immobilization in soils and uptake in potatoes, were investigated in a contaminated soil by pot experiments. The result showed that the applications of combined amendments significantly decreased the bioavailable Cd concentrations extracted by TCLP, DTPA-TEA and MgCl 2 in the contaminated soils, and changed the soluble and exchangeable and specifically sorbed fractions to oxide-bound and organic-bound fractions. Compared to the control group, the concentrations of Cd in the potato tubers grown in n-HA, n-HA + Fly ash, n-HA + Lime, n-HA + Bone mill and n-HA + Zeolite soil were reduced 17.4%, 20.7%, 15.2%, 32.6% and 39.1%, respectively. Nano-hydroxyapatite combined amendments was more effective in reducing bioavailable Cd concentrations and Cd accumulations in potatoes, especially for n-HA + Z.

Soil treatment technologies combined

International Nuclear Information System (INIS)

Davis, K.J.; Russell, D.J.

1993-01-01

The Superfund Amendments and Reauthorization Act (SARA) presents a legislative mandate to select effective and long-term remediation options. SARA has spurred the development of innovative technologies and other remedial alternatives that can be applied to the diverse contaminated media at hazardous waste sites. Even though many treatment technologies have been investigated for use at hazardous waste sites, only a few have been used successfully. Soil vapor extraction and soil composting have achieved cleanup goals at sites with soils contaminated with solvents, aromatic hydrocarbons and petroleum derivatives. With the increased use of innovative on-site technologies, the integration of multiple technologies to remediate sites with complex contaminants becomes a viable and cost-effective remedial alternative. Soil vapor extraction and composting have been applied successfully as individual technologies at hazardous waste sites. An integration of these two technologies also has been used to remediate a complex contaminated site

[Effects of combined application of biochar and inorganic fertilizers on the available phosphorus content of upland red soil].

Science.gov (United States)

Jing, Yan; Chen, Xiao-min; Liu, Zu-xiang; Huang, Qian-ru; LiI, Qiu-xia; Chen, Chen; Lu, Shao-shan

2013-04-01

Aiming at the low content of available phosphorus in upland red soil of Southern China, this paper studied the effects of combined application of biochar and inorganic fertilizers on the available phosphorus and organic carbon contents and the pH of this soil. With the combined application of biochar and inorganic fertilizers, the soil physical and chemical properties improved to different degrees. As compared with the control, the soil pH and the soil organic carbon and available phosphorus contents at different growth stages of oil rape after the combined application of biochar and inorganic fertilizers all had an improvement, with the increments at bolting stage, flowering stage, and ripening stage being 16%, 24% and 26%, 23%, 34% and 38%, and 100%, 191% and 317% , respectively. The soil pH and the soil organic carbon and available phosphorus contents were increased with the increasing amount of applied biochar. Under-the application of biochar, the soil available phosphorus had a significant correlation with the soil pH and soil organic carbon content. This study could provide scientific basis to improve the phosphorus deficiency and the physical and chemical properties of upland red soil.

Combined Effects of Biochar and Fertilizer on Cadmium Contaminated Soil Remediation

OpenAIRE

WANG Qi-kai; GUO Wen-juan; SUN Guo-hong; LIN Da-song; XU Ying-ming; LIU Jing-ru; YU Shi-lei

2015-01-01

The field experiment was employed to study on the combined effects of biochar and chicken manure and N, P and K compound chemical fertilizer on cadmium contaminated soil remediation, and the immobilization mechanism was elucidated through fractionation of cadmium in the tested soil. Results showed that the addition of these ammendments could significantly reduce the edible Cd accumulation in Lactuca sativa L., decreased from 32.6% to 54.8% compared with the control. The application of these a...

Combined effects of DOM extracted from site soil/compost and biosurfactant on the sorption and desorption of PAHs in a soil-water system

Energy Technology Data Exchange (ETDEWEB)

Yu Hui, E-mail: yuhui200@uregina.ca [Environmental Systems Engineering Program, Faculty of Engineering and Applied Science, University of Regina, Regina, SK S4S 0A2 (Canada); Huang Guohe, E-mail: gordon.huang@uregina.ca [Environmental Systems Engineering Program, Faculty of Engineering and Applied Science, University of Regina, Regina, SK S4S 0A2 (Canada); An Chunjiang, E-mail: an209@uregina.ca [Environmental Systems Engineering Program, Faculty of Engineering and Applied Science, University of Regina, Regina, SK S4S 0A2 (Canada); Wei Jia, E-mail: jia.wei@iseis.org [Environmental Systems Engineering Program, Faculty of Engineering and Applied Science, University of Regina, Regina, SK S4S 0A2 (Canada)

2011-06-15

Highlights: {yields} The combined DOM and biosurfactant significantly enhanced desorption of PAHs. {yields} Compost DOM exhibited higher desorption enhancement capacity than the soil DOM. {yields} Competition among PAHs, DOM and biosurfactant for sorption site determined desorption of PAHs from soil. {yields} Formation of DOM-biosurfactant complex enhance desorption extent of PAHs. - Abstract: The combined effects of DOM and biosurfactant on the sorption/desorption behavior of phenanthrene (PHE) and pyrene (PYR) in soil water systems were systematically investigated. Two origins of DOMs (extracted from soil and extracted from food waste compost) and an anionic biosurfactant (rhamnolipid) were introduced. The presence of DOM in the aqueous phase could decrease the sorption of PAHs, thus influence their mobility. Desorption enhancement for both PHE and PYR in the system with compost DOM was greater than that in the soil DOM system. This is due to the differences in specific molecular structures and functional groups of two DOMs. With the co-existence of biosurfactant and DOM, partitioning is the predominant process and the desorption extent was much higher than the system with DOM or biosurfactant individually. For PHE, the desorption enhancement of combined DOM and biosurfactant was larger than the sum of DOM or biosurfactant; however desorption enhancement for PYR in the combined system was less than the additive enhancement in two individual system under low PAH concentration. This could be explained as the competition sorption among PAHs, DOM and biosurfactant. The results of this study will help to clarify the transport of petroleum pollutants in the remediation of HOCs-contaminated soils.

Combined effects of DOM extracted from site soil/compost and biosurfactant on the sorption and desorption of PAHs in a soil-water system

International Nuclear Information System (INIS)

Yu Hui; Huang Guohe; An Chunjiang; Wei Jia

2011-01-01

Highlights: → The combined DOM and biosurfactant significantly enhanced desorption of PAHs. → Compost DOM exhibited higher desorption enhancement capacity than the soil DOM. → Competition among PAHs, DOM and biosurfactant for sorption site determined desorption of PAHs from soil. → Formation of DOM-biosurfactant complex enhance desorption extent of PAHs. - Abstract: The combined effects of DOM and biosurfactant on the sorption/desorption behavior of phenanthrene (PHE) and pyrene (PYR) in soil water systems were systematically investigated. Two origins of DOMs (extracted from soil and extracted from food waste compost) and an anionic biosurfactant (rhamnolipid) were introduced. The presence of DOM in the aqueous phase could decrease the sorption of PAHs, thus influence their mobility. Desorption enhancement for both PHE and PYR in the system with compost DOM was greater than that in the soil DOM system. This is due to the differences in specific molecular structures and functional groups of two DOMs. With the co-existence of biosurfactant and DOM, partitioning is the predominant process and the desorption extent was much higher than the system with DOM or biosurfactant individually. For PHE, the desorption enhancement of combined DOM and biosurfactant was larger than the sum of DOM or biosurfactant; however desorption enhancement for PYR in the combined system was less than the additive enhancement in two individual system under low PAH concentration. This could be explained as the competition sorption among PAHs, DOM and biosurfactant. The results of this study will help to clarify the transport of petroleum pollutants in the remediation of HOCs-contaminated soils.

Sand-RAPG combination simulating fertile clayey soil (Part I to IV)

International Nuclear Information System (INIS)

Azzam, R.; El-Hady, O.A.; Lotfy, A.A.; Hegela, M.

1983-01-01

I. Radiation Preparation of RAPG. Sites of co-ordination and reinforcement are dominated in reclaimer ameliorator polymeric gel (RAPG). It is a modified acrylonitrile base multifunction polymer grafted upon a binder of worthless cellulosic agricultural discard. It varies chemically from non-ionic through anionic and cationic to ampholite. The hydroproperty of the gel is similarly controlled. Thus, RAPG can be tailored for any soil texture under various climatic conditions. II. Structure Stability and Maintenance. Sinai dune sand is treated with non-ionic and anionic RAPGs at rates varying from 0.05 to 0.2 wt.%. The stability increased with RAPG anionicity and application rate. The structure formed maintained three cycles of complete destruction and re-formation without significant changes in erosion index. The resistance of sand-RAPG combination to breakdown by tillage, as well as to wind and water erosion, is practically proved. This is in addition to the beneficial changes in bulk density, void ratio and microporosity, which were also achieved. III. Water Preservation. Inshas sandy soil treated by RAPG is compared with fertile clayey soil. The water-holding capacity and retention at different suctions are increased. The available water to plants in treated sand has reached 15 times that of the control, and even exceeded clay by 11%. Water losses by evaporation and leaching as well as deep percolation are all reduced to a minimum. IV. Plantation and Nutritional Status. Pepper seed germination, growth and dry matter are increased in the sand-RAPG combination relative to fertile clayey soil. The optimum rate and anionicity of RAPG are determined. This increases water-use efficiency to twice that of the fertile clayey soil. Macro- and micro-nutrient uptake have also increased. Thus, fertilizer use efficiency is increased by almost three times over that of clay. These factors lead convincingly to the conclusion that RAPG furnishes adequate conditions for sandy soil

Combined analyses of bacterial, fungal and nematode communities in andosolic agricultural soils in Japan.

Science.gov (United States)

Bao, Zhihua; Ikunaga, Yoko; Matsushita, Yuko; Morimoto, Sho; Takada-Hoshino, Yuko; Okada, Hiroaki; Oba, Hirosuke; Takemoto, Shuhei; Niwa, Shigeru; Ohigashi, Kentaro; Suzuki, Chika; Nagaoka, Kazunari; Takenaka, Makoto; Urashima, Yasufumi; Sekiguchi, Hiroyuki; Kushida, Atsuhiko; Toyota, Koki; Saito, Masanori; Tsushima, Seiya

2012-01-01

We simultaneously examined the bacteria, fungi and nematode communities in Andosols from four agro-geographical sites in Japan using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and statistical analyses to test the effects of environmental factors including soil properties on these communities depending on geographical sites. Statistical analyses such as Principal component analysis (PCA) and Redundancy analysis (RDA) revealed that the compositions of the three soil biota communities were strongly affected by geographical sites, which were in turn strongly associated with soil characteristics such as total C (TC), total N (TN), C/N ratio and annual mean soil temperature (ST). In particular, the TC, TN and C/N ratio had stronger effects on bacterial and fungal communities than on the nematode community. Additionally, two-way cluster analysis using the combined DGGE profile also indicated that all soil samples were classified into four clusters corresponding to the four sites, showing high site specificity of soil samples, and all DNA bands were classified into four clusters, showing the coexistence of specific DGGE bands of bacteria, fungi and nematodes in Andosol fields. The results of this study suggest that geography relative to soil properties has a simultaneous impact on soil microbial and nematode community compositions. This is the first combined profile analysis of bacteria, fungi and nematodes at different sites with agricultural Andosols.

Bioleaching of ilmenite and basalt in the presence of iron-oxidizing and iron-scavenging bacteria

Science.gov (United States)

Navarrete, Jesica U.; Cappelle, Ian J.; Schnittker, Kimberlin; Borrok, David M.

2013-04-01

Bioleaching has been suggested as an alternative to traditional mining techniques in extraterrestrial environments because it does not require extensive infrastructure and bulky hardware. In situ bioleaching of silicate minerals, such as those found on the moon or Mars, has been proposed as a feasible alternative to traditional extraction techniques that require either extreme heat and/or substantial chemical treatment. In this study, we investigated the biotic and abiotic leaching of basaltic rocks (analogues to those found on the moon and Mars) and the mineral ilmenite (FeTiO3) in aqueous environments under acidic (pH ˜ 2.5) and circumneutral pH conditions. The biological leaching experiments were conducted using Acidithiobacillus ferrooxidans, an iron (Fe)-oxidizing bacteria, and Pseudomonas mendocina, an Fe-scavenging bacteria. We found that both strains were able to grow using the Fe(II) derived from the tested basaltic rocks and ilmenite. Although silica leaching rates were the same or slightly less in the bacterial systems with A. ferrooxidans than in the abiotic control systems, the extent of Fe, Al and Ti released (and re-precipitated in new solid phases) was actually greater in the biotic systems. This is likely because the Fe(II) leached from the basalt was immediately oxidized by A. ferrooxidans, and precipitated into Fe(III) phases which causes a change in the equilibrium of the system, i.e. Le Chatelier's principle. Iron(II) in the abiotic experiment was allowed to build up in solution which led to a decrease in its overall release rate. For example, the percentage of Fe, Al and Ti leached (dissolved + reactive mineral precipitates) from the Mars simulant in the A. ferrooxidans experimental system was 34, 41 and 13% of the total Fe, Al and Ti in the basalt, respectively, while the abiotic experimental system released totals of only 11, 25 and 2%. There was, however, no measurable difference in the amounts of Fe and Ti released from ilmenite in the

Combination of magnetic parameters: an efficient way to discriminate soil-contamination sources (south France)

International Nuclear Information System (INIS)

Lecoanet, H.; Leveque, F.; Ambrosi, J.-P.

2003-01-01

Biplots combining magnetic parameters allow identification of different pollutant emission sources. - Biplots combining magnetic parameters allow to identification and differentiation different pollutant emission sources. A major problem in soil pollution is the characterization of the relative contributions of different anthropogenic particles sources. This paper demonstrates the efficiency of magnetic techniques to provide identification and differentiation of contaminating emission sources. About 100 soil samples were collected across a mixed agricultural and industrial area (Crau plain/Berre-Fos basin) in southern France. Nine soil profiles were realized. They are aligned along a transect, from the Mediterranean cost to the north. Measurements of initial magnetic susceptibility (χ) and remanent magnetization (ARM, IRM) have been carried out at room temperature. Several ratios of magnetic parameters were calculated and tested. Bivariate analyses allow to characterize different pollution sources and graphic results suggest three dominant contributions originated from road traffic, airport and steel industry. Moreover, magnetic grain-size discrimination between surface-soil samples and bottom-soil samples is obtained. An increase of hard magnetic components from topsoil towards the bottom of the profiles is evidenced

Combined effects of biocontrol agents and soil amendments on soil microbial populations, plant growth and incidence of charcoal rot of cowpea and wilt of cumin

Directory of Open Access Journals (Sweden)

Vijeta SINGH

2012-09-01

Full Text Available Field experiments were conducted for 2 years to determine the effectiveness of combined use of two biocontrol agents, Bacillus firmus and Aspergillus versicolor for control of Macrophomina phaseolina induced charcoal rot of cowpea and Fusarium oxysporum f. sp. cumini induced wilt of cumin. The lowest level of plant mortality (3‒4% due to charcoal rot of cowpea was recorded when bacterium coated seeds were sown in radish compost amended soil compared to the non-amended soil (13.8‒20.5%, but this was not significantly better than some other treatments. Cowpea roots from B. firmus coated seeds had better nodulation than any of the individual A. versicolor treatments. Although B. firmus coated seeds + A. versicolor + farmyard manure resulted in maximum nodulation this was not significantly different to B. firmus seed coating. Root colonization by the combined biocontrol agent treatments was better than the individual biocontrol agent treatments. Combining A. versicolor with farmyard manure supported the maximum populations of total fungi and actinomycetes. In both winter seasons, the lowest incidence of wilt (1.0‒5.2% on cumin was recorded when A. versicolor was amended with neem compost compared to the non-amended soil (5.7‒10.5%. Maximum colonization of A. versicolor on roots was observed in B. firmus + A. versicolor + farmyard manure amended plots. During both years, the treatment combination of A. versicolor in neem compost amended plots resulted in maximum populations of fungi, bacteria and A. versicolor in the soil, which was greater than in the non-amended soil. Significant increases in disease control were not recorded after single or repeated delivery of A. versicolor. These results suggest that combining B. firmus as seed coatings with A. versicolor as soil applications gives improved control of M. phaseolina and Fusarium induced diseases on legume and seed spice crops in arid soils.

Removal of phenanthrene in contaminated soil by combination of alfalfa, white-rot fungus, and earthworms.

Science.gov (United States)

Deng, Shuguang; Zeng, Defang

2017-03-01

The aim of this study was to investigate the removal of phenanthrene by combination of alfalfa, white-rot fungus, and earthworms in soil. A 60-day experiment was conducted. Inoculation with earthworms and/or white-rot fungus increased alfalfa biomass and phenanthrene accumulation in alfalfa. However, inoculations of alfalfa and white-rot fungus can significantly decrease the accumulation of phenanthrene in earthworms. The removal rates for phenanthrene in soil were 33, 48, 66, 74, 85, and 93% under treatments control, only earthworms, only alfalfa, earthworms + alfalfa, alfalfa + white-rot fungus, and alfalfa + earthworms + white-rot fungus, respectively. The present study demonstrated that the combination of alfalfa, earthworms, and white-rot fungus is an effective way to remove phenanthrene in the soil. The removal is mainly via stimulating both microbial development and soil enzyme activity.

Simultaneous heat and moisture transfer in soils combined with building simulation

Energy Technology Data Exchange (ETDEWEB)

Santos, G. H. dos; Mendes, N. [Pontifical Catholic University of Parana, PUCPR/CCET, Thermal Systems Laboratory (LST), Curitiba (Brazil)

2006-07-01

In order to precisely predict ground heat transfer, room air temperature and humidity, a combined model has been developed and conceived to calculate both the coupled heat and moisture transfer in soil and floor and the psychrometrics condition of indoor air. The present methodology for the soil is based on the theory of Philip and De Vries, using variable thermophysical properties for different materials. The governing equations were discretized using the finite-volume method and a three-dimensional model for describing the physical phenomena of heat and mass transfer in unsaturated moist porous soils and floor. Additionally, a lumped transient approach for a building room and a finite-volume multi-layer model for the building envelope have been developed to integrate with the soil model. Results are presented in terms of temperature, humidity and heat flux at the interface between room air and the floor, showing the importance of the approach presented and the model robustness for long-term simulations with a high time step. (author)

Immiscible melt droplets in garnet, as represented by ilmenite-magnetite-spinel spheroids in an eclogite-garnet peridotite association, Blanský les Granulite Massif, Czech Republic

Czech Academy of Sciences Publication Activity Database

Vrána, S.; Ackerman, Lukáš; Erban, V.; Halodová, P.

2016-01-01

Roč. 101, č. 1 (2016), s. 82-92 ISSN 0003-004X Institutional support: RVO:67985831 Keywords : eclogite * Fe-Ti-rich melt * garnet peridotite * garnetite * Ilmenite-magnetite-spinel * Invited Centennial article * Moldanubian Zone * UHP crystallization Subject RIV: DD - Geochemistry Impact factor: 2.021, year: 2016

Biochar affects carbon composition and stability in soil: a combined spectroscopy-microscopy study

Science.gov (United States)

Hernandez-Soriano, Maria C.; Kerré, Bart; Kopittke, Peter M.; Horemans, Benjamin; Smolders, Erik

2016-01-01

The use of biochar can contribute to carbon (C) storage in soil. Upon addition of biochar, there is a spatial reorganization of C within soil particles, but the mechanisms remain unclear. Here, we used Fourier transformed infrared-microscopy and confocal laser scanning microscopy to examine this reorganization. A silty-loam soil was amended with three different organic residues and with the biochar produced from these residues and incubated for 237 d. Soil respiration was lower in biochar-amended soils than in residue-amended soils. Fluorescence analysis of the dissolved organic matter revealed that biochar application increased a humic-like fluorescent component, likely associated with biochar-C in solution. The combined spectroscopy-microscopy approach revealed the accumulation of aromatic-C in discrete spots in the solid-phase of microaggregates and its co-localization with clay minerals for soil amended with raw residue or biochar.The co-localization of aromatic-C:polysaccharides-C was consistently reduced upon biochar application. We conclude that reduced C metabolism is an important mechanism for C stabilization in biochar-amended soils. PMID:27113269

Biochar affects carbon composition and stability in soil: a combined spectroscopy-microscopy study

Science.gov (United States)

Hernandez-Soriano, Maria C.; Kerré, Bart; Kopittke, Peter M.; Horemans, Benjamin; Smolders, Erik

2016-04-01

The use of biochar can contribute to carbon (C) storage in soil. Upon addition of biochar, there is a spatial reorganization of C within soil particles, but the mechanisms remain unclear. Here, we used Fourier transformed infrared-microscopy and confocal laser scanning microscopy to examine this reorganization. A silty-loam soil was amended with three different organic residues and with the biochar produced from these residues and incubated for 237 d. Soil respiration was lower in biochar-amended soils than in residue-amended soils. Fluorescence analysis of the dissolved organic matter revealed that biochar application increased a humic-like fluorescent component, likely associated with biochar-C in solution. The combined spectroscopy-microscopy approach revealed the accumulation of aromatic-C in discrete spots in the solid-phase of microaggregates and its co-localization with clay minerals for soil amended with raw residue or biochar.The co-localization of aromatic-C:polysaccharides-C was consistently reduced upon biochar application. We conclude that reduced C metabolism is an important mechanism for C stabilization in biochar-amended soils.

X-ray fluorescence and gamma-ray spectrometry combined with multivariate analysis for topographic studies in agricultural soil

International Nuclear Information System (INIS)

Castilhos, Natara D.B. de; Melquiades, Fábio L.; Thomaz, Edivaldo L.; Bastos, Rodrigo Oliveira

2015-01-01

Physical and chemical properties of soils play a major role in the evaluation of different geochemical signature, soil quality, discrimination of land use type, soil provenance and soil degradation. The objectives of the present study are the soil elemental characterization and soil differentiation in topographic sequence and depth, using Energy Dispersive X-Ray Fluorescence (EDXRF) as well as gamma-ray spectrometry data combined with Principal Component Analysis (PCA). The study area is an agricultural region of Boa Vista catchment which is located at Guamiranga municipality, Brazil. PCA analysis was performed with four different data sets: spectral data from EDXRF, spectral data from gamma-ray spectrometry, concentration values from EDXRF measurements and concentration values from gamma-ray spectrometry. All PCAs showed similar results, confirmed by hierarchical cluster analysis, allowing the data grouping into top, bottom and riparian zone samples, i.e. the samples were separated due to its landscape position. The two hillslopes present the same behavior independent of the land use history. There are distinctive and characteristic patterns in the analyzed soil. The methodologies presented are promising and could be used to infer significant information about the region to be studied. - Highlights: • Characterization of topographic sequence of two hillslopes from agricultural soil. • Employment of EDXRF and gamma-ray spectrometry data combined with PCA. • The combination of green analytical methodologies with chemometric studies allowed soil differentiation. • The innovative methodology is promising for direct characterization of agricultural catchments

Do shallow soil, low water availability, or their combination increase the competition between grasses with different root systems in karst soil?

Science.gov (United States)

Zhao, Yajie; Li, Zhou; Zhang, Jing; Song, Haiyan; Liang, Qianhui; Tao, Jianping; Cornelissen, Johannes H C; Liu, Jinchun

2017-04-01

Uneven soil depth and low water availability are the key limiting factors to vegetation restoration and reconstruction in limestone soils such as in vulnerable karst regions. Belowground competition will possibly increase under limited soil resources. Here, we investigate whether low resource availability (including shallow soil, low water availability, and shallow soil and low water availability combined) stimulates the competition between grasses with different root systems in karst soil, by assessing their growth response, biomass allocation, and morphological plasticity. In a full three-way factorial blocked design of soil depth by water availability by neighbor identity, we grew Festuca arundinacea (deep-rooted) and Lolium perenne (shallow-rooted) under normal versus shallow soil depth, high versus low water availability, and in monoculture (conspecific neighbor) versus mixture (neighbor of the other species). The key results were as follows: (1) total biomass and aboveground biomass in either of the species decreased with reduction of resources but were not affected by planting patterns (monoculture or mixture) even at low resource levels. (2) For F. arundinacea, root biomass, root mass fraction, total root length, and root volume were higher in mixture than in monoculture at high resource level (consistent with resource use complementarity), but lower in mixture than in monoculture at low resource levels (consistent with interspecific competition). In contrast for L. perenne, either at high or low resource level, these root traits had mostly similar values at both planting patterns. These results suggest that deep-rooted and shallow-rooted plant species can coexist in karst regions under current climatic regimes. Declining resources, due to shallow soil, a decrease in precipitation, or combined shallow soil and karst drought, increased the root competition between plants of deep-rooted and shallow-rooted species. The root systems of deep-rooted plants may be

Electrokinetic-Enhanced Remediation of Phenanthrene-Contaminated Soil Combined with Sphingomonas sp. GY2B and Biosurfactant.

Science.gov (United States)

Lin, Weijia; Guo, Chuling; Zhang, Hui; Liang, Xujun; Wei, Yanfu; Lu, Guining; Dang, Zhi

2016-04-01

Electrokinetic-microbial remediation (EMR) has emerged as a promising option for the removal of polycyclic aromatic hydrocarbons (PAHs) from contaminated soils. The aim of this study was to enhance degradation of phenanthrene (Phe)-contaminated soils using EMR combined with biosurfactants. The electrokinetic (EK) remediation, combined with Phe-degrading Sphingomonas sp. GY2B, and biosurfactant obtained by fermentation of Pseudomonas sp. MZ01, degraded Phe in the soil with an efficiency of up to 65.1 % at the anode, 49.9 % at the cathode after 5 days of the treatment. The presence of biosurfactants, electricity, and a neutral electrolyte stimulated the growth of the degrading bacteria as shown by a rapid increase in microbial biomass with time. The electrical conductivity and pH changed little during the course of the treatment, which benefitted the growth of microorganisms and the remediation of Phe-contaminated soil. The EMR system with the addition of biosurfactant had the highest Phe removal, demonstrating the biosurfactant may enhance the bioavailability of Phe and the interaction with the microorganism. This study suggests that the EMR combined with biosurfactants can be used to enhance in situ bioremediation of PAH-contaminated soils.

Investigation On Natural Background Radioactivity At TanLong, Lagi, BinhThuan Residential Area On Ilmenite Deposit Location

International Nuclear Information System (INIS)

Pham Thi Kim Loan; Tran Van Luyen; Thai Khac Dinh

2008-01-01

An Ilmenite deposit zone located at TanLong, Lagi, Binh Thuan province. After the year of 2000, a new village of population has set up at this place. To estimate the effect on the human health of radioactivity accompanying with the deposit, the sand samples were collected and natural radioactive analyzed at center for nuclear techniques. The average year doses D annual , hazard radiation exposed index H ex and Radium equivalence Ra eq were calculated based on the natural radioactivities. The results show that these factors are overcome the international average as well as southern Vietnam values. (author)

Assessing the combined risks of PAHs and metals in urban soils by urbanization indicators

International Nuclear Information System (INIS)

Peng, Chi; Ouyang, Zhiyun; Wang, Meie; Chen, Weiping; Li, Xiaoma; Crittenden, John C.

2013-01-01

We quantitatively describe the impacts of urbanization on the accumulation of polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) in urban soils as well as their health risks to residents. Residential building age, population density, road density, and distance from urban center were used as urbanization level indicators. Significant correlations were found between those urbanization indicators and the amounts of PAHs, Cu, Cd, Pb, Zn and As in residential soils. The exposure time of soils to urban air was the primary factor affecting soil pollution, followed by local road density and population density. Factor analysis suggested that 59.0% of the elevated pollutant concentrations were caused by citywide uniform deposition, and 15.3% were resulted from short-range deposition and/or non-combustion processes. The combined health risks posed by soil PAHs and HMs were aggravated with time and can be expressed as functions of residence age, road density, and other urbanization indicators. Highlights: •The soil PAH and HM contents were closely related to urbanization progression. •The PAH and HM contents were primarily affected by soil exposure time. •Local input loads of pollutants correlated with road density and population density. •The combined risks of PAHs and HMs increased with the urban development level. •The carcinogenic risks of PAHs and As were above 10 −5 and increased over time. -- The health risks of PAHs and HMs in residential soils were connected to building age, population density and road density of the community as well as its distance from urban center

At last! The single-crystal X-ray structure of a naturally occurring sample of the ilmenite-type oxide FeCrO3.

Science.gov (United States)

Pérez-Cruz, María Ana; Elizalde-González, María de la Paz; Escudero, Roberto; Bernès, Sylvain; Silva-González, Rutilo; Reyes-Ortega, Yasmi

2015-10-01

A natural single crystal of the ferrimagnetic oxide FeCrO3, which was found in an opencast mine situated in the San Luis Potosí State in Mexico, has been characterized in order to elucidate some outstanding issues about the actual structure of this material. The single-crystal X-ray analysis unambiguously shows that transition metal cations are segregated in alternating layers normal to the threefold crystallographic axis, affording a structure isomorphous to that of ilmenite (FeTiO3), in the space group R3̅. The possible occurrence of cation antisite and vacancy defects is below the limit of detection available from X-ray data. Structural and magnetic results are in agreement with the coherent slow intergrowth of magnetic phases provided by the two antiferromagnetic corundum-type parent oxides Fe2O3 (hematite) and Cr2O3 (eskolaite). Our results are consistent with the most recent density functional theory (DFT) studies carried out on digital FeCrO3 [Sadat Nabi & Pentcheva (2011). Phys. Rev. B, 83, 214424], and suggest that synthetic samples of FeCrO3 might present a cation distribution different to that of the ilmenite structural type.

Combining a coupled FTIR-EGA system and in situ DRIFTS for studying soil organic matter in arable soils

Directory of Open Access Journals (Sweden)

M. S. Demyan

2013-05-01

Full Text Available An optimized spectroscopic method combining quantitative evolved gas analysis via Fourier transform infrared spectroscopy (FTIR-EGA in combination with a qualitative in situ thermal reaction monitoring via diffuse reflectance Fourier transform infrared spectroscopy (in situT DRIFTS is being proposed to rapidly characterize soil organic matter (SOM to study its dynamics and stability. A thermal reaction chamber coupled with an infrared gas cell was used to study the pattern of thermal evolution of carbon dioxide (CO2 in order to relate evolved gas (i.e., CO2 to different qualities of SOM. Soil samples were taken from three different arable sites in Germany: (i the Static Fertilization Experiment, Bad Lauchstädt (Chernozem, from treatments of farmyard manure (FYM, mineral fertilizer (NPK, their combination (FYM + NPK and control without fertilizer inputs; (ii Kraichgau; and (iii Swabian Alb (Cambisols areas, Southwest Germany. The two latter soils were further fractionated into particulate organic matter (POM, sand and stable aggregates (Sa + A, silt and clay (Si + C, and NaOCl oxidized Si + C (rSOC to gain OM of different inferred stabilities; respiration was measured from fresh soil samples incubated at 20 °C and 50% water holding capacity for 490 days. A variable long path length gas cell was used to record the mid-infrared absorbance intensity of CO2 (2400 to 2200 cm−1 being evolved during soil heating from 25 to 700 °C with a heating rate of 68 °C min−1 and holding time of 10 min at 700 °C. Separately, the heating chamber was placed in a diffuse reflectance chamber (DRIFTS for measuring the mid-infrared absorbance of the soil sample during heating. Thermal stability of the bulk soils and fractions was measured via the temperature of maximum CO2 evolution (CO2max. Results indicated that the FYM + NPK and FYM treatments of the Chernozem soils had a lower CO2max as compared to both NPK and CON treatments. On average, CO2max of the

Changes in heavy metal mobility and availability from contaminated wetland soil remediated with combined biochar-compost.

Science.gov (United States)

Liang, Jie; Yang, Zhaoxue; Tang, Lin; Zeng, Guangming; Yu, Man; Li, Xiaodong; Wu, Haipeng; Qian, Yingying; Li, Xuemei; Luo, Yuan

2017-08-01

The combination of biochar and compost has been proven to be effective in heavy metals contaminated wetland soil restoration. However, the influence of different proportions between biochar and compost on immobilization of heavy metals in soil has been less studied up to date. Therefore, we investigated the effect of different ratios of biochar-compost mixtures on availability and speciation distribution of heavy metals (Cd, Zn and Cu) in wetland soil. The results showed that applying all amendment combinations into wetland soil increased gradually the total organic carbon (TOC) and water-extract organic carbon (WEOC) as the compost percentage rose in biochar-composts. The higher pH was obtained in a certain biochar addition (20% and 40%) in combinations due to efficient interaction of biochar with compost. All amendments could significantly decrease availability of Cd and Zn mainly from pH change, but increase available Cu concentration as the result of increased water-extract organic carbon and high total Cu content in compost. Moreover, amendments can decrease easily exchangeable fraction and increase reducible of Cd and Zn greatly with increase of compost content in combinations, while amendments containing compost promote transformation of Cu from Fe/Mn oxide and residual fractions to organic bindings. These results demonstrate that different ratios of biochar and compost have a significant effect on availability and speciation of heavy metals in multi-metal-contaminated wetland soil. Copyright © 2017 Elsevier Ltd. All rights reserved.

Combination of biochar amendment and phytoremediation for hydrocarbon removal in petroleum-contaminated soil

OpenAIRE

Han, Tao; Zhao, Zhipeng; Bartlam, Mark; Wang, Yingying

2016-01-01

Remediation of soils contaminated with petroleum is a challenging task. Four different bioremediation strategies, including natural attenuation, biochar amendment, phytoremediation with ryegrass, and a combination of biochar and ryegrass, were investigated with greenhouse pot experiments over a 90-day period. The results showed that planting ryegrass in soil can significantly improve the removal rate of total petroleum hydrocarbons (TPHs) and the number of microorganisms. Within TPHs, the rem...

Amelioration of soil PAH and heavy metals by combined application of fly ash and biochar

Science.gov (United States)

Masto, Reginald; George, Joshy; Ansari, Md; Ram, Lal

2016-04-01

Generation of electricity through coal combustion produces huge quantities of fly ash. Sustainable disposal and utilization of these fly ash is a major challenge. Fly ash along with other amendments like biochar could be used for amelioration of soil. In this study, fly ash and biochar were used together for amelioration of polycyclic aromatic hydrocarbon (PAH) contaminated soil. Field experiment was conducted to investigate the effects of fly ash and biochar on the amelioration of soil PAH, and the yield of Zea mays. The treatments were control, biochar (4 t/ha), fly ash (4 t/ha), ash + biochar ( 2 + 2 t/ha). Soil samples were collected after the harvest of maize crop and analysed for chemical and biological parameters. Thirteen PAHs were analysed in the postharvest soil samples. Soil PAHs were extracted in a microwave oven at 120 °C using hexane : acetone (1:1) mixture. The extracted solutions were concentrated, cleaned and the 13 PAHs [Acenaphthene (Ace), fluorene (Flr), phenanthrene (Phn), anthracene(Ant), pyrene(Pyr), benz(a)anthracene (BaA), chrysene (Chy), benzo(b)fluoranthene (BbF), benzo(k)fluoranthene (BkF), benzo(a)pyrene, benzo(g,h,i)perylene (BghiP), dibenzo(a,h)anthracene, and indeno(1,2,3-cd)pyrene)(Inp)] were analysed using GC-MS. The mean pH increased from 6.09 in control to 6.64 and 6.58 at biochar and fly ash treated soils, respectively. N content was not affected, whereas addition of biochar alone and in combination with fly ash, has significantly increased the soil organic carbon content. P content was almost double in combined (9.06 mg/kg) treatment as compared to control (4.32 mg/kg). The increase in K due to biochar was 118%, whereas char + ash increased soil K by 64%. Soil heavy metals were decreased: Zn (-48.4%), Ni (-41.4%), Co (-36.9%), Cu (-35.7%), Mn (-34.3%), Cd (-33.2%), and Pb (-30.4%). Soil dehydrogenase activity was significantly increased by ash and biochar treatments and the maximum activity was observed for the combined

Simultaneous Removal of Lindane, Lead and Cadmium from Soils by Rhamnolipids Combined with Citric Acid

Science.gov (United States)

Long, Tao; Ying, Rongrong; Ye, Mao; Zhang, Shengtian; Li, Qun; Zhou, Yan; Lin, Yusuo

2015-01-01

This study investigated the performance of rhamnolipids-citric acid mixed agents in simultaneous desorption of lindane and heavy metals from soils. The capacity of the mixed agents to solubilize lindane, lead and cadmium in aqueous solution was also explored. The results showed that the presence of citric acid greatly enhanced the solubilization of lindane and cadmium by rhamnolipids. A combined effect of the mixed agents on lindane and heavy metals removal from soils was observed. The maximum desorption ratios for lindane, cadmium and lead were 85.4%, 76.4% and 28.1%, respectively, for the mixed agents containing 1% rhamnolipidsand 0.1 mol/L citric acid. The results also suggest that the removal efficiencies of lead and cadmium were strongly related to their speciations in soils, and metals in the exchangeable and carbonate forms were easier to be removed. Our study suggests that the combining use of rhamnolipids and citric acid is a promising alternative to simultaneously remove organochlorine pesticides and heavy metals from soils. PMID:26087302

Selective removal of chromium from sulphuric acid leach liquor of ilmenite ore by solvent extraction with trioctylamine

Directory of Open Access Journals (Sweden)

E.O. Olanipekun

2000-12-01

Full Text Available The selective removal of chromium, a trace impurity that degrades the whiteness of titanium(IV oxide pigments, from sulphuric acid leach liquor of ilmenite, was investigated by solvent extraction with xylene solutions of trioctylamine. Important factors of commercial significance affecting the extraction operation have been examined. More than 99% of the chromium was selectively removed in multiple batch extractions from the leach liquor and titanium losses were minimal (< 1%. The chromium content of extracted solutions was reduced to less than 1 ppm and thermal hydrolysis of these solutions yielded white titanium(IV oxide pigments that are suitable for use in the coatings pigment industry.

Infrared spectra of lunar soils. [using a Michelson interferometer

Science.gov (United States)

Aronson, J. R.; Emslie, A. G.; Smith, E. M.

1979-01-01

Measured data obtained by Michelson interferometer spectrometer were stored in a computer file and smoothed by being passed forward and backward through a digital four-pole low pass filter. Infrared spectra of the 10 lunar samples are presented in the format of brightness temperature versus frequency. The mol % of feldspar, pyroxene, olivine, ilmenite and ferromagnetic silicate in each sample is presented in tables. The reflectance spectra of ilmenite and enstatite are shown in graphs.

Combining mid infrared and total X-ray fluorescence spectroscopy for prediction of soil properties

Science.gov (United States)

Towett, Erick; Shepherd, Keith; Sila, Andrew; Aynekulu, Ermias; Cadisch, Georg

2015-04-01

Mid-infrared diffuse reflectance spectroscopy (MIR) can predict many soil properties but extractable nutrients are often predicted poorly. We evaluated the potential of MIR and total elemental analysis using total X-ray fluorescence spectroscopy (TXRF), both individually and combined, to predict results of conventional soil tests. Total multi-elemental analysis provides a fingerprint of soil mineralogy and could predict some soil properties and help improve MIR predictions. A set of 700 georeferenced soil samples associated with the Africa Soil Information Service (AfSIS) (www.africasoils.net) from 44 stratified randomly-located 100-km2 sentinel sites distributed across sub-Saharan Africa were analysed for physico-chemical composition using conventional reference methods, and compared to MIR and TXRF spectra using the Random Forests regression algorithm and an internal out-of-bag validation. MIR spectra resulted in good prediction models (R2 >0.80) for organic C and total N, Mehlich-3 Ca and Al, and pH. To test the combined spectroscopic approach, TXRF element concentration data was included as a property predictor along with the first derivative of MIR spectral data using the RF algorithm. Including TXRF did not improve prediction of these properties. TXRF was poorer (R2 0.86) as these elements are not directly determined with TXRF, however the variance explained is still quite high and may be attributable to TXRF signatures relating to mineralogy correlated with protection of soil organic matter. TXRF model for Mehlich-3 Al had excellent prediction capability explaining 81% of the observed variation in extractable Al content and was comparable to that of MIR (R2 = 0.86). However, models for pH and Mehlich-3 exchangeable Ca exhibited R2 values of 0.74 and 0.79 respectively and thus had moderate predictive accuracy, compared to MIR alone with R2 values of 0.82 and 0.84 respectively. Both MIR and TXRF methods predicted soil properties that relate to nutrient

Development of a combined soil-wash/in-furnace vitrification system for soil remediation at DOE sites

International Nuclear Information System (INIS)

Pegg, I.L.; Guo, Y.; Lahoda, E.J.; Lai, Shan-Tao; Muller, I.S.; Ruller, J.; Grant, D.C.

1993-01-01

This report addresses research and development of technologies for treatment of radioactive and hazardous waste streams at DOE sites. Weldon Spring raffinate sludges were used in a direct vitrification study to investigate their use as fluxing agents in glass formulations when blended with site soil. Storm sewer sediments from the Oak Ridge, TN, Y-12 facility were used for soil washing followed by vitrification of the concentrates. Both waste streams were extensively characterized. Testing showed that both mercury and uranium could be removed from the Y-12 soil by chemical extraction resulting in an 80% volume reduction. Thermal desorption was used on the contaminant-enriched minority fraction to separate the mercury from the uranium. Vitrification tests demonstrated that high waste loading glasses could be produced from the radioactive stream and from the Weldon Spring wastes which showed very good leach resistance, and viscosities and electrical conductivities in the range suitable for joule-heated ceramic melter (JHCM) processing. The conceptual process described combines soil washing, thermal desorption, and vitrification to produce clean soil (about 90% of the input waste stream), non-radioactive mercury, and a glass wasteform; the estimated processing costs for that system are about $260--$400/yd 3 . Results from continuous melter tests performed using Duratek's advanced JHCM (Duramelter) system are also presented. Since life cycle cost estimates are driven largely by volume reduction considerations, the large volume reductions possible with these multi-technology, blended waste stream approaches can produce a more leach resistant wasteform at a lower overall cost than alternative technologies such as cementation

First oxygen from lunar basalt

Science.gov (United States)

Gibson, M. A.; Knudsen, C. W.; Brueneman, D. J.; Kanamori, H.; Ness, R. O.; Sharp, L. L.; Brekke, D. W.; Allen, C. C.; Morris, R. V.; Keller, L. P.

1993-01-01

The Carbotek/Shimizu process to produce oxygen from lunar soils has been successfully demonstrated on actual lunar samples in laboratory facilities at Carbotek with Shimizu funding and support. Apollo sample 70035 containing approximately 25 percent ilmenite (FeTiO3) was used in seven separate reactions with hydrogen varying temperature and pressure: FeTiO3 + H2 yields Fe + TiO2 + H2O. The experiments gave extremely encouraging results as all ilmenite was reduced in every experiment. The lunar ilmenite was found to be about twice as reactive as terrestrial ilmenite samples. Analytical techniques of the lunar and terrestrial ilmenite experiments performed by NASA Johnson Space Center include iron Mossbauer spectroscopy (FeMS), optical microscopy, SEM, TEM, and XRD. The Energy and Environmental Research Center at the University of North Dakota performed three SEM techniques (point count method, morphology determination, elemental mapping), XRD, and optical microscopy.

Combined impacts of land use and soil property changes on soil erosion in a mollisol area under long-term agricultural development.

Science.gov (United States)

Ouyang, Wei; Wu, Yuyang; Hao, Zengchao; Zhang, Qi; Bu, Qingwei; Gao, Xiang

2018-02-01

Soil erosion exhibits special characteristics in the process of agricultural development. Understanding the combined impacts of land use and soil property changes on soil erosion, especially in the area under long-term agricultural cultivations, is vital to watershed agricultural and soil management. This study investigated the temporal-spatial patterns of the soil erosion based on a modified version of Universal Soil Loss Equation (USLE) and conducted a soil erosion contribution analysis. The land use data were interpreted from Landsat series images, and soil properties were obtained from field sampling, laboratory tests and SPAW (Soil-Plant-Atmosphere-Water) model calculations. Over a long period of agricultural development, the average erosion modulus decreased from 187.7tkm -2 a -1 in 1979 to 158.4tkm -2 a -1 in 2014. The land use types were transformed mainly in the reclamation of paddy fields and the shrinking of wetlands on a large scale. Most of the soils were converted to loam from silty or clay loam and the saturated hydraulic conductivity (K s ) of most soil types decreased by 1.11% to 43.6%. The rapidly increasing area of 49.8km 2 of paddy fields together with the moderate decrease of 14.0km 2 of forests, as well as K s values explained 87.4% of the total variance in soil erosion. Although changes in soil physical and water characteristics indicated that soil erosion loads should have become higher, the upsurge in paddy fields played an important role in mitigating soil erosion in this study area. These results demonstrated that land use changes had more significant impacts than soil property changes on soil erosion. This study suggested that rational measures should be taken to extend paddy fields and control the dry land farming. These findings will benefit watershed agricultural targeting and management. Copyright © 2017 Elsevier B.V. All rights reserved.

Magnetic properties of ilmenite-hematite single crystals from the Ecstall pluton near Prince Rupert, British Columbia

DEFF Research Database (Denmark)

Brownlee, Sarah J.; Feinberg, Joshua M.; Kasama, Takeshi

2011-01-01

Paleomagnetic studies of the 91 Ma Ecstall pluton and other Cretaceous plutons of British Columbia imply large northward tectonic movements (>2000 km) may have occurred during the tectonic evolution of western North America. However, more recent studies have shown that the eastern edge...... of the Ecstall pluton experienced considerable mineralogical changes as younger Eocene plutons, such as the ∼58 Ma Quottoon Pluton, were emplaced along its margins. We investigated changes in the rock magnetic properties associated with this reheating event by examining isolated grains of intergrown ilmenite...... and hematite, the primary paleomagnetic recorder in the Ecstall pluton. Measurements of hysteresis properties, low-temperature remanence, and room temperature isothermal remanent magnetization acquisition and observations from magnetic force microscopy and off-axis electron holography indicate that samples...

Combining a coupled FTIR-EGA system and in situ DRIFTS for studying soil organic matter in arable soils

Science.gov (United States)

Demyan, M. S.; Rasche, F.; Schütt, M.; Smirnova, N.; Schulz, E.; Cadisch, G.

2013-05-01

An optimized spectroscopic method combining quantitative evolved gas analysis via Fourier transform infrared spectroscopy (FTIR-EGA) in combination with a qualitative in situ thermal reaction monitoring via diffuse reflectance Fourier transform infrared spectroscopy (in situT DRIFTS) is being proposed to rapidly characterize soil organic matter (SOM) to study its dynamics and stability. A thermal reaction chamber coupled with an infrared gas cell was used to study the pattern of thermal evolution of carbon dioxide (CO2) in order to relate evolved gas (i.e., CO2) to different qualities of SOM. Soil samples were taken from three different arable sites in Germany: (i) the Static Fertilization Experiment, Bad Lauchstädt (Chernozem), from treatments of farmyard manure (FYM), mineral fertilizer (NPK), their combination (FYM + NPK) and control without fertilizer inputs; (ii) Kraichgau; and (iii) Swabian Alb (Cambisols) areas, Southwest Germany. The two latter soils were further fractionated into particulate organic matter (POM), sand and stable aggregates (Sa + A), silt and clay (Si + C), and NaOCl oxidized Si + C (rSOC) to gain OM of different inferred stabilities; respiration was measured from fresh soil samples incubated at 20 °C and 50% water holding capacity for 490 days. A variable long path length gas cell was used to record the mid-infrared absorbance intensity of CO2 (2400 to 2200 cm-1) being evolved during soil heating from 25 to 700 °C with a heating rate of 68 °C min-1 and holding time of 10 min at 700 °C. Separately, the heating chamber was placed in a diffuse reflectance chamber (DRIFTS) for measuring the mid-infrared absorbance of the soil sample during heating. Thermal stability of the bulk soils and fractions was measured via the temperature of maximum CO2 evolution (CO2max). Results indicated that the FYM + NPK and FYM treatments of the Chernozem soils had a lower CO2max as compared to both NPK and CON treatments. On average, CO2max of the Chernozem

Briquetting of Egyptian ilmenite ore with different organic binder and reduced its in hydrogen in temperature range 800-1200°C

Directory of Open Access Journals (Sweden)

Abd El-Gawad H.H.

2014-01-01

Full Text Available Ilmenite ore fine was briquetted with different amounts of molasses or pitch pressed under different pressure was studied in this investigation. The results show at optimum amount of molasses added was 1.5 % and pitch, the pressure was 294.3 M.Pa.. Also the characterizations of raw materials were studied by different methods of analyses such as Xray and screen analyses. The produced briquettes were reduced by different amounts of hydrogen at different temperatures, and the reduction kinetics was determined.

Generation of stress-strain state in combined strip pile foundation beds through pressing of soil

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Stepanov Maxim

2017-01-01

Full Text Available When erecting high-rise buildings, weak underlying soils cause a number of problems in design and construction. In order to ensure the required non-exceedance of the ultimate limit settlements, the combined strip pile foundation has been developed allowing the soil bed to be pre-stressed. This is achieved by injection of pressurized mortar (pressing. The paper analyzes the effect of soil pre-stressing followed by pressing of foundation with the cement mortar, as applied to existing structures using the Plaxis 3D software package in conditions of volume deformation and the Hardening Soil Model. Variable order of foundation pressing allows the required parameters of soil bed to be achieved in plan and depth, thus improving interaction with the foundation and superstructure.

The Effects of Fungicide, Soil Fumigant, Bio-Organic Fertilizer and Their Combined Application on Chrysanthemum Fusarium Wilt Controlling, Soil Enzyme Activities and Microbial Properties

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Shuang Zhao

2016-04-01

Full Text Available Sustained monoculture often leads to a decline in soil quality, in particular to the build-up of pathogen populations, a problem that is conventionally addressed by the use of either fungicide and/or soil fumigation. This practice is no longer considered to be either environmentally sustainable or safe. While the application of organic fertilizer is seen as a means of combating declining soil fertility, it has also been suggested as providing some control over certain soil-borne plant pathogens. Here, a greenhouse comparison was made of the Fusarium wilt control efficacy of various treatments given to a soil in which chrysanthemum had been produced continuously for many years. The treatments comprised the fungicide carbendazim (MBC, the soil fumigant dazomet (DAZ, the incorporation of a Paenibacillus polymyxa SQR21 (P. polymyxa SQR21, fungal antagonist enhanced bio-organic fertilizer (BOF, and applications of BOF combined with either MBC or DAZ. Data suggest that all the treatments evaluated show good control over Fusarium wilt. The MBC and DAZ treatments were effective in suppressing the disease, but led to significant decrease in urease activity and no enhancement of catalase activity in the rhizosphere soils. BOF including treatments showed significant enhancement in soil enzyme activities and microbial communities compared to the MBC and DAZ, evidenced by differences in bacterial/fungi (B/F ratios, Shannon–Wiener indexes and urease, catalase and sucrase activities in the rhizosphere soil of chrysanthemum. Of all the treatments evaluated, DAZ/BOF application not only greatly suppressed Fusarium wilt and enhanced soil enzyme activities and microbial communities but also promoted the quality of chrysanthemum obviously. Our findings suggest that combined BOF with DAZ could more effectively control Fusarium wilt disease of chrysanthemum.

Combining different frequencies for electrical heating of saturated and unsaturated soil zones

Energy Technology Data Exchange (ETDEWEB)

Roland, U.; Holzer, F.; Kopinke, F.D. [Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Engineering, Leipzig (Germany)

2011-10-15

In situ electrical heating of soil was studied applying different frequencies: low-frequency energy for resistive heating and radio-frequency energy for dielectric heating. Steep temperature gradients were observed for each heating mode under the condition of the coexistence of saturated and unsaturated soil zones. By combining the two heating modes, this undesired effect can be avoided, thus allowing efficient soil remediation especially when organic phases are accumulated at the capillary fringe. A parallel application of both frequencies was demonstrated as the most suitable method to reduce temperature gradients. By using electronic filters, both electric fields can be established by only one electrode array. This innovative concept is especially applicable for optimizing thermal remediation of light non-aqueous phase liquid contaminations or realizing thermally-enhanced electrokinetic removal of heavy metals. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Clusters and holes: Exchange networks in hematite-ilmenite solid solutions

Science.gov (United States)

Fabian, K.; McEnroe, S. A.; Robinson, P.

2009-04-01

Holes and clusters of exchange networks dominate the low-temperature, metastable phase diagram of the system (1 - x)Fe2O3 xF eTiO3 (Ilmx ). By our measurements we have probed and extended the phase diagram of Ishikawa et al. (1985) in the light of magnetic influences of the random exchange links, which originate either by replacing random pairs of Fe2+ and Ti4+ ions in the ordered ilmenite lattice by two Fe3+ions (ordered Ilmx phase), or by randomly replacing two Fe3+ ions in the hematite lattice by a pair of Fe2+ and Ti4+ ions (disordered Ilmx phase). Now a large dataset is available from these measurements, and we propose several new ideas to interpret the sometimes unexpected results. By refining a method of Ishikawa (1967), we analyze the PM' region of the phase diagram in terms of a mean field theory of interacting clusters. This allows to determine cluster sizes and interaction field distribution by inverting hysteresis measurements of Ilm92 and Ilm97. To understand the relation between ordered and disordered phases we design a mean field theory to determine Neel and Curie temperatures of both. An especially interesting finding is that the experimentally observed intersection of PM-PM' crossover with the AF phase boundary close to Ilm97 can be explained by analyzing average exchange interaction strengths.

Testing Single and Combinations of Amendments for Stabilization of Metals in Contrasting Extremely Contaminated Soils

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Siebielec G.

2013-04-01

Full Text Available Metals can be stabilized by soil amendments that increase metals adsorption or alter their chemical forms. Such treatments may limit the risk related to the contamination through reduction of metal transfer to the food chain (reduction of metal uptake by plants and its availability to soil organisms and metals migration within the environment. There is a need for experiments comparing various soil amendments available at reasonable amounts under similar environmental conditions. The other question is whether all components of soil environment or soil functions are similarly protected after remediation treatment. We conducted a series of pot studies to test some traditional and novel amendments and their combinations. The treatments were tested for several highly Zn/Cd/Pb contaminated soils. Among traditional amendments composts were the most effective – they ensured plant growth, increased soil microbial activity, reduced Cd in earthworms, reduced Pb bioaccessibility and increased share of unavailable forms of Cd and Pb.

Fluorimetric determination of uranium in certain refractory minerals, environmental samples and industrial waste materials

International Nuclear Information System (INIS)

Premadas, A.; Saravanakumar, G.

2005-01-01

A simple sample decomposition and laser fluorimetric determination of uranium at trace level is reported in certain refractory minerals, like ilmenite, rutile, zircon and monazite; environmental samples viz. soil and sediments; industrial waste materials, such as, coal fly ash and red mud. Ilmenite sample is decomposed by heating with ammonium fluoride. Rutile, zircon and monazite minerals are decomposed by fusion using a mixture of potassium bifluoride and sodium fluoride. Environmental and industrial waste materials are brought into solution by treating with a mixture of hydrofluoric and nitric acids. The laser induced fluorimetric determination of uranium is carried out directly in rutile, zircon and in monazite minerals and after separation in other samples. The determination limit was 1 μg x g -1 for ilmenite, soil, sediment, coal fly ash and red mud samples, and it is 5 μg x g -1 for rutile, zircon and monazite. The method is also developed for the optical fluorimetric determination of uranium (determination limit 10 μg x g -1 ) in ilmenite, rutile, zircon and monazite minerals. The methods are simple, accurate, and precise and they require small quantity of sample and can be applied for the routine analysis. (author)

Removal of heavy metals and arsenic from a co-contaminated soil by sieving combined with washing process.

Science.gov (United States)

Liao, Xiaoyong; Li, You; Yan, Xiulan

2016-03-01

Batch experiments were conducted with a heavy metals and arsenic co-contaminated soil from an abandoned mine to evaluate the feasibility of a remediation technology that combines sieving with soil washing. Leaching of the arsenic and heavy metals from the different particle size fractions was found to decrease in the order: 2mm. With increased contact time, the concentration of heavy metals in the leachate was significantly decreased for small particles, probably because of adsorption by the clay soil component. For the different particle sizes, the removal efficiencies for Pb and Cd were 75%-87%, and 61%-77% for Zn and Cu, although the extent of removal was decreased for As and Cr at 2mm, although good metal removal efficiencies were also achieved in the small particle size fractions. Through SEM-EDS observations and correlation analysis, the leaching regularity of the heavy metals and arsenic was found to be closely related to Fe, Mn, and Ca contents of the soil fractions. The remediation of heavy metal-contaminated soil by sieving combined with soil washing was proven to be efficient, and practical remediation parameters were also recommended. Copyright © 2015. Published by Elsevier B.V.

Assessing the combined risks of PAHs and metals in urban soils by urbanization indicators.

Science.gov (United States)

Peng, Chi; Ouyang, Zhiyun; Wang, Meie; Chen, Weiping; Li, Xiaoma; Crittenden, John C

2013-07-01

We quantitatively describe the impacts of urbanization on the accumulation of polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) in urban soils as well as their health risks to residents. Residential building age, population density, road density, and distance from urban center were used as urbanization level indicators. Significant correlations were found between those urbanization indicators and the amounts of PAHs, Cu, Cd, Pb, Zn and As in residential soils. The exposure time of soils to urban air was the primary factor affecting soil pollution, followed by local road density and population density. Factor analysis suggested that 59.0% of the elevated pollutant concentrations were caused by citywide uniform deposition, and 15.3% were resulted from short-range deposition and/or non-combustion processes. The combined health risks posed by soil PAHs and HMs were aggravated with time and can be expressed as functions of residence age, road density, and other urbanization indicators. Copyright © 2013 Elsevier Ltd. All rights reserved.

Changes to soil water content and biomass yield under combined maize and maize-weed vegetation with different fertilization treatments in loam soil

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Lehoczky Éva

2016-06-01

Full Text Available Especially during early developmental stages, competition with weeds can reduce crop growth and have a serious effect on productivity. Here, the effects of interactions between soil water content (SWC, nutrient availability, and competition from weeds on early stage crop growth were investigated, to better understand this problem. Field experiments were conducted in 2013 and 2014 using long-term study plots on loam soil in Hungary. Plots of maize (Zea mays L. and a weed-maize combination were exposed to five fertilization treatments. SWC was observed along the 0–80 cm depth soil profile and harvested aboveground biomass (HAB was measured.

Recycling of organic wastes in burnt soils: combined application of poultry manure and plant cultivation.

Science.gov (United States)

Villar, M C; Petrikova, V; Díaz-Raviña, M; Carballas, T

2004-01-01

A pot experiment was conducted to investigate the efficacy of a post-fire land management practice, including plant cultivation (Lolium perenne) combined with poultry manure addition, for restoring the protective vegetation cover in soils degraded by high intensity wildfires. The greenhouse experiment was performed with three burnt pine forest soils with added poultry manure at two doses of application and comparing the data with those obtained using NPK fertilizer. A significant effect of the amendment, soil properties and the interaction between amendment and soil properties on vegetation cover (phytomass production, nutrient content) was detected, but often the amendment treatment explained most of the variance. Changes induced by the organic amendment were more marked than those induced by inorganic fertilization. The increase of phytomass and nutrient uptake with poultry manure addition indicated the beneficial effects of this soil management practice. These findings can serve to develop field experiments and burnt soils reclamation technology.

Mycoextraction by Clitocybe maxima combined with metal immobilization by biochar and activated carbon in an aged soil.

Science.gov (United States)

Wu, Bin; Cheng, Guanglei; Jiao, Kai; Shi, Wenjin; Wang, Can; Xu, Heng

2016-08-15

To develop an eco-friendly and efficient route to remediate soil highly polluted with heavy metals, the idea of mycoextraction combined with metal immobilization by carbonaceous sorbents (biochar and activated carbon) was investigated in this study. Results showed that the application of carbonaceous amendments decreased acid soluble Cd and Cu by 5.13-14.06% and 26.86-49.58%, respectively, whereas the reducible and oxidizable fractions increased significantly as the amount of carbonaceous amendments added increased. The biological activities (microbial biomass, soil enzyme activities) for treatments with carbonaceous sorbents were higher than those of samples without carbonaceous amendments. Clitocybe maxima (C. maxima) simultaneously increased soil enzyme activities and the total number of microbes. Biochar and activated carbon both showed a positive effect on C. maxima growth and metal accumulation. The mycoextraction efficiency of Cd and Cu in treatments with carbonaceous amendments enhanced by 25.64-153.85% and 15.18-107.22%, respectively, in response to that in non-treated soil, which showed positive correlation to the augment of biochar and activated carbon in soil. Therefore, this work suggested the effectiveness of mycoextraction by C. maxima combined the application of biochar and activated carbon in immobilising heavy metal in contaminated soil. Copyright © 2016. Published by Elsevier B.V.

Combining multi-objective optimization and bayesian model averaging to calibrate forecast ensembles of soil hydraulic models

Energy Technology Data Exchange (ETDEWEB)

Vrugt, Jasper A [Los Alamos National Laboratory; Wohling, Thomas [NON LANL

2008-01-01

Most studies in vadose zone hydrology use a single conceptual model for predictive inference and analysis. Focusing on the outcome of a single model is prone to statistical bias and underestimation of uncertainty. In this study, we combine multi-objective optimization and Bayesian Model Averaging (BMA) to generate forecast ensembles of soil hydraulic models. To illustrate our method, we use observed tensiometric pressure head data at three different depths in a layered vadose zone of volcanic origin in New Zealand. A set of seven different soil hydraulic models is calibrated using a multi-objective formulation with three different objective functions that each measure the mismatch between observed and predicted soil water pressure head at one specific depth. The Pareto solution space corresponding to these three objectives is estimated with AMALGAM, and used to generate four different model ensembles. These ensembles are post-processed with BMA and used for predictive analysis and uncertainty estimation. Our most important conclusions for the vadose zone under consideration are: (1) the mean BMA forecast exhibits similar predictive capabilities as the best individual performing soil hydraulic model, (2) the size of the BMA uncertainty ranges increase with increasing depth and dryness in the soil profile, (3) the best performing ensemble corresponds to the compromise (or balanced) solution of the three-objective Pareto surface, and (4) the combined multi-objective optimization and BMA framework proposed in this paper is very useful to generate forecast ensembles of soil hydraulic models.

Trichoderma harzianum in combination with sheep manure amendment enhances soil suppressiveness of Fusarium wilt of tomato

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R. M. Barakat

2010-01-01

Full Text Available The effect that the biocontrol agent Trichoderma harzianum (isolate Jn14 in combination with an amendment of sheep manure has on the soil suppressiveness of Fusarium wilt of tomato was investigated over a 28-month period. A combination of T. harzianum and organic amendment at concentrations (w:w of 6 and 10% reduced tomato wilt by 21–36 % and 29–36% respectively, after 0–28 months of soil incubation. When the amendment was added at concentration of 2%, the wilt was suppressed only after 18–28 months. A combination of T. harzianum and the amendment at 6% also increased tomato plant fresh weights by 52% after 28 months, and the 10% amendment increased fresh weights by 56, 40, and 63%, after 18, 24, and 28 months respectively, compared to the experimental controls. Organic amendment at the higher concentrations further stimulated T. harzianum populations, enhanced microbial activity against Fusarium oxysporum in the soil and reduced pathogen populations. Without T. harzianum, the organic amendment at a concentration of 10% reduced disease by only 22, 24, and 23% and only after 18, 24 and 28 months of soil incubation respectively, compared with the controls. However, tomato wilt was not reduced at a 2% manure concentration in less than 12 months of incubation. Organic amendment alone at 6 and 10% reduced the pathogen population by 25% and 37% respectively after 28 months of soil incubation compared with the control. T. harzianum produced fungitoxic metabolites that reduced mycelial growth of Fusarium by 37% and conidium germination by 55% when the pathogen was grown on potato dextrose agar amended with a T. harzianum culture filtrate.

The EDTA effect on phytoextraction of single and combined metals-contaminated soils using rainbow pink (Dianthus chinensis).

Science.gov (United States)

Lai, Hung-Yu; Chen, Zueng-Sang

2005-08-01

Rainbow pink (Dianthus chinensis), a potential phytoextraction plant, can accumulate high concentrations of Cd from metal-contaminated soils. The soils used in this study were artificially added with different metals including (1) CK: original soil, (2) Cd-treated soil: 10 mg Cd kg(-1), (3) Zn-treated soil: 100 mg Zn kg(-1), (4) Pb-treated soil: 1000 mg Pb kg(-1), (5) Cd-Zn-treated soil: 10 mg Cd kg(-1) and 100 mg Zn kg(-1), (6) Cd-Pb-treated soil: 10 mg Cd kg(-1) and 1000 mg Pb kg(-1), (7) Zn-Pb-treated soil: 100 mg Zn kg(-1) and 1000 mg Pb kg(-1), and (8) Cd-Zn-Pb-treated soil: 10 mg Cd kg(-1), 100 mg Zn kg(-1), and 1000 mg Pb kg(-1). Three concentrations of 2Na-EDTA solutions (0 (control), 2, and 5 mmol kg(-1) soil) were added to the different metals-treated soils to study the influence of applied EDTA on single and combined metals-contaminated soils phytoextraction using rainbow pink. The results showed that the Cd, Zn, Pb, Fe, or Mn concentrations in different metals-treated soil solutions significantly increased after applying 5 mmol EDTA kg(-1) (p<0.05). The metal concentrations in different metals-treated soils extracted by deionized water also significantly increased after applying 5 mmol EDTA kg(-1) (p<0.05). Because of the high extraction capacity of both 0.005 M DTPA (pH 5.3) and 0.05 M EDTA (pH 7.0), applying EDTA did not significantly increase the Cd, Zn, or Pb concentration in both extracts for most of the treatments. Applying EDTA solutions can significantly increase the Cd and Pb concentrations in the shoots of rainbow pink (p<0.05). However, this was not statistically significant for Zn because of the low Zn concentration added into the contaminated soils. The results from this study indicate that applying 5 mmol EDTA kg(-1) can significantly increase the Cd, Zn, or Pb concentrations both in the soil solution or extracted using deionized water in single or combined metals-contaminated soils, thus increasing the accumulated metals concentrations in

Ecological effects of combined pollution associated with e-waste recycling on the composition and diversity of soil microbial communities.

Science.gov (United States)

Liu, Jun; He, Xiao-Xin; Lin, Xue-Rui; Chen, Wen-Ce; Zhou, Qi-Xing; Shu, Wen-Sheng; Huang, Li-Nan

2015-06-02

The crude processing of electronic waste (e-waste) has led to serious contamination in soils. While microorganisms may play a key role in remediation of the contaminated soils, the ecological effects of combined pollution (heavy metals, polychlorinated biphenyls, and polybrominated diphenyl ethers) on the composition and diversity of microbial communities remain unknown. In this study, a suite of e-waste contaminated soils were collected from Guiyu, China, and the indigenous microbial assemblages were profiled by 16S rRNA high-throughput sequencing and clone library analysis. Our data revealed significant differences in microbial taxonomic composition between the contaminated and the reference soils, with Proteobacteria, Acidobacteria, Bacteroidetes, and Firmicutes dominating the e-waste-affected communities. Genera previously identified as organic pollutants-degrading bacteria, such as Acinetobacter, Pseudomonas, and Alcanivorax, were frequently detected. Canonical correspondence analysis revealed that approximately 70% of the observed variation in microbial assemblages in the contaminated soils was explained by eight environmental variables (including soil physiochemical parameters and organic pollutants) together, among which moisture content, decabromodiphenyl ether (BDE-209), and copper were the major factors. These results provide the first detailed phylogenetic look at the microbial communities in e-waste contaminated soils, demonstrating that the complex combined pollution resulting from improper e-waste recycling may significantly alter soil microbiota.

Wood-derived-biochar combined with compost or iron grit for in situ stabilization of Cd, Pb, and Zn in a contaminated soil.

Science.gov (United States)

Oustriere, Nadège; Marchand, Lilian; Rosette, Gabriel; Friesl-Hanl, Wolfgang; Mench, Michel

2017-03-01

In situ stabilization of Cd, Pb, and Zn in an Austrian agricultural soil contaminated by atmospheric depositions from a smelter plant was assessed with a pine bark chip-derived biochar, alone and in combination with either compost or iron grit. Biochar amendment was also trialed in an uncontaminated soil to detect any detrimental effect. The pot experiment consisted in ten soil treatments (% w/w): untreated contaminated soil (Unt); Unt soil amended with biochar alone (1%: B1; 2.5%: B2.5) and in combination: B1 and B2.5 + 5% compost (B1C and B2.5C), B1 and B2.5 + 1% iron grit (B1Z and B2.5Z); uncontaminated soil (Ctrl); Ctrl soil amended with 1 or 2.5% biochar (CtrlB1, CtrlB2.5). After a 3-month reaction period, the soil pore water (SPW) was sampled in potted soils and dwarf beans were grown for a 2-week period. The SPW Cd, Pb, and Zn concentrations decreased in all amended-contaminated soils. The biochar effects increased with its addition rate and its combination with either compost or iron grit. Shoot Cd and Zn removals by beans were reduced and shoot Cd, Pb, and Zn concentrations decreased to common values in all amended soils except the B1 soil. Decreases in the SPW Cd/Pb/Zn concentrations did not improve the root and shoot yields of plants as compared to the Ctrl soil.

Toxicokinetics of Zn and Cd in the earthworm Eisenia andrei exposed to metal-contaminated soils under different combinations of air temperature and soil moisture content.

Science.gov (United States)

González-Alcaraz, M Nazaret; Loureiro, Susana; van Gestel, Cornelis A M

2018-04-01

This study evaluated how different combinations of air temperature (20 °C and 25 °C) and soil moisture content (50% and 30% of the soil water holding capacity, WHC), reflecting realistic climate change scenarios, affect the bioaccumulation kinetics of Zn and Cd in the earthworm Eisenia andrei. Earthworms were exposed for 21 d to two metal-contaminated soils (uptake phase), followed by 21 d incubation in non-contaminated soil (elimination phase). Body Zn and Cd concentrations were checked in time and metal uptake (k 1 ) and elimination (k 2 ) rate constants determined; metal bioaccumulation factor (BAF) was calculated as k 1 /k 2 . Earthworms showed extremely fast uptake and elimination of Zn, regardless of the exposure level. Climate conditions had no major impacts on the bioaccumulation kinetics of Zn, although a tendency towards lower k 1 and k 2 values was observed at 25 °C + 30% WHC. Earthworm Cd concentrations gradually increased with time upon exposure to metal-contaminated soils, especially at 50% WHC, and remained constant or slowly decreased following transfer to non-contaminated soil. Different combinations of air temperature and soil moisture content changed the bioaccumulation kinetics of Cd, leading to higher k 1 and k 2 values for earthworms incubated at 25 °C + 50% WHC and slower Cd kinetics at 25 °C + 30% WHC. This resulted in greater BAFs for Cd at warmer and drier environments which could imply higher toxicity risks but also of transfer of Cd within the food chain under the current global warming perspective. Copyright © 2018 Elsevier Ltd. All rights reserved.

Identification and characterization of tebuconazole transformation products in soil by combining suspect screening and molecular typology

International Nuclear Information System (INIS)

Storck, Veronika; Lucini, Luigi; Mamy, Laure; Ferrari, Federico; Papadopoulou, Evangelia S.; Nikolaki, Sofia; Karas, Panagiotis A.; Servien, Remi; Karpouzas, Dimitrios G.; Trevisan, Marco; Benoit, Pierre; Martin-Laurent, Fabrice

2016-01-01

Pesticides generate transformation products (TPs) when they are released into the environment. These TPs may be of ecotoxicological importance. Past studies have demonstrated how difficult it is to predict the occurrence of pesticide TPs and their environmental risk. The monitoring approaches mostly used in current regulatory frameworks target only known ecotoxicologically relevant TPs. Here, we present a novel combined approach which identifies and categorizes known and unknown pesticide TPs in soil by combining suspect screening time-of-flight mass spectrometry with in silico molecular typology. We used an empirical and theoretical pesticide TP library for compound identification by both non-target and target time-of-flight (tandem) mass spectrometry, followed by structural proposition through a molecular structure correlation program. In silico molecular typology was then used to group TPs according to common molecular descriptors and to indirectly elucidate their environmental parameters by analogy to known pesticide compounds with similar molecular descriptors. This approach was evaluated via the identification of TPs of the triazole fungicide tebuconazole occurring in soil during a field dissipation study. Overall, 22 empirical and 12 yet unknown TPs were detected, and categorized into three groups with defined environmental properties. This approach combining suspect screening time-of-flight mass spectrometry with molecular typology could be extended to other organic pollutants and used to rationalize the choice of TPs to be investigated towards a more comprehensive environmental risk assessment scheme. - Highlights: • Combined method to detect and categorize pesticide transformation products in soil. • Detection by QTOF-MS of new tebuconazole transformation products without standards. • Estimation by in silico molecular typology of their environmental parameters. • Method to rationally choose relevant transformation products to be studied. • The

Evidences of the stability of magnetite in soil from Northeastern Argentina by Moessbauer spectroscopy and magnetization measurements

International Nuclear Information System (INIS)

Causevic, H.; Morras, H.; Mijovilovich, A.; Saragovi, C.

2004-01-01

In red soils from southern Brazil magnetite was reported to be pedogenically unstable, weathering to maghemite. However, in similar soils from northeastern Argentina magnetite was found in all size fractions. This finding motivates the mineralogical study of an Ultisol at different depths in order to understand the influence of anthropic and natural factors in the weathering of the magnetic minerals of these subtropical soils. The sand fraction of the B t22 horizon (105-155 cm depth) of a clayey red Ultisol from the subtropical forest of Misiones, Argentina, was studied by X-ray diffraction, saturation magnetization σ s , optical microscopy and Moessbauer spectroscopy. Saturation magnetization for the whole sand fraction (wsf), the non-magnetic sand fraction (nmsf) and the magnetic sand fraction (msf) are 10.79, 1.50 and 16.92 JT -1 kg -1 , respectively. Mainly quartz, ilmenite, Al-substituted hematite, goethite, maghemite and magnetite are found. Magnetite-maghemite contents are high, and magnetite is predominant in the msf. Results are compared with those from the upper B 1 horizon (10-35 cm depth) of the same soil in which a lower σ s(wsf) value, and higher values of σ s(msf) and of (σ s(msf) -σ s(wsf) ) were measured. These results confirm the stability of magnetite in this soil contrasting with other results on soils from neighbouring areas

Combined effects of traveling seismic waves and soil nonlinearity on nuclear power plant response

International Nuclear Information System (INIS)

Lee, T.H.; Charman, C.M.

1981-01-01

The effects of ground motion nonuniformity on the seismic input have been actively studied in recent years by considering the passage of traveling seismic waves. These studies gave rise to a new class of soil-structure interaction problems in which the seismic input is modified as a result of the spatial variations of ground motion. The phenomena were usually studied by using the elastic half-space simulation or discrete spring-models for modeling the soil medium. Finite element methods were also used recently on a limited scope. Results obtained from these investigations are often manifested by an attenuation of translational excitation along with an addition of rotational ground motion input. The decrease in structural response resulting from the input loss in the translational component was often insignificant since the response reduction tends to be offset by the effects from rotational input. The traveling wave effects have, so far, been investigated within the framework of linear theory with soil nonlinearity ignored. Conversely, the incorporation of soil nonlinearity in soil-structure interaction analyses has been done without including wave effect. Seismic analyses considering the hysteretic behavior of soil have been performed using highly idealized models for steady-state solution. More elaborate nonlinear seismic models deal with only the strain-dependent soil modulus rather than the transient unloading-reloading type of hysteretic characteristics of soil under a time-function input of earthquake trace. Apparently, the traveling wave effect and soil nonlinearity have been separately treated in the past. The purpose of this paper is to demonstrate that these two major effects can be combined in one model such that the influence of wave passage is reflected through the hysteretic behavior of soil particles, and thereby achieving significant reduction in seismic loads. (orig./RW)

Combination of biochar amendment and phytoremediation for hydrocarbon removal in petroleum-contaminated soil.

Science.gov (United States)

Han, Tao; Zhao, Zhipeng; Bartlam, Mark; Wang, Yingying

2016-11-01

Remediation of soils contaminated with petroleum is a challenging task. Four different bioremediation strategies, including natural attenuation, biochar amendment, phytoremediation with ryegrass, and a combination of biochar and ryegrass, were investigated with greenhouse pot experiments over a 90-day period. The results showed that planting ryegrass in soil can significantly improve the removal rate of total petroleum hydrocarbons (TPHs) and the number of microorganisms. Within TPHs, the removal rate of total n-alkanes (45.83 %) was higher than that of polycyclic aromatic hydrocarbons (30.34 %). The amendment of biochar did not result in significant improvement of TPH removal. In contrast, it showed a clear negative impact on the growth of ryegrass and the removal of TPHs by ryegrass. The removal rate of TPHs was significantly lower after the amendment of biochar. The results indicated that planting ryegrass is an effective remediation strategy, while the amendment of biochar may not be suitable for the phytoremediation of soil contaminated with petroleum hydrocarbons.

Combining hyperspectral imagery and legacy measured soil profiles to map subsurface soil properties in a Mediterranean area (Cap-Bon, Tunisia)

Science.gov (United States)

Lagacherie, Philippe; Sneep, Anne-Ruth; Gomez, Cécile

2013-04-01

Previous studies have demonstrated that Visible Near InfraRed (Vis-NIR) Hyperspectral imagery is a cost-efficient way for mapping soil properties at fine resolutions (~5m) over large areas. However, such mapping is only feasible for soil surface since the effective penetration depths of optical sensors do not exceed several millimetres. This study aimed to extend the use of Vis-NIR hyperspectral imagery to the mapping of subsurface properties at three intervals of depth (15-30 cm, 30-60 cm and 60-100 cm) as specified by the GlobalSoilMap project. To avoid additional data collection, our basic idea was to develop an original Digital Soil Mapping approach that combines the digital maps of surface soil properties obtained from Vis-NIR hyperspectral imagery with legacy soil profiles of the region and with easily available images of DEM-derived parameters. The study was conducted in a pedologically-contrasted 300km² cultivated area located in the Cap Bon region (Northern Tunisia). AISA-Dual Vis-NIR hyperspectral airborne data were acquired over the studied area with a fine spatial resolution (5 m) and fine spectral resolution (260 spectral bands from 450 to 2500nm). Vegetated surfaces were masked to conserve only bare soil surface which represented around 50% of the study area. Three soil surface properties (clay and sand contents, Cation Exchange Capacity) were successfully mapped over the bare soils, from these data using Partial Least Square Regression models (R2 > 0.7). We used as additional data a set of images of landscape covariates derived from a 30 meter DEM and a local database of 152 legacy soil profiles from which soil properties values at the required intervals of depths were computed using an equal-area-spline algorithm. Our Digital Soil Mapping approach followed two steps: i) the development of surface-subsurface functions - linear models and random forests - that estimates subsurface property values from surface ones and landscape covariates and that

Combined Effects of Nutrient and Pesticide Management on Soil Microbial Activity in Hybrid Rice Double Annual Cropping System

Institute of Scientific and Technical Information of China (English)

XIEXiao-mei; LIAOMin; LIUWei-ping; SusanneKLOSE

2004-01-01

Combined effects on soil microbial activity of nutrient and pesticide management in hybrid rice double annual cropping system were studied. Results of field experiment demonstrated significant changes in soil microbial biomass phospholipid contents,abundance of heterotrophic bacteria and proteolytic bacteria, electron transport system (ETS)/dehydrogenase activity, soil protein contents under different management practices and at various growth stages. Marked depletions in the soil microbial biomass phospholipid contents were found with the advancement of crop growth stages, while the incorporation of fertilizers and/or pesticides also induced slight changes, and the lowest microbial biomass phospholipid content was found with pesticides application alone. A decline in the bacterial abundance of heterotrophic bacteria and proteolytic bacteria was observed during the continuance of crop growth, while the lowest abundance of heterotrophic bacteria and proteolyrJc bacteria was found with pesticides application alone, which coincided with the decline of soil microbial biomass. A consistent increase in the electron transport svstem activit), was measured during the different crop growth stages of rice. The use of fertilizers (NPK) alone or combined with pesticides increased it, while a decline was noticed with pesticides application alone as compared with the control.The soil protein content was found to be relatively stable with fertilizers and/or pesticides application at various growth stages in both crops undertaken, but notable changes were detected at different growrh stages

Combined Effects of Nutrient and Pesticide Management on Soil Microbial Activity in Hybrid Rice Double Annual Cropping System

Institute of Scientific and Technical Information of China (English)

XIE Xiao-mei; LIAO Min; LIU Wei-ping; Susanne KLOSE

2004-01-01

Combined effects on soil microbial activity of nutrient and pesticide management in hybrid rice double annual cropping system were studied. Results of field experiment demonstrated significant changes in soil microbial biomass phospholipid contents,abundance of heterotrophic bacteria and proteolytic bacteria, electron transport system (ETS)/dehydrogenase activity, soil protein contents under different management practices and at various growth stages. Marked depletions in the soil microbial biomass phospholipid contents were found with the advancement of crop growth stages, while the incorporation of fertilizers and/or pesticides also induced slight changes, and the lowest microbial biomass phospholipid content was found with pesticides application alone. A decline in the bacterial abundance of heterotrophic bacteria and proteolytic bacteria was observed during the continuance of crop growth, while the lowest abundance of heterotrophic bacteria and proteolytic bacteria was found with pesticides application alone, which coincided with the decline of soil microbial biomass. A consistent increase in the electron transport system activity was measured during the different crop growth stages of rice. The use of fertilizers (NPK) alone or combined with pesticides increased it, while a decline was noticed with pesticides application alone as compared with the control.The soil protein content was found to be relatively stable with fertilizers and/or pesticides application at various growth stages in both crops undertaken, but notable changes were detected at different growth stages.

Combining emission inventory and isotope ratio analyses for quantitative source apportionment of heavy metals in agricultural soil.

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Chen, Lian; Zhou, Shenglu; Wu, Shaohua; Wang, Chunhui; Li, Baojie; Li, Yan; Wang, Junxiao

2018-08-01

Two quantitative methods (emission inventory and isotope ratio analysis) were combined to apportion source contributions of heavy metals entering agricultural soils in the Lihe River watershed (Taihu region, east China). Source apportionment based on the emission inventory method indicated that for Cd, Cr, Cu, Pb, and Zn, the mean percentage input from atmospheric deposition was highest (62-85%), followed by irrigation (12-27%) and fertilization (1-14%). Thus, the heavy metals were derived mainly from industrial activities and traffic emissions. For Ni the combined percentage input from irrigation and fertilization was approximately 20% higher than that from atmospheric deposition, indicating that Ni was mainly derived from agricultural activities. Based on isotope ratio analysis, atmospheric deposition accounted for 57-93% of Pb entering soil, with the mean value of 69.3%, which indicates that this was the major source of Pb entering soil in the study area. The mean contributions of irrigation and fertilization to Pb pollution of soil ranged from 0% to 10%, indicating that they played only a marginally important role. Overall, the results obtained using the two methods were similar. This study provides a reliable approach for source apportionment of heavy metals entering agricultural soils in the study area, and clearly have potential application for future studies in other regions. Copyright © 2018 Elsevier Ltd. All rights reserved.

A combined approach of physicochemical and biological methods for the characterization of petroleum hydrocarbon-contaminated soil.

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Masakorala, Kanaji; Yao, Jun; Chandankere, Radhika; Liu, Haijun; Liu, Wenjuan; Cai, Minmin; Choi, Martin M F

2014-01-01

Main physicochemical and microbiological parameters of collected petroleum-contaminated soils with different degrees of contamination from DaGang oil field (southeast of Tianjin, northeast China) were comparatively analyzed in order to assess the influence of petroleum contaminants on the physicochemical and microbiological properties of soil. An integration of microcalorimetric technique with urease enzyme analysis was used with the aim to assess a general status of soil metabolism and the potential availability of nitrogen nutrient in soils stressed by petroleum-derived contaminants. The total petroleum hydrocarbon (TPH) content of contaminated soils varied from 752.3 to 29,114 mg kg(−1). Although the studied physicochemical and biological parameters showed variations dependent on TPH content, the correlation matrix showed also highly significant correlation coefficients among parameters, suggesting their utility in describing a complex matrix such as soil even in the presence of a high level of contaminants. The microcalorimetric measures gave evidence of microbial adaptation under highest TPH concentration; this would help in assessing the potential of a polluted soil to promote self-degradation of oil-derived hydrocarbon under natural or assisted remediation. The results highlighted the importance of the application of combined approach in the study of those parameters driving the soil amelioration and bioremediation.

Quality evaluation of soil-cement-plant residue bricks by the combination of destructive and non-destructive tests

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Regis de C. Ferreira

Full Text Available ABSTRACT Residues from agricultural activity can be used to improve the quality of soil-based bricks, constituting an interesting alternative for their destination. The technical quality of soil-cement-plant residue bricks was evaluated by the combination of non-destructive and destructive methods. A predominant clayey soil, Portland cement and residues of husks of both rice and Brachiaria brizantha cv. Marandu (0, 10, 20, 30 and 40%, in mass, in substitution to the 10% cement content were used. The bricks were submitted to destructive (water absorption and compressive strength and nondestructive (ultrasound tests for their physical and mechanical characterization. Results from both destructive and non-destructive tests were combined to determine the quantitative parameter named “anisotropic resistance” in order to evaluate the quality of the bricks. The addition that promoted best technical quality was 10% residue content, regardless of the residue type. The anisotropic resistance proved to be adequate for the technical quality evaluation of the bricks.

Investigations into the application of a combination of bioventing and biotrickling filter technologies for soil decontamination processes--a transition regime between bioventing and soil vapour extraction.

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Magalhães, S M C; Ferreira Jorge, R M; Castro, P M L

2009-10-30

Bioventing has emerged as one of the most cost-effective in situ technologies available to address petroleum light-hydrocarbon spills, one of the most common sources of soil pollution. However, the major drawback associated with this technology is the extended treatment time often required. The present study aimed to illustrate how an intended air-injection bioventing technology can be transformed into a soil vapour extraction effort when the air flow rates are pushed to a stripping mode, thus leading to the treatment of the off-gas resulting from volatilisation. As such, a combination of an air-injection bioventing system and a biotrickling filter was applied for the treatment of contaminated soil, the latter aiming at the treatment of the emissions resulting from the bioventing process. With a moisture content of 10%, soil contaminated with toluene at two different concentrations, namely 2 and 14 mg g soil(-1), were treated successfully using an air-injection bioventing system at a constant air flow rate of ca. 0.13 dm(3) min(-1), which led to the removal of ca. 99% toluene, after a period of ca. 5 days of treatment. A biotrickling filter was simultaneously used to treat the outlet gas emissions, which presented average removal efficiencies of ca. 86%. The proposed combination of biotechnologies proved to be an efficient solution for the decontamination process, when an excessive air flow rate was applied, reducing both the soil contamination and the outlet gas emissions, whilst being able to reduce the treatment time required by bioventing only.

Limiting nitrogen and veterinary pharmaceutical input into groundwater: combining hydrogeophysics and soil science

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Noell, Ursula; Stadler, Susanne

2017-04-01

The EU Interreg project TOPSOIL investigates opportunities to improve surface and groundwater quality as well as water management strategies under the consideration of climate adaptation challenges. Within the framework of the project, we investigate the transport behavior of percolation water in the unsaturated zone, the migration of nitrogen and veterinary pharmaceuticals in soils, and - together with different stakeholders (e.g. farmers, water supply companies) - develop common strategies to minimize the migration of these substances into the groundwater. In our study we focus on distinguishing preferential and diffuse flow using soil scientific and geophysical methods. During the first investigation campaign, we combined soil sampling with radiometry and electrical conductivity overview measurements on the typical sandy soil of the studied area south of Oldenburg, Germany. We used the CMD explorer for the electromagnetic mapping (horizontal and vertical dipoles, intercoil spacing of 1.48/2.82/4.49 m, investigations depths of appr. 0 - 6 m) and the radiometry detector comprised five sodium-iodide crystals each with a volume of 4 litres. The spectral data are evaluated for potassium (1.37 - 1.57 MeV), uranium (Bi-214) (1.66 - 1.86MeV) and thorium (T-208) (2.41 - 2.81MeV) and total counts (0.41-2.81MeV). A total of 292 soil samples were taken from 46 ram coring profiles (depth range: 0 to 3 m) and analyzed for soil chemical parameters and water content. The first evaluation showed a good correlation between conductivity and radiometry measurements. While the uranium and thorium values are generally low, the potassium values possibly reflect higher clay contents as do the higher conductivity values. The geophysical overview measurements were used to select the locations for soil sampling and we specifically targeted presumably clay-rich as well as clay-poor areas for sampling.

Effect of soil washing with only chelators or combining with ferric chloride on soil heavy metal removal and phytoavailability: Field experiments.

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Guo, Xiaofang; Wei, Zebin; Wu, Qitang; Li, Chunping; Qian, Tianwei; Zheng, Wei

2016-03-01

In a field experiment on multi-metal contaminated soil, we investigated the efficiency of Cd, Pb, Zn, and Cu removal by only mixture of chelators (MC) or combining with FeCl3. After washing treatment, a co-cropping system was performed for heavy metals to be extracted by Sedum alfredii and to produce safe food from Zea mays. We analyzed the concentration of heavy metals in groundwater to evaluate the leashing risk of soil washing with FeCl3 and MC. Results showed that addition of FeCl3 was favorable to the removal of heavy metals in the topsoil. Metal leaching occurred mainly in rain season during the first co-cropping. The removal rates of Cd, Zn, Pb, and Cu in topsoil were 28%, 53%, 41%, and 21% with washing by FeCl3+MC after first harvest. The application of FeCl3 reduced the yield of S. alfredii and increased the metals concentration of Z. mays in first harvest. However, after amending soil, the metals concentration of Z. mays in FeCl3+MC treatment were similar to that only washing by MC. The grains and shoots of Z. mays were safe for use in feed production. Soil washing did not worsen groundwater contamination during the study period. But the concentration of Cd in groundwater was higher than the limit value of Standard concentrations for Groundwater IV. This study suggests that soil washing using FeCl3 and MC for the remediation of multi-metal contaminated soil is potential feasibility. However, the subsequent measure to improve the washed soil environment for planting crop is considered. Copyright © 2016. Published by Elsevier Ltd.

An Approach to Flooding Inundation Combining the Streamflow Prediction Tool (SPT) and Downscaled Soil Moisture

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Cotterman, K. A.; Follum, M. L.; Pradhan, N. R.; Niemann, J. D.

2017-12-01

Flooding impacts numerous aspects of society, from localized flash floods to continental-scale flood events. Many numerical flood models focus solely on riverine flooding, with some capable of capturing both localized and continental-scale flood events. However, these models neglect flooding away from channels that are related to excessive ponding, typically found in areas with flat terrain and poorly draining soils. In order to obtain a holistic view of flooding, we combine flood results from the Streamflow Prediction Tool (SPT), a riverine flood model, with soil moisture downscaling techniques to determine if a better representation of flooding is obtained. This allows for a more holistic understanding of potential flood prone areas, increasing the opportunity for more accurate warnings and evacuations during flooding conditions. Thirty-five years of near-global historical streamflow is reconstructed with continental-scale flow routing of runoff from global land surface models. Elevation data was also obtained worldwide, to establish a relationship between topographic attributes and soil moisture patterns. Derived soil moisture data is validated against observed soil moisture, increasing confidence in the ability to accurately capture soil moisture patterns. Potential flooding situations can be examined worldwide, with this study focusing on the United States, Central America, and the Philippines.

Enhancing the fertility of an acid sulfate soil for rice cultivation using lime in combination with bio-organic fertilizer

International Nuclear Information System (INIS)

Farhana, A.; Shamshuddin, J.; Fauziah, C.I.; Panhwar, Q.A.

2017-01-01

The acid sulfate soils contain pyrite (FeS/sub 2/) which is due to oxidation results in the production of high amount of acidity, aluminum and iron significantly affecting rice growth. A glasshouse study was arranged to determine the effect of ground magnesium limestone (GML) in combination with bio-organic fertilizer (JITUTM) application on the chemical properties of soils and rice yield. Three rice seedlings were transplanted in pots which were previously amended with 0, 2, 4, 6 and 8 t/ha GML with or without bio-organic fertilizer. The common rice varieties (MR 219 and MR 253) were cultivated for two seasons in the same pots. The critical Fe2+ and Al3+ activities for MR 219 were 14.45 and 4.23 mu M, while for MR 253 were 7.45 and 5.53 mu M, respectively. However, without applying the amendments, rice grown on the soils was affected severely by the high acidity (Fe2+ and Al3+ toxicity). The soil pH increased to 5 and the higher grain yield of MR 219 (99.77 and 121.38 g/pot) and MR253 (98.63 and 112.60 g/pot) was in first and second season with the application of 2 t GML application combined with 0.25 t JITUTM/ha respectively. In addition, 1000 grain weight, number of panicle, number of spikelets panicle-1 and the percentage of filled spikelet, were also higher than without the soil amendments. Hence, the infertility of acid sulfate soils for sustainable rice cultivation in Malaysia can be improved by applying 2 t GML/ha combined with 0.25 t JITUTM/ha for two seasons in long run. (author)

Potential use of lime combined with additives on (im)mobilization and phytoavailability of heavy metals from Pb/Zn smelter contaminated soils.

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Hussain Lahori, Altaf; Zhang, Zengqiang; Guo, Zhanyu; Mahar, Amanullah; Li, Ronghua; Kumar Awasthi, Mukesh; Ali Sial, Tanveer; Kumbhar, Farhana; Wang, Ping; Shen, Feng; Zhao, Junchao; Huang, Hui

2017-11-01

This explorative study was aimed to assess the efficiency of lime alone and in combined with additives to immobilize Pb, Cd, Cu and Zn in soil and reduce their phytoavailability for plant. A greenhouse pot experiment was performed by using low and heavily contaminated top soils viz. Tongguan contaminated (TG-C); Fengxian heavily contaminated (FX-HC) and Fengxian low contaminated (FX-LC). The contaminated soils were treated with lime (L) alone and in combined with Ca-bentonite (CB), Tobacco biochar (TB) and Zeolite (Z) at 1% and cultivated by Chinese cabbage (Brassica campestris L). Results revealed that all amendments (plime alone and in combined with additives were drastically decreased the dry biomass yield of Brassica campestris L. as compared with control. Thus, these feasible amendments potentially maximum reduced the uptake by plant shoots upto Pb 53.47 and Zn 67.93% with L+Z and L+TB in FX-LC soil, while Cd 68.58 and Cu 60.29% with L+TB, L+CB in TG-C soil but Cu uptake in plant shoot was observed 27.26% and 30.17% amended with L+TB and L+Z in FX-HC and FX-LC soils. On the other hand, these amendments were effectively reduced the potentially toxic metals (PTMs) in roots upto Pb77.77% L alone in FX-HC, Cd 96.76% with L+TB in TG-C, while, Cu 66.70 and Zn 60.18% with L+Z in FX-LC. Meanwhile, all amendments were responsible for increasing soil pH and CEC but decreased soils EC level. Based on this result, these feasible soil amendments were recommended for long term-study under field condition to see the response of another hyper accumulator crop. Copyright © 2017. Published by Elsevier Inc.

Effect of Nitrogen Fertilizer on Combined Forms and Transformation of Fluorine in Tea Garden Soil

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ZHANG Yong-li

2015-10-01

Full Text Available In order to investigate the effect of nitrogen fertilizer on combined forms and transformation of fluorine in tea garden soil, soil pot experiment was carried out. The research object was red-yellow soil in Shizipu tea plantation in the south of Anhui Province. Five treatments were N0P0K0 (CK, N0P1K1 (N0, N1P1K1 (N1, N2P1K1 (N2, N3P1K1 (N3. Water-soluble fluorine content, exchangeable fluorine content, Fe/Mn oxide-bound fluorine content, organic matter-bound fluorine content, ammonium nitrogen content and soil pH value in 0~15 cm soil layer were analyzed in 10, 20, 30, 50, 70, 90 days after fertilization. The results showed that compared with CK, in the short term (10 or 20 days after applying NPK, the content of water-soluble fluorine in 0~15 cm soil layer was decreased and the content of exchangeable fluorine, Fe/Mn oxide-bound fluorine and organic matter-bound fluorine were increased. After 20 days, the content of soil water-soluble fluorine was increased and the content of soil exchangeable fluorine, Fe/Mn oxide-bound fluorine and organic matter-bound fluorine were reduced. The effect on water-soluble fluorine and exchangeable fluorine increased with time and the application rate of nitrogen. The content of water-soluble fluorine in tea garden soil had a moderately positive correlation with the application rate of nitrogen while the content of exchangeable fluorine had a moderately or highly negative correlation with the application rate of nitrogen. The content of water-soluble fluorine had a quite highly negative correlation with the soil pH (P<0.01, but the content of exchangeable fluorine had a moderately or highly negative correlation with the soil pH (P<0.01. Therefore, nitrogen fertilizer changed the soil pH during its form transformation and thus affected the transformation and the availability of fluorine in soil.

Combining position-specific 13C labeling with compound-specific isotope analysis: first steps towards soil fluxomics

Science.gov (United States)

Dippold, Michaela; Kuzyakov, Yakov

2015-04-01

Understanding the soil organic matter (SOM) dynamics is one of the most important challenges in soil science. Transformation of low molecular weight organic substances (LMWOS) is a key step in biogeochemical cycles because 1) all high molecular substances pass this stage during their decomposition and 2) only LMWOS will be taken up by microorganisms. Previous studies on LMWOS were focused on determining net fluxes through the LMWOS pool, but they rarely identified transformations. As LMWOS are the preferred C and energy source for microorganisms, the transformations of LMWOS are dominated by biochemical pathways of the soil microorganisms. Thus, understanding fluxes and transformations in soils requires a detailed knowledge on the biochemical pathways and its controlling factors. Tracing C fate in soil by isotopes became on of the most applied and promising biogeochemistry tools. Up to now, studies on LMWOS were nearly exclusively based on uniformly labeled organic substances i.e. all C atoms in the molecules were labeled with 13C or 14C. However, this classical approach did not allow the differentiation between use of intact initial substances in any process, or whether they were transformed to metabolites. The novel tool of position-specific labeling enables to trace molecule atoms separately and thus to determine the cleavage of molecules - a prerequisite for metabolic tracing. Position-specific labeling of LMWOS and quantification of 13CO2 and 13C in bulk soil enabled following the basic metabolic pathways of soil microorganisms. However, only the combination of position-specific 13C labeling with compound-specific isotope analysis of microbial biomarkers and metabolites allowed 1) tracing specific anabolic pathways in diverse microbial communities in soils and 2) identification of specific pathways of individual functional microbial groups. So, these are the prerequisites for soil fluxomics. Our studies combining position-specific labeled glucose with amino

Effect of combined N applied at low level on the nitrogen fixation by grasses and contribution to nitrogen fertility in soil

International Nuclear Information System (INIS)

Yao Yunyin; Chen Ming; Ma Changlin

1990-01-01

This paper reports the study on the effect of combined N applied at low level on teh nitrogen fixation by alfalfa in monoculture and mixed culture with meadow fescue, and the effect on the absorption and utilization of indigenous soil nitrogen and nitrogen fertilizer. Amount of nitrogen fixed by alfalfa could be raised and duration of high peak of symbiotic nitrogen fixation activity could be extended when nitrogen fertilizer was applied reasonably. It was especially important for the early pastures or pastures with low supporting nitrogen capacity. Transfer of nitrogen fixed by alfalfa to meadow fescue occured in mixed culture. Nitrogen fixed from alfalfa was uptaken more easily than indigenous nitrogen in soil. Planting alfalfa could raise soil fertility significantly. Meadow fescue may be able to fix nitrogen from the air in some way. When combined N was appropriately applied to soil, on which alfalfa and meadow fescue had been planted, it could promote increasing nitrogen fertility in soil

Albendazole versus combined pyrantel pamoate-mebendazole in the treatment of mixed infection of soil-transmitted helminthiasis

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Tiangsa Sembiring

2006-12-01

Full Text Available Background Soil transmitted helminthiasis is still highly prevalent in Indonesia, especially in rural area and among poor socio-economic population. Helminthiasis is frequently found as a single or mixed infection. It is difficult to get a medication with better efficacy, low cost, and simple administration for all types of worms. Objective The aim of this sudy was to compare the effectiveness of albendazole and pyrantel pamoate-mebendazole combination in treating soil-transmitted helminthiasis. Methods A randomized clinical trial was perionned in September until November 1995 on students of a primary school in Tanjung Anom Village whose stool examinations showed mixed infection of helminthiasis. Subjects were randomly allocated into two groups. The A group was treated with 400 mg oral albendazole as a single dose, while the B group was treated with the combination of pyrantel pamoate 10 mg/kg body weight as a single dose and mebendazole 100 mg twice a day for three consecutive days. Cure was considered if in the stool examination, no wonn eggs were found. Statistical analysis was periormed by Chi-square test with confidence interval of 95% and p value of < 0.05 was considered significant. Results Out of 541 children, mixed infection of soil-transmitted helminthiasis was found in 374 children (69%. Three hundreds sixty-six children completed the study, consisted of 182 children in group A and 184 in group B. At 3 weeks after treatment, the cure rate in the A group was significantly better compared to that in B group. Conclusions Albendazole was more effective than the combination of pyrantel pamoate - mebendazole for treating mixed infection of soil-transmitted helminthiasis. Besides the administration was simpler and caused minimal side effect.

Combining phytoextraction and biochar addition improves soil biochemical properties in a soil contaminated with Cd.

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Lu, Huanping; Li, Zhian; Fu, Shenglei; Méndez, Ana; Gascó, Gabriel; Paz-Ferreiro, Jorge

2015-01-01

The main goal of phytoremediation is to improve ecosystem functioning. Soil biochemical properties are considered as effective indicators of soil quality and are sensitive to various environmental stresses, including heavy metal contamination. The biochemical response in a soil contaminated with cadmium was tested after several treatments aimed to reduce heavy metal availability including liming, biochar addition and phytoextraction using Amaranthus tricolor L. Two biochars were added to the soil: eucalyptus pyrolysed at 600 °C (EB) and poultry litter at 400 °C (PLB). Two liming treatments were chosen with the aim of bringing soil pH to the same values as in the treatments EB and PLB. The properties studied included soil microbial biomass C, soil respiration and the activities of invertase, β-glucosidase, β-glucosaminidase, urease and phosphomonoesterase. Both phytoremediation and biochar addition improved soil biochemical properties, although results were enzyme specific. For biochar addition these changes were partly, but not exclusively, mediated by alterations in soil pH. A careful choice of biochar must be undertaken to optimize the remediation process from the point of view of metal phytoextraction and soil biological activity. Copyright © 2014 Elsevier Ltd. All rights reserved.

The combined effect of decabromodiphenyl ether (BDE-209) and copper (Cu) on soil enzyme activities and microbial community structure.

Science.gov (United States)

Zhang, Wei; Zhang, Meng; An, Shuai; Lin, Kuangfei; Li, Hui; Cui, Changzheng; Fu, Rongbing; Zhu, Jiang

2012-09-01

Waste electrical and electronic equipment (e-waste) is now the fastest growing waste stream in the world. It is reported that polybrominated diphenyl ethers (PBDEs) and heavy metals were main contaminants in e-waste recycling site. Among these contaminants BDE-209 and Cu were widespread, yet their combined effect on soil enzyme activities and microbial community structure are not well understood. In this study, the ecotoxicological effects of both combined and single pollution of BDE-209 and Cu at different concentration levels were studied under laboratory conditions. The activities of soil catalase, urease and saccharase were sensitive to BDE-209 and Cu pollution. Although the enzyme activities varied over time, the concentration effects were obvious. Statistical analyses revealed that, at the same incubation time, as the concentration of BDE-209 or Cu increased, the enzyme activities were decreased. Combined effects of both BDE-209 and Cu were different from that of BDE-209 or Cu alone. Enzyme activities data were essentially based on the multiple regression technique. The results showed that the action and interaction between BDE-209 and Cu were strongly dependent on the exposure time, as the combined effects of BDE-209 and Cu were either synergistic or antagonistic at different incubation times. Soil catalase and saccharase were more comfortable used as indicators of BDE-209 and Cu combined pollution, as the variation trends were similar to the single contaminant treatments, and the responses were quick and significant. Denaturing Gradient Gel Electrophoresis (DGGE) analysis of bacterial 16S rDNA gene showed that BDE-209 and Cu pollution altered the bacterial community structure by promoting changes in species composition and species richness. The existence of BDE-209 and Cu in soils reduced the microbial diversity, and the concentration effects were obvious. Overall, microbial diversity in the combined treatments were lower than the single ones, and when the

Multipurpose units: combining of technological operations of a soil cultivating and seeding

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D. A. Petukhov

2015-01-01

Full Text Available The modern domestic market of technique for grain crops seeding differs variety of machines brands and types. The intensive type technologies combining technological operations of a soil cultivating and grain crops seeding in one pass are more widely used. The authors have established that one-operational units in new machine park have to be replaced multipurpose, universal and combined machines. Such approach will reduce number of machines in grain production from 20-30 to 5-6 name titles. Possibilities of multipurpose sowing units for simultaneous fertilizers application, soil cultivating and weeds destruction were analyzed. It was specified that nowadays there are several technologies types with two, four or six operations overlapping. Operational performance, technological and economical efficiency of the best multipurpose and also efficiency of technological operations overlapping at grain crops cultivating in the conditions of their real operation and at a trial establishment in the Kuban research institute of information and technical and economic studies of agro-industrial complex engineering and technical services were studied. Tit was defined that use of multipurpose sowing units and also studied efficiency of decreases operational costs by 48-71 percent, fuel consumption - by 41-76 percent and reduces labor input by 72-80 percent. Thus grain crops seeding is possible in optimal agrotime because of 4-6 technological operations overlapping in one pass.

Combining 137Cs and topographic surveys for measuring soil erosion/deposition patterns in a rapidly accreting area

International Nuclear Information System (INIS)

Ritchie, J.C.

2000-01-01

Narrow, stiff grass hedges are biological barriers designed to slow runoff and capture soils carried in runoff water. This study was designed to measure quantitatively the deposition of soil up slope of a narrow, stiff grass hedge using topographic and 137 Cs surveys. Topographic surveys made in 1991, 1995, and 1998 measured 1 to 2 cm yr -1 of recent sediment deposited up slope of the grass hedge. 137 Cs analyses of soil samples were used to determine the medium-term (45 years) soil redistribution patterns. Erosion rates and patterns determined using 137 Cs measured medium-term erosion near the hedge do not reflect the recent deposition patterns near the grass hedge measured by topographic surveys. Using the combination of topographic and 137 Cs surveys allows a better understanding of the role of grass hedges as barriers for capturing eroding soils and suggest that the recent deposition is associated with the grass hedge but that there is still a net loss of soil near the hedge position over the past 45 years. (author)

Preparation of calibration materials for microanalysis of Ti minerals by direct fusion of synthetic and natural materials: experience with LA-ICP-MS analysis of some important minor and trace elements in ilmenite and rutile.

Science.gov (United States)

Odegård, M; Mansfeld, J; Dundas, S H

2001-08-01

Calibration materials for microanalysis of Ti minerals have been prepared by direct fusion of synthetic and natural materials by resistance heating in high-purity graphite electrodes. Synthetic materials were FeTiO3 and TiO2 reagents doped with minor and trace elements; CRMs for ilmenite, rutile, and a Ti-rich magnetite were used as natural materials. Problems occurred during fusion of Fe2O3-rich materials, because at atmospheric pressure Fe2O3 decomposes into Fe3O4 and O2 at 1462 degrees C. An alternative fusion technique under pressure was tested, but the resulting materials were characterized by extensive segregation and development of separate phases. Fe2O3-rich materials were therefore fused below this temperature, resulting in a form of sintering, without conversion of the materials into amorphous glasses. The fused materials were studied by optical microscopy and EPMA, and tested as calibration materials by inductively coupled plasma mass spectrometry, equipped with laser ablation for sample introduction (LA-ICP-MS). It was demonstrated that calibration curves based on materials of rutile composition, within normal analytical uncertainty, generally coincide with calibration curves based on materials of ilmenite composition. It is, therefore, concluded that LA-ICP-MS analysis of Ti minerals can with advantage be based exclusively on calibration materials prepared for rutile, thereby avoiding the special fusion problems related to oxide mixtures of ilmenite composition. It is documented that sintered materials were in good overall agreement with homogeneous glass materials, an observation that indicates that in other situations also sintered mineral concentrates might be a useful alternative for instrument calibration, e.g. as alternative to pressed powders.

[Effects of straw returning combined with medium and microelements application on soil organic carbon sequestration in cropland.

Science.gov (United States)

Jiang, Zhen Hui; Shi, Jiang Lan; Jia, Zhou; Ding, Ting Ting; Tian, Xiao Hong

2016-04-22

A 52-day incubation experiment was conducted to investigate the effects of maize straw decomposition with combined medium element (S) and microelements (Fe and Zn) application on arable soil organic carbon sequestration. During the straw decomposition, the soil microbial biomass carbon (MBC) content and CO 2 -C mineralization rate increased with the addition of S, Fe and Zn, respectively. Also, the cumulative CO 2 -C efflux after 52-day laboratory incubation significantly increased in the treatments with S, or Fe, or Zn addition, while there was no significant reduction of soil organic carbon content in the treatments. In addition, Fe or Zn application increased the inert C pools and their proportion, and apparent balance of soil organic carbon, indicating a promoting effect of Fe or Zn addition on soil organic carbon sequestration. In contrast, S addition decreased the proportion of inert C pools and apparent balance of soil organic carbon, indicating an adverse effect of S addition on soil organic carbon sequestration. The results suggested that when nitrogen and phosphorus fertilizers were applied, inclusion of S, or Fe, or Zn in straw incorporation could promote soil organic carbon mineralization process, while organic carbon sequestration was favored by Fe or Zn addition, but not by S addition.

Remediation of PAH-contaminated soil by the combination of tall fescue, arbuscular mycorrhizal fungus and epigeic earthworms.

Science.gov (United States)

Lu, Yan-Fei; Lu, Mang

2015-03-21

A 120-day experiment was performed to investigate the effect of a multi-component bioremediation system consisting of tall fescue (Festuca arundinacea), arbuscular mycorrhizal fungus (AMF) (Glomus caledoniun L.), and epigeic earthworms (Eisenia foetida) for cleaning up polycyclic aromatic hydrocarbons (PAHs)-contaminated soil. Inoculation with AMF and/or earthworms increased plant yield and PAH accumulation in plants. However, PAH uptake by tall fescue accounted for a negligible portion of soil PAH removal. Mycorrhizal tall fescue significantly enhanced PAH dissipation, PAH degrader density and polyphenol oxidase activity in soil. The highest PAH dissipation (93.4%) was observed in the combination treatment: i.e., AMF+earthworms+tall fescue, in which the soil PAH concentration decreased from an initial value of 620 to 41 mg kg(-1) in 120 days. This concentration is below the threshold level required for Chinese soil PAH quality (45 mg kg(-1) dry weight) for residential use. Copyright © 2014 Elsevier B.V. All rights reserved.

Carbon dioxide emissions from semi-arid soils amended with biochar alone or combined with mineral and organic fertilizers.

Science.gov (United States)

Fernández, José M; Nieto, M Aurora; López-de-Sá, Esther G; Gascó, Gabriel; Méndez, Ana; Plaza, César

2014-06-01

Semi-arid soils cover a significant area of Earth's land surface and typically contain large amounts of inorganic C. Determining the effects of biochar additions on CO2 emissions from semi-arid soils is therefore essential for evaluating the potential of biochar as a climate change mitigation strategy. Here, we measured the CO2 that evolved from semi-arid calcareous soils amended with biochar at rates of 0 and 20tha(-1) in a full factorial combination with three different fertilizers (mineral fertilizer, municipal solid waste compost, and sewage sludge) applied at four rates (equivalent to 0, 75, 150, and 225kg potentially available Nha(-1)) during 182 days of aerobic incubation. A double exponential model, which describes cumulative CO2 emissions from two active soil C compartments with different turnover rates (one relatively stable and the other more labile), was found to fit very well all the experimental datasets. In general, the organic fertilizers increased the size and decomposition rate of the stable and labile soil C pools. In contrast, biochar addition had no effects on any of the double exponential model parameters and did not interact with the effects ascribed to the type and rate of fertilizer. After 182 days of incubation, soil organic and microbial biomass C contents tended to increase with increasing the application rates of organic fertilizer, especially of compost, whereas increasing the rate of mineral fertilizer tended to suppress microbial biomass. Biochar was found to increase both organic and inorganic C contents in soil and not to interact with the effects of type and rate of fertilizer on C fractions. As a whole, our results suggest that the use of biochar as enhancer of semi-arid soils, either alone or combined with mineral and organic fertilizers, is unlikely to increase abiotic and biotic soil CO2 emissions. Copyright © 2014 Elsevier B.V. All rights reserved.

Preparation of Fe-Al Intermetallic / TiC-Al2O3 Ceramic Composites from Ilmenite by SHS

Institute of Scientific and Technical Information of China (English)

无

2007-01-01

Fe-Al intermetallic/TiC-Al2O3 ceramic composites were successfully prepared by self-propagating high-temperature synthesis (SHS) from natural ilmenite, aluminium and carbon as the raw materials. The effects of carbon sources, preheating time and heat treatment temperature on synthesis process and products were investigated in detail, and the reaction process of the FeTiO3-Al-C system was also discussed.It is shown that the temperature and velocity of the combustion wave are higher when graphite is used as the carbon source, which can reflect the effect of the carbon source structure on the combustion synthesis;Prolonging the preheating time or heat treatment temperature is beneficial to the formation of the ordered intermetallics; The temperature and velocity of the combustion wave arc improved, but the disordered alloys are difficult to eliminate with the preheating time prolonged. The compound powders mainly containing ordered Fe3Al intermetallic can be prepared through heat treatment at 750 ℃.

Structural changes induced by lattice-electron interactions: SiO2 stishovite and FeTiO3 ilmenite.

Science.gov (United States)

Yamanaka, Takamitsu

2005-09-01

The bright source and highly collimated beam of synchrotron radiation offers many advantages for single-crystal structure analysis under non-ambient conditions. The structure changes induced by the lattice-electron interaction under high pressure have been investigated using a diamond anvil pressure cell. The pressure dependence of electron density distributions around atoms is elucidated by a single-crystal diffraction study using deformation electron density analysis and the maximum entropy method. In order to understand the bonding electrons under pressure, diffraction intensity measurements of FeTiO3 ilmenite and gamma-SiO2 stishovite single crystals at high pressures were made using synchrotron radiation. Both diffraction studies describe the electron density distribution including bonding electrons and provide the effective charge of the cations. In both cases the valence electrons are more localized around the cations with increasing pressure. This is consistent with molecular orbital calculations, proving that the bonding electron density becomes smaller with pressure. The thermal displacement parameters of both samples are reduced with increasing pressure.

Soil variability and effectiveness of soil and water conservation in the Sahel.

NARCIS (Netherlands)

Hien, F.G.; Rietkerk, M.; Stroosnijder, L.

1997-01-01

Sahelian sylvopastoral lands often degrade into bare and crusted areas where regeneration of soil and vegetation is impossible in the short term unless soil and water conservation measures are implemented. Five combinations of tillage with and without mulch on three crust type/soil type combinations

Applying Limestone or Basalt in Combination with Bio-Fertilizer to Sustain Rice Production on an Acid Sulfate Soil in Malaysia

Directory of Open Access Journals (Sweden)

Qurban Ali Panhwar

2016-07-01

Full Text Available A study was conducted to determine the efficacy of applying ground magnesium limestone (GML or ground basalt in combination with bio-fertilizer to sustain rice production on an acid sulfate soil in Malaysia. Soils from Kelantan Plains, Malaysia, were treated with GML, ground basalt, bio-fertilizer, GML + bio-fertilizer, and ground basalt + bio-fertilizer (4 t·ha−1 each. Results showed that soil fertility was improved by applying the soil amendments. GML and basalt contain some Zn and Cu; thus, application of these amendments would increase their contents in the soil needed for the healthy growth of rice. Basalt applied in combination with bio-fertilizer appeared to be the best agronomic option to improve the fertility of acid sulfate soils for sustainable rice production in the long run. In addition to increasing Ca, Mg, Zn, and Cu reserves in the soil, water pH increased and precipitated Al3+ and/or Fe2+. Ground basalt is cheaper than GML, but basalt dissolution in the acidic soil was slow. As such, its ameliorative effects could only be seen significantly from the second season onwards. The specially-formulated bio-fertilizer for alleviating the infertility of acid sulfate soil could also enhance rice growth. The use of the bio-fertilizer fortified with N2-fixing bacteria is a green technology that would help reduce NO3− and/or NO2− pollution and reduce the cost of rice production. The phosphate-solubilizing bacteria (PSB present in the bio-fertilizer not only increased the available P, but also helped release organic acids that would inactivate Al3+ and/or Fe2+ via the process of chelation.

The combined effects of moss-dominated biocrusts and vegetation on erosion and soil moisture and implications for disturbance on the Loess Plateau, China.

Science.gov (United States)

Bu, Chongfeng; Wu, Shufang; Han, Fengpeng; Yang, Yongsheng; Meng, Jie

2015-01-01

Biological soil crusts (BSCs, or biocrusts) have important positive ecological functions such as erosion control and soil fertility improvement, and they may also have negative effects on soil moisture in some cases. Simultaneous discussions of the two-sided impacts of BSCs are key to the rational use of this resource. This study focused on the contribution of BSCs while combining with specific types of vegetation to erosion reduction and their effects on soil moisture, and it addressed the feasibility of removal or raking disturbance. Twelve plots measuring 4 m × 2 m and six treatments (two plots for each) were established on a 15° slope in a small watershed in the Loess Plateau using BSCs, bare land (as a control, BL), Stipa bungeana Trin. (STBU), Caragana korshinskii Kom. (CAKO), STBU planted with BSCs (STBU+BSCs) and CAKO planted with BSCs (CAKO+BSCs). The runoff, soil loss and soil moisture to a depth of 3 m were measured throughout the rainy season (from June to September) of 2010. The results showed that BSCs significantly reduced runoff by 37.3% and soil loss by 81.0% and increased infiltration by 12.4% in comparison with BL. However, when combined with STBU or CAKO, BSCs only made negligible contributions to erosion control (a runoff reduction of 7.4% and 5.7% and a soil loss reduction of 0.7% and 0.3%). Generally, the soil moisture of the vegetation plots was lower in the upper layer than that of the BL plots, although when accompanied with a higher amount of infiltration, this soil moisture consumption phenomenon was much clearer when combining vegetation with BSCs. Because of the trivial contributions from BSCs to erosion control and the remaining exacerbated consumption of soil water, moderate disturbance by BSCs should be considered in plots with adequate vegetation cover to improve soil moisture levels without a significant erosion increase, which was implied to be necessary and feasible.

Economic benefits of combining soil and water conservation measures with nutrient management in semiarid Burkina Faso

NARCIS (Netherlands)

Zougmoré, R.; Mando, A.; Stroosnijder, L.; Ouédraogo, E.

2004-01-01

Nutrient limitation is the main cause of per capita decline in crop production in the Sahel, where water shortage also limits an efficient use of available nutrients. Combining soil and water conservation measures with locally available nutrient inputs may optimize crop production and economic

A practical approach for deriving all-weather soil moisture content using combined satellite and meteorological data

Science.gov (United States)

Leng, Pei; Li, Zhao-Liang; Duan, Si-Bo; Gao, Mao-Fang; Huo, Hong-Yuan

2017-09-01

Soil moisture has long been recognized as one of the essential variables in the water cycle and energy budget between Earth's surface and atmosphere. The present study develops a practical approach for deriving all-weather soil moisture using combined satellite images and gridded meteorological products. In this approach, soil moisture over the Moderate Resolution Imaging Spectroradiometer (MODIS) clear-sky pixels are estimated from the Vegetation Index/Temperature (VIT) trapezoid scheme in which theoretical dry and wet edges were determined pixel to pixel by China Meteorological Administration Land Data Assimilation System (CLDAS) meteorological products, including air temperature, solar radiation, wind speed and specific humidity. For cloudy pixels, soil moisture values are derived by the calculation of surface and aerodynamic resistances from wind speed. The approach is capable of filling the soil moisture gaps over remaining cloudy pixels by traditional optical/thermal infrared methods, allowing for a spatially complete soil moisture map over large areas. Evaluation over agricultural fields indicates that the proposed approach can produce an overall generally reasonable distribution of all-weather soil moisture. An acceptable accuracy between the estimated all-weather soil moisture and in-situ measurements at different depths could be found with an Root Mean Square Error (RMSE) varying from 0.067 m3/m3 to 0.079 m3/m3 and a slight bias ranging from 0.004 m3/m3 to -0.011 m3/m3. The proposed approach reveals significant potential to derive all-weather soil moisture using currently available satellite images and meteorological products at a regional or global scale in future developments.

Precipitation of Oriented Rutile and Ilmenite Needles in Garnet, Northeastern Connecticut, USA: Evidence for Extreme Metamorphic Conditions?

Science.gov (United States)

Ague, J. J.; Eckert, J. O.

2011-12-01

We report the discovery of oriented needles of rutile and, less commonly, ilmenite in the cores of garnets from northeastern CT, USA. The rocks preserve granulite facies mineral assemblages, form part of the Merrimack Synclinorium, and underwent metamorphism and deformation during the Acadian orogeny. The needles appear identical to those reported from a number of extreme P-T environments worldwide, including UHP metamorphic rocks, high-P granulites, and garnet peridotites. The needles are predominantly oriented along directions in garnet. The long axes of the rutile needles commonly do not go extinct parallel to the cross hairs under cross-polarized light (e.g., Griffin et al., 1971). This anomalous extinction indicates that the needles do not preserve a specific crystallographic relationship with their garnet hosts (e.g., Hwang et al., 2007). The needles range from a few hundred nm to a few um in diameter, and can be mm-scale in length. Micrometer-scale plates of rutile, srilankite and crichtonite have also been observed in some garnets together with the Fe-Ti oxide needles. Several origins for the needles have been proposed in the literature; we investigate the hypothesis that they precipitated in situ from originally Ti-rich garnet. Chemical profiles across garnets indicate that some retain Ti zoning, with elevated-Ti concentrations in the cores dropping to low values in the rims. For these zoned garnets, high-resolution, 2-D chemical mapping using the JEOL JXA-8530F field emission gun electron microprobe at Yale University reveals that the needles are surrounded by well-defined Ti-depletion halos. Chemical profiles also document strong depletions of Cr (which is present in both rutile and ilmenite) directly adjacent to needles. The observed Ti-depletions demonstrate that the needles precipitated from Ti-bearing garnet, probably during cooling and/or decompression associated with exhumation. The rutile precipitates must be largely incoherent with respect to the

Combined climate factors alleviate changes in gross soil nitrogen dynamics in heathlands

DEFF Research Database (Denmark)

Bjorsne, Anna-Karin; Rutting, Tobias; Ambus, Per

2014-01-01

of exposure to three climate change factors, i.e. warming, elevated CO2 (eCO(2)) and summer drought, applied both in isolation and in combination. By conducting laboratory N-15 tracing experiments we show that warming increased both gross N mineralization and nitrification rates. In contrast, gross......The ongoing climate change affects biogeochemical cycling in terrestrial ecosystems, but the magnitude and direction of this impact is yet unclear. To shed further light on the climate change impact, we investigated alterations in the soil nitrogen (N) cycling in a Danish heathland after 5 years......CO(2). In the full treatment combination, simulating the predicted climate for the year 2075, gross N transformations were only moderately affected compared to control, suggesting a minor alteration of the N cycle due to climate change. Overall, our study confirms the importance of multifactorial field...

Effects of Combined Application of Biogas Slurry and Chemical Fertilizer on Soil Aggregation and C/N Distribution in an Ultisol

Science.gov (United States)

Zheng, Xuebo; Fan, Jianbo; Xu, Lei; Zhou, Jing

2017-01-01

Unreasonable use of chemical fertilizer (CF) on agricultural soil leads to massive losses of soil organic carbon (SOC) and total nitrogen (TN) in tropical and subtropical areas, where soil conditions are unfavorable for aggregate formation. This study evaluated the effects of combined application of biogas slurry (BS) plus CF on soil aggregation and aggregate—associated C/N concentration and storage in an Ultisol. Six treatments included: no fertilizer (T1), CF only (T2), partial (15% (T3), 30% (T4) and 45% (T5)) substitution of TN with BS and BS only (T6). Soil mechanical—stable aggregates (MSAs) formation and stability as well as MSAs—associated C/N concentration and storage were observed in different aggregate sizes (>5, 5–2, 2–1, 1.0–0.5, 0.50–0.25 and 5 mm significantly increased with BS substitution (T5), while the proportions of MSAs 1.0–0.5 mm, MSAs 0.50–0.25 mm and MSAs 0.5 mm that constituted 72–82% of MSAs. Stepwise regression analysis showed that MSAs >5 mm, SOC in MSAs >5 mm and TN in MSAs >5 mm were the dominant variables affecting aggregate stability. Meanwhile SOC in MSAs <0.25 mm and TN in MSAs 2–1 mm were independent variables affecting SOC and TN concentrations in bulk soils. Therefore, certain rate of combined application of BS plus CF is an effective, eco—friendly way to improve soil quality in an Ultisol. PMID:28125647

Transmission electron microscope studies of extraterrestrial materials

Science.gov (United States)

Keller, Lindsay P.

1995-01-01

Transmission Electron Microscopy, X-Ray spectrometry and electron-energy-loss spectroscopy are used to analyse carbon in interplanetary dust particles. Optical micrographs are shown depicting cross sections of the dust particles embedded in sulphur. Selected-area electron diffraction patterns are shown. Transmission Electron Microscope specimens of lunar soil were prepared using two methods: ion-milling and ultramicrotomy. A combination of high resolution TEM imaging and electron diffraction is used to characterize the opaque assemblages. The opaque assemblages analyzed in this study are dominated by ilmenite with lesser rutile and spinel exsolutions, and traces of Fe metal.

Ecopiling: A combined Phytoremediation and Passive Biopiling System for Remediating Hydrocarbon Impacted Soils at Field Scale

Directory of Open Access Journals (Sweden)

Kieran J Germaine

2015-01-01

Full Text Available Biopiling is an ex situ bioremediation technology that has been extensively used for remediating a wide range of petrochemical contaminants in soils. Biopiling involves the assembling of contaminated soils into piles and stimulating the biodegrading activity of microbial populations by creating near optimum growth conditions. Phytoremediation is another very successful bioremediation technique and involves the use of plants and their associated microbiomes to degrade, sequester or bio-accumulate pollutants from contaminated soil and water. The objective of this study was to investigate the effectiveness of a combined phytoremediation/biopiling system, termed Ecopiling, to remediate hydrocarbon impacted industrial soil. The large scale project was carried out on a sandy loam, petroleum impacted soil (1613 mg Total Petroleum Hydrocarbons (TPH kg-1 soil. The contaminated soil was amended with chemical fertilisers, inoculated with TPH degrading bacterial consortia and then used to construct passive biopiles. Finally, a phyto-cap of perennial rye grass (Lolium multiflorum and white clover (Trifolium repens was sown on the soil surface to complete the Ecopile. Monitoring of important physico-chemical parameters was carried out at regular intervals throughout the trial. Two years after construction the TPH levels in the petroleum impacted Ecopiles were below detectable limits in all but 1 subsample (152mg TPH kg-1 soil. The Ecopile system is a multi-factorial bioremediation process involving bio-stimulation, bio-augmentation and phytoremediation. One of the key advantages to this system is the reduced costs of the remediation process, as once constructed, there is little additional cost in terms of labour and maintenance (although the longer process time may incur additional monitoring costs. The other major advantage is that many ecological functions are rapidly restored to the site and the process is aesthetically pleasing.

Ecopiling: a combined phytoremediation and passive biopiling system for remediating hydrocarbon impacted soils at field scale.

Science.gov (United States)

Germaine, Kieran J; Byrne, John; Liu, Xuemei; Keohane, Jer; Culhane, John; Lally, Richard D; Kiwanuka, Samuel; Ryan, David; Dowling, David N

2014-01-01

Biopiling is an ex situ bioremediation technology that has been extensively used for remediating a wide range of petrochemical contaminants in soils. Biopiling involves the assembling of contaminated soils into piles and stimulating the biodegrading activity of microbial populations by creating near optimum growth conditions. Phytoremediation is another very successful bioremediation technique and involves the use of plants and their associated microbiomes to degrade, sequester or bio-accumulate pollutants from contaminated soil and water. The objective of this study was to investigate the effectiveness of a combined phytoremediation/biopiling system, termed Ecopiling, to remediate hydrocarbon impacted industrial soil. The large scale project was carried out on a sandy loam, petroleum impacted soil [1613 mg total petroleum hydrocarbons (TPHs) kg(-1) soil]. The contaminated soil was amended with chemical fertilizers, inoculated with TPH degrading bacterial consortia and then used to construct passive biopiles. Finally, a phyto-cap of perennial rye grass (Lolium perenne) and white clover (Trifolium repens) was sown on the soil surface to complete the Ecopile. Monitoring of important physico-chemical parameters was carried out at regular intervals throughout the trial. Two years after construction the TPH levels in the petroleum impacted Ecopiles were below detectable limits in all but one subsample (152 mg TPH kg(-1) soil). The Ecopile system is a multi-factorial bioremediation process involving bio-stimulation, bio-augmentation and phytoremediation. One of the key advantages to this system is the reduced costs of the remediation process, as once constructed, there is little additional cost in terms of labor and maintenance (although the longer process time may incur additional monitoring costs). The other major advantage is that many ecological functions are rapidly restored to the site and the process is esthetically pleasing.

Combining Partial Least Squares and the Gradient-Boosting Method for Soil Property Retrieval Using Visible Near-Infrared Shortwave Infrared Spectra

Directory of Open Access Journals (Sweden)

Lanfa Liu

2017-12-01

Full Text Available Soil spectroscopy has experienced a tremendous increase in soil property characterisation, and can be used not only in the laboratory but also from the space (imaging spectroscopy. Partial least squares (PLS regression is one of the most common approaches for the calibration of soil properties using soil spectra. Besides functioning as a calibration method, PLS can also be used as a dimension reduction tool, which has scarcely been studied in soil spectroscopy. PLS components retained from high-dimensional spectral data can further be explored with the gradient-boosted decision tree (GBDT method. Three soil sample categories were extracted from the Land Use/Land Cover Area Frame Survey (LUCAS soil library according to the type of land cover (woodland, grassland, and cropland. First, PLS regression and GBDT were separately applied to build the spectroscopic models for soil organic carbon (OC, total nitrogen content (N, and clay for each soil category. Then, PLS-derived components were used as input variables for the GBDT model. The results demonstrate that the combined PLS-GBDT approach has better performance than PLS or GBDT alone. The relative important variables for soil property estimation revealed by the proposed method demonstrated that the PLS method is a useful dimension reduction tool for soil spectra to retain target-related information.

Remediation of highly contaminated soils from an industrial site by employing a combined treatment with exogeneous humic substances and oxidative biomimetic catalysis

International Nuclear Information System (INIS)

Sannino, Filomena; Spaccini, Riccardo; Savy, Davide; Piccolo, Alessandro

2013-01-01

Highlights: • Remediation of two polluted soils from a highly contaminated industrial site in Italy. • Restoration of soil quality by introducing additional carbon into polluted soil with humic matter amendments. • Detoxification of contaminants by covalent binding to humic molecules. • Prevention of environmental transport of pollutants. -- Abstract: Remediation of two polluted soils from a northern Italian industrial site heavily contaminated with organic contaminants was attempted here by subjecting soils first to addition with an exogenous humic acid (HA), and, then, to an oxidation reaction catalyzed by a water-soluble iron-porphyrin (FeP). An expected decrease of detectable organic pollutants (>50%) was already observed when soils were treated only with the H 2 O 2 oxidant. This reduction was substantially enhanced when oxidation was catalyzed by iron-porphyrin (FeP + H 2 O 2 ) and the largest effect was observed for the most highly polluted soil. Even more significant was the decrease in detectable pollutants (70–90%) when soils were first amended with HA and then subjected to the FeP + H 2 O 2 treatment. This reduction in extractable pollutants after the combined HA + FeP + H 2 O 2 treatment was due to formation of covalent C-C and C-O-C bonds between soil contaminants and amended humic molecules. Moreover, the concomitant detection of condensation products in soil extracts following FeP addition confirmed the occurrence of free-radical coupling reactions catalyzed by FeP. These findings indicate that a combined technique based on the action of both humic matter and a metal-porhyrin catalyst, may become useful to quantitatively reduce the toxicity of heavily contaminated soils and prevent the environmental transport of pollutants

Remediation of highly contaminated soils from an industrial site by employing a combined treatment with exogeneous humic substances and oxidative biomimetic catalysis

Energy Technology Data Exchange (ETDEWEB)

Sannino, Filomena, E-mail: fsannino@unina.it [Dipartimento di Agraria, Università di Napoli “Federico II”, Via Università 100, 80055 Portici (Italy); Spaccini, Riccardo [Dipartimento di Agraria, Università di Napoli “Federico II”, Via Università 100, 80055 Portici (Italy); Centro Interdipartimentale di Ricerca sulla Risonanza Magnetica Nucleare per l’Ambiente, l’Agro-Alimentare ed i Nuovi Materiali (CERMANU), Via Università 100, 80055 Portici (Italy); Savy, Davide [Dipartimento di Agraria, Università di Napoli “Federico II”, Via Università 100, 80055 Portici (Italy); Piccolo, Alessandro [Dipartimento di Agraria, Università di Napoli “Federico II”, Via Università 100, 80055 Portici (Italy); Centro Interdipartimentale di Ricerca sulla Risonanza Magnetica Nucleare per l’Ambiente, l’Agro-Alimentare ed i Nuovi Materiali (CERMANU), Via Università 100, 80055 Portici (Italy)

2013-10-15

Highlights: • Remediation of two polluted soils from a highly contaminated industrial site in Italy. • Restoration of soil quality by introducing additional carbon into polluted soil with humic matter amendments. • Detoxification of contaminants by covalent binding to humic molecules. • Prevention of environmental transport of pollutants. -- Abstract: Remediation of two polluted soils from a northern Italian industrial site heavily contaminated with organic contaminants was attempted here by subjecting soils first to addition with an exogenous humic acid (HA), and, then, to an oxidation reaction catalyzed by a water-soluble iron-porphyrin (FeP). An expected decrease of detectable organic pollutants (>50%) was already observed when soils were treated only with the H{sub 2}O{sub 2} oxidant. This reduction was substantially enhanced when oxidation was catalyzed by iron-porphyrin (FeP + H{sub 2}O{sub 2}) and the largest effect was observed for the most highly polluted soil. Even more significant was the decrease in detectable pollutants (70–90%) when soils were first amended with HA and then subjected to the FeP + H{sub 2}O{sub 2} treatment. This reduction in extractable pollutants after the combined HA + FeP + H{sub 2}O{sub 2} treatment was due to formation of covalent C-C and C-O-C bonds between soil contaminants and amended humic molecules. Moreover, the concomitant detection of condensation products in soil extracts following FeP addition confirmed the occurrence of free-radical coupling reactions catalyzed by FeP. These findings indicate that a combined technique based on the action of both humic matter and a metal-porhyrin catalyst, may become useful to quantitatively reduce the toxicity of heavily contaminated soils and prevent the environmental transport of pollutants.

AN ACTIVE-PASSIVE COMBINED ALGORITHM FOR HIGH SPATIAL RESOLUTION RETRIEVAL OF SOIL MOISTURE FROM SATELLITE SENSORS (Invited)

Science.gov (United States)

Lakshmi, V.; Mladenova, I. E.; Narayan, U.

2009-12-01

Soil moisture is known to be an essential factor in controlling the partitioning of rainfall into surface runoff and infiltration and solar energy into latent and sensible heat fluxes. Remote sensing has long proven its capability to obtain soil moisture in near real-time. However, at the present time we have the Advanced Scanning Microwave Radiometer (AMSR-E) on board NASA’s AQUA platform is the only satellite sensor that supplies a soil moisture product. AMSR-E coarse spatial resolution (~ 50 km at 6.9 GHz) strongly limits its applicability for small scale studies. A very promising technique for spatial disaggregation by combining radar and radiometer observations has been demonstrated by the authors using a methodology is based on the assumption that any change in measured brightness temperature and backscatter from one to the next time step is due primarily to change in soil wetness. The approach uses radiometric estimates of soil moisture at a lower resolution to compute the sensitivity of radar to soil moisture at the lower resolution. This estimate of sensitivity is then disaggregated using vegetation water content, vegetation type and soil texture information, which are the variables on which determine the radar sensitivity to soil moisture and are generally available at a scale of radar observation. This change detection algorithm is applied to several locations. We have used aircraft observed active and passive data over Walnut Creek watershed in Central Iowa in 2002; the Little Washita Watershed in Oklahoma in 2003 and the Murrumbidgee Catchment in southeastern Australia for 2006. All of these locations have different soils and land cover conditions which leads to a rigorous test of the disaggregation algorithm. Furthermore, we compare the derived high spatial resolution soil moisture to in-situ sampling and ground observation networks

Monitoring snowmelt and solute transport at Oslo airport by combining time-lapse electrical resistivity, soil water sampling and tensiometer measurements

Science.gov (United States)

Bloem, E.; French, H. K.

2013-12-01

Monitoring contaminant transport at contaminated sites requires optimization of the configuration of a limited number of samplings points combined with heterogeneous flow and preferential flowpaths. Especially monitoring processes in the unsaturated zone is a major challenge due to the limited volume monitored by for example suction cups and their risk to clog in a highly active degradation zone. To make progress on soil contamination assessment and site characterization there is a strong need to integrate field-sale extensively instrumented tools, with non-invasive (geophysical) methods which provide spatially integrated measurements also in the unsaturated zone. Examples of sites that might require monitoring activities in the unsaturated zone are airports with winter frost where large quantities of de-icing chemicals are used each winter; salt and contaminant infiltration along roads; constructed infiltration systems for treatment of sewerage or landfill seepage. Electrical resistivity methods have proved to be useful as an indirect measurement of subsurface properties and processes at the field-scale. The non-uniqueness of the interpretation techniques can be reduced by constraining the inversion through the addition of independent geophysical measurements along the same profile. Or interpretation and understanding of geophysical images can be improved by the combination with classical measurements of soil physical properties, soil suction, contaminant concentration and temperatures. In our experiment, at the research field station at Gardermoen, Oslo airport, we applied a degradable de-icing chemical and an inactive tracer to the snow cover prior to snowmelt. To study the solute transport processes in the unsaturated zone time-lapse cross borehole electrical resistivity tomography (ERT) measurements were conducted at the same time as soil water samples were extracted at multiple depths with suction cups. Measurements of soil temperature, and soil tension were

iSOIL: Interactions between soil related sciences - Linking geophysics, soil science and digital soil mapping

Science.gov (United States)

Dietrich, Peter; Werban, Ulrike; Sauer, Uta

2010-05-01

High-resolution soil property maps are one major prerequisite for the specific protection of soil functions and restoration of degraded soils as well as sustainable land use, water and environmental management. To generate such maps the combination of digital soil mapping approaches and remote as well as proximal soil sensing techniques is most promising. However, a feasible and reliable combination of these technologies for the investigation of large areas (e.g. catchments and landscapes) and the assessment of soil degradation threats is missing. Furthermore, there is insufficient dissemination of knowledge on digital soil mapping and proximal soil sensing in the scientific community, to relevant authorities as well as prospective users. As one consequence there is inadequate standardization of techniques. At the poster we present the EU collaborative project iSOIL within the 7th framework program of the European Commission. iSOIL focuses on improving fast and reliable mapping methods of soil properties, soil functions and soil degradation risks. This requires the improvement and integration of advanced soil sampling approaches, geophysical and spectroscopic measuring techniques, as well as pedometric and pedophysical approaches. The focus of the iSOIL project is to develop new and to improve existing strategies and innovative methods for generating accurate, high resolution soil property maps. At the same time the developments will reduce costs compared to traditional soil mapping. ISOIL tackles the challenges by the integration of three major components: (i)high resolution, non-destructive geophysical (e.g. Electromagnetic Induction EMI; Ground Penetrating Radar, GPR; magnetics, seismics) and spectroscopic (e.g., Near Surface Infrared, NIR) methods, (ii)Concepts of Digital Soil Mapping (DSM) and pedometrics as well as (iii)optimized soil sampling with respect to profound soil scientific and (geo)statistical strategies. A special focus of iSOIL lies on the

Combination of pseudomonas putida and EK method to reduce the amount of mercury on landfill soil

Science.gov (United States)

Nabila, A. T. A.; Azhar, A. T. S.; Nurshuhaila, M. S.; Azim, M. A. M.; Amirah, S. N.

2017-11-01

Landfills usually lack of environment measures especially on soil. There are no guarantee that the landfill soil is free from being contaminated. It may cause harm for humans, animals and plants at surrounding area. In order to solve this problem, advance remediation technique is essential such as the electrokinetic combined with microorganisms known as electrokinetic bioremediation technique. The aim of this study is to investigate the performance of P.putida with 15 volt electric current supply (Ek-bio) and without electric current (Bio) in removal of mercury in landfill soil. Both treatments were running throughout 14 days. The P.putida was placed at anode compartment meanwhile sterile distilled water poured at cathode compartment. According to the both results, Ek-bio was removed mercury up to 48 % but by using standard bioremediation treatment, the removal only 32 %. Besides that, the migration of P.putida react more aggressively during the present of electric current compared with bioremediation. As the results, it was proven that by using Ek-bio technique can increase the activity of bacteria beside and the removal of mercury. Therefore, Ek-bio method can be commercialized to the parties concerned to solve the contaminated soil by mercury.

Soil washing in combination with homogeneous Fenton-like oxidation for the removal of 2,4,4'-trichlorodiphenyl from soil contaminated with capacitor oil.

Science.gov (United States)

Ma, Xiao-Hong; Zhao, Ling; Lin, Zhi-Rong; Dong, Yuan-Hua

2016-04-01

Detoxification by chemical oxidation of polychlorinated biphenyls (PCBs) in contaminated soils is very difficult and inefficient because PCBs typically associate with the solid phase or exist as non-aqueous-phase liquids due to their low solubility and slow desorption rates, and thus, they are difficult to remove from soils by using traditional, water-based elution techniques. Surfactant can enhance washing efficiency of PCBs from contaminated soils. This study used Brij 58, Brij 30, Tween 80, and 2-hydroxypropyl-β-cyclodextrin (HPCD) to solubilize 2,4,4'-trichlorodiphenyl (PCB28) from soil contaminated with capacitor oil into solution. The feasibility of PCB28 oxidation in soil washing wastewater through a Fe(3+)-catalyzed Fenton-like reaction was subsequently examined. Washing with 10 g L(-1) Brij 58 solution showed the highest extraction efficiency (up to 61.5 %) compared with that of the three other surfactants. The total concentration of PCB28 in contaminated soil at 25 °C after 48-h extraction was 286 mg L(-1). In contrast to conditions in which no washing agent was added, addition of the four washing agents decreased the efficiency of PCB28 degradation by the Fenton-like reaction, with the decrease due to addition of 10 g L(-1) Brij 58 solution being the smallest. The optimal concentration of H2O2 for preventing its useless decomposition was found to be 50 mM. The efficiency of PCB28 removal was lower when the initial concentration of PCB28 treated in the Fenton-like reaction was higher. The degradation efficiencies of PCB28 at initial concentrations of 0.1, 10, and 176 mg L(-1) in 10 g L(-1) Brij 58 solution at 25 °C and pH 3.0 and 9 h of reaction using 50 mM H2O2 were 64.1, 42.0, and 34.6 %, respectively. This result indicates that soil washing combined with Fenton-like oxidation may be a practical approach for the remediation of PCB-contaminated soil.

Combining Sequential Extractions and X-ray Absorption Spectroscopy for Quantitative and Qualitative Zinc Speciation in Soil

Science.gov (United States)

Bauer, Tatiana; Minkina, Tatiana; Batukaev, Abdulmalik; Nevidomskaya, Dina; Burachevskaya, Marina; Tsitsuashvili, Viktoriya; Urazgildieva, Kamilya

2017-04-01

The combined use of X-ray absorption spectrometry and extractive fractionation is an effective approach for studying the interaction of metal ions with soil compounds and identifying the phases-carriers of metals in soil and their stable fixation. These studies were carried out using the technique of X-ray absorption spectroscopy and chemical extractive fractionation. In a model experiment the samples taken in Calcic Chernozem were artificially contaminated with higher portion of Zn(NO3)2 (2000 mg/kg). The metal were incubated in soil samples for 2 year. The samples of soil mineral and organic phases (calcite, kaolinite, bentonite, humic acids) were saturated with Zn2+ from a solution of nitrate salts of metal. The total content of Zn in soil and soil various phases was determined using the X-ray fluorescence method. Extended X-ray absorption fine structure (EXAFS) Zn was measured at the Structural Materials Science beamline of the Kurchatov Center for Synchrotron Radiation. Sequential fractionation of Zn in soil conducted by Tessier method (Tessier et al., 1979) which determining 5 fractions of metals in soil: exchangeable, bound to Fe-Mn oxide, bound to carbonate, bound to the organic matter, and bound to silicate (residual). This methodology has so far more than 4000 citations (Web of Science), which demonstrates the popularity of this approach. Much Zn compounds are contained in uncontaminated soils in stable primary and secondary silicates inherited from the parental rocks (67% of the total concentrations in all fractions), which is a regional trait of soils in the fore-Caucasian plain. Extracted fractionation of metal compounds in soil samples, artificially contaminated with Zn salts, indicates the priority holding of Zn2+ ions by silicates, carbonates and Fe-Mn oxides. The Zn content significantly increases in the exchangeable fraction. Atomic structure study of the soil various phases saturated with Zn2+ ion by using (XANES) X-ray absorption spectroscopy

Plant tolerance to mercury in a contaminated soil is enhanced by the combined effects of humic matter addition and inoculation with arbuscular mycorrhizal fungi.

Science.gov (United States)

Cozzolino, V; De Martino, A; Nebbioso, A; Di Meo, V; Salluzzo, A; Piccolo, A

2016-06-01

In a greenhouse pot experiment, lettuce plants (Lactuca sativa L.) were grown in a Hg-contaminated sandy soil with and without inoculation with arbuscular mycorrhizal fungi (AMF) (a commercial inoculum containing infective propagules of Rhizophagus irregularis and Funneliformis mosseae) amended with different rates of a humic acid (0, 1, and 2 g kg(-1) of soil), with the objective of verifying the synergistic effects of the two soil treatments on the Hg tolerance of lettuce plants. Our results indicated that the plant biomass was significantly increased by the combined effect of AMF and humic acid treatments. Addition of humic matter to soil boosted the AMF effect on improving the nutritional plant status, enhancing the pigment content in plant leaves, and inhibiting both Hg uptake and Hg translocation from the roots to the shoots. This was attributed not only to the Hg immobilization by stable complexes with HA and with extraradical mycorrhizal mycelium in soil and root surfaces but also to an improved mineral nutrition promoted by AMF. This work indicates that the combined use of AMF and humic acids may become a useful practice in Hg-contaminated soils to reduce Hg toxicity to crops.

Effect of arbuscular mycorrhizal fungal inoculation in combination with different organic fertilizers on maize crop in eroded soils

International Nuclear Information System (INIS)

Sharif, M.; Saud, S.; Khan, F.

2012-01-01

A pot experiment was conducted to study the effect of inoculating maize (Zea mays L. Azam) with Arbuscular mycorrhizal (AM) fungi in 2 different series of North West Pakistan during the year 2007. Data showed significant increase in shoots and roots yield of maize with the inoculation of AM fungi alone and in combination with farm yard manure (FYM), poultry manure (PM) and humic acid (HA) over control and N-P-K treatments. Accumulation of N by maize shoots increased significantly by the addition of HA, PM and FYM plus N-P-K with or without inoculation of AM fungi over the treatments of N-P-K and control. Plants P accumulation increased significantly over control and N-P-K treatments with the inoculation of AM fungi alone and in combination with FYM, PM and HA in missa soil series. In missa gullied soil series, significantly increased plants P accumulation was noted by the treatments of AM inoculation with PM followed by HA. Accumulation of Mn by maize shoots increased significantly with AM inoculation with HA and PM over all other treatments, Fe increased with PM, HA and FYM. Plants Cu accumulation in missa series increased significantly over control and N-P-K treatments by AM alone and in combination with PM, FYM and HA and by AM fungi with PM, FYM and HA in missa gullied series. Maximum Mycorrhizal root infection rate of 51 % was recorded in the treatment of AM fungal inoculation with HA followed by the treatment inoculated with AM fungi with FYM. In missa gullied soil series, Maximum (59 %) and significantly increased roots infection rates over all treatments were observed in the treatment of AM fungal inoculation with HA followed by PM. Spores concentrations of AM fungi increased significantly with AM inoculation alone and with FYM, PM and HA. Maximum spores numbers of 50 in 20 g soil were recorded by the inoculation of AM fungi alone and with HA. (author)

[Zoological diagnostics of soils: imperatives, purposes, and place within soil zoology and pedology].

Science.gov (United States)

Mordokovich, V G

2013-01-01

Zoological diagnostics of soils was conceived by M.S. Ghilarov as a part of soil zoology and intended to be closely related to pedology. He considered zoo-agents as an ecological factor, one among many others, of soil formation. Contemporary soil diagnostics pursues mostly utilitarian goals and is based on conservative properties of the stable part of soil substrate. However, it is admitted that these properties are generated by specific combinations of biological, chemical, and physical phenomena that are called "elementary soil processes" (ESP) and occur nowhere but in soils. Certain ESPs are associated with distinctive combinations of biota, including invertebrates. Pedobionts act as producers of detritus and contribute to humus formation, which is necessary for any ESP starting, thus being its active party. That is why animals, being the most complex and active part of the ESP system, may be treated not only as its indicators but also as its navigators. Monitoring and studying of ESPs in soil is complicated because of inevitable disturbance of soil profile natural composition. Zoo-agents, at the same time, can be registered without habitats changing. Taking into account ecological potency of soil invertebrates that participate in an ESP, spectra of their eco-groups, life forms, and results of their activity, it is possible to diagnose a soil state at different stages of certain ESPs development, with their different combinations, and in different regions or parts of natural environmental gradients.

System of Antioxidant Protection of Corn Roots in Case of Adaptation to Combined Action of Herbicides and Soil Drought

Directory of Open Access Journals (Sweden)

G. S. Rossihina

2005-09-01

Full Text Available Reaction of antioxidant enzymes in the maize root (Kadr 267 MVhybrid to the combined action of herbicides and soil drought was studied. These conditions activated superoxide dismutase (SOD and peroxidase and coused oscillation in the catalase enzymatic activity.

Effects of Cu, Zn and Pb Combined Pollution on Soil Hydrolase Activities

Directory of Open Access Journals (Sweden)

FENG Dan

2015-08-01

Full Text Available To study the relations between soil enzyme activities and heavy metal pollution, the combined effects of Cu, Zn and Pb on the three hydrolase activities, including invertase(IN, urease(Uand alkaline phosphatase(ALPwere investigated via an orthogonal experiment. Results showed as the following: When the concentration of Cu was 400 mg·kg-1, the U and ALP activities were decreased 51% and 44%, separately; When Zn was at 500 mg·kg-1, IN and ALP activities were only decreased 3% and 9%, while U activity was increased; When Pb was at 500 mg·kg-1, IN and U activities were increased, while ALP activity was decreased 13%. As a whole, Cu was considered as the most remarkable influence factor for IN, U and ALP activity regardless of interactions among the heavy metals, Zn came second, and Pb mainly showed activation. Considering interactions, Cu×Zn could significantly influence U activity(P<0.05, effects of Cu×Pb and Cu×Zn on ALP activity were remarkable(95% confidence interval. The response of ALP activity was more sensitive than the other two enzymes. Soil ALP activity might be a sensitive tool for assessing the pollution degree of Cu.

The combined effect of fertiliser nitrogen and phosphorus on herbage yield and change in soil nutrients of a grass/clover and grass-only sward

NARCIS (Netherlands)

Schils, R.L.M.; Snijders, P.J.M.

2004-01-01

The combined effect of reduced nitrogen ( N ) and phosphorus ( P ) application on the production of grass- only and grass/ clover swards was studied in a five- year cutting experiment on a marine clay soil, established on newly sown swards. Furthermore, changes in soil N, P and carbon ( C ) were

Soil Carbon Mapping in Low Relief Areas with Combined Land Use Types and Percentages

Science.gov (United States)

Liu, Y. L.; Wu, Z. H.; Chen, Y. Y.; Wang, B. Z.

2018-05-01

Accurate mapping of soil carbon in low relief areas is of great challenge because of the defect of conventional "soil-landscape" model. Efforts have been made to integrate the land use information in the modelling and mapping of soil organic carbon (SOC), in which the spatial context was ignored. With 256 topsoil samples collected from Jianghan Plain, we aim to (i) explore the land-use dependency of SOC via one-way ANOVA; (ii) investigate the "spillover effect" of land use on SOC content; (iii) examine the feasibility of land use types and percentages (obtained with a 200-meter buffer) for soil mapping via regression Kriging (RK) models. Results showed that the SOC of paddy fields was higher than that of woodlands and irrigated lands. The land use type could explain 20.5 % variation of the SOC, and the value increased to 24.7 % when the land use percentages were considered. SOC was positively correlated with the percentage of water area and irrigation canals. Further research indicated that SOC of irrigated lands was significantly correlated with the percentage of water area and irrigation canals, while paddy fields and woodlands did not show similar trends. RK model that combined land use types and percentages outperformed the other models with the lowest values of RMSEC (5.644 g/kg) and RMSEP (6.229 g/kg), and the highest R2C (0.193) and R2P (0.197). In conclusions, land use types and percentages serve as efficient indicators for the SOC mapping in plain areas. Additionally, irrigation facilities contributed to the farmland SOC sequestration especially in irrigated lands.

Evaluating the importance of surface soil contributions to reservoir sediment in alpine environments: a combined modelling and fingerprinting approach in the Posets-Maladeta Natural Park

Science.gov (United States)

Palazón, L.; Gaspar, L.; Latorre, B.; Blake, W. H.; Navas, A.

2014-09-01

Soil in alpine environments plays a key role in the development of ecosystem services and in order to maintain and preserve this important resource, information is required on processes that lead to soil erosion. Similar to other mountain alpine environments, the Benasque catchment is characterised by temperatures below freezing that can last from November to April, intense rainfall events, typically in spring and autumn, and rugged topography which makes assessment of erosion challenging. Indirect approaches to soil erosion assessment, such as combined model approaches, offer an opportunity to evaluate soil erosion in such areas. In this study (i) the SWAT (Soil and Water Assessment Tool) hydrological and erosion model and (ii) sediment fingerprinting procedures were used in parallel to assess the viability of a combined modelling and tracing approach to evaluate soil erosion processes in the area of the Posets-Maladeta Natural Park (central Spanish Pyrenees). Soil erosion rates and sediment contribution of potential sediment sources defined by soil type (Kastanozems/Phaeozems; Fluvisols and Cambisols) were assessed. The SWAT model suggested that, with the highest specific sediment yields, Cambisols are the main source of sediment in the Benasque catchment and Phaeozems and Fluvisols were identified as the lowest sediment contributors. Spring and winter model runs gave the highest and lowest specific sediment yield, respectively. In contrast, sediment fingerprinting analysis identified Fluvisols, which dominate the riparian zone, as the main sediment source at the time of sampling. This indicates the importance of connectivity as well as potential differences in the source dynamic of material in storage versus that transported efficiently from the system at times of high flow. The combined approach enabled us to better understand soil erosion processes in the Benasque alpine catchment, wherein SWAT identified areas of potential high sediment yield in large flood

Combined effects of soil moisture and carbaryl to earthworms and plants: Simulation of flood and drought scenarios

Energy Technology Data Exchange (ETDEWEB)

Lima, Maria P.R.; Soares, Amadeu M.V.M. [Department of Biology and CESAM, University of Aveiro, 3810-193 Aveiro (Portugal); Loureiro, Susana, E-mail: sloureiro@ua.pt [Department of Biology and CESAM, University of Aveiro, 3810-193 Aveiro (Portugal)

2011-07-15

Studying tolerance limits in organisms exposed to climatic variations is key to understanding effects on behaviour and physiology. The presence of pollutants may influence these tolerance limits, by altering the toxicity or bioavailability of the chemical. In this work, the plant species Brassica rapa and Triticum aestivum and the earthworm Eisenia andrei were exposed to different levels of soil moisture and carbaryl, as natural and chemical stressors, respectively. Both stress factors were tested individually, as well as in combination. Acute and chronic tests were performed and results were discussed in order to evaluate the responses of organisms to the combination of stressors. When possible, data was fitted to widely employed models for describing chemical mixture responses. Synergistic interactions were observed in earthworms exposed to carbaryl and drought conditions, while antagonistic interactions were more representative for plants, especially in relation to biomass loss under flood-simulation conditions. - Highlights: > Climate variations may cause changes on chemicals' toxicity or bioavailability. > Earthworms and plants are exposed simultaneously to carbaryl and flood and drought conditions. > The IA model and possible deviations were used to evaluate combination exposures. > Synergism was observed for earthworms exposed to carbaryl and drought conditions. > Antagonistic interactions were observed for plants, in flood conditions and carbaryl. - Soil moisture can play an important role in carbaryl toxicity towards plants and earthworms.

Combined effects of soil moisture and carbaryl to earthworms and plants: Simulation of flood and drought scenarios

International Nuclear Information System (INIS)

Lima, Maria P.R.; Soares, Amadeu M.V.M.; Loureiro, Susana

2011-01-01

Studying tolerance limits in organisms exposed to climatic variations is key to understanding effects on behaviour and physiology. The presence of pollutants may influence these tolerance limits, by altering the toxicity or bioavailability of the chemical. In this work, the plant species Brassica rapa and Triticum aestivum and the earthworm Eisenia andrei were exposed to different levels of soil moisture and carbaryl, as natural and chemical stressors, respectively. Both stress factors were tested individually, as well as in combination. Acute and chronic tests were performed and results were discussed in order to evaluate the responses of organisms to the combination of stressors. When possible, data was fitted to widely employed models for describing chemical mixture responses. Synergistic interactions were observed in earthworms exposed to carbaryl and drought conditions, while antagonistic interactions were more representative for plants, especially in relation to biomass loss under flood-simulation conditions. - Highlights: → Climate variations may cause changes on chemicals' toxicity or bioavailability. → Earthworms and plants are exposed simultaneously to carbaryl and flood and drought conditions. → The IA model and possible deviations were used to evaluate combination exposures. → Synergism was observed for earthworms exposed to carbaryl and drought conditions. → Antagonistic interactions were observed for plants, in flood conditions and carbaryl. - Soil moisture can play an important role in carbaryl toxicity towards plants and earthworms.

Identification of optimal soil hydraulic functions and parameters for predicting soil moisture

Science.gov (United States)

We examined the accuracy of several commonly used soil hydraulic functions and associated parameters for predicting observed soil moisture data. We used six combined methods formed by three commonly used soil hydraulic functions – i.e., Brooks and Corey (1964) (BC), Campbell (19...

Topographic soil wetness index derived from combined Alaska-British Columbia datasets for the Gulf of Alaska region

Science.gov (United States)

D'Amore, D. V.; Biles, F. E.

2016-12-01

The flow of water is often highlighted as a priority in land management planning and assessments related to climate change. Improved measurement and modeling of soil moisture is required to develop predictive estimates for plant distributions, soil moisture, and snowpack, which all play important roles in ecosystem planning in the face of climate change. Drainage indexes are commonly derived from GIS tools with digital elevation models. Soil moisture classes derived from these tools are useful digital proxies for ecosystem functions associated with the concentration of water on the landscape. We developed a spatially explicit topographically derived soil wetness index (TWI) across the perhumid coastal temperate rainforest (PCTR) of Alaska and British Columbia. Developing applicable drainage indexes in complex terrain and across broad areas required careful application of the appropriate DEM, caution with artifacts in GIS covers and mapping realistic zones of wetlands with the indicator. The large spatial extent of the model has facilitated the mapping of forest habitat and the development of water table depth mapping in the region. A key element of the TWI is the merging of elevation datasets across the US-Canada border where major rivers transect the international boundary. The unified TWI allows for seemless mapping across the international border and unified ecological applications. A python program combined with the unified DEM allows end users to quickly apply the TWI to all areas of the PCTR. This common platform can facilitate model comparison and improvements to local soil moisture conditions, generation of streamflow, and ecological site conditions. In this presentation we highlight the application of the TWI for mapping risk factors related to forest decline and the development of a regional water table depth map. Improved soil moisture maps are critical for deriving spatial models of changes in soil moisture for both plant growth and streamflow across

Effect of chemically processed bonemeal alone and in combination with organic materials on plant growth. [Part] I : Rice-wheat rotation in an alluvial soil

International Nuclear Information System (INIS)

Ramasami, S.; Vimal, O.P.

1975-01-01

The effect of chemically processed bonemeal added 60 kg P 2 O /ha alone and in combination with various organic materials viz., wheat straw and rice straw 3 tons/hs, starch 500 kg/ha and EDTA 250 kg/ha was studied on rice in an alluvial soil. The residual effect was studied on wheat using 32 P as a tracer. The results showed that in the first crop(rice) bonemeal organic matter combination had a significant effect both on dry matter yield and nutrient uptake. In the second crop (wheat) except chemically processed honemeal in combination with EDTA, all other combinations showed a marked positive effect on yield, total P-uptake and 'A' values. Comparison of P-uptake from soil and fertilizer indicated that there was a marked residual effect on the subsequent wheat crop. (author)

Combining Footwear with Public Health Iconography to Prevent Soil-Transmitted Helminth Infections.

Science.gov (United States)

Paige, Sarah B; Friant, Sagan; Clech, Lucie; Malavé, Carly; Kemigabo, Catherine; Obeti, Richard; Goldberg, Tony L

2017-01-11

Shoes are effective for blocking soil-transmitted helminths (STHs) that penetrate the skin. Unfortunately, shoe-wearing is uncommon in many areas where STHs are prevalent, in part because local populations are unaware of the health benefits of wearing shoes. This is especially true in low-literacy populations, where information dissemination through written messages is not possible. We launched a public health intervention that combines a public health image with sandals. The image is a "lenticular image" that combines two alternating pictures to depict the efficacy of shoes for preventing STH infection. This image is adhered to the shoe, such that the message is linked directly to the primary means of prevention. To create a culturally appropriate image, we conducted five focus group discussions, each with a different gender and age combination. Results of focus group discussions reinforced the importance of refining public health messages well in advance of distribution so that cultural acceptability is strong. After the image was finalized, we deployed shoes with the image in communities in western Uganda where hookworm is prevalent. We found that the frequency of shoe-wearing was 25% higher in communities receiving the shoes than in control communities. Microscopic analyses of fecal samples for parasites showed a sustained reduction in infection intensity for parasites transmitted directly through the feet when people received shoes with a public health image. Our results show that combining culturally appropriate images with public health interventions can be effective in low-literacy populations. © The American Society of Tropical Medicine and Hygiene.

Volatile and non-volatile elements in grain-size separated samples of Apollo 17 lunar soils

International Nuclear Information System (INIS)

Giovanoli, R.; Gunten, H.R. von; Kraehenbuehl, U.; Meyer, G.; Wegmueller, F.; Gruetter, A.; Wyttenbach, A.

1977-01-01

Three samples of Apollo 17 lunar soils (75081, 72501 and 72461) were separated into 9 grain-size fractions between 540 and 1 μm mean diameter. In order to detect mineral fractionations caused during the separation procedures major elements were determined by instrumental neutron activation analyses performed on small aliquots of the separated samples. Twenty elements were measured in each size fraction using instrumental and radiochemical neutron activation techniques. The concentration of the main elements in sample 75081 does not change with the grain-size. Exceptions are Fe and Ti which decrease slightly and Al which increases slightly with the decrease in the grain-size. These changes in the composition in main elements suggest a decrease in Ilmenite and an increase in Anorthite with decreasing grain-size. However, it can be concluded that the mineral composition of the fractions changes less than a factor of 2. Samples 72501 and 72461 are not yet analyzed for the main elements. (Auth.)

Soil base saturation combines with beech bark disease to influence composition and structure of sugar maple-beech forests in an acid rain-impacted region

Science.gov (United States)

Gregory B. Lawrence; Todd C. McDonnell; Timothy J. Sullivan; Martin Dovciak; Scott W. Bailey; Michael R. Antidormi; Michael R. Zarfos

2017-01-01

Sugar maple, an abundant and highly valued tree species in eastern North America, has experienced decline from soil calcium (Ca) depletion by acidic deposition, while beech, which often coexists with sugar maple, has been afflicted with beech bark disease (BBD) over the same period. To investigate how variations in soil base saturation combine with effects of BBD in...

[Effects of combined pollution of lead and benzo[a] pyrene on seed growth of wheat in soils].

Science.gov (United States)

Wang, Hong-Qi; Wang, Shuai; Ning, Shao-Wei; Sun, Yan-Ling; Hou, Ze-Qing

2011-03-01

Seed germination, root elongation, shoot elongation and ratio of shoot to root of wheat in soils polluted by lead (Pb) and benzo (a)pyrene (B[a] P) with medium-low concentrations were studied to reveal the ecological effects of combined pollution and screen the indicative markers. Results indicated that seed germination was not sensitive to single or combined pollution of Pb or B[a] P. Root elongation was inhibited by single pollution of Pb or B[a]P to different extents. Extensive interactions between Pb and B[a]P occurred to root elongation of wheat, including synergistic-stimulatory effect and antagonistic-inhibitory effect. The joint action was mainly antagonistic. Single pollution of B [a] P had an inhibitory effect on shoot elongation. Under combined pollution conditions, the shoot elongation of wheat correlated well with Pb contents (p pollutants had little effect on shoot elongation of wheat. The joint action on shoot elongation was consistently antagonistic. The response pattern of the ratio of shoot to root was similar to the response pattern of shoot elongation. However, the former had better correlation than the latter, indicating it as a more suitable indicative marker for Pb pollution. If lead acetate was employed instead of lead nitrate, longer root elongation, shorter shoot elongation and no effect on ratio of shoot to root were found. Therefore, the forms of Pb salt had significant influence on seed growth of wheat in soils.

Sequential extraction combined with isotope analysis as a tool for the investigation of lead mobilisation in soils: Application to organic-rich soils in an upland catchment in Scotland

International Nuclear Information System (INIS)

Bacon, Jeffrey R.; Farmer, John G.; Dunn, Sarah M.; Graham, Margaret C.; Vinogradoff, Susan I.

2006-01-01

Sequential extraction (modified BCR procedure) combined with isotope analysis has been investigated as a tool for assessing mobilisation of lead into streams at an upland catchment in NE Scotland. The maximum lead concentrations (up to 110 mg kg -1 in air-dried soil) occurred not at the surface but at about 10 cm depth. The lowest 206 Pb/ 207 Pb ratios in any profile occurred, with one exception, at 2.5-5 cm depth. In the one exception, closest to the only road in the area, significantly lower 206 Pb/ 207 Pb ratios in the surface soil together with much increased chloride concentrations (in comparison to other surface waters) indicated the possible mobilisation of roadside lead and transfer to the stream. The 206 Pb/ 207 Pb ratios in extractable fractions tended at depth towards the ratio measured in the residual phase but the ratios in the oxidizable fraction increased to a value higher than that of the residual phase. - Sequential extraction combined with isotope analysis was used as a tool to assess mobilisation of lead into streams

Combination of bioleaching by gross bacterial biosurfactants and flocculation: A potential remediation for the heavy metal contaminated soils.

Science.gov (United States)

Yang, Zhihui; Shi, Wei; Yang, Weichun; Liang, Lifen; Yao, Wenbin; Chai, Liyuan; Gao, Shikang; Liao, Qi

2018-09-01

Combining bioleaching by the gross biosurfactants of Burkholderia sp. Z-90 and flocculation by poly aluminium chloride (PAC) was proposed to develop a potential environment-friendly and cost-effective technique to remediate the severely contaminated soils by heavy metals. The factors affecting soil bioleaching by the gross biosurfactants of Burkholderia sp. Z-90 were optimized. The results showed the optimal removing efficiencies of Zn, Pb, Mn, Cd, Cu, and As by the Burkholderia sp. Z-90 leachate were 44.0, 32.5, 52.2, 37.7, 24.1 and 31.6%, respectively at soil liquid ratio of 1:20 (w/v) for 5 d, which were more efficient than that by 0.1% of rhamnolipid. The amounts of the bioleached heavy metals by the Burkholderia sp. Z-90 leachate were higher than that by other biosurfactants in the previous studies, although the removal efficiencies of the metals by the leachate were relatively lower. It was suggested that more heavy metals caused more competitive to chelate with function groups of the gross biosurfactants and the metal removal efficiencies by biosurfactants in natural soils were lower than in the artificially contaminated soils. Moreover, the Burkholderia sp. Z-90 leachate facilitated the metals to be transformed to the easily migrating speciation fractions. Additional, the results showed that PAC was efficient in the following flocculation to remove heavy metals in the waste bio-leachates. Our study will provide support for developing a bioleaching technique model to remediate the soils extremely contaminated by heavy metals. Copyright © 2018 Elsevier Ltd. All rights reserved.

Investigating CH4 production in an oxic plant-soil system -a new approach combining isotopic labelling (13C) and inhibitors

Science.gov (United States)

Lenhart, Katharina; Keppler, Frank

2017-04-01

Typically, aerated soil are net sinks of atmospheric methane (CH4), being highest in native ecosystems (pristine forests > managed forests > grasslands > crop fields). However, this does not exclude a simultaneous endogenic CH4 production in the plant-soil system, which cannot be detected simply via CH4 flux measurements. Methanogenic archaea producing CH4 under anoxic conditions were thought to be the only biotic source of CH4 in the soil. However, until recently a non-archaeal pathway of CH4 formation is known where CH4 is produced under oxic conditions in plants (Keppler et al. 2006) and fungi (Lenhart et al. 2012). Additionally, abiotic formation of CH4 from soil organic matter was reported (Jugold et al. 2012) and may be ubiquitous in terrestrial ecosystems. The major goal of this project was to determine soil endogenic CH4 sources and to estimate their contribution to the endogenic CH4 production. Especially the effect of plants and fungi on soil CH4 production was investigated. Therefore, a series of experiments was carried out on field fresh soil collected in a grassland and a forest ecosystem under controlled laboratory conditions. By combining selective inhibitors and 13C labelling, CH4 production rates of several CH4 sources were quantified. The major difficulty was to detect the comparatively small flux of CH4 production against the background of the high CH4 consumption rates due to methanotrophic bacteria. Therefore, we supplemented bare soil and soil with vegetation with selective inhibitors and 13C labelled substrates in a closed chamber system. In a first step, CH4 production was determined by the inhibition of CH4 oxidizing bacteria with Difluoromethane (DFM, 2ml l-1). In the following, a 13C labelled substrate (either CO2, Acetate, or Methionine -S-CH3 labelled) was added in combination with a specific inhibitor -either for archaeal methanogenesis (Bromoethanesulfonate), bacteria (Streptomycin), or fungi (Captan, Cycloheximide). Gas samples were

REE Distribution in Cultivated and No Cultivated Soils in Two Viticultural Areas of Central Chile: Mineralogical, Pedological and Anthropic Influences

Science.gov (United States)

Castillo, P.; Townley, B.; Aburto, F.

2017-12-01

Within the scope of a Corfo-Innova Project (I+D Wines of Chile-University of Chile) we have recognized remarkable REE patterns in soils of two vineyards located in traditional vinicultural areas: Casablanca and Santa Cruz. Both vineyards have granitic parent rock, with similar petrographic features and REE patterns. We studied REE distribution on twelve cultivated soil profiles at each vineyard, where a full mineralogical, geochemical and pedogenic sampling and characterization was performed. To establish the effect of management no cultivated soil profiles were included from each vineyard location. REE in soil samples were measured by ICP-MS using two digestion methods: lithium metaborate/tetraborate fusion to obtain REE contents in total soil and MMI® partial extraction technique for REE contents on bioavailable phases.Soils display similar signatures of REEs respect to the rock source at both vineyards, but showing relative enrichments in soils of Casablanca and depletion in soils of Santa Cruz. Bioavailable phase data indicates a relative depletion of LREEs compared to HREEs and different anomalies for Ce (positive vs negative) in different areas of the same vineyard. Similar patterns of soils and parent rock suggest that REEs are adequate tracers of lithological source. Enrichments and/or depletions of REE patterns in soils respect to the rock source and Ce anomalies, evidence differential pedogenetic processes occurring at each sampled site. Results of bioavailable phase are coherent with the immobilization and fractionation of LREEs by stable minerals within soils as clays and Fe oxides. Mineralogical results in soil thin sections of Casablanca evidence the occurrence of Ti phases as sphene, ilmenite and rutile, which probably control the relative REE enrichment, since these minerals are considered more stable under pedogenic conditions.Finally, cultivated soils show a depleted but analogous pattern of REE regarding to no cultivated soil, indicating the

the use of integrated soil fertility approach in the improvement of soil

African Journals Online (AJOL)

Sammy

Innovational practices in the management of organic matters in semi-arid soil, ... Compared to other areas, a large proportion of soil in semi-arid areas has low .... combine old and new methods of nutrient management into ecologically sound and ... Furthermore, organic matter is the energy source for soil fauna and micro ...

Organics removal of combined wastewater through shallow soil infiltration treatment: a field and laboratory study.

Science.gov (United States)

Zhang, Zhiyin; Lei, Zhongfang; Zhang, Zhenya; Sugiura, Norio; Xu, Xiaotian; Yin, Didi

2007-11-19

Soil infiltration treatment (SIT) was proved to be an effective and low-cost treatment technique for decentralized effluents in the areas without perfect sewage systems. Field-scale experiments were conducted under several conditions to assess organics removals through a shallow soil infiltration treatment (SSIT, with effective depth 0.3m) of combined wastewater (discharge from toilets, restaurants and a gas station), while bench-scale soil column experiments were performed in laboratory in parallel to investigate biological and abiological effects of this kind of system. From the start-up to the 10th month, the field SSIT trenches experienced the lowest and highest temperatures of the operation period in Shanghai and exhibited effective organics removals after maturation, with the highest removal rate 75.8% of chemical oxygen demand (COD), highest ultraviolet absorption at 254 nm (UV(254)) decrease by 67.2% and 35.2-100% removals of phenolic and phthalate pollutants. The laboratory results indicated that more organics could be removed in room-temperatured (25+/-2 degrees C) SSIT systems under different influent COD concentrations from 45 mg/l to 406 mg/l, and the highest total COD removal rate could reach 94.0%, in which biological effect accounted for 57.7-71.9%. The results showed that temperature and hydraulic loading rate were the most important factors influencing the removals of COD and organic pollutants in SSIT.

Partitioning of hexachlorobenzene in a kaolin/humic acid/surfactant/water system: Combined effect of surfactant and soil organic matter

Energy Technology Data Exchange (ETDEWEB)

Wan, Jinzhong; Wang, Lingling [Environmental Science Research Institute, Huazhong University of Science and Technology, Wuhan 430074 (China); Lu, Xiaohua, E-mail: hust-esri2009@hotmail.com [Environmental Science Research Institute, Huazhong University of Science and Technology, Wuhan 430074 (China); Lin, Yusuo; Zhang, Shengtian [Nanjing Institute of Environmental Science, Ministry of Environmental Protection of China, Nanjing 210042 (China)

2011-11-30

Highlights: Black-Right-Pointing-Pointer We study HCB partitioning in a kaolin/humic acid/TX100/water system. Black-Right-Pointing-Pointer We reveal influence of TX100-HA interaction on TX100 and HA sorption to kaolin. Black-Right-Pointing-Pointer We verify combined effect of TX100 and HA on HCB desorption from clay. - Abstract: Understanding the combined effect of soil organic matter (SOM) and surfactants on the partitioning of hydrophobic organic compounds in soil/water systems is important to predict the effectiveness of surfactant-enhanced remediation (SER). In the present study we investigate the partitioning of hexachlorobenzene (HCB) within a humic acid (HA)-coated kaolin/Triton X-100 (TX100)/water system, with special emphasis on the interaction between TX100 and HA, and their combined effect on HCB sorption. HA firstly enhanced then suppressed TX100 sorption to kaolin as the amounts of HA increased, while the addition of TX100 led to a consistent reduction in HA sorption. In the HA-coated kaolin/TX100/water system, TX100 played a primary role in enhancing desorption of HCB, while the role could be suppressed and then enhanced as HA coating amounts increased. Only at HA coating above 2.4%, dissolved HA outcompeted clay-bound HA for HCB partitioning, resulting in dissolved HA enhanced desorption. The presence of dissolved HA at these conditions further promoted the effectiveness of TX100 enhanced desorption. Despite a reduced TX100 sorption to clay was achieved due to the presence of dissolved HA, the effect on HCB desorption was comparatively slight. A reliable cumulative influence of HA and TX100 on HCB desorption was observed, although HCB desorption by HA/TX100 mixed was less than the sum of HA and TX100 individually. Our study suggests that for soils of high organic contents, the combined effect of SOM and surfactants on HOCs desorption can be applied to improve the performance of SER.

Clay-illuvial soils in the Polish and international soil classifications

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Kabała Cezary

2015-12-01

Full Text Available Soil with a clay-illuvial subsurface horizon are the most widespread soil type in Poland and significantly differ in morphology and properties developed under variable environmental conditions. Despite the long history of investigations, the rules of classification and cartography of clay-illuvial soils have been permanently discussed and modified. The distinction of clay-illuvial soils into three soil types, introduced to the Polish soil classification in 2011, has been criticized as excessively extended, non-coherent with the other parts and rules of the classification, hard to introduce in soil cartography and poorly correlated with the international soil classifications. One type of clay-illuvial soils (“gleby płowe” was justified and recommended to reintroduce in soil classification in Poland, as well as 10 soil subtypes listed in a hierarchical order. The subtypes may be combined if the soil has diagnostic features of more than one soil subtypes. Clear rules of soil name generalization (reduction of subtype number for one soil were suggested for soil cartography on various scales. One of the most important among the distinguished soil sub-types are the “eroded” or “truncated” clay-illuvial soils.

Soil health: a comparison between organically and conventionally managed arable soils in the Netherlands

NARCIS (Netherlands)

Diepeningen, van A.D.; Blok, W.J.; Korthals, G.W.; Bruggen, van A.H.C.; Ariena, H.C.

2005-01-01

A comparative study of 13 organic and 13 neighboring conventional arable farming systems was conducted in the Netherlands to determine the effect of management practices on chemical and biological soil properties and soil health. Soils were analyzed using a polyphasic approach combining traditional

Combined spatial prediction of schistosomiasis and soil-transmitted helminthiasis in Sierra Leone: a tool for integrated disease control.

Directory of Open Access Journals (Sweden)

Mary H Hodges

Full Text Available BACKGROUND: A national mapping of Schistosoma haematobium was conducted in Sierra Leone before the mass drug administration (MDA with praziquantel. Together with the separate mapping of S. mansoni and soil-transmitted helminths, the national control programme was able to plan the MDA strategies according to the World Health Organization guidelines for preventive chemotherapy for these diseases. METHODOLOGY/PRINCIPAL FINDINGS: A total of 52 sites/schools were selected according to prior knowledge of S. haematobium endemicity taking into account a good spatial coverage within each district, and a total of 2293 children aged 9-14 years were examined. Spatial analysis showed that S. haematobium is heterogeneously distributed in the country with significant spatial clustering in the central and eastern regions of the country, most prevalent in Bo (24.6% and 8.79 eggs/10 ml, Koinadugu (20.4% and 3.53 eggs/10 ml and Kono (25.3% and 7.91 eggs/10 ml districts. By combining this map with the previously reported maps on intestinal schistosomiasis using a simple probabilistic model, the combined schistosomiasis prevalence map highlights the presence of high-risk communities in an extensive area in the northeastern half of the country. By further combining the hookworm prevalence map, the at-risk population of school-age children requiring integrated schistosomiasis/soil-transmitted helminth treatment regimens according to the coendemicity was estimated. CONCLUSIONS/SIGNIFICANCE: The first comprehensive national mapping of urogenital schistosomiasis in Sierra Leone was conducted. Using a new method for calculating the combined prevalence of schistosomiasis using estimates from two separate surveys, we provided a robust coendemicity mapping for overall urogenital and intestinal schistosomiasis. We also produced a coendemicity map of schistosomiasis and hookworm. These coendemicity maps can be used to guide the decision making for MDA strategies in combination

Combined spatial prediction of schistosomiasis and soil-transmitted helminthiasis in Sierra Leone: a tool for integrated disease control.

Science.gov (United States)

Hodges, Mary H; Soares Magalhães, Ricardo J; Paye, Jusufu; Koroma, Joseph B; Sonnie, Mustapha; Clements, Archie; Zhang, Yaobi

2012-01-01

A national mapping of Schistosoma haematobium was conducted in Sierra Leone before the mass drug administration (MDA) with praziquantel. Together with the separate mapping of S. mansoni and soil-transmitted helminths, the national control programme was able to plan the MDA strategies according to the World Health Organization guidelines for preventive chemotherapy for these diseases. A total of 52 sites/schools were selected according to prior knowledge of S. haematobium endemicity taking into account a good spatial coverage within each district, and a total of 2293 children aged 9-14 years were examined. Spatial analysis showed that S. haematobium is heterogeneously distributed in the country with significant spatial clustering in the central and eastern regions of the country, most prevalent in Bo (24.6% and 8.79 eggs/10 ml), Koinadugu (20.4% and 3.53 eggs/10 ml) and Kono (25.3% and 7.91 eggs/10 ml) districts. By combining this map with the previously reported maps on intestinal schistosomiasis using a simple probabilistic model, the combined schistosomiasis prevalence map highlights the presence of high-risk communities in an extensive area in the northeastern half of the country. By further combining the hookworm prevalence map, the at-risk population of school-age children requiring integrated schistosomiasis/soil-transmitted helminth treatment regimens according to the coendemicity was estimated. The first comprehensive national mapping of urogenital schistosomiasis in Sierra Leone was conducted. Using a new method for calculating the combined prevalence of schistosomiasis using estimates from two separate surveys, we provided a robust coendemicity mapping for overall urogenital and intestinal schistosomiasis. We also produced a coendemicity map of schistosomiasis and hookworm. These coendemicity maps can be used to guide the decision making for MDA strategies in combination with the local knowledge and programme needs.

Combined effect of soil amendment with oil cakes and seed priming in the control of root rot fungi of leguminous and non-leguminous crops

International Nuclear Information System (INIS)

Rafi, H.; Dawar, S.; Tariq, M.

2016-01-01

Organic amendments of soil help in proper aeration, rising of temperature and water holding capacity which results in better uptake of nutrients with root system gets extensive establishment. In this study, effects of soil amendment with oil seed cakes including mustard (Brassica campestris L.), cotton (Gossypium hirsutum L.), almond (Prunus amygdalus L.) and black seed (Nigella sativa L.) cakes at the rate of 0.1 and 1% w/w and priming of seeds with Acacia nilotica (L.) Willd. ex Delile and Sapindus mukorossi (L.) leaves extracts and microbial antagonists (Trichoderma harzianum and Rhizobium melilotii) was observed on the growth of plants and in the suppression of root infecting fungi. The results obtained showed that combined effect of bio-priming of seeds with T. harzianum spore suspension and amendment of soil with mustard cake at the rate of 1% was found to be most effective for the growth of leguminous and non-leguminous crop plants (peanut, chickpea, okra and sunflower) and for the reduction of root infecting fungi like Macrophomina phaseolina, Fusarium spp followed by R. meliloti primed seeds in combination with cotton, almond and black seed cakes amendment respectively as compared to control (non treated seeds and soil). (author)

Towards the development of multifunctional molecular indicators combining soil biogeochemical and microbiological variables to predict the ecological integrity of silvicultural practices.

Science.gov (United States)

Peck, Vincent; Quiza, Liliana; Buffet, Jean-Philippe; Khdhiri, Mondher; Durand, Audrey-Anne; Paquette, Alain; Thiffault, Nelson; Messier, Christian; Beaulieu, Nadyre; Guertin, Claude; Constant, Philippe

2016-05-01

The impact of mechanical site preparation (MSP) on soil biogeochemical structure in young larch plantations was investigated. Soil samples were collected in replicated plots comprising simple trenching, double trenching, mounding and inverting site preparation. Unlogged natural mixed forest areas were used as a reference. Analysis of soil nutrients, abundance of bacteria and gas exchanges unveiled no significant difference among the plots. However, inverting site preparation resulted in higher variations of gas exchanges when compared with trenching, mounding and unlogged natural forest. A combination of the biological and physicochemical variables was used to define a multifunctional classification of the soil samples into four distinct groups categorized as a function of their deviation from baseline ecological conditions. According to this classification model, simple trenching was the approach that represented the lowest ecological risk potential at the microsite level. No relationship was observed between MSP method and soil bacterial community structure as assessed by high-throughput sequencing of bacterial 16S rRNA gene; however, indicator genotypes were identified for each multifunctional soil class. This is the first identification of multifunctional molecular indicators for baseline and disturbed ecological conditions in soil, demonstrating the potential of applied microbial ecology to guide silvicultural practices and ecological risk assessment. © 2016 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Development and assessment of transparent soil and particle image velocimetry in dynamic soil-structure interaction

Science.gov (United States)

2007-02-01

This research combines Particle Image Velocimetry (PIV) and transparent soil to investigate the dynamic rigid block and soil interaction. In order to get a low viscosity pore fluid for the transparent soil, 12 different types of chemical solvents wer...

DDT uptake by arbuscular mycorrhizal alfalfa and depletion in soil as influenced by soil application of a non-ionic surfactant

International Nuclear Information System (INIS)

Wu Naiying; Zhang Shuzhen; Huang Honglin; Shan Xiaoquan; Christie, Peter; Wang Youshan

2008-01-01

A greenhouse pot experiment was conducted to investigate the colonization of alfalfa roots by the arbuscular mycorrhizal (AM) fungus Glomus etunicatum and application of the non-ionic surfactant Triton X-100 on DDT uptake by alfalfa and depletion in soil. Mycorrhizal colonization led to an increase in the accumulation of DDT in roots but a decrease in shoots. The combination of AM inoculation and Triton X-100 application enhanced DDT uptake by both the roots and shoots. Application of Triton X-100 gave much lower residual concentrations of DDT in the bulk soil than in the rhizosphere soil or in the bulk soil without Triton X-100. AM colonization significantly increased bacterial and fungal counts and dehydrogenase activity in the rhizosphere soil. The combined AM inoculation of plants and soil application of surfactant may have potential as a biotechnological approach for the decontamination of soil polluted with DDT. - Combined colonization of alfalfa roots by an arbuscular mycorrhizal fungus and addition of non-ionic surfactant to the soil promoted root and shoot uptake and soil dissipation of DDT

DDT uptake by arbuscular mycorrhizal alfalfa and depletion in soil as influenced by soil application of a non-ionic surfactant

Energy Technology Data Exchange (ETDEWEB)

Wu Naiying [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China); Zhang Shuzhen [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China)], E-mail: szzhang@rcees.ac.cn; Huang Honglin; Shan Xiaoquan [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China); Christie, Peter [Agricultural and Environmental Science Department, Queen' s University Belfast, Newforge Lane, Belfast BT9 5PX (United Kingdom); Wang Youshan [Municipal Academy of Agriculture and Forestry, Institute of Plant Nutrition and Resources, Beijing 100097 (China)

2008-02-15

A greenhouse pot experiment was conducted to investigate the colonization of alfalfa roots by the arbuscular mycorrhizal (AM) fungus Glomus etunicatum and application of the non-ionic surfactant Triton X-100 on DDT uptake by alfalfa and depletion in soil. Mycorrhizal colonization led to an increase in the accumulation of DDT in roots but a decrease in shoots. The combination of AM inoculation and Triton X-100 application enhanced DDT uptake by both the roots and shoots. Application of Triton X-100 gave much lower residual concentrations of DDT in the bulk soil than in the rhizosphere soil or in the bulk soil without Triton X-100. AM colonization significantly increased bacterial and fungal counts and dehydrogenase activity in the rhizosphere soil. The combined AM inoculation of plants and soil application of surfactant may have potential as a biotechnological approach for the decontamination of soil polluted with DDT. - Combined colonization of alfalfa roots by an arbuscular mycorrhizal fungus and addition of non-ionic surfactant to the soil promoted root and shoot uptake and soil dissipation of DDT.

Persistence of glyphosate and aminomethylphosphonic acid in loess soil under different combinations of temperature, soil moisture and light/darkness

NARCIS (Netherlands)

Martins Bento, Celia; Yang, Xiaomei; Gort, Gerrit; Xue, Sha; Dam, van Ruud; Zomer, Paul; Mol, Hans G.J.; Ritsema, Coen J.; Geissen, Violette

2016-01-01

The dissipation kinetics of glyphosate and its metabolite aminomethylphosphonic acid (AMPA) were studied in loess soil, under biotic and abiotic conditions, as affected by temperature, soil moisture (SM) and light/darkness. Nonsterile and sterile soil samples were spiked with 16 mg kg⁻

Effects of soil surface management practices on soil and tree ...

African Journals Online (AJOL)

Effects on soil, leaf and fruit element concentrations of organic (compost, straw mulch and hand weeding) and integrated (inorganic fertilisers and herbicide usage; IP) soil surface management practices in the tree rows, in combination with weed covers, cover crops and straw mulch in the work rows, were investigated in a ...

Combined in-situ and ex-situ bioremediation of petroleum hydrocarbon contaminated soils by closed-loop soil vapor extraction and air injection

International Nuclear Information System (INIS)

Hu, S.S.; Buckler, M.J.

1993-01-01

Treatment and restoration of petroleum hydrocarbon contaminated soils at a bulk petroleum above-ground storage tank (AST) site in Michigan is being conducted through in-situ and ex-situ closed-loop soil vapor extraction (SVE), soil vapor treatment, and treated air injection (AI) processes. The soil vapor extraction process applies a vacuum through the petroleum hydrocarbon affected soils in the ex-situ bio-remediation pile (bio-pile) and along the perimeter of excavated area (in-situ area) to remove the volatile or light petroleum hydrocarbons. This process also draws ambient air into the ex-situ bio-pile and in-situ vadose zone soil along the perimeter of excavated area to enhance biodegradation of light and heavy petroleum hydrocarbons in the soil. The extracted soil vapor is treated using a custom-designed air bio-remediation filter (bio-filter) to degrade the petroleum hydrocarbon compounds in the soil vapor extraction air streams. The treated air is then injected into a flush grade soil bed in the backfill area to perform final polishing of the air stream, and to form a closed-loop air flow with the soil vapor extraction perforated pipes along the perimeter of the excavated area

Soil Plasticity Model for Analysis of Collapse Load on Layers Soil

Directory of Open Access Journals (Sweden)

Md Nujid Masyitah

2016-01-01

Full Text Available Natural soil consist of soil deposits which is a soil layer overlying a thick stratum of another soil. The bearing capacity of layered soil studies have been conducted using different approach whether theoretical, experimental and combination of both. Numerical method in computer programme has become a powerful tool in solving complex geotechnical problems. Thus in numerical modelling, stress-strain soil behaviour is well predicted, design and interpreted using appropriate soil model. It is also important to identify parameters and soil model involve in prediction real soil problem. The sand layer overlaid clay layer soil is modelled with Mohr-Coulomb and Drucker-Prager criterion. The bearing capacity in loaddisplacement analysis from COMSOL Multiphysics is obtained and presented. In addition the stress distribution and evolution of plastic strain for each thickness ratio below centre of footing are investigated. The results indicate the linear relation on load-displacement which have similar trend for both soil models while stress and plastic strain increase as thickness ratio increase.

Soil aggregation and slope stability related to soil density, root length, and mycorrhiza

Science.gov (United States)

Graf, Frank; Frei, Martin

2013-04-01

Eco-engineering measures combine the use of living plants and inert mechanical constructions to protect slopes against erosion and shallow mass movement. Whereas in geotechnical engineering several performance standards and guidelines for structural safety and serviceability of construction exist, there is a lack of comparable tools in the field of ecological restoration. Various indicators have been proposed, including the fractal dimension of soil particle size distribution, microbiological parameters, and soil aggregate stability. We present results of an soil aggregate stability investigation and compare them with literature data of the angle of internal friction ?' which is conventionally used in slope stability analysis and soil failure calculation. Aggregate stability tests were performed with samples of differently treated moraine, including soil at low (~15.5 kN/m³) and high (~19.0 kN/m³) dry unit weight, soil planted with Alnus incana (White Alder) as well as the combination of soil planted with alder and inoculated with the mycorrhizal fungus Melanogaster variegatus s.l. After a 20 weeks growth period in a greenhouse, a total of 100 samples was tested and evaluated. Positive correlations were found between the soil aggregate stability and the three variables dry unit weight, root length per soil volume, and degree of mycorrhization. Based on robust statistics it turned out that dry unit weight and mycorrhization degree were strongest correlated with soil aggregate stability. Compared to the non-inoculated control plants, mycorrhized White Alder produced significantly more roots and higher soil aggregate stability. Furthermore, the combined biological effect of plant roots and mycorrhizal mycelia on aggregate stability on soil with low density (~15.5 kN/m³) was comparable to the compaction effect of the pure soil from 15.5 to ~19.0 kN/m³. Literature data on the effect of vegetation on the angle of internal friction ?' of the same moraine showed

Determination of mobile form contents of Zn, Cd, Pb and Cu in soil extracts by combined stripping voltammetry

International Nuclear Information System (INIS)

Nedeltcheva, T.; Atanassova, M.; Dimitrov, J.; Stanislavova, L.

2005-01-01

The amount of mobile forms of Zn, Pb, Cd and Cu in extracts obtained by treating soil samples with ammonium nitrate were determined by an appropriate combination of anodic and cathodic stripping voltammetry with hanging mercury drop electrode. Every analysis required three mercury drops: on the first one, zinc was determined; on the second, cadmium and lead; on the third, copper was determined. Zinc, lead and cadmium were determined by conventional differential-pulse anodic stripping voltammetry. For copper determination, adsorptive differential-pulse cathodic stripping voltammetry with amalgamation using chloride ions as a complexing agent was applied. The standard deviation of the results was from 1 to 10% depending on the metal content in the sample. Voltammetric results were in good agreement with the AAS analysis. No microwave digestion of soil extracts was necessary

Determination of mobile form contents of Zn, Cd, Pb and Cu in soil extracts by combined stripping voltammetry

Energy Technology Data Exchange (ETDEWEB)

Nedeltcheva, T. [Department of Analytical Chemistry, University of Chemical Technology and Metallurgy, 8 Kl. Ohridsi Blvd., 1756 Sofia (Bulgaria)]. E-mail: nedel@uctm.edu; Atanassova, M. [Department of Analytical Chemistry, University of Chemical Technology and Metallurgy, 8 Kl. Ohridsi Blvd., 1756 Sofia (Bulgaria); Dimitrov, J. [N. Pushkarov Institute of Soil Science and Agroecology, 7 Shosse Bankya St., 1080 Sofia (Bulgaria); Stanislavova, L. [N. Pushkarov Institute of Soil Science and Agroecology, 7 Shosse Bankya St., 1080 Sofia (Bulgaria)

2005-01-10

The amount of mobile forms of Zn, Pb, Cd and Cu in extracts obtained by treating soil samples with ammonium nitrate were determined by an appropriate combination of anodic and cathodic stripping voltammetry with hanging mercury drop electrode. Every analysis required three mercury drops: on the first one, zinc was determined; on the second, cadmium and lead; on the third, copper was determined. Zinc, lead and cadmium were determined by conventional differential-pulse anodic stripping voltammetry. For copper determination, adsorptive differential-pulse cathodic stripping voltammetry with amalgamation using chloride ions as a complexing agent was applied. The standard deviation of the results was from 1 to 10% depending on the metal content in the sample. Voltammetric results were in good agreement with the AAS analysis. No microwave digestion of soil extracts was necessary.

Decontamination of electronic waste-polluted soil by ultrasound-assisted soil washing.

Science.gov (United States)

Chen, Fu; Yang, Baodan; Ma, Jing; Qu, Junfeng; Liu, Gangjun

2016-10-01

Laboratorial scale experiments were performed to evaluate the efficacy of a washing process using the combination of methyl-β-cyclodextrin (MCD) and tea saponin (TS) for simultaneous desorption of hydrophobic organic contaminants (HOCs) and heavy metals from an electronic waste (e-waste) site. Ultrasonically aided mixing of the field contaminated soil with a combination of MCD and TS solutions simultaneously mobilizes most of polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and the analyte metal (Pb, Cu, and Ni) burdens. It is found that 15 g/L MCD and 10 g/L TS is an efficient reagent combination reconciling extraction performance and reagent costs. Under these conditions, the removal efficiencies of HOCs and heavy metals are 93.5 and 91.2 %, respectively, after 2 cycles of 60-min ultrasound-assisted washing cycles. By contrast, 86.3 % of HOCs and 88.4 % of metals are removed from the soil in the absence of ultrasound after 3 cycles of 120-min washing. The ultrasound-assisted soil washing could generate high removal efficiency and decrease the operating time significantly. Finally, the feasibility of regenerating and reusing the spent washing solution in extracting pollutants from the soil is also demonstrated. By application of this integrated technology, it is possible to recycle the washing solution for a purpose to reduce the consumption of surfactant solutions. Collectively, it has provided an effective and economic treatment of e-waste-polluted soil.

Combined effects of zinc and earthworm density on soil ecosystem functioning

NARCIS (Netherlands)

Lahr, J.; Kools, S.A.E.; Hout, van der A.; Faber, J.H.

2008-01-01

In traditional environmental risk assessment for soils, interactions between biota, contaminants and soil functioning are seldom taken into account. Also, single species toxicity tests are conducted with a fixed number of test animals. The objective of this study was to investigate effects of zinc

Soil-ecological risks for soil degradation estimation

Science.gov (United States)

Trifonova, Tatiana; Shirkin, Leonid; Kust, German; Andreeva, Olga

2016-04-01

Soil degradation includes the processes of soil properties and quality worsening, primarily from the point of view of their productivity and decrease of ecosystem services quality. Complete soil cover destruction and/or functioning termination of soil forms of organic life are considered as extreme stages of soil degradation, and for the fragile ecosystems they are normally considered in the network of their desertification, land degradation and droughts /DLDD/ concept. Block-model of ecotoxic effects, generating soil and ecosystem degradation, has been developed as a result of the long-term field and laboratory research of sod-podzol soils, contaminated with waste, containing heavy metals. The model highlights soil degradation mechanisms, caused by direct and indirect impact of ecotoxicants on "phytocenosis- soil" system and their combination, frequently causing synergistic effect. The sequence of occurring changes here can be formalized as a theory of change (succession of interrelated events). Several stages are distinguished here - from heavy metals leaching (releasing) in waste and their migration downward the soil profile to phytoproductivity decrease and certain phytocenosis composition changes. Phytoproductivity decrease leads to the reduction of cellulose content introduced into the soil. The described feedback mechanism acts as a factor of sod-podzolic soil self-purification and stability. It has been shown, that using phytomass productivity index, integrally reflecting the worsening of soil properties complex, it is possible to solve the problems dealing with the dose-reflecting reactions creation and determination of critical levels of load for phytocenosis and corresponding soil-ecological risks. Soil-ecological risk in "phytocenosis- soil" system means probable negative changes and the loss of some ecosystem functions during the transformation process of dead organic substance energy for the new biomass composition. Soil-ecological risks estimation is

Soil heavy metals

Energy Technology Data Exchange (ETDEWEB)

Sherameti, Irena [Jena Univ. (Germany). Inst. fuer Allgemeine Botanik und Pflanzenphysiologie; Varma, Ajit (eds.) [Amity Univ., Uttar Pradesh (India). Amity Inst. of Microbial Technology; Amity Science, Technology and Innovation Foundation, Noida, UP (India)

2010-07-01

Human activities have dramatically changed the composition and organisation of soils. Industrial and urban wastes, agricultural application and also mining activities resulted in an increased concentration of heavy metals in soils. How plants and soil microorganisms cope with this situation and the sophisticated techniques developed for survival in contaminated soils is discussed in this volume. The topics presented include: the general role of heavy metals in biological soil systems; the relation of inorganic and organic pollutions; heavy metal, salt tolerance and combined effects with salinity; effects on abuscular mycorrhizal and on saprophytic soil fungi; heavy metal resistance by streptomycetes; trace element determination of environmental samples; the use of microbiological communities as indicators; phytostabilization of lead polluted sites by native plants; effects of soil earthworms on removal of heavy metals and the remediation of heavy metal contaminated tropical land. (orig.)

Soil functional types: surveying the biophysical dimensions of soil security

Science.gov (United States)

Cécillon, Lauric; Barré, Pierre

2015-04-01

Soil is a natural capital that can deliver key ecosystem services (ES) to humans through the realization of a series of soil processes controlling ecosystem functioning. Soil is also a diverse and endangered natural resource. A huge pedodiversity has been described at all scales, which is strongly altered by global change. The multidimensional concept soil security, encompassing biophysical, economic, social, policy and legal frameworks of soils has recently been proposed, recognizing the role of soils in global environmental sustainability challenges. The biophysical dimensions of soil security focus on the functionality of a given soil that can be viewed as the combination of its capability and its condition [1]. Indeed, all soils are not equal in term of functionality. They show different processes, provide different ES to humans and respond specifically to global change. Knowledge of soil functionality in space and time is thus a crucial step towards the achievement soil security. All soil classification systems incorporate some functional information, but soil taxonomy alone cannot fully describe the functioning, limitations, resistance and resilience of soils. Droogers and Bouma [2] introduced functional variants (phenoforms) for each soil type (genoform) so as to fit more closely to soil functionality. However, different genoforms can have the same functionality. As stated by McBratney and colleagues [1], there is a great need of an agreed methodology for defining the reference state of soil functionality. Here, we propose soil functional types (SFT) as a relevant classification system for the biophysical dimensions of soil security. Following the definition of plant functional types widely used in ecology, we define a soil functional type as "a set of soil taxons or phenoforms sharing similar processes (e.g. soil respiration), similar effects on ecosystem functioning (e.g. primary productivity) and similar responses to global change (land-use, management or

Pedotransfer functions estimating soil hydraulic properties using different soil parameters

DEFF Research Database (Denmark)

Børgesen, Christen Duus; Iversen, Bo Vangsø; Jacobsen, Ole Hørbye

2008-01-01

Estimates of soil hydraulic properties using pedotransfer functions (PTF) are useful in many studies such as hydrochemical modelling and soil mapping. The objective of this study was to calibrate and test parametric PTFs that predict soil water retention and unsaturated hydraulic conductivity...... parameters. The PTFs are based on neural networks and the Bootstrap method using different sets of predictors and predict the van Genuchten/Mualem parameters. A Danish soil data set (152 horizons) dominated by sandy and sandy loamy soils was used in the development of PTFs to predict the Mualem hydraulic...... conductivity parameters. A larger data set (1618 horizons) with a broader textural range was used in the development of PTFs to predict the van Genuchten parameters. The PTFs using either three or seven textural classes combined with soil organic mater and bulk density gave the most reliable predictions...

Changes in Soil Chemical Properties and Lettuce Yield Response Following Incorporation of Biochar and Cow Dung to Highly Weathered Acidic Soils

DEFF Research Database (Denmark)

Agyei Frimpong, Kwame; Amoakwah, Emmanuel; Osei, Benjamin A

2016-01-01

imposed on two highly weathered, acidic soils from the coastal savanna and tropical rainforest agroecological zones of Ghana, respectively, to elucidate their effect on yield of lettuce. The study showed that application of biochar solely or in combination with cow dung increased soil pH, total organic...... carbon, and cation exchange capacity, and temporarily increased soil respiration and microbial biomass carbon. Further, incorporation of combined application of cow dung and biochar increased lettuce yield more than sole incorporation of either amendment. The study demonstrated that corn cob biochar can...... improve soil chemical properties and lettuce yield if applied solely or in combination with cow dung....

Dynamical soil-structure interactions: influence of soil behaviour nonlinearities

International Nuclear Information System (INIS)

Gandomzadeh, Ali

2011-01-01

the soil and the response of the soil-structure system. Through these parametric studies we show that depending on the soil properties, frequency content of the soil response could change significantly due to the soil nonlinearity. The peaks of the transfer function between free field and outcropping responses shift to lower frequencies and amplification happens at this frequency range. Amplification reduction for the high frequencies and even de-amplification may happen for high level input motions. These changes influence the structural response. We show that depending on the combination of the fundamental frequency of the structure and the the natural frequency of the soil, the effect of soil-structure interaction could be significant or negligible. However, the effect of structure weight and rocking of the superstructure could change the results. Finally, the basin of Nice is used as an example of wave propagation on a heterogeneous nonlinear media and dynamic soil-structure interaction. The basin response is strongly dependent on the combination of soil nonlinearity, topographic effects and impedance contrast between soil layers. For the selected structures and soil profiles of this work, the performed numerical simulations show that the shift of the fundamental frequency is not a good index to discriminate linear from nonlinear soil behavior. (author)

Lunar mare TiO2 abundances estimated from UV/Vis reflectance

Science.gov (United States)

Sato, Hiroyuki; Robinson, Mark S.; Lawrence, Samuel J.; Denevi, Brett W.; Hapke, Bruce; Jolliff, Bradley L.; Hiesinger, Harald

2017-11-01

The visible (400-700 nm) and near-infrared (700-2800 nm) reflectance of the lunar regolith is dominantly controlled by variations in the abundance of plagioclase, iron-bearing silicate minerals, opaque minerals (e.g., ilmenite), and maturation products (e.g., agglutinate glass, radiation-produced rims on soil grains, and Fe-metal). The same materials control reflectance into the near-UV (250-400 nm) with varying degrees of importance. A key difference is that while ilmenite is spectrally neutral in the visible to near-infrared, it exhibits a diagnostic upturn in reflectance in the near-UV, at wavelengths shorter than about 450 nm. The Lunar Reconnaissance Orbiter Wide Angle Camera (WAC) filters were specifically designed to take advantage of this spectral feature to enable more accurate mapping of ilmenite within mare soils than previously possible. Using the reflectance measured at 321 and 415 nm during 62 months of repeated near-global WAC observations, first we found a linear correlation between the TiO2 contents of the lunar soil samples and the 321/415 nm ratio of each sample return site. We then used the coefficients from the linear regression and the near-global WAC multispectral mosaic to derive a new TiO2 map. The average TiO2 content is 3.9 wt% for the 17 major maria. The highest TiO2 values were found in Mare Tranquillitatis (∼12.6 wt%) and Oceanus Procellarum (∼11.6 wt%). Regions contaminated by highland ejecta, lunar swirls, and the low-TiO2 maria (e.g., Mare Frigoris, the northeastern units of Mare Imbrium) exhibit very low TiO2 values (2.6 Ga), whereas only medium to high TiO2 values (average = 6.8 wt%, minimum = 4.5 wt%) are found for younger mare units (<2.6 Ga).

Soil-plant transfer models for metals to improve soil screening value guidelines valid for São Paulo, Brazil.

NARCIS (Netherlands)

Dos Santos-Araujo, Sabrina N; Swartjes, Frank A; Versluijs, Kees W; Moreno, Fabio Netto; Alleoni, Luís R F

2017-01-01

In Brazil, there is a lack of combined soil-plant data attempting to explain the influence of specific climate, soil conditions, and crop management on heavy metal uptake and accumulation by plants. As a consequence, soil-plant relationships to be used in risk assessments or for derivation of soil

Soil physical properties affecting soil erosion in tropical soils

International Nuclear Information System (INIS)

Lobo Lujan, D.

2004-01-01

The total vegetated land area of the earth is about 11,500 hectare. Of this, about 12% is in South America. Of this, about 14% is degraded area. Water erosion, chemical degradation, wind erosion, and physical degradation have been reported as main types of degradation. In South America water erosion is a major process for soil degradation. Nevertheless, water erosion can be a consequence of degradation of the soil structure, especially the functional attributes of soil pores to transmit and retain water, and to facilitate root growth. Climate, soil and topographic characteristics determine runoff and erosion potential from agricultural lands. The main factors causing soil erosion can be divided into three groups: Energy factors: rainfall erosivity, runoff volume, wind strength, relief, slope angle, slope length; Protection factors: population density, plant cover, amenity value (pressure for use) and land management; and resistance factors: soil erodibility, infiltration capacity and soil management. The degree of soil erosion in a particular climatic zone, with particular soils, land use and socioeconomic conditions, will always result from a combination of the above mentioned factors. It is not easy to isolate a single factor. However, the soil physical properties that determine the soil erosion process, because the deterioration of soil physical properties is manifested through interrelated problems of surface sealing, crusting, soil compaction, poor drainage, impeded root growth, excessive runoff and accelerated erosion. When an unprotected soil surface is exposed to the direct impact of raindrops it can produce different responses: Production of smaller aggregates, dispersed particles, particles in suspension and translocation and deposition of particles. When this has occurred, the material is reorganized at the location into a surface seal. Aggregate breakdown under rainfall depends on soil strength and a certain threshold kinetic energy is needed to start

A comparative study of radiation damage in Al2O3, FeTiO3, and MgTiO3

International Nuclear Information System (INIS)

Mitchell, J.N.; Yu, Ning; Sickafus, K.E.; Nastasi, M.; Taylor, T.N.; McClellan, K.J.; Nord, G.L. Jr.

1995-01-01

Oriented single crystals of synthetic alpha-alumina (α-Al 2 O 3 ), geikielite (MgTiO 3 ) natural ilmenite (FeTiO 3 ) were irradiated with 200 keV argon ions under cryogenic conditions (100 K) to assess their damage response. Using Rutherford backscattering spectrometry combined with ion channeling techniques, it was found that ilmenite amorphized readily at doses below 5x10 14 , alumina amorphized at a dose of 1-2x 15 , and geikielite was amorphized at ∼2x10 15 Ar cm -2 . The radiation damage response of the ilmenite crystal may be complicated by the presence of hematite exsolution lamellae and the experimentally induced oxidation of iron. The relative radiation-resistance of geikielite holds promise for similar behavior in other Mg-Ti oxides

Dispersive liquid-liquid microextraction combined with gas chromatography-electron capture detection for the determination of polychlorinated biphenyls in soils

International Nuclear Information System (INIS)

Hu Jia; Fu Lingyan; Zhao Xinna; Liu Xiujuan; Wang Huili; Wang Xuedong; Dai Liyan

2009-01-01

In this article, dispersive liquid-liquid microextraction (DLLME) and gas chromatography-electron capture detection (GC-ECD) were presented for the extraction and determination of five polychlorinated biphenyls (PCBs) in soil samples. Acetone was used as extraction solvent for the extraction of PCBs from soil samples. In DLLME, the target analytes in the extraction solvent were rapidly transferred from the acetone extract to chlorobenzene when the extraction process began. The main advantages of this method are quick speed, high enrichment factor, high recovery and good repeatability. Under the optimum conditions, the method yields a linear calibration curve in the concentration range from 2 to 2000 μg kg -1 for PCB 52, and 0.4 to 400 μg kg -1 for other target analytes. Coefficients of correlation (r 2 ) ranged from 0.9993 to 0.9999. The repeatability was tested by spiking soil samples at a concentration level of 10 μg kg -1 for PCBs. The relative standard deviations (RSDs, n = 11) varied between 2.2% and 6.4%. The limits of detection (LODs), based on signal-to-noise (S/N) of 3, were between 0.20 and 0.50 μg kg -1 . The relative recoveries of the five PCBs from soil S1, S2 and S3 at spiking levels of 10, 20 and 50 μg kg -1 were in the range of 88.70-103.8%, 82.50-106.3% and 82.30-113.6%, respectively. Therefore, DLLME combined with GC-ECD can be successfully applied for the determination of trace PCB residues in real soil samples.

Combined effects of antimony and sodium diethyldithiocarbamate on soil microbial activity and speciation change of heavy metals. Implications for contaminated lands hazardous material pollution in nonferrous metal mining areas.

Science.gov (United States)

Zhu, Xiaozhe; Yao, Jun; Wang, Fei; Yuan, Zhimin; Liu, Jianli; Jordan, Gyozo; Knudsen, Tatjana Šolević; Avdalović, Jelena

2018-05-05

The combined effects of antimony (Sb) and sodium diethyldithiocarbamate (DDTC), a common organic flotation reagent, on soil microbial activity and speciation changes of heavy metals were investigated for the first time. The results showed that the exchangeable fraction of Sb was transformed to a stable residual fraction during the incubation period, and the addition of DDTC promoted the transformation compared with single Sb pollution, probably because DDTC can react with heavy metals to form a complex. In addition, the presence of DDTC and Sb inhibited the soil microbial activity to varying degrees. The growth rate constant k of different interaction systems was in the following order on the 28th day: control group ≥ single DDTC pollution > combined pollution > single Sb pollution. A correlation analysis showed that the concentration of exchangeable Sb was the primary factor that affected the toxic reaction under combined pollution conditions, and it significantly affected the characteristics of the soil microorganisms. All the observations provide useful information for a better understanding of the toxic effects and potential risks of combined Sb and DDTC pollution in antimony mining areas. Copyright © 2018 Elsevier B.V. All rights reserved.

Soil base saturation combines with Beech Bark Disease to influence composition and structure of Sugar Maple-Beech forests in an acid rain-impacted region

Science.gov (United States)

Lawrence, Gregory B.; McDonnell, Todd C.; Sullivan, Timothy J.; Dovciak, Martin; Bailey, Scott W.; Antidormi, Michael; Zarfos, Michael R.

2018-01-01

Sugar maple, an abundant and highly valued tree species in eastern North America, has experienced decline from soil calcium (Ca) depletion by acidic deposition, while beech, which often coexists with sugar maple, has been afflicted with beech bark disease (BBD) over the same period. To investigate how variations in soil base saturation combine with effects of BBD in influencing stand composition and structure, measurements of soils, canopy, subcanopy, and seedlings were taken in 21 watersheds in the Adirondack region of NY (USA), where sugar maple and beech were the predominant canopy species and base saturation of the upper B horizon ranged from 4.4 to 67%. The base saturation value corresponding to the threshold for Al mobilization (16.8%) helped to define the species composition of canopy trees and seedlings. Canopy vigor and diameter at breast height (DBH) were positively correlated (P soils, soil-Ca depletion and BBD may have created opportunities for gap-exploiting species such as red maple and black cherry, whereas in high-base saturation soils, sugar maple dominated the canopy. Where soils were beginning to recover from acidic deposition effects, sugar maple DBH and basal area increased progressively from 2000 to 2015, whereas for beech, average DBH did not change and basal area did not increase after 2010.

Synthesis of Nano-Ilmenite (FeTiO3) doped TiO2/Ti Electrode for Photoelectrocatalytic System

Science.gov (United States)

Hikmawati; Watoni, A. H.; Wibowo, D.; Maulidiyah; Nurdin, M.

2017-11-01

Ilmenite (FeTiO3) doped on Ti and TiO2/Ti electrodes were successfully prepared by using the sol-gel method. The structure, morphology, and optical properties of FeTiO3 are characterized by XRD, UV-Vis DRS, and SEM. The FeTiO3 and TiO2 greatly affect the photoelectrocatalysis performance characterized by Linear Sweep Voltammetry (LSV) and Cyclic Voltammetry (CV). The characterization result shows a band gap of FeTiO3 is 2.94 eV. XRD data showed that FeTiO3 formed at 2θ were 35.1° (110), 49.9° (024), and 61.2° (214). The morphology of FeTiO3/Ti and FeTiO3.TiO2/Ti using SEM shows that the formation of FeTiO3 thin layer signifies the Liquid Phase Deposition method effectively in the coating process. Photoelectrochemical (PEC) test showed that FeTiO3.TiO2/Ti electrode was highly oxidation responsive under visible light compared to the FeTiO3/Ti electrodes i.e. 7.87×10-4 A and 9.87×10-5 A. Degradation test of FeTiO3/Ti and FeTiO3.TiO2/Ti electrodes on titan yellow showed that the percentages of degradation with photoelectrocatalysis at 0.5 mg/L were 41% and 43%, respectively.

PAH exposure through soil ingestion: Combining digestion models and bioassays

Energy Technology Data Exchange (ETDEWEB)

Wiele, T.R. van de; Verstraete, W. [Ghent University (BE).Laboratory Microbial Ecology and Technology (LabMET); Siciliano, S.D. [University of Saskatchewan (Canada). Department of Soil Science

2003-07-01

Exposure to environmental contaminants through soil ingestion is an important issue in current health risk assessment. Polycyclic aromatic hydrocarbons (PAH) or their metabolites pose risks to humans due to their toxic, mutagenic, carcinogenic or even (anti)estrogenic properties. PAH mobilization from a soil matrix (49.1{+-}1.5 mg PAH/kg DW) was assessed using a Simulator of the Human Intestinal Microbial Ecosystem (SHIME). PAH GC-MS analysis was performed on the pellet and supernatant of SHIME digests and gave 101, 92, 89 and 97% recovery for water, stomach, duodenal and colon digests, respectively. PAH release was highest for the water extract (0.51%) and the stomach digestion (0.44%). Lower mobilized fractions in the duodenum (0.13%) and colon (0.30%) digests could be attributed to PAH complexation with bile salts, dissolved organic matter or colon microbiota. The digestion model provides us with relevant information to what extent soil bound PAHs are mobilized in the gastrointestinal tract and thus reach the gut wall, prior to absorption. (orig.)

Effects of foliar dressing of selenite and silicate alone or combined with different soil ameliorants on the accumulation of As and Cd and antioxidant system in Brassica campestris.

Science.gov (United States)

Ding, Yongzhen; Wang, Yongjiu; Zheng, Xiangqun; Cheng, Weimin; Shi, Rongguang; Feng, Renwei

2017-08-01

This study was conducted to investigate the possibility of using a combined technology to synchronously reduce As and Cd accumulation in the edible parts of Brassica campestris. The results showed that a foliar application of selenite (Se) and silicon (Si) combined with soil ameliorants (including Ca-Mg-P fertilizer, sodium silicate and red mud) showed limited effects on the growth of B. campestris. The As concentration in the leaves of B. campestris in all treatments was below the Chinese safety standard. When sodium silicate and Ca-Mg-P fertilizer were added to the soil, the additional foliar application of Se and Si could in some cases help further reduce the concentrations of As and Cd in the leaves of B. campestris. However, when red mud was applied to the soil, the foliar application of Se and Si enhanced the Cd concentration in the leaves of B. campestris. In most cases, high levels of soil ameliorants plus foliar application of Se and Si significantly enhanced the As concentrations in both the soil solution and the roots of B. campestris but reduced the soil solution Cd concentration and the leaf As concentration. Most of the treatments reduced the thiobarbituric acid reactive substances (TBARS) concentration in the leaves of B. campestris, and the foliar application of Se and Si helped the soil ameliorants alleviate the oxidative stress resulting from As and Cd exposure. In this study, several treatments significantly increased the activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX). However, the enzymes peroxidase (POD) and catalase (CAT) were not induced by most treatments. In summary, the combined treatment of 1gkg -1 Ca-Mg-P fertilizer plus foliar spraying 2mmolL -1 sodium selenite was most effective in reducing the Cd concentration and a rather strong ability to reduce the As concentration and trigger the activities of SOD and APX in the leaves of B. campestris. Copyright © 2017 Elsevier Inc. All rights reserved.

EFFECTS OF ALKALINE SANDY LOAM ON SULFURIC SOIL ACIDITY AND SULFIDIC SOIL OXIDATION

Directory of Open Access Journals (Sweden)

Patrick S. Michael

2015-08-01

Full Text Available  In poor soils, addition of alkaline sandy loam containing an adequate proportion of sand, silt and clay would add value by improving the texture, structure and organic matter (OM for general use of the soils. In acid sulfate soils (ASS, addition of alkaline sandy would improve the texture and leach out salts as well as add a sufficient proportion of OM for vegetation establishment. In this study, addition of alkaline sandy loam into sulfuric soil effectively increased the pH, lowered the redox and reduced the sulfate content, the magnitude of the effects dependent on moisture content. Addition of alkaline sandy loam in combination with OM was highly effective than the effects of the lone alkaline sandy loam. When alkaline sandy was added alone or in combination with OM into sulfidic soil, the effects on pH and the redox were similar as in the sulfuric soil but the effect on sulfate content was variable. The effects under aerobic conditions were higher than under anaerobic conditions. The findings of this study have important implications for the general management of ASS where lime availability is a concern and its application is limited.International Journal of Environment Volume-4, Issue-3, June-August 2015Page: 42-54

Long-term impact of farm management and crops on soil microorganisms assessed by combined DGGE and PLFA analyses.

Science.gov (United States)

Stagnari, Fabio; Perpetuini, Giorgia; Tofalo, Rosanna; Campanelli, Gabriele; Leteo, Fabrizio; Della Vella, Umberto; Schirone, Maria; Suzzi, Giovanna; Pisante, Michele

2014-01-01

In the present study, long-term organic and conventional managements were compared at the experimental field of Monsampolo del Tronto (Marche region, Italy) with the aim of investigating soil chemical fertility and microbial community structure. A polyphasic approach, combining soil fertility indicators with microbiological analyses (plate counts, PCR-denaturing gradient gel electrophoresis [DGGE] and phospholipid fatty acid analysis [PLFA]) was applied. Organic matter, N as well as some important macro and micronutrients (K, P, Mg, Mn, Cu, and Zn) for crop growth, were more available under organic management. Bacterial counts were higher in organic management. A significant influence of management system and management x crop interaction was observed for total mesophilic bacteria, nitrogen fixing bacteria and actinobacteria. Interestingly, cultivable fungi were not detected in all analyzed samples. PLFA biomass was higher in the organic and Gram positive bacteria dominated the microbial community in both systems. Even if fungal biomass was higher in organic management, fungal PCR-DGGE fingerprinting revealed that the two systems were very similar in terms of fungal species suggesting that 10 years were not enough to establish a new dynamic equilibrium among ecosystem components. A better knowledge of soil biota and in particular of fungal community structure will be useful for the development of sustainable management strategies.

Steam and electroheating remediation of tight soils

Energy Technology Data Exchange (ETDEWEB)

Balshaw-Biddle, K.; Oubre, C.L.; Ward, C.H. [eds.; Dablow, J.F. III; Pearce, J.A.; Johnson, P.C.

2000-07-01

In the past few decades the need for soil remediation has become urgent, even more necessary--innovative, cost effective methods. Steam and Electroheating Remediation of Tight Soils presents the results of a field study testing the cleanup of semi-volatile fuels from tight soils using combination of hydraulic fracturing and soil heating technologies.

Soil Fertility Status on Organic Paddy Experiment

Directory of Open Access Journals (Sweden)

Mujiyo

2015-07-01

Full Text Available The study aims to determine fertility status of the soil after organic paddy experiments using kinds and doses of organic fertilizers. Experiment was conducted at greenhouse laboratory in Faculty of Agriculture Sebelas Maret University Surakarta. Experimental design used completely randomized design with 9 kinds of treatment was replicated 3 times. Experiments were the use of cow manure, Azolla fertilizer, Azolla inoculum and its combinations that are based on fulfilling nutrient requirements of 120 kg N ha-1. Result shows that the use of cow manure, Azolla fertilizers and Azolla inoculum had no effect on changes of soil fertility status. Soil fertility status was not significantly correlated with cow manure (0,16ns, Azolla fertilizer (0,26ns and Azolla inoculum (0,16ns. Average of final soil fertility status included fertile category, which was similar as the initial soil fertility status. Average of final soil properties of treatment but nevertheless was relatively higher than in no treatment, indicating the use of cow manure, Azolla fertilizer, Azolla inoculum and its combinations had greater impact to soil properties. Cow manure despite increased available K2O and dry grain, but it did not significantly increase the soil fertility status from fertile to very fertile. This was presumably due to the relatively short experiment period, only one planting season had not given significant effect to soil properties. Implication of this study is the use of cow manure, Azolla fertilizer, Azolla inoculum and its combinations although did not increase the soil fertility status but could maintain soil fertility status as the initial conditions before planting.

The Effect of Gasification Biochar on Soil Carbon Sequestration, Soil Quality and Crop Growth

DEFF Research Database (Denmark)

Hansen, Veronika

and pot and field experiments was used to study the effect of straw and wood biochar on carbon sequestration, soil quality and crop growth. Overall, the biochar amendment improved soil chemical and physical properties and plant growth and showed a potential for soil carbon sequestration without having any......New synergies between agriculture and the energy sector making use of agricultural residues for bioenergy production and recycling recalcitrant residuals to soil may offer climate change mitigation potential through the substitution of fossil fuels and soil carbon sequestration. However, concerns...... have been raised about the potential negative impacts of incorporating bioenergy residuals (biochar) in soil and increasing the removal of crop residues such as straw, possibly reducing important soil functions and services for maintaining soil quality. Therefore, a combination of incubation studies...

Quicklime-induced changes of soil properties: Implications for enhanced remediation of volatile chlorinated hydrocarbon contaminated soils via mechanical soil aeration.

Science.gov (United States)

Ma, Yan; Dong, Binbin; He, Xiaosong; Shi, Yi; Xu, Mingyue; He, Xuwen; Du, Xiaoming; Li, Fasheng

2017-04-01

Mechanical soil aeration is used for soil remediation at sites contaminated by volatile organic compounds. However, the effectiveness of the method is limited by low soil temperature, high soil moisture, and high soil viscosity. Combined with mechanical soil aeration, quicklime has a practical application value related to reinforcement remediation and to its action in the remediation of soil contaminated with volatile organic compounds. In this study, the target pollutant was trichloroethylene, which is a volatile chlorinated hydrocarbon pollutant commonly found in contaminated soils. A restoration experiment was carried out, using a set of mechanical soil-aeration simulation tests, by adding quicklime (mass ratios of 3, 10, and 20%) to the contaminated soil. The results clearly indicate that quicklime changed the physical properties of the soil, which affected the environmental behaviour of trichloroethylene in the soil. The addition of CaO increased soil temperature and reduced soil moisture to improve the mass transfer of trichloroethylene. In addition, it improved the macroporous cumulative pore volume and average pore size, which increased soil permeability. As soil pH increased, the clay mineral content in the soils decreased, the cation exchange capacity and the redox potential decreased, and the removal of trichloroethylene from the soil was enhanced to a certain extent. After the addition of quicklime, the functional group COO of soil organic matter could interact with calcium ions, which increased soil polarity and promoted the removal of trichloroethylene. Copyright © 2017 Elsevier Ltd. All rights reserved.

The influence of land-use and land-management on Soil Organic Carbon concentrations: Limitations of making predictions using only soil order data

Science.gov (United States)

Bell, M. J.; Worrall, F.

2009-04-01

In light of recent concern over the extent of global warming and the role of soil carbon as a potential store of atmospheric carbon, there is increasing demand for regions to estimate their current soil organic carbon (SOC) stocks with the greatest possible accuracy. Several previous attempts at calculating SOC baselines at global, national or regional scale have used mean values for soil orders and multiplied these values by the mapped areas of the soils they represent. Other methods have approached the task from a land cover point of view, making estimates using only land-use, or soil order/land-use combinations and others have included variables such as altitude, climate and soil texture. This study aimed to assess the major controls on SOC concentrations (%SOC) at the National Trust Wallington estate in Northumberland, NE England (area = 55km2) where an extensive soil sampling campaign was used to test what level of accuracy could be achieved in modelling the %SOC values on the Estate. Mapped %SOC values were compared to the values predicted from The National Soils Resources Institute (NSRI) representative soil profile data for major soil group, soil series and land-use corrected soil series values, as well as land-use/major soil group combinations from the Countryside Survey database. The results of this study can be summarised as follows: When only soil series or land-use were used as predictors only 48% and 44% of the variation in the dataset were explained. When soil series/land-use combinations were used explanatory power increased to 57% both altitude and soil pH are major controls on %SOC and including these variables gave an improvement to 59% A further improvement from 59% to 66% in the ability to predict %SOC levels at point locations when farm tenancy was included indicates that differences in land-management practices between farm tenancies explained more of the variation than either soil series or land-use in %SOC. Further work will involve a

Socioeconomic modifications of the universal soil loss equation

Science.gov (United States)

Erol, A.; Koşkan, Ö.; Başaran, M. A.

2015-08-01

While social scientists have long focused on socioeconomic and demographic factors, physical modelers typically study soil loss using physical factors. In the current environment, it is becoming increasingly important to consider both approaches simultaneously for the conservation of soil and water, and the improvement of land use conditions. This study uses physical and socioeconomic factors to find a coefficient that evaluates the combination of these factors. It aims to determine the effect of socioeconomic factors on soil loss and, in turn, to modify the universal soil loss equation (USLE). The methodology employed in this study specifies that soil loss can be calculated and predicted by comparing the degree of soil loss in watersheds, with and without human influence, given the same overall conditions. A coefficient for socioeconomic factors, therefore, has been determined based on adjoining watersheds (WS I and II), employing simulation methods. Combinations of C and P factors were used in the USLE to find the impact of their contributions to soil loss. The results revealed that these combinations provided good estimation of soil loss amounts for the second watershed, i.e., WS II, from the adjoining watersheds studied in this work. This study shows that a coefficient of 0.008 modified the USLE to reflect the socioeconomic factors, such as settlement, influencing the amount of soil loss in the studied watersheds.

Petroleum Contaminated Soil Treatment Using Surfactant and Hydrogen Peroxide

Directory of Open Access Journals (Sweden)

Ilza Lobo

2010-12-01

Full Text Available The process of washing soil with surfactants, sodium lauryl ether sulphate (LESS and sodium lauryl sulphate (SDS was combined with chemical oxidation using hydrogen peroxide, with a view to in situ remediation of clay soil contaminated with hydrocarbons oil. The evaluation of the efficiency of the procedure was the removal of polyaromatic hydrocarbons and the comparison of physical and chemical characteristics of contaminated soil and uncontaminated from the same region. The combination of these two techniques, soil washing and application of an oxidizing agent, presented as a process of effective remediation for soils contaminated with petroleum products in subtropical regions.

Monitor Soil Degradation or Triage for Soil Security? An Australian Challenge

Directory of Open Access Journals (Sweden)

Andrea Koch

2015-04-01

Full Text Available The Australian National Soil Research, Development and Extension Strategy identifies soil security as a foundation for the current and future productivity and profitability of Australian agriculture. Current agricultural production is attenuated by soil degradation. Future production is highly dependent on the condition of Australian soils. Soil degradation in Australia is dominated in its areal extent by soil erosion. We reiterate the use of soil erosion as a reliable indicator of soil condition/quality and a practical measure of soil degradation. We describe three key phases of soil degradation since European settlement, and show a clear link between inappropriate agricultural practices and the resultant soil degradation. We demonstrate that modern agricultural practices have had a marked effect on reducing erosion. Current advances in agricultural soil management could lead to further stabilization and slowing of soil degradation in addition to improving productivity. However, policy complacency towards soil degradation, combined with future climate projections of increased rainfall intensity but decreased volumes, warmer temperatures and increased time in drought may once again accelerate soil degradation and susceptibility to erosion and thus limit the ability of agriculture to advance without further improving soil management practices. Monitoring soil degradation may indicate land degradation, but we contend that monitoring will not lead to soil security. We propose the adoption of a triaging approach to soil degradation using the soil security framework, to prioritise treatment plans that engage science and agriculture to develop practices that simultaneously increase productivity and improve soil condition. This will provide a public policy platform for efficient allocation of public and private resources to secure Australia’s soil resource.

Soil architecture relationships with dynamic soil physical processes: a conceptual study using natural, artificial, and 3D-printed soil cores

DEFF Research Database (Denmark)

Lamandé, Mathieu; Schjønning, Per; Dal Ferro, Nicola

Pore system architecture is a key feature for understanding physical, biological and chemical processes in soils. Development of visualisation technics, especially x-ray CT, during recent years has been useful in describing the complex relationships between soil architecture and soil functions. We...... believe that combining visualization with physical models is a step further towards a better understanding of these relationships. We conducted a concept study using natural, artificial and 3D-printed soil cores. Eight natural soil cores (100 cm3) were sampled in a cultivated stagnic Luvisol at two depths...... (topsoil and subsoil), representing contrasting soil pore systems. Cylinders (100 cm3) were produced from plastic or from autoclaved aerated concrete. Holes of diameters 1.5 and 3 mm were drilled in the cylinder direction for the plastic cylinder and for one of the AAC cylinders. All natural and artificial...

Combined effect of diuron and simazine on photosystem II photochemistry in a sandy soil and soil amended with solid olive-mill waste.

Science.gov (United States)

Redondo-Gómez, Susana; Cox, Lucía; Cornejo, Juan; Figueroa, Enrique

2007-01-01

Diuron (3-(3,4-dichlorophenyl)- = 1,1-dimethylurea) and simazine (6-chloro-N(2), N(4)-diethyl-1,3,5-triazine-2,4-diamine) are soil-applied herbicides used in olive crops. The objective of this study is to investigate the effect of these herbicides on Photosystem II photochemistry of Olea europaea L., and whether the amendment of soil with an organic waste (OW) from olive oil production industry modifies this effect. For this purpose, herbicide soil adsorption studies, with unamended and OW-amended soil, and chlorophyll fluorescence measurements in adult olive leaves, after one, two and three weeks of soil herbicide treatment and/or OW amendment, were performed. Soil application of these herbicides reduced the efficiency of Photosystem II photochemistry of olive trees due to chronic photoinhibition, and this effect is counterbalanced by the addition of OW to the soil. OW reduces herbicide uptake by the plant due to an increase in herbicide adsorption.

Decrease of the solar flare/solar wind flux ratio in the past several aeons from solar neon and tracks in lunar soil plagioclases

International Nuclear Information System (INIS)

Wieler, R.; Etique, Ph.; Signer, P.; Poupeau, G.

1982-08-01

The He, Ne, and Ar concentrations and isotopic compositions of mineral separates of six lunar subsurface samples and of two regolith breccias which were exposed to the sun as early as 2 - 3 billion years ago are determined. The results are compared with our noble gas data obtained previously on mineral separates of lunar surface soil samples most of which contain recently implanted solar gases. The mean solar flare track densities were determined on aliquots of several of the plagioclase separates analyzed for noble gases. Solar wind retentive mafic minerals and ilmenites show that a possible secular increase of the 20 Ne/ 22 Ne ratio in the solar wind during the last 2 - 3 Ga. is 20 Ne/ 22 Ne of approximately 11.3 - 11.8, reported for solar flare Ne retained in plagioclase separates from lunar soils. The solar flare track data and the Ne data independently show that plagioclases exposed to the sun over the last 10 8 years recorded a lower mean ratio of solar flare to solar wind intensities than samples exposed about 1 - 3 billion years ago. On the basis of track data these ratios are estimated to differ by a factor approximately 2. (Author) [pt

Predicting Soil Organic Carbon at Field Scale Using a National Soil Spectral Library

DEFF Research Database (Denmark)

Peng, Yi; Knadel, Maria; Gislum, René

2013-01-01

and the spectral library, 2718 samples) and (iii) three sub-sets selected from the spectral library. In an attempt to improve prediction accuracy, sub-sets of the soil spectral library were made using three different sample selection methods: those geographically closest (84 samples), those with the same landscape......Visible and near infrared diffuse reflectance (vis-NIR) spectroscopy is a low-cost, efficient and accurate soil analysis technique and is thus becoming increasingly popular. Soil spectral libraries are commonly constructed as the basis for estimating soil texture and properties. In this study......, partial least squares regression was used to develop models to predict the soil organic carbon (SOC) content of 35 soil samples from one field using (i) the Danish soil spectral library (2688 samples), (ii) a spiked spectral library (a combination of 30 samples selected from the local area...

Global-scale assessment and combination of SMAP with ASCAT (active) and AMSR2 (passive) soil moisture products

Science.gov (United States)

Kim, Hyunglok; Parinussa, Robert; Konings, Alexandra G.; Wagner, Wolfgang; Cosh, Michael H.; Lakshmi, Venkat; Zohaib, Muhammad; Choi, Minha

2018-01-01

Global-scale surface soil moisture (SSM) products retrieved from active and passive microwave remote sensing provide an effective method for monitoring near-real-time SSM content with nearly daily temporal resolution. In the present study, we first inter-compared global-scale error patterns and combined the Soil Moisture Active Passive (SMAP), Advanced Scatterometer (ASCAT), and Advanced Microwave Scanning Radiometer 2 (AMSR2) SSM products using a triple collocation (TC) analysis and the maximized Pearson correlation coefficient (R) method from April 2015 to December 2016. The Global Land Data Assimilation System (GLDAS) and global in situ observations were utilized to investigate and to compare the quality of satellite-based SSM products. The average R-values of SMAP, ASCAT, and AMSR2 were 0.74, 0.64, and 0.65 when they compared with in situ networks, respectively. The ubRMSD values were (0.0411, 0.0625, and 0.0708) m3 m- 3; and the bias values were (- 0.0460, 0.0010, and 0.0418) m3 m- 3 for SMAP, ASCAT, and AMSR2, respectively. The highest average R-values from SMAP against the in situ results are very encouraging; only SMAP showed higher R-values than GLDAS in several in situ networks with low ubRMSD (0.0438 m3 m- 3). Overall, SMAP showed a dry bias (- 0.0460 m3 m- 3) and AMSR2 had a wet bias (0.0418 m3 m- 3); while ASCAT showed the least bias (0.0010 m3 m- 3) among all the products. Each product was evaluated using TC metrics with respect to the different ranges of vegetation optical depth (VOD). Under vegetation scarce conditions (VOD 0.40) ASCAT showed comparatively better performance than did the other products. Using the maximized R method, SMAP, ASCAT, and AMSR2 products were combined one by one using the GLDAS dataset for reference SSM values. When the satellite products were combined, R-values of the combined products were improved or degraded depending on the VOD ranges produced, when compared with the results from the original products alone. The

Biochar Decelerates Soil Organic Nitrogen Cycling but Stimulates Soil Nitrification in a Temperate Arable Field Trial

Science.gov (United States)

Prommer, Judith; Wanek, Wolfgang; Hofhansl, Florian; Trojan, Daniela; Offre, Pierre; Urich, Tim; Schleper, Christa; Sassmann, Stefan; Kitzler, Barbara; Soja, Gerhard; Hood-Nowotny, Rebecca Clare

2014-01-01

Biochar production and subsequent soil incorporation could provide carbon farming solutions to global climate change and escalating food demand. There is evidence that biochar amendment causes fundamental changes in soil nutrient cycles, often resulting in marked increases in crop production, particularly in acidic and in infertile soils with low soil organic matter contents, although comparable outcomes in temperate soils are variable. We offer insight into the mechanisms underlying these findings by focusing attention on the soil nitrogen (N) cycle, specifically on hitherto unmeasured processes of organic N cycling in arable soils. We here investigated the impacts of biochar addition on soil organic and inorganic N pools and on gross transformation rates of both pools in a biochar field trial on arable land (Chernozem) in Traismauer, Lower Austria. We found that biochar increased total soil organic carbon but decreased the extractable organic C pool and soil nitrate. While gross rates of organic N transformation processes were reduced by 50–80%, gross N mineralization of organic N was not affected. In contrast, biochar promoted soil ammonia-oxidizer populations (bacterial and archaeal nitrifiers) and accelerated gross nitrification rates more than two-fold. Our findings indicate a de-coupling of the soil organic and inorganic N cycles, with a build-up of organic N, and deceleration of inorganic N release from this pool. The results therefore suggest that addition of inorganic fertilizer-N in combination with biochar could compensate for the reduction in organic N mineralization, with plants and microbes drawing on fertilizer-N for growth, in turn fuelling the belowground build-up of organic N. We conclude that combined addition of biochar with fertilizer-N may increase soil organic N in turn enhancing soil carbon sequestration and thereby could play a fundamental role in future soil management strategies. PMID:24497947

Biochar decelerates soil organic nitrogen cycling but stimulates soil nitrification in a temperate arable field trial.

Directory of Open Access Journals (Sweden)

Judith Prommer

Full Text Available Biochar production and subsequent soil incorporation could provide carbon farming solutions to global climate change and escalating food demand. There is evidence that biochar amendment causes fundamental changes in soil nutrient cycles, often resulting in marked increases in crop production, particularly in acidic and in infertile soils with low soil organic matter contents, although comparable outcomes in temperate soils are variable. We offer insight into the mechanisms underlying these findings by focusing attention on the soil nitrogen (N cycle, specifically on hitherto unmeasured processes of organic N cycling in arable soils. We here investigated the impacts of biochar addition on soil organic and inorganic N pools and on gross transformation rates of both pools in a biochar field trial on arable land (Chernozem in Traismauer, Lower Austria. We found that biochar increased total soil organic carbon but decreased the extractable organic C pool and soil nitrate. While gross rates of organic N transformation processes were reduced by 50-80%, gross N mineralization of organic N was not affected. In contrast, biochar promoted soil ammonia-oxidizer populations (bacterial and archaeal nitrifiers and accelerated gross nitrification rates more than two-fold. Our findings indicate a de-coupling of the soil organic and inorganic N cycles, with a build-up of organic N, and deceleration of inorganic N release from this pool. The results therefore suggest that addition of inorganic fertilizer-N in combination with biochar could compensate for the reduction in organic N mineralization, with plants and microbes drawing on fertilizer-N for growth, in turn fuelling the belowground build-up of organic N. We conclude that combined addition of biochar with fertilizer-N may increase soil organic N in turn enhancing soil carbon sequestration and thereby could play a fundamental role in future soil management strategies.

Biochar decelerates soil organic nitrogen cycling but stimulates soil nitrification in a temperate arable field trial.

Science.gov (United States)

Prommer, Judith; Wanek, Wolfgang; Hofhansl, Florian; Trojan, Daniela; Offre, Pierre; Urich, Tim; Schleper, Christa; Sassmann, Stefan; Kitzler, Barbara; Soja, Gerhard; Hood-Nowotny, Rebecca Clare

2014-01-01

Biochar production and subsequent soil incorporation could provide carbon farming solutions to global climate change and escalating food demand. There is evidence that biochar amendment causes fundamental changes in soil nutrient cycles, often resulting in marked increases in crop production, particularly in acidic and in infertile soils with low soil organic matter contents, although comparable outcomes in temperate soils are variable. We offer insight into the mechanisms underlying these findings by focusing attention on the soil nitrogen (N) cycle, specifically on hitherto unmeasured processes of organic N cycling in arable soils. We here investigated the impacts of biochar addition on soil organic and inorganic N pools and on gross transformation rates of both pools in a biochar field trial on arable land (Chernozem) in Traismauer, Lower Austria. We found that biochar increased total soil organic carbon but decreased the extractable organic C pool and soil nitrate. While gross rates of organic N transformation processes were reduced by 50-80%, gross N mineralization of organic N was not affected. In contrast, biochar promoted soil ammonia-oxidizer populations (bacterial and archaeal nitrifiers) and accelerated gross nitrification rates more than two-fold. Our findings indicate a de-coupling of the soil organic and inorganic N cycles, with a build-up of organic N, and deceleration of inorganic N release from this pool. The results therefore suggest that addition of inorganic fertilizer-N in combination with biochar could compensate for the reduction in organic N mineralization, with plants and microbes drawing on fertilizer-N for growth, in turn fuelling the belowground build-up of organic N. We conclude that combined addition of biochar with fertilizer-N may increase soil organic N in turn enhancing soil carbon sequestration and thereby could play a fundamental role in future soil management strategies.

Physical root-soil interactions

Science.gov (United States)

Kolb, Evelyne; Legué, Valérie; Bogeat-Triboulot, Marie-Béatrice

2017-12-01

Plant root system development is highly modulated by the physical properties of the soil and especially by its mechanical resistance to penetration. The interplay between the mechanical stresses exerted by the soil and root growth is of particular interest for many communities, in agronomy and soil science as well as in biomechanics and plant morphogenesis. In contrast to aerial organs, roots apices must exert a growth pressure to penetrate strong soils and reorient their growth trajectory to cope with obstacles like stones or hardpans or to follow the tortuous paths of the soil porosity. In this review, we present the main macroscopic investigations of soil-root physical interactions in the field and combine them with simple mechanistic modeling derived from model experiments at the scale of the individual root apex.

Geophysical surveys combined with laboratory soil column experiments to identify and explore risk areas for soil and water pollution in feedlots

Science.gov (United States)

Espejo-Pérez, Antonio Jesus; Sainato, Claudia Mabel; Jairo Márquez-Molina, John; Giráldez, Juan Vicente; Vanderlinden, Karl

2014-05-01

Changes of land use without a correct planning may produce its deterioration with their social, economical and environmental irreversible consequences over short to medium time range. In Argentina, the expansion of soybean fields induced a reduction of the area of pastures dedicated to stockbreeding. As cattle activity is being progressively concentrated on small pens, at feedlots farms, problems of soil and water pollution, mainly by nitrate, have been detected. The characterization of the spatial and temporal variability of soil water content is very important because the mostly advective transport of solutes. To avoid intensive soil samplings, very expensive, one has to recur to geophysical exploration methods. The objective of this work was to identify risk areas within a feedlot of the NW zone of Buenos Aires Province, in Argentina through geophysical methods. The surveys were carried out with an electromagnetic induction profiler EMI-400 (GSSI) and a Time domain Reflectometry (TDR) survey of depth 0-0.10 m with soil sampling and measurement of moisture content with gravimetric method (0-1.0 m). Several trenches were dug inside the pens and also at a test site, where texture, apparent density, saturated hydraulic conductivity (Ks), electrical conductivity of the saturation paste extract and organic matter content (OM) were measured. The water retention curves for these soils were also determined. At one of the pens undisturbed soil columns were extracted at 3 locations. Laboratory analysis for 0-1.0 m indicated that soil texture was classified as sandy loam, average organic matter content (OM) was greater than 2.3% with low values of apparent density in the first 10 cm. The range of spatial dependence of data suggested that the number of soil samples could be reduced. Soil apparent electrical conductivity (ECa) and soil moisture were well correlated and indicated a clear spatial pattern in the corrals. TDR performance was acceptable to identify the spatial

The removal of heavy metals from contaminated soil by a combination of sulfidisation and flotation.

Science.gov (United States)

Vanthuyne, Mathias; Maes, André

2002-05-06

The possibility of removing cadmium, copper, lead and zinc from Belgian loamy soil by a combination of sulfidisation pre-treatment and Denver flotation was investigated. The potentially available--sulfide convertible--metal content of the metal polluted soil was estimated by EDTA (0.1 M, pH 4.65) extraction and BCR sequential extraction. EDTA extraction is better at approximating the metal percentage that is expected to be convertible into a metal sulfide phase, in contrast to the sequential extraction procedure of 'Int. J. Environ. Anal. Chem. 51 (1993) pp. 135-151' in which transition metals present as iron oxide co-precipitates are dissolved by hydroxylammoniumchloride in the second extraction step. To compare the surface characteristics of metal sulfides formed by sulfidisation with those of crystalline metal sulfides, two types of synthetic sediments were prepared and extracted with 0.1 M EDTA (pH 4.65) in anoxic conditions. Separate metal sulfides or co-precipitates with iron sulfide were formed by sulfide conditioning. The Denver flotation of both types of synthetic sediments (kerosene as collector at high background electrolyte concentrations) resulted in similar concentrating factors for freshly formed metal sulfides as for fine-grained crystalline metal sulfides. The selective flotation of metal sulfides after sulfide conditioning of a polluted soil, using kerosene or potassium ethyl xanthate as collectors and MIBC as frother, was studied at high background electrolyte concentrations. The sulfidisations were made in ambient air and inside an anoxic glove box. The concentrating factors corrected by the potentially available metal percentage, determined by 0.1 M EDTA extraction, lie between 2 and 3. The selective flotation of these finely dispersed, amorphous, metal sulfides can possibly be improved by optimising the bubble-particle interaction.

Response of three soils in the derived savanna zone of southwestern Nigeria to combined application of organic and inorganic fertilizer as affecting phosphorus fractions

Directory of Open Access Journals (Sweden)

Abigail O. Ojo

2018-04-01

Full Text Available Phosphorus inputs to the soil are primarily from the application of fertilizer P and organic resources. A ten week incubation study was carried out to determine the effects of organic and inorganic P sources on phosphorus fractions in three derived savanna soils. Poultry manure was applied at 0, 0.75g, 1.5g, 2.25g and 3g per 300g weight of soil while single superphosphate was applied at 0.0023g, 0.0046g, 0.0069g and 0.0092g per 300g of soil. Sampling was done at two weeks interval. At 0 week of the incubation study, Ekiti series had the largest amount of P fractions i.e. Fe-P, Al-P, residual P, reductant soluble P, occluded P, organic P and occluded P while Ca-P was high in Apomu series. However, increases in Fe-P, Al-P, Ca-P and organic P were observed in the three soil series evaluated and poultry manure was notably effective in reducing P occlusion. In conclusion, it was observed that irrespective of the soil series at different stages of the incubation studies, poultry manure and the combined application of poultry manure and Single superphosphate was highly effective in increasing P fractions.

Influence of biochars, compost and iron grit, alone and in combination, on copper solubility and phytotoxicity in a Cu-contaminated soil from a wood preservation site.

Science.gov (United States)

Oustriere, Nadège; Marchand, Lilian; Galland, William; Gabbon, Lunel; Lottier, Nathalie; Motelica, Mikael; Mench, Michel

2016-10-01

Two biochars, a green waste compost and iron grit were used, alone and in combination, as amendment to improve soil properties and in situ stabilize Cu in a contaminated soil (964mgCukg(-1)) from a wood preservation site. The pot experiment consisted in 9 soil treatments (% w/w): untreated Cu-contaminated soil (Unt); Unt soil amended respectively with compost (5%, C), iron grit (1%, Z), pine bark-derived biochar (1%, PB), poultry-manure-derived biochar (1%, AB), PB or AB+C (5%, PBC and ABC), and PB or AB+Z (1%, PBZ and ABZ). After a 3-month reaction period, the soil pore water (SPW) was sampled in potted soils and dwarf beans were grown for a 2-week period. In the SPW, all amendments decreased the Cu(2+) concentration, but total Cu concentration increased in all AB-amended soils due to high dissolved organic matter (DOM) concentration. No treatment improved root and shoot DW yields, which even decreased in the ABC and ABZ treatments. The PBZ treatment decreased total Cu concentration in the SPW while reducing the gap with common values for root and shoot yields of dwarf bean plants. A field trial is underway before any recommendation for the PB-based treatments. Copyright © 2016 Elsevier B.V. All rights reserved.

Soil-plant transfer models for metals to improve soil screening value guidelines valid for São Paulo, Brazil.

Science.gov (United States)

Dos Santos-Araujo, Sabrina N; Swartjes, Frank A; Versluijs, Kees W; Moreno, Fabio Netto; Alleoni, Luís R F

2017-11-07

In Brazil, there is a lack of combined soil-plant data attempting to explain the influence of specific climate, soil conditions, and crop management on heavy metal uptake and accumulation by plants. As a consequence, soil-plant relationships to be used in risk assessments or for derivation of soil screening values are not available. Our objective in this study was to develop empirical soil-plant models for Cd, Cu, Pb, Ni, and Zn, in order to derive appropriate soil screening values representative of humid tropical regions such as the state of São Paulo (SP), Brazil. Soil and plant samples from 25 vegetable species in the production areas of SP were collected. The concentrations of metals found in these soil samples were relatively low. Therefore, data from temperate regions were included in our study. The soil-plant relations derived had a good performance for SP conditions for 8 out of 10 combinations of metal and vegetable species. The bioconcentration factor (BCF) values for Cd, Cu, Ni, Pb, and Zn in lettuce and for Cd, Cu, Pb, and Zn in carrot were determined under three exposure scenarios at pH 5 and 6. The application of soil-plant models and the BCFs proposed in this study can be an important tool to derive national soil quality criteria. However, this methodological approach includes data assessed under different climatic conditions and soil types and need to be carefully considered.

Effect of some soil amendments on soil properties and plant growth in Southern Thailand acid upland soil

Directory of Open Access Journals (Sweden)

Onthong, C.

2007-01-01

Full Text Available One of the major factors limiting plant growth is acid soil. In general lime is used for soil amendment in acid soil. However, It has been reported that gypsum or phosphogypsum can be used for ameliorating soilacidity. Pot experiment was conducted to study the effects of lime, phosphogypsum and kieserite on soil properties and plant growth in Kho Hong soil series (coarse loamy, kaolinitic,isohyperthermic, TypicKandiudults which was considered as acid upland soil (pH 5.07. Sweet corn variety INSEE 2 was used as the test crop. The experiment was a completely randomized design with 4 replications and 19 treatments asfollow : unamended, application of hydrated lime and dolomite to raise soil pH at 5.5, application of hydrated lime and dolomite combined with phosphogypsum at the rate that can supply calcium 0.25, 0.50,0.75 and 1 time of both limes, application of hydrated lime and dolomite combined with kieserite at the rate 0.25, 0.50,0.75 and 1 times of sulfur requirement for corn (40 kg S ha-1. The result showed that shoot and root dry weights of corn were increased when lime materials, phosphogypsum and kieserite were applied and the drymatter weights were increased according to the increasing of phosphogypsum and kieserite. The maximum shoot dry weight (18.98 g pot-1 was obtained when 1 times of kieserite was supplied with dolomite and wassignificantly (P<0.01 higher than those of the unamended treatment, only hydrated lime and dolomite treatments, which had dry weights of 12.64, 15.18 and 15.67 g pot-1 respectively. Phosphorus and K uptakewere not significantly different in all treatments and the lowest uptake of N, Ca, Mg and S was obtained in the unamended treatment. The maximum uptake of N (512.10 mg pot-1 was found when 0.5 times ofphosphogypsum was applied together with dolomite. Calcium and Mg uptake was likely to increase according to the increasing rate of soil amendment application. Highest uptake of Ca (42.51 mg pot-1 was obtainedwhen

Numerical combination for nonlinear analysis of structures coupled to layered soils

Directory of Open Access Journals (Sweden)

Wagner Queiroz Silva

Full Text Available This paper presents an alternative coupling strategy between the Boundary Element Method (BEM and the Finite Element Method (FEM in order to create a computational code for the analysis of geometrical nonlinear 2D frames coupled to layered soils. The soil is modeled via BEM, considering multiple inclusions and internal load lines, through an alternative formulation to eliminate traction variables on subregions interfaces. A total Lagrangean formulation based on positions is adopted for the consideration of the geometric nonlinear behavior of frame structures with exact kinematics. The numerical coupling is performed by an algebraic strategy that extracts and condenses the equivalent soil's stiffness matrix and contact forces to be introduced into the frame structures hessian matrix and internal force vector, respectively. The formulation covers the analysis of shallow foundation structures and piles in any direction. Furthermore, the piles can pass through different layers. Numerical examples are shown in order to illustrate and confirm the accuracy and applicability of the proposed technique.

Effect of Curing Conditions and Freeze-Thaw Cycles on the Strength of an Expansive Soil Stabilized with a Combination of Lime, Jaggery, and Gallnut Powder

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Jijo James

2018-01-01

Full Text Available This investigation involved the utilization of the combination of lime, jaggery, and gallnut powder, adopted in South India traditionally. This combination of materials, used for the manufacture of lime-based mortars, was adopted in stabilization of an expansive soil. Three combinations of lime, jaggery, and gallnut powder (LJG in the ratios of 8 : 2 : 2, 8 : 2 : 1, and 8 : 1 : 2 were put into use. The effect of subjecting the combinations to alternate cycles of freeze-thaw (up to 3 cycles and three different curing conditions of air, moisture, and heat was also investigated. In addition, a mineralogical investigation for studying the reaction products was also carried out. The investigation proceeded with the determination of the unconfined compression strength (UCS of stabilized specimens of dimensions 38 mm × 76 mm, cured for periods of 3, 7, 14, and 28 days. The results of the investigation revealed that the addition of LJG resulted in an increase in the strength of the stabilized soil. Freeze-thaw cycles resulted in a reduction in strength with LJG821 proving to be the most optimal combination developing the maximum strength and least strength loss due to freeze-thaw cycles. Thermal curing proved to be the most optimal curing condition out of all curing conditions evaluated.

Salinity and spectral reflectance of soils

Science.gov (United States)

Szilagyi, A.; Baumgardner, M. F.

1991-01-01

The basic spectral response related to the salt content of soils in the visible and reflective IR wavelengths is analyzed in order to explore remote sensing applications for monitoring processes of the earth system. The bidirectional reflectance factor (BRF) was determined at 10 nm of increments over the 520-2320-nm spectral range. The effect of salts on reflectance was analyzed on the basis of 162 spectral measurements. MSS and TM bands were simulated within the measured spectral region. A strong relationship was found in variations of reflectance and soil characteristics pertaining to salinization and desalinization. Although the individual MSS bands had high R-squared values and 75-79 percent of soil/treatment combinations were separable, there was a large number of soil/treatment combinations not distinguished by any of the four highly correlated MSS bands under consideration.

A method to detect soil carbon degradation during soil erosion

OpenAIRE

F. Conen; M. Schaub; C. Alewell

2009-01-01

Soil erosion has been discussed intensively but controversial both as a significant source or a significant sink of atmospheric carbon possibly explaining the gap in the global carbon budget. One of the major points of discussion has been whether or not carbon is degraded and mineralized to CO₂ during detachment, transport and deposition of soil material. By combining the caesium-137 (¹³⁷Cs) approach (quantification of erosion rates) with stable c...

NOAA Soil Moisture Products System (SMOPS) Daily Blended Products

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Soil Moisture Operational Products System (SMOPS) combines soil moisture retrievals from multiple satellite sensors to provide a global soil moisture map with...

Socio-economic modifications of the Universal Soil Loss Equation

Science.gov (United States)

Erol, A.; Koşkan, Ö.; Başaran, M. A.

2015-06-01

While social scientists have long focused on socio-economic and demographic factors, physical modelers typically study soil loss using physical factors. In the current environment, it is becoming increasingly important to consider both approaches simultaneously for the conservation of soil and water, and the improvement of land use conditions. This study uses physical and socio-economic factors to find a coefficient that evaluates the combination of these factors. It aims to determine the effect of socio-economic factors on soil loss and, in turn, to modify the Universal Soil Loss Equation (USLE). The methodology employed in this study specifies that soil loss can be calculated and predicted by comparing the degree of soil loss in watersheds, with and without human influence, given the same overall conditions. A coefficient for socio-economic factors, therefore, has been determined based on adjoining watersheds (WS I and II), employing simulation methods. Combinations of C and P factors were used in the USLE to find the impact of their contributions on soil loss. The results revealed that these combinations provided good estimation of soil loss amounts for the second watershed, i.e. WS II, from the adjoining watersheds studied in this work. This study shows that a coefficient of 0.008 modified the USLE to reflect the socio-economic factors as settlement influencing the amount of soil loss in the watersheds studied.

Soil and soil cover changes in spruce forests after final logging

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E. M. Lapteva

2015-10-01

Full Text Available Soil cover transformation and changes of morphological and chemical properties of Albeluvisols in clear-cuttings of middle taiga spruce forests were studied. The observed changes in structure and properties of podzolic texturally-differentiated soils at cuttings of spruce forests in the middle taiga subzone do not cause their transition to any other soil type. Soil cover of secondary deciduous-coniferous forests which replace cut forests are characterized with a varied soil contour and a combination of the main type of podzolic soils under undisturbed spruce forests. The increased surface hydromorphism in cut areas causes formation of complicated sub-types of podzolic texturally differentiated soils (podzolic surface-gley soils with microprofile of podzol and enlarges their ratio (up to 35–38 % in soil cover structure. Temporary soil over-wetting at the initial (5–10 years stage of after-cutting self-restoring vegetation succession provides for soil gleyzation, improves yield and segregation of iron compounds, increases the migratory activity of humic substances. Low content and resources of total nitrogen in forest litters mark anthropogenic transformation processes of podzolic soils at this stage. Later (in 30–40 years after logging, soils in cut areas still retain signs of hydromorphism. Forest litters are denser, less acidic and thick with a low weight ratio of organic carbon as compared with Albeluvisols of undisturbed spruce forest. The upper mineral soil horizons under secondary deciduous-coniferous forests contain larger amounts of total iron, its mobile (oxalate-dissolvable components, and Fe-Mn-concretions.

Soil Erosion Research Based on USLE in Great Khinggan

OpenAIRE

Wei Li; Wenyi Fan; Xuegang Mao

2014-01-01

Based on the amended model of USLE universal soil loss equation and GIS technology, combined with the natural geographical features of Great Khinggan area, it has conducted quantitative analysis of the factor in Soil loss equation. Uses 2011 years TM/ETM images classification are land uses/cover type figure, combination Great Khinggan area Digital Elevation Model (DEM) and soil type distribution figure and research regional rainfall information, we gets all factors values of space distributio...

Toluene removal from sandy soils via in situ technologies with an emphasis on factors influencing soil vapor extraction.

Science.gov (United States)

Amin, Mohammad Mehdi; Hatamipour, Mohammad Sadegh; Momenbeik, Fariborz; Nourmoradi, Heshmatollah; Farhadkhani, Marzieh; Mohammadi-Moghadam, Fazel

2014-01-01

The integration of bioventing (BV) and soil vapor extraction (SVE) appears to be an effective combination method for soil decontamination. This paper serves two main purposes: it evaluates the effects of soil water content (SWC) and air flow rate on SVE and it investigates the transition regime between BV and SVE for toluene removal from sandy soils. 96 hours after air injection, more than 97% removal efficiency was achieved in all five experiments (carried out for SVE) including 5, 10, and 15% for SWC and 250 and 500 mL/min for air flow rate on SVE. The highest removal efficiency (>99.5%) of toluene was obtained by the combination of BV and SVE (AIBV: Air Injection Bioventing) after 96 h of air injection at a constant flow rate of 250 mL/min. It was found that AIBV has the highest efficiency for toluene removal from sandy soils and can remediate the vadose zone effectively to meet the soil guideline values for protection of groundwater.

Toluene Removal from Sandy Soils via In Situ Technologies with an Emphasis on Factors Influencing Soil Vapor Extraction

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Mohammad Mehdi Amin

2014-01-01

Full Text Available The integration of bioventing (BV and soil vapor extraction (SVE appears to be an effective combination method for soil decontamination. This paper serves two main purposes: it evaluates the effects of soil water content (SWC and air flow rate on SVE and it investigates the transition regime between BV and SVE for toluene removal from sandy soils. 96 hours after air injection, more than 97% removal efficiency was achieved in all five experiments (carried out for SVE including 5, 10, and 15% for SWC and 250 and 500 mL/min for air flow rate on SVE. The highest removal efficiency (>99.5% of toluene was obtained by the combination of BV and SVE (AIBV: Air Injection Bioventing after 96 h of air injection at a constant flow rate of 250 mL/min. It was found that AIBV has the highest efficiency for toluene removal from sandy soils and can remediate the vadose zone effectively to meet the soil guideline values for protection of groundwater.

Application of nanoparticle of rock phosphate and biofertilizer in increasing some soil chemical characteristics of variable charge soil

Science.gov (United States)

Devnita, Rina; Joy, Benny; Arifin, Mahfud; Hudaya, Ridha; Oktaviani, Nurul

2018-02-01

Soils in Indonesia are dominated by variable charge soils where the technology like fertilization did not give the same result as the soils with permanent charge. The objectives of this research is to increase some chemical characteristic of variable charge soils by using the high negative charge ameliorations like rock phosphate in nanoparticle combined with biofertilizer. The research used a complete randomized experimental design in factorial with two factors. The first factor was nanoparticle of rock phosphate consists of four doses on soil weight percentage (0%, 2.5%, 5.0% and 7.5%). The second factor was biofertilizer consisted of two doses (without biofertilizer and 1 g.kg-1 soil biofertilizer). The combination treatments replicated three times. Variable charge soil used was Andisol. Andisol and the treatments were incubated for 4 months. Soil samples were taken after one and four months during incubation period to be analyzed for P-retention, available P and potential P. The result showed that all combinations of rock phosphate and biofertilizer decreased the P-retention to 75-77% after one month. Independently, application of 7.5% of rock phosphate decreased P-retention to 87.22% after four months, increased available P (245.37 and 19.12 mg.kg-1) and potential P (1354.78 and 3000.99 mg/100) after one and four months. Independently, biofertilizer increased the P-retention to 91.66% after four months, decreased available P to 121.55 mg.kg-1 after one month but increased to 12.55 mg.kg-1 after four months, decreased potential P to 635.30 after one month but increased to 1810.40 mg.100 g-1 after four months.

Combined mild soil washing and compost-assisted phytoremediation in treatment of silt loams contaminated with copper, nickel, and chromium.

Science.gov (United States)

Sung, Menghau; Lee, Chi-Yi; Lee, Suen-Zone

2011-06-15

A new soil remediation option, combining the soil washing process using pure water followed by the compost-assisted phytoextraction, is evaluated using silt loams contaminated with plating wastewater containing Cu, Ni, and Cr. Plants utilized in this study are the rapeseeds, sunflowers, tomatoes, and soapworts. Phytoextraction operation was carried out in pot experiments over a period of 4 months. Metal concentrations in roots and shoots of plants were analyzed upon completion of each pot experiment. Hypothesis testing was employed in assessing the significance of difference in the experimental data. Results indicated that the rapeseed, a hyperaccumulator, is most effective in extracting metals from the compost-amended silt loams. The fast-growing sunflowers and tomatoes are comparable to rapeseeds in accumulating metals despite their relatively low metal concentrations in tissues. Bioaccumulation coefficients obtained for all plants are less than one, indicating that phytostabilization rather than phytoextraction is the dominant mechanism at this simulated final-phase condition. Copyright © 2011 Elsevier B.V. All rights reserved.

Application of UV-visible absorption spectroscopy combined with two-dimensional correlation for insight into DOM fractions from native halophyte soils in a larger estuarine delta.

Science.gov (United States)

Wei, Huaibin; Yu, Huibin; Pan, Hongwei; Gao, Hongjie

2018-05-01

UV-visible absorption spectroscopy combined with principal component analysis (PCA) and two-dimensional correlation (2D correlation) is used to trace components of dissolved organic matter (DOM) extracted from soils in a larger estuarine delta and to investigate spatial variations of DOM fractions. Soil samples of different depths were collected from native halophyte soils along a saline gradient, i.e., Suaeda salsa Comm. (SSC), Chenopodium album Comm. (CAC), Phragmites australis Comm. (PAC), and Artemisia selengensis Comm. (ASC). Molecular weights of DOM within the SSC soil profile were the lowest, followed by the CAC, PAC, and ASC soil profiles. Humification degree of DOM within the ASC soil profile was the highest, followed by the PAC, SSC, and CAC soil profiles. DOM within the soil profiles mainly contained phenolic, carboxylic, microbial products, and aromatic and alkyl groups through the PCA, which presented the significant differentiation among the four native halophyte soil profiles. The 2D UV correlation spectra of DOM within the SSC soil profile indicated that the variations of the phenolic groups were the largest, followed by the carboxylic groups, microbial products, and humified organic materials according to the band changing order of 285 → 365 → 425 → 520 nm. The 2D UV correlation spectra of DOM within the CAC soil profiles determined that the decreasing order of the variations was phenolic groups > carboxylic groups > microbial products according the band changing order of 285 → 365 → 425 nm. The 2D UV correlation spectra of DOM within the PAC soil profile proved that the variations of the phenolic groups were larger than those of the carboxylic groups according to the band changing order of 285 → 365 nm. The 2D UV correlation spectra of DOM within the ASC soil profile demonstrated that the variations of the phenolic groups were larger than those of the other DOM fractions according to the broad cross-peak at

Zeolite Combined with Alum and Polyaluminum Chloride Mixed with Agricultural Slurries Reduces Carbon Losses in Runoff from Grassed Soil Boxes.

Science.gov (United States)

Murnane, J G; Brennan, R B; Fenton, O; Healy, M G

2016-11-01

Carbon (C) losses from agricultural soils to surface waters can migrate through water treatment plants and result in the formation of disinfection by-products, which are potentially harmful to human health. This study aimed to quantify total organic carbon (TOC) and total inorganic C losses in runoff after application of dairy slurry, pig slurry, or milk house wash water (MWW) to land and to mitigate these losses through coamendment of the slurries with zeolite (2.36-3.35 mm clinoptilolite) and liquid polyaluminum chloride (PAC) (10% AlO) for dairy and pig slurries or liquid aluminum sulfate (alum) (8% AlO) for MWW. Four treatments under repeated 30-min simulated rainfall events (9.6 mm h) were examined in a laboratory study using grassed soil runoff boxes (0.225 m wide, 1 m long; 10% slope): control soil, unamended slurries, PAC-amended dairy and pig slurries (13.3 and 11.7 kg t, respectively), alum-amended MWW (3.2 kg t), combined zeolite and PAC-amended dairy (160 and 13.3 kg t zeolite and PAC, respectively) and pig slurries (158 and 11.7 kg t zeolite and PAC, respectively), and combined zeolite and alum-amended MWW (72 and 3.2 kg t zeolite and alum, respectively). The unamended and amended slurries were applied at net rates of 31, 34, and 50 t ha for pig and dairy slurries and MWW, respectively. Significant reductions of TOC in runoff compared with unamended slurries were measured for PAC-amended dairy and pig slurries (52 and 56%, respectively) but not for alum-amended MWW. Dual zeolite and alum-amended MWW significantly reduced TOC in runoff compared with alum amendment only. We conclude that use of PAC-amended dairy and pig slurries and dual zeolite and alum-amended MWW, although effective, may not be economically viable to reduce TOC losses from organic slurries given the relatively low amounts of TOC measured in runoff from unamended slurries compared with the amounts applied. Copyright © by the American Society of Agronomy, Crop Science Society of

Soil physical land degradation processes

Science.gov (United States)

Horn, Rainer

2017-04-01

According to the European Soil Framework Directive (2006) soil compaction is besides water and wind erosion one of the main physical reasons and threats of soil degradation. It is estimated, that 32% of the subsoils in Europe are highly degraded and 18% moderately vulnerable to compaction. The problem is not limited to crop land or forest areas (especially because of non-site adjusted harvesting machines) but is also prevalent in rangelands and grassland, and even in so called natural non-disturbed systems. The main reasons for an intense increase in compacted agricultural or forested regions are the still increasing masses of the machines as well the increased frequency of wheeling under non favorable site conditions. Shear and vibration induced soil deformation enhances the deterioration of soil properties especially if the soil water content is very high and the internal soil strength very low. The same is true for animal trampling in combination with overgrazing of moist to wet pastures which subsequently causes a denser (i.e. reduced proportion of coarse pores with smaller continuity) but still structured soil horizons and will finally end in a compacted platy structure. In combination with high water content and shearing due to trampling therefore results in a complete muddy homogeneous soil with no structure at all. (Krümmelbein et al. 2013) Site managements of arable, forestry or horticulture soils requires a sufficiently rigid pore system which guarantees water, gas and heat exchange, nutrient transport and adsorption as well as an optimal rootability in order to avoid subsoil compaction. Such pore system also guarantees a sufficient microbial activity and composition in order to also decompose the plant etc. debris. It is therefore essential that well structured horizons dominate in soils with at best subangular blocky structure or in the top A- horizons a crumbly structure due to biological activity. In contrast defines the formation of a platy

Adaptive Surface Modeling of Soil Properties in Complex Landforms

Directory of Open Access Journals (Sweden)

Wei Liu

2017-06-01

Full Text Available Abstract: Spatial discontinuity often causes poor accuracy when a single model is used for the surface modeling of soil properties in complex geomorphic areas. Here we present a method for adaptive surface modeling of combined secondary variables to improve prediction accuracy during the interpolation of soil properties (ASM-SP. Using various secondary variables and multiple base interpolation models, ASM-SP was used to interpolate soil K+ in a typical complex geomorphic area (Qinghai Lake Basin, China. Five methods, including inverse distance weighting (IDW, ordinary kriging (OK, and OK combined with different secondary variables (e.g., OK-Landuse, OK-Geology, and OK-Soil, were used to validate the proposed method. The mean error (ME, mean absolute error (MAE, root mean square error (RMSE, mean relative error (MRE, and accuracy (AC were used as evaluation indicators. Results showed that: (1 The OK interpolation result is spatially smooth and has a weak bull's-eye effect, and the IDW has a stronger ‘bull’s-eye’ effect, relatively. They both have obvious deficiencies in depicting spatial variability of soil K+. (2 The methods incorporating combinations of different secondary variables (e.g., ASM-SP, OK-Landuse, OK-Geology, and OK-Soil were associated with lower estimation bias. Compared with IDW, OK, OK-Landuse, OK-Geology, and OK-Soil, the accuracy of ASM-SP increased by 13.63%, 10.85%, 9.98%, 8.32%, and 7.66%, respectively. Furthermore, ASM-SP was more stable, with lower MEs, MAEs, RMSEs, and MREs. (3 ASM-SP presents more details than others in the abrupt boundary, which can render the result consistent with the true secondary variables. In conclusion, ASM-SP can not only consider the nonlinear relationship between secondary variables and soil properties, but can also adaptively combine the advantages of multiple models, which contributes to making the spatial interpolation of soil K+ more reasonable.

Radionuclide contaminated soil: Laboratory study and economic analysis of soil washing. Final report

International Nuclear Information System (INIS)

Fuhrmann, M.; Zhou, H.; Patel, B.; Bowerman, B.; Brower, J.

1996-01-01

The objective of the work discussed in this report is to determine if soil washing is a feasible method to remediate contaminated soils from the Hazardous Waste Management Facility (HWMF) at Brookhaven National Laboratory (BNL). The contaminants are predominantly Cs-137 and Sr-90. The authors have assumed that the target activity for Cs-137 is 50 pCi/g and that remediation is required for soils having greater activities. Cs-137 is the limiting contaminant because it is present in much greater quantities than Sr-90. This work was done in three parts, in which they: estimated the volume of contaminated soil as a function of Cs-137 content, determined if simple removal of the fine grained fraction of the soil (the material that is less than 0.063 mm) would effectively reduce the activity of the remaining soil to levels below the 50 pCi/g target, assessed the effectiveness of chemical and mechanical (as well as combinations of the two) methods of soil decontamination. From this analysis the authors were then able to develop a cost estimate for soil washing and for a baseline against which soil washing was compared

Combining X-ray computed tomography and visible near-infrared spectroscopy for prediction of soil structural properties

DEFF Research Database (Denmark)

Katuwal, Sheela; Hermansen, Cecilie; Knadel, Maria

2018-01-01

agricultural fields within Denmark with a wide range of textural properties and organic C (OC) contents were studied. Macroporosity (>1.2 mm in diameter) and CTmatrix (the density of the field-moist soil matrix devoid of large macropores and stones) were determined from X-ray CT scans of undisturbed soil cores...... (19 by 20 cm). Both macroporosity and CTmatix are soil structural properties that affect the degree of preferential transport. Bulk soils from the 127 sampling locations were scanned with a vis-NIR spectrometer (400–2500 nm). Macroporosity and CTmatrix were statistically predicted with partial least......Soil structure is a key soil property affecting a soil’s flow and transport behavior. X-ray computed tomography (CT) is increasingly used to quantify soil structure. However, the availability, cost, time, and skills required for processing are still limiting the number of soils studied. Visible...

Fertilization increases paddy soil organic carbon density*

Science.gov (United States)

Wang, Shao-xian; Liang, Xin-qiang; Luo, Qi-xiang; Fan, Fang; Chen, Ying-xu; Li, Zu-zhang; Sun, Huo-xi; Dai, Tian-fang; Wan, Jun-nan; Li, Xiao-jun

2012-01-01

Field experiments provide an opportunity to study the effects of fertilization on soil organic carbon (SOC) sequestration. We sampled soils from a long-term (25 years) paddy experiment in subtropical China. The experiment included eight treatments: (1) check, (2) PK, (3) NP, (4) NK, (5) NPK, (6) 7F:3M (N, P, K inorganic fertilizers+30% organic N), (7) 5F:5M (N, P, K inorganic fertilizers+50% organic N), (8) 3F:7M (N, P, K inorganic fertilizers+70% organic N). Fertilization increased SOC content in the plow layers compared to the non-fertilized check treatment. The SOC density in the top 100 cm of soil ranged from 73.12 to 91.36 Mg/ha. The SOC densities of all fertilizer treatments were greater than that of the check. Those treatments that combined inorganic fertilizers and organic amendments had greater SOC densities than those receiving only inorganic fertilizers. The SOC density was closely correlated to the sum of the soil carbon converted from organic amendments and rice residues. Carbon sequestration in paddy soils could be achieved by balanced and combined fertilization. Fertilization combining both inorganic fertilizers and organic amendments is an effective sustainable practice to sequestrate SOC. PMID:22467369

Fertilization increases paddy soil organic carbon density.

Science.gov (United States)

Wang, Shao-xian; Liang, Xin-qiang; Luo, Qi-xiang; Fan, Fang; Chen, Ying-xu; Li, Zu-zhang; Sun, Huo-xi; Dai, Tian-fang; Wan, Jun-nan; Li, Xiao-jun

2012-04-01

Field experiments provide an opportunity to study the effects of fertilization on soil organic carbon (SOC) sequestration. We sampled soils from a long-term (25 years) paddy experiment in subtropical China. The experiment included eight treatments: (1) check, (2) PK, (3) NP, (4) NK, (5) NPK, (6) 7F:3M (N, P, K inorganic fertilizers+30% organic N), (7) 5F:5M (N, P, K inorganic fertilizers+50% organic N), (8) 3F:7M (N, P, K inorganic fertilizers+70% organic N). Fertilization increased SOC content in the plow layers compared to the non-fertilized check treatment. The SOC density in the top 100 cm of soil ranged from 73.12 to 91.36 Mg/ha. The SOC densities of all fertilizer treatments were greater than that of the check. Those treatments that combined inorganic fertilizers and organic amendments had greater SOC densities than those receiving only inorganic fertilizers. The SOC density was closely correlated to the sum of the soil carbon converted from organic amendments and rice residues. Carbon sequestration in paddy soils could be achieved by balanced and combined fertilization. Fertilization combining both inorganic fertilizers and organic amendments is an effective sustainable practice to sequestrate SOC.

Assessment of the soil water balance by the combination of cosmic ray neutron sensing and eddy covariance technique in an irrigated citrus orchard (Marrakesh, Morocco)

Science.gov (United States)

Mroos, Katja; Baroni, Gabriele; Er-Raki, Salah; Francke, Till; Khabba, Said; Jarlan, Lionel; Hanich, Lahoucine; Oswald, Sascha E.

2014-05-01

Irrigation water requirement plays a crucial role in many agricultural areas and especially in arid and semi-arid landscapes. Improvements in the water management and the performance of the irrigation systems require a correct evaluation of the hydrological processes involved. However, some difficulties can arise due to the heterogeneity of the soil-plant system and of the irrigation scheme. To overcome these limitations, in this study, the soil water balance is analyzed by the combination of the Eddy Covariance technique (EC) and Cosmic Ray neutron Sensing (CRS). EC provides the measurement of the actual evapotranspiration over the area as it was presented in many field conditions. Moreover CRS showed to be a valuable approach to measure the root zone soil moisture integrated in a footprint of ~30 ha. In this way, the combination of the two methodologies should provide a better analysis of the soil water balance at field scale, as opposed to point observations, e.g. by TDR, evaporimeter and fluxmeter. Then, this could increase the capability to assess the irrigation efficiency and the agricultural water management. The study is conducted in a citrus orchard situated in a semi-arid region, 30 km southwest of Marrakesh (Morocco). The site is flat and planted with trees of same age growing in parallel rows with drip irrigation lines and application of fertilizer and pesticides. The original soil seems modified on the surface by the agricultural use, creating differences between trees, rows and lines. In addition, the drip irrigation creates also a spatial variability of the water flux distribution in the field, making this site an interesting area to test the methodology. Particular attention is given to the adaptation of the standard soil sampling campaign used for the calibration of the CRS and the introduction of a weighing function. Data were collected from June to December 2013, which corresponds to the high plant transpiration. Despite the intention of the

The Combination of DGT Technique and Traditional Chemical Methods for Evaluation of Cadmium Bioavailability in Contaminated Soils with Organic Amendment

Science.gov (United States)

Yao, Yu; Sun, Qin; Wang, Chao; Wang, Pei-Fang; Miao, Ling-Zhan; Ding, Shi-Ming

2016-01-01

Organic amendments have been proposed as a means of remediation for Cd-contaminated soils. However, understanding the inhibitory effects of organic materials on metal immobilization requires further research. In this study colza cake, a typical organic amendment material, was investigated in order to elucidate the ability of this material to reduce toxicity of Cd-contaminated soil. Available concentrations of Cd in soils were measured using an in situ diffusive gradients in thin films (DGT) technique in combination with traditional chemical methods, such as HOAc (aqua regia), EDTA (ethylene diamine tetraacetic acid), NaOAc (sodium acetate), CaCl2, and labile Cd in pore water. These results were applied to predict the Cd bioavailability after the addition of colza cake to Cd-contaminated soil. Two commonly grown cash crops, wheat and maize, were selected for Cd accumulation studies, and were found to be sensitive to Cd bioavailability. Results showed that the addition of colza cake may inhibit the growth of wheat and maize. Furthermore, the addition of increasing colza cake doses led to decreasing shoot and root biomass accumulation. However, increasing colza cake doses did lead to the reduction of Cd accumulation in plant tissues, as indicated by the decreasing Cd concentrations in shoots and roots. The labile concentration of Cd obtained by DGT measurements and the traditional chemical extraction methods, showed the clear decrease of Cd with the addition of increasing colza cake doses. All indicators showed significant positive correlations (p soil solution decreased with increasing colza cake doses. This was reflected by the decreases in the ratio (R) value of CDGT to Csol. Our study suggests that the sharp decrease in R values could not only reflect the extremely low capability of labile Cd to be released from its solid phase, but may also be applied to evaluate the abnormal growth of the plants. PMID:27314376

The Combination of DGT Technique and Traditional Chemical Methods for Evaluation of Cadmium Bioavailability in Contaminated Soils with Organic Amendment.

Science.gov (United States)

Yao, Yu; Sun, Qin; Wang, Chao; Wang, Pei-Fang; Miao, Ling-Zhan; Ding, Shi-Ming

2016-06-15

Organic amendments have been proposed as a means of remediation for Cd-contaminated soils. However, understanding the inhibitory effects of organic materials on metal immobilization requires further research. In this study colza cake, a typical organic amendment material, was investigated in order to elucidate the ability of this material to reduce toxicity of Cd-contaminated soil. Available concentrations of Cd in soils were measured using an in situ diffusive gradients in thin films (DGT) technique in combination with traditional chemical methods, such as HOAc (aqua regia), EDTA (ethylene diamine tetraacetic acid), NaOAc (sodium acetate), CaCl₂, and labile Cd in pore water. These results were applied to predict the Cd bioavailability after the addition of colza cake to Cd-contaminated soil. Two commonly grown cash crops, wheat and maize, were selected for Cd accumulation studies, and were found to be sensitive to Cd bioavailability. Results showed that the addition of colza cake may inhibit the growth of wheat and maize. Furthermore, the addition of increasing colza cake doses led to decreasing shoot and root biomass accumulation. However, increasing colza cake doses did lead to the reduction of Cd accumulation in plant tissues, as indicated by the decreasing Cd concentrations in shoots and roots. The labile concentration of Cd obtained by DGT measurements and the traditional chemical extraction methods, showed the clear decrease of Cd with the addition of increasing colza cake doses. All indicators showed significant positive correlations (p soil solution decreased with increasing colza cake doses. This was reflected by the decreases in the ratio (R) value of CDGT to Csol. Our study suggests that the sharp decrease in R values could not only reflect the extremely low capability of labile Cd to be released from its solid phase, but may also be applied to evaluate the abnormal growth of the plants.

[Transformation of Cu forms in Cynodon dactylon rhizosphere soil of copper tailings yard].

Science.gov (United States)

Wang, You-bao; Huang, Yong-jie; Zhen, Quan; Yan, Mi; Yang, Hong-fei; Liu, Deng-yi

2007-06-01

The study on the Cu forms in Cynodon dactylon rhizosphere soil of copper tailings yard in Tongling City, Anhui Province showed that among the test Cu forms, the amount of residual form occupied the majority, while that of exchangeable form was relatively low. Compared with non-rhizosphere soil, rhizosphere soil had a higher organic matter content but a lower pH. With the growth of C. dactylon, the contents of organically combined and exchangeable Cu in rhizosphere soil increased by 7.89% and 5%, respectively, while those of carbonate-combined and Fe-Mn oxides-combined Cu decreased. The growth of C. dactylon accelerated the transformation of Cu forms in rhizosphere soil, and decreased the rhizosphere soil Cu content through its absorption.

Soil Functional Mapping: A Geospatial Framework for Scaling Soil Carbon Cycling

Science.gov (United States)

Lawrence, C. R.

2017-12-01

Climate change is dramatically altering biogeochemical cycles in most terrestrial ecosystems, particularly the cycles of water and carbon (C). These changes will affect myriad ecosystem processes of importance, including plant productivity, C exports to aquatic systems, and terrestrial C storage. Soil C storage represents a critical feedback to climate change as soils store more C than the atmosphere and aboveground plant biomass combined. While we know plant and soil C cycling are strongly coupled with soil moisture, substantial unknowns remain regarding how these relationships can be scaled up from soil profiles to ecosystems. This greatly limits our ability to build a process-based understanding of the controls on and consequences of climate change at regional scales. In an effort to address this limitation we: (1) describe an approach to classifying soils that is based on underlying differences in soil functional characteristics and (2) examine the utility of this approach as a scaling tool that honors the underlying soil processes. First, geospatial datasets are analyzed in the context of our current understanding of soil C and water cycling in order to predict soil functional units that can be mapped at the scale of ecosystems or watersheds. Next, the integrity of each soil functional unit is evaluated using available soil C data and mapping units are refined as needed. Finally, targeted sampling is conducted to further differentiate functional units or fill in any data gaps that are identified. Completion of this workflow provides new geospatial datasets that are based on specific soil functions, in this case the coupling of soil C and water cycling, and are well suited for integration with regional-scale soil models. Preliminary results from this effort highlight the advantages of a scaling approach that balances theory, measurement, and modeling.

Effect of Soil Amendments on Microbial Resilience Capacity of Acid Soil Under Copper Stress.

Science.gov (United States)

Mounissamy, Vassanda Coumar; Kundu, Samaresh; Selladurai, Rajendiran; Saha, Jayanta Kumar; Biswas, Ashish Kumar; Adhikari, Tapan; Patra, Ashok Kumar

2017-11-01

An incubation study was undertaken to study microbial resilience capacity of acid soil amended with farmyard manure (FYM), charcoal and lime under copper (Cu) perturbation. Copper stress significantly reduced enzymatic activities and microbial biomass carbon (MBC) in soil. Percent reduction in microbial activity of soil due to Cu stress was 74.7% in dehydrogenase activity, 59.9% in MBC, 48.2% in alkaline phosphatase activity and 15.1% in acid phosphatase activity. Soil treated with FYM + charcoal showed highest resistance index for enzymatic activities and MBC. Similarly, the highest resilience index for acid phosphatase activity was observed in soil amended with FYM (0.40), whereas FYM + charcoal-treated soil showed the highest resilience indices for alkaline, dehydrogenase activity and MBC: 0.50, 0.22 and 0.25, respectively. This investigation showed that FYM and charcoal application, either alone or in combination, proved to be better than lime with respect to microbial functional resistance and resilience of acid soil under Cu perturbation.

Determination of chemical availability of cadmium and zinc in soils using inert soil moisture samplers.

Science.gov (United States)

Knight, B P; Chaudri, A M; McGrath, S P; Giller, K E

1998-01-01

A rapid method for extracting soil solutions using porous plastic soil-moisture samplers was combined with a cation resin equilibration based speciation technique to look at the chemical availability of metals in soil. Industrially polluted, metal sulphate amended and sewage sludge treated soils were used in our study. Cadmium sulphate amended and industrially contaminated soils all had > 65% of the total soil solution Cd present as free Cd2+. However, increasing total soil Cd concentrations by adding CdSO4 resulted in smaller total soil solution Cd. Consequently, the free Cd2+ concentrations in soil solutions extracted from these soils were smaller than in the same soil contaminated by sewage sludge addition. Amendment with ZnSO4 gave much greater concentrations of free Zn2+ in soil solutions compared with the same soil after long-term Zn contamination via sewage sludge additions. Our results demonstrate the difficulty in comparing total soil solution and free metal ion concentrations for soils from different areas with different physiochemical properties and sources of contamination. However, when comparing the same Woburn soil, Cd was much less available as Cd2+ in soil solution from the CdSO4 amended soils compared with soil contaminated by about 36 years of sewage sludge additions. In contrast, much more Zn was available in soil solution as free Zn2+ in the ZnSO4 amended soils compared with the sewage sludge treated soils.

Phytostabilisation-A Sustainable Remediation Technique for Zinc in Soils

Energy Technology Data Exchange (ETDEWEB)

Padmavathiamma, Prabha [University of British Columbia, Faculty of Land and Food Systems (Canada); Li, Loretta, E-mail: lli@civil.ubc.c [University of British Columbia, Department of Civil Engineering (Canada)

2009-08-15

Two studies were conducted to determine a feasible and practical phytoremediation strategy for Zn-contaminated soils. The aim of the first study was to identify promising plant species capable of Zn remediation for the soils and climatic conditions of British Columbia. The purpose of the second study was to assess the effects of soil amendments in modifying the soil properties and providing the right conditions for the plants to immobilise Zn. Promising plants for phytostabilisation in the first study (Lolium perenne, Festuca rubra and Poa pratensis) were tested in the presence of soil amendments (lime, phosphate and compost, both individually and in combination) in the second study. The efficiency of treatments to stabilise Zn was based on Zn fractionation in the soil and on absorption and partitioning of Zn in plants. Maximum Zn immobilisation was achieved in the soil by a combination of lime, phosphate and compost, in conjunction with growth of P. pratensis.

Linking soil O2, CO2, and CH4 concentrations in a wetland soil

DEFF Research Database (Denmark)

Elberling, Bo; Jensen, Louise Askær; Jørgensen, Christian Juncher

2011-01-01

and CH4 were measured in the laboratory during flooding of soil columns using a combination of planar O2 optodes and membrane inlet mass spectrometry. Microsensors were used to assess apparent diffusivity under both field and laboratory conditions. Gas concentration profiles were analyzed...... plants tissue on soil gas dynamics and greenhouse gas emissions following marked changes in water level....

Evaluation of Phosphorus Leaching in an Agricultural Soil under Different Soil Amendments

OpenAIRE

ERDONA DEMIRAJ; FERDI BRAHUSHI; JAMARBËR MALLTEZI; SULEJMAN SULÇE

2017-01-01

The transport of Phosphorus (P) from agricultural soils to surface waters sensitive to eutrophication has long been a world-wide environmental concern. The intensive agricultural activity in the upper Shkodra fields, combined with others point source pollution, probably, intensify eutrophication of the Shkodra Lake. These Clay Loamy soils (calcaric Regosols) are characterized by low organic matter, N and P, with a high water percolation. An experiment was conducted at Greenhouse Research Stat...

Understanding the Impacts of Soil, Climate, and Farming Practices on Soil Organic Carbon Sequestration: A Simulation Study in Australia.

Science.gov (United States)

Godde, Cécile M; Thorburn, Peter J; Biggs, Jody S; Meier, Elizabeth A

2016-01-01

Carbon sequestration in agricultural soils has the capacity to mitigate greenhouse gas emissions, as well as to improve soil biological, physical, and chemical properties. The review of literature pertaining to soil organic carbon (SOC) dynamics within Australian grain farming systems does not enable us to conclude on the best farming practices to increase or maintain SOC for a specific combination of soil and climate. This study aimed to further explore the complex interactions of soil, climate, and farming practices on SOC. We undertook a modeling study with the Agricultural Production Systems sIMulator modeling framework, by combining contrasting Australian soils, climates, and farming practices (crop rotations, and management within rotations, such as fertilization, tillage, and residue management) in a factorial design. This design resulted in the transposition of contrasting soils and climates in our simulations, giving soil-climate combinations that do not occur in the study area to help provide insights into the importance of the climate constraints on SOC. We statistically analyzed the model's outputs to determinate the relative contributions of soil parameters, climate, and farming practices on SOC. The initial SOC content had the largest impact on the value of SOC, followed by the climate and the fertilization practices. These factors explained 66, 18, and 15% of SOC variations, respectively, after 80 years of constant farming practices in the simulation. Tillage and stubble management had the lowest impacts on SOC. This study highlighted the possible negative impact on SOC of a chickpea phase in a wheat-chickpea rotation and the potential positive impact of a cover crop in a sub-tropical climate (QLD, Australia) on SOC. It also showed the complexities in managing to achieve increased SOC, while simultaneously aiming to minimize nitrous oxide (N2O) emissions and nitrate leaching in farming systems. The transposition of contrasting soils and climates in

Understanding the Impacts of Soil, Climate and Farming Practices on Soil Organic Carbon Sequestration: a Simulation Study in Australia

Directory of Open Access Journals (Sweden)

Cecile Marie Godde

2016-05-01

Full Text Available Carbon sequestration in agricultural soils has the capacity to mitigate greenhouse gas emissions, as well as to improve soil biological, physical and chemical properties. The review of literature pertaining to soil organic carbon (SOC dynamics within Australian grain farming systems does not enable us to conclude on the best farming practices to increase or maintain SOC for a specific combination of soil and climate. This study aimed to further explore the complex interactions of soil, climate and farming practices on SOC. We undertook a modeling study with the APSIM (Agricultural Production Systems sIMulator modeling framework, by combining contrasting Australian soils, climates and farming practices (crop rotations, and management within rotations, such as fertilization, tillage and residue management in a factorial design. This design resulted in the transposition of contrasting soils and climates in our simulations, giving soil-climate combinations that do not occur in the study area to help provide insights into the importance of the climate constraints on SOC. We statistically analyzed the model’s outputs to determinate the relative contributions of soil parameters, climate and farming practices on SOC. The initial SOC content had the largest impact on the value of SOC, followed by the climate and the fertilization practices. These factors explained 66%, 18% and 15% of SOC variations, respectively, after 80 years of constant farming practices in the simulation. Tillage and stubble management had the lowest impacts on SOC. This study highlighted the possible negative impact on SOC of a chickpea phase in a wheat-chickpea rotation and the potential positive impact of a cover crop in a sub-tropical climate (Queensland on SOC. It also showed the complexities in managing to achieve increased SOC, while simultaneously aiming to minimize nitrous oxide (N2O emissions and nitrate leaching in farming systems. The transposition of contrasting soils

Influences of rising atmospheric carbon dioxide and ozone concentrations on soil respiration, soil microbial biomass, nutrient availability and soil C dynamics in a soybean-wheat no-till system

Science.gov (United States)

Effects of the elevated carbon dioxide and ozone on agroecosystems include effects on root growth, soil microbiology and soil C dynamics although the combined effects of these gases on belowground processes have been little studied. The objective of this experiment was to determine the separate and...

Silvicultural practices and soil protection

International Nuclear Information System (INIS)

Ranger, Jacques; Nys, Claude; Legout, Arnaud; Dambrine, Etienne; Augusto, Laurent; Berthelot, Alain; Bouchon, Jean; Ottorini, Jean-Marc; Cacot, Emmanuel; Gavaland, Andre; Laclau, Jean-Paul; Saint-Andre, Laurent; Nicolas, Manuel; Ponette, Quentin

2011-01-01

The purpose of this work is to assess the risks deriving from current forestry practices on the sustainability of soil function and ecosystems. The relationship between the production function and the soil conservation function translates as a certain conflict between these two options. Stresses on the chemical fertility of the soil were analysed from the least intensive to the most intensive treatments, i.e. from forest reserves to very short rotation, treated lignocellulosic crops. Under the extensive systems, high grade biological recycling is sustainable if logging is confined to trunks alone. Dressings can correct the slow but inevitable acidification of soils. When treatments are intensive, the natural fertility of forest soils cannot sustain production; only soils with suitable physical qualities combined with application of appropriate inputs enable sustained high levels of output to be achieved, in particular under the short rotation systems. (authors)

Effect of soil type and soil management on soil physical, chemical and biological properties in commercial organic olive orchards in Southern Spain

Science.gov (United States)

Gomez, Jose Alfonso; Auxiliadora Soriano, Maria; Montes-Borrego, Miguel; Navas, Juan Antonio; Landa, Blanca B.

2014-05-01

One of the objectives of organic agriculture is to maintain and improve soil quality, while simultaneously producing an adequate yield. A key element in organic olive production is soil management, which properly implemented can optimize the use of rainfall water enhancing infiltration rates and controlling competition for soil water by weeds. There are different soil management strategies: eg. weed mowing (M), green manure with surface tillage in spring (T), or combination with animal grazing among the trees (G). That variability in soil management combined with the large variability in soil types on which organic olive trees are grown in Southern Spain, difficult the evaluation of the impact of different soil management on soil properties, and yield as well as its interpretation in terms of improvement of soil quality. This communications presents the results and analysis of soil physical, chemical and biological properties on 58 soils in Southern Spain during 2005 and 2006, and analyzed and evaluated in different studies since them. Those 58 soils were sampled in 46 certified commercial organic olive orchards with four soil types as well as 12 undisturbed areas with natural vegetation near the olive orchards. The four soil types considered were Eutric Regosol (RGeu, n= 16), Eutric Cambisol (CMeu, n=16), Calcaric Regosol (RGca, n=13 soils sampled) and Calcic Cambisol (CMcc), and the soil management systems (SMS) include were 10 light tillage (LT), 16 sheep grazing (G), 10 tillage (T), 10 mechanical mowing (M), and 12 undisturbed areas covered by natural vegetation (NV-C and NV-S). Our results indicate that soil management had a significant effect on olive yield as well as on key soil properties. Among these soil properties are physical ones, such as infiltration rate or bulk density, chemical ones, especially organic carbon concentration, and biological ones such as soil microbial respiration and bacterial community composition. Superimpose to that soil

Estimating soil hydrological response by combining precipitation-runoff modeling and hydro-functional soil homogeneous units

Science.gov (United States)

Aroca-Jimenez, Estefania; Bodoque, Jose Maria; Diez-Herrero, Andres

2015-04-01

Flash floods constitute one of the natural hazards better able to generate risk, particularly with regard to Society. The complexity of this process and its dependence on various factors related to the characteristics of the basin and rainfall make flash floods are difficult to characterize in terms of their hydrological response.To do this, it is essential a proper analysis of the so called 'initial abstractions'. Among all of these processes, infiltration plays a crucial role in explaining the occurrence of floods in mountainous basins.For its characterization the Green-Ampt model , which depends on the characteristics of rainfall and physical properties of soil has been used in this work.This is a method enabling to simulate floods in mountainous basins where hydrological response is sub-daily. However, it has the disadvantage that it is based on physical properties of soil which have a high spatial variability. To address this difficulty soil mapping units have been delineated according to the geomorphological landforms and elements. They represent hydro-functional mapping units that are theoretically homogeneous from the perspective of the pedostructure parameters of the pedon. So the soil texture of each homogeneous group of landform units was studied by granulometric analyses using standarized sieves and Sedigraph devices. In addition, uncertainty associated with the parameterization of the Green-Ampt method has been estimated by implementing a Monte Carlo approach, which required assignment of the proper distribution function to each parameter.The suitability of this method was contrasted by calibrating and validating a hydrological model, in which the generation of runoff hydrograph has been simulated using the SCS unit hydrograph (HEC-GeoHMS software), while flood wave routing has been characterized using the Muskingum-Cunge method. Calibration and validation of the model was from the use of an automatic routine based on the employ of the search algorithm

Sustainable Soil Management

DEFF Research Database (Denmark)

Green, Ole; Evgrafova, Alevtina; Kirkegaard Nielsen, Søren

Linket til højre henviser til rapporten i trykt format til download. This report provides an overview on new technologies for integrate sustainable and resilient management practices in arable ecosystems for advanced farmers, consultants, NGOs and policy makers. By following sustainable soil...... and soil quality in short- and long-terms. This report also illustrates the importance to combine a system approach for plant production by assessing field readiness, managing in-field traffic management, implementing the sitespecific controlled as well as sensor-controlled seedbed preparation, seeding...

Stabilization of expansive soil using bagasse ash & lime | Wubshet ...

African Journals Online (AJOL)

7-5 soil on the AASHTO classification was stabilized using 3% lime, 15% bagasse ash and 15% bagasse ash in combination with 3% lime by dry weight of the soil. The effect of the additives on the soil was investigated with respect to plastcity, ...

Combined remediation of Cd-phenanthrene co-contaminated soil by Pleurotus cornucopiae and Bacillus thuringiensis FQ1 and the antioxidant responses in Pleurotus cornucopiae.

Science.gov (United States)

Jiang, Juan; Liu, Hongying; Li, Qiao; Gao, Ni; Yao, Yuan; Xu, Heng

2015-10-01

Remediation of soil co-contaminated with heavy metals and PAHs by mushroom and bacteria is a novel technique. In this study, the combined remediation effect of mushroom (Pleurotus cornucopiae) and bacteria (FQ1, Bacillus thuringiensis) on Cd and phenanthrene co-contaminated soil was investigated. The effect of bacteria (B. thuringiensis) on mushroom growth, Cd accumulation, phenanthrene degradation by P. cornucopiae and antioxidative responses of P. cornucopiae were studied. P. cornucopiae could adapt easily and grow well in Cd-phenanthrene co-contaminated soil. It was found that inoculation of FQ1 enhanced mushroom growth (biomass) and Cd accumulation with the increment of 26.68-43.58% and 14.29-97.67% respectively. Up to 100% and 95.07% of phenanthrene were removed in the bacteria-mushroom (B+M) treatment respectively spiked with 200mg/kg and 500mg/kg phenanthrene. In addition, bacterial inoculation alleviated oxidative stress caused by co-contamination with relative decreases in lipid peroxidation and enzyme activity, including malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD). This study demonstrated that the integrated remediation strategy of bacteria and mushroom is an effective and promising method for Cd-phenanthrene co-contaminated soil bioremediation. Copyright © 2015 Elsevier Inc. All rights reserved.

In situ enhanced soil mixing. Innovative technology summary report

International Nuclear Information System (INIS)

1996-02-01

In Situ Enhanced Soil Mixing (ISESM) is a treatment technology that has been demonstrated and deployed to remediate soils contaminated with volatile organic compounds (VOCs). The technology has been developed by industry and has been demonstrated with the assistance of the U.S. Department of Energy's Office of Science and Technology and the Office of Environmental Restoration. The technology is particularly suited to shallow applications, above the water table, but can be used at greater depths. ISESM technologies demonstrated for this project include: (1) Soil mixing with vapor extraction combined with ambient air injection. [Contaminated soil is mixed with ambient air to vaporize volatile organic compounds (VOCs). The mixing auger is moved up and down to assist in removal of contaminated vapors. The vapors are collected in a shroud covering the treatment area and run through a treatment unit containing a carbon filter or a catalytic oxidation unit with a wet scrubber system and a high efficiency particulate air (HEPA) filter.] (2) soil mixing with vapor extraction combined with hot air injection [This process is the same as the ambient air injection except that hot air or steam is injected.] (3) soil mixing with hydrogen peroxide injection [Contaminated soil is mixed with ambient air that contains a mist of diluted hydrogen peroxide (H 2 O 2 ) solution. The H 2 O 2 solution chemically oxidizes the VOCs to carbon dioxide (CO 2 ) and water.] (4) soil mixing with grout injection for solidification/stabilization [Contaminated soil is mixed as a cement grout is injected under pressure to solidify and immobilize the contaminated soil in a concrete-like form.] The soils are mixed with a single-blade auger or with a combination of augers ranging in diameter from 3 to 12 feet

Stress Coefficients for Soil Water Balance Combined with Water Stress Indicators for Irrigation Scheduling of Woody Crops

Directory of Open Access Journals (Sweden)

Maria Isabel Ferreira

2017-06-01

Full Text Available There are several causes for the failure of empirical models to estimate soil water depletion and to calculate irrigation depths, and the problem is particularly critical in tall, uneven, deficit irrigated (DI crops in Mediterranean climates. Locally measured indicators that quantify water status are useful for addressing those causes and providing feed-back information for improving the adequacy of simple models. Because of their high aerodynamic resistance, the canopy conductance of woody crops is an important factor in determining evapotranspiration (ET, and accurate stress coefficient (Ks values are needed to quantify the impact of stomatal closure on ET. A brief overview of basic general principles for irrigation scheduling is presented with emphasis on DI applications that require Ks modelling. The limitations of existing technology related to scheduling of woody crops are discussed, including the shortcomings of plant-based approaches. In relation to soil water deficit and/or predawn leaf water potential, several woody crop Ks functions are presented in a secondary analysis. Whenever the total and readily available water data were available, a simple Ks model was tested. The ultimate aim of this discussion is to illustrate the central concept: that a combination of simple ET models and water stress indicators is required for scheduling irrigation of deep-rooted woody crops.

The Instructional Design of Case Method Combined With Role-Playing in the Soil and Groundwater Training Courses

Directory of Open Access Journals (Sweden)

Mei-Yin Hwa

2013-12-01

Full Text Available Almost all environmental problems are caused by human. Besides being good at environmental engineering theory and technology, to enhance the ability to solve environmental problems, the environmental practitioners need a closer understanding of the stance of different stakeholders. This study is an instructional design combining both "case method" and "role-playing" into the “Soil and Groundwater Talent Training Courses” in Taipei. The curriculum is based on the hexavalent chromium pollution case in Yunlin County. Each group of students is encouraged to play four roles, inculding leather factory owners, farmers, environmental officials, and soil testing professionals. Each group of students has to propose solution strategies after discussion and consultation. The study adopts a single group posttest design. The qualitative data were analyzed using content analysis. The quantitative data were analyzed through proportion and Pearson correlation. Results were as follows: (1 The solution strategies identified by the students include: “mutual communication”, “consensus-building”, and “the formation of an environmental committee". (2 More than 80% of students were satisfied with the instruction, and they found it helpful in terms of knowledge and skills in doing surveying. A moderate positive correlation exists between students’ participation and learning satisfaction. A reflection concerning this instruction design along with some recommendations are provided.

Opportunities and future directions for visual soil evaluation methods in soil structure research

DEFF Research Database (Denmark)

Guimaraes, R.M.L.; Lamandé, Mathieu; Munkholm, Lars Juhl

2017-01-01

to provide spatial information for soil process models, e.g. compaction models. VSE could be combined with sensing techniques at the field or landscape scale for better management of fields in the context of precision farming. Further work should be done to integrate plant vigour, roots and soil fauna......As the use of visual soil evaluation (VSE) methods has spread globally, they have been exposed to different climatic and pedological scenarios, resulting in the need to elucidate limitations, encourage refinements and open up new avenues of research. The main objective of this paper is to outline...... the potential of VSE methods to develop novel soil structure research and how this potential could be developed and integrated within existing research. We provide a brief overview of VSE methods in order to summarize the soil information that is obtained by VSE. More detailed VSE methods could be developed...

Soil properties influence kinetics of soil acid phosphatase in response to arsenic toxicity.

Science.gov (United States)

Wang, Ziquan; Tan, Xiangping; Lu, Guannan; Liu, Yanju; Naidu, Ravi; He, Wenxiang

2018-01-01

Soil phosphatase, which plays an important role in phosphorus cycling, is strongly inhibited by Arsenic (As). However, the inhibition mechanism in kinetics is not adequately investigated. In this study, we investigated the kinetic characteristics of soil acid phosphatase (ACP) in 14 soils with varied properties, and also explored how kinetic properties of soil ACP changed with different spiked As concentrations. The results showed that the Michaelis constant (K m ) and maximum reaction velocity (V max ) values of soil ACP ranged from 1.18 to 3.77mM and 0.025-0.133mMh -1 in uncontaminated soils. The kinetic parameters of soil ACP in different soils changed differently with As contamination. The K m remained unchanged and V max decreased with increase of As concentration in most acid and neutral soils, indicating a noncompetitive inhibition mechanism. However, in alkaline soils, the K m increased linearly and V max decreased with increase of As concentration, indicating a mixed inhibition mechanism that include competitive and noncompetitive. The competitive inhibition constant (K ic ) and noncompetitive inhibition constant (K iu ) varied among soils and ranged from 0.38 to 3.65mM and 0.84-7.43mM respectively. The inhibitory effect of As on soil ACP was mostly affected by soil organic matter and cation exchange capacity. Those factors influenced the combination of As with enzyme, which resulted in a difference of As toxicity to soil ACP. Catalytic efficiency (V max /K m ) of soil ACP was a sensitive kinetic parameter to assess the ecological risks of soil As contamination. Copyright © 2017 Elsevier Inc. All rights reserved.

Importance of soil nitrogen and select intensifying measures in the soil-plant-fertilizer system demonstrated in sugar beets

International Nuclear Information System (INIS)

Rauhe, K.; Sielaff, B.; Barth, F.J.

1981-01-01

Sugar beets were gradually fertilized with 15 N-labelled nitrogen fertilizer without or in combination with irrigation. To gain optimum crop yields 180 - 200 kg/ha fertilizer nitrogen were required. Within the range of maximum yield the total nitrogen uptake amounted to 300 - 360 kg/ha under conditions of irrigation. Nitrogen was taken up from the fertilizer by 40% and from the soil by 60%. The immobilization rate of fertilizer nitrogen was near 30% after 2 years of vegetation. Only 33% and 25%, resp., of soil nitrogen could be replaced by fertilizing without and combined with irrigation, resp. It was shown that despite of increased application of the main intensifying factors, nitrogen and water, the soil nitrogen was mineralized intensively

Soil-Transmitted Helminths in Top Soils Used for Horticultural Purposes in Cape Coast, Ghana

Directory of Open Access Journals (Sweden)

David Oscar Yawson

2018-01-01

Full Text Available This paper investigated the concentrations of eggs of three helminths (roundworm, hookworm, and whipworm in the so-called black soils used for domestic and urban landscaping, home gardening and as growth medium for potted plants and pot experiments. The black soils are largely collected from active or abandoned waste dumpsites and fallowed or vegetated idle sites in the urban fringe or rural areas. Users buy black soils from dealers. Samples of black soils used for various purposes and at different places were collected for analysis of helminth eggs. The Modified EPA Method, which combines flotation and sedimentation, was used to isolate the eggs. The results show that these black soils have substantial loads of helminth eggs, with roundworm being dominant, followed by hookworm. Mean concentrations of helminth eggs were 2.45 (roundworm, 1.38 (hookworm, and 0.25 (whipworm g−1 soil, respectively. The helminth egg loads also declined with duration of use of the black soils. It is concluded that black soils used for horticultural purposes in Ghana can be a potential source of helminth infestation. Therefore, treatment of black soils, regulation of black soil market and use, and development of growth media industry should be important components of helminth control strategy.

Combined effect of capillary barrier and layered slope on water, solute and nanoparticle transfer in an unsaturated soil at lysimeter scale.

Science.gov (United States)

Prédélus, Dieuseul; Coutinho, Artur Paiva; Lassabatere, Laurent; Bien, Le Binh; Winiarski, Thierry; Angulo-Jaramillo, Rafael

2015-10-01

It is well recognized that colloidal nanoparticles are highly mobile in soils and can facilitate the transport of contaminants through the vadose zone. This work presents the combined effect of the capillary barrier and soil layer slope on the transport of water, bromide and nanoparticles through an unsaturated soil. Experiments were performed in a lysimeter (1×1×1.6m(3)) called LUGH (Lysimeter for Urban Groundwater Hydrology). The LUGH has 15 outputs that identify the temporal and spatial evolution of water flow, solute flux and nanoparticles in relation to the soil surface conditions and the 3D system configuration. Two different soil structures were set up in the lysimeter. The first structure comprises a layer of sand (0-0.2cm, in diameter) 35cm thick placed horizontally above a layer of bimodal mixture also 35cm thick to create a capillary barrier at the interface between the sand and bimodal material. The bimodal material is composed of a mixture 50% by weight of sand and gravel (0.4-1.1cm, in diameter). The second structure, using the same amount of sand and bimodal mixture as the first structure represents an interface with a 25% slope. A 3D numerical model based on Richards equation for flow and the convection dispersion equations coupled with a mechanical module for nanoparticle trapping was developed. The results showed that under the effect of the capillary barrier, water accumulated at the interface of the two materials. The sloped structure deflects flow in contrast to the structure with zero slope. Approximately 80% of nanoparticles are retained in the lysimeter, with a greater retention at the interface of two materials. Finally, the model makes a good reproduction of physical mechanisms observed and appears to be a useful tool for identifying key processes leading to a better understanding of the effect of capillary barrier on nanoparticle transfer in an unsaturated heterogeneous soil. Copyright © 2015 Elsevier B.V. All rights reserved.

Six phase soil heating. Innovative technology summary report

International Nuclear Information System (INIS)

1995-04-01

Six Phase Soil Heating (SPSH) was developed to remediate soils contaminated with volatile and semi-volatile organic compounds. SPSH is designed to enhance the removal of contaminates from the subsurface during soil vapor extraction. The innovation combines an emerging technology, six-phase electric heating, with a baseline technology, soil vapor extraction, to produce a more efficient in situ remediation systems for difficult soil and/or contaminate applications. This document describes the technology and reports on field demonstrations conducted at Savannah River and the Hanford Reservation

Molecular investigations of the soil, rhizosphere and transgenic glufosinate-resistant rape and maize plants in combination with herbicide (Basta) application under field conditions.

Science.gov (United States)

Ernst, Dieter; Rosenbrock-Krestel, Hilkea; Kirchhof, Gudrun; Bieber, Evi; Giunaschwili, Nathela; Müller, Rüdiger; Fischbeck, Gerhard; Wagner, Tobias; Sandermann, Heinrich; Hartmann, Anton

2008-01-01

A field study was conducted during 1994 to 1998 on the Experimental Farm Roggenstein, near Fürstenfeldbruck, Bavaria, Germany to determine the effect of transgenic glufosinate-resistant rape in combination with the herbicide Basta [glufosinate-ammonium, phosphinothricin, ammonium (2RS)-2-amino-4-(methylphosphinato) butyric acid] application on soil microorganisms and the behaviour of the synthetic transgenic DNA in response to normal agricultural practice. No influence of Basta on microbial biomass could be detected. The phospholipid fatty acid analysis of soil extracts showed no difference between Basta application and mechanical weed control, whereas conventional herbicide application revealed a different pattern. Basta application resulted in a changed population of weeds with a selective effect for Viola arvensis. During senescence, transgenic rape DNA was degraded similar to endogenous control DNA. After ploughing the chopped plant material in the soil, transgenic as well as endogenous control DNA sequences could be detected for up to 4 weeks for rape and up to 7 months for maize, whereas PCR analysis of composted transgenic maize revealed the presence of the transgene over a period of 22 months.

Simultaneous removal of phenanthrene and cadmium from contaminated soils by saponin, a plant-derived biosurfactant

International Nuclear Information System (INIS)

Song Saisai; Zhu Lizhong; Zhou Wenjun

2008-01-01

Batch experiments were conducted to evaluate the performance of saponin, a plant-derived biosurfactant, for simultaneously removing phenanthrene and cadmium from the combined contaminated soils. Results showed that phenanthrene was desorbed from the contaminated soils by saponin with the partition of phenanthrene into surfactant micelle, meanwhile cadmium was effectively removed from the contaminated soils by the complexation of cadmium with the external carboxyl groups of saponin micelle. The efficiencies of saponin for the removal of phenanthrene and cadmium from the contaminated soils were greater than that of Triton X100 and citric acid, respectively. At concentration of 3750 mg/L, saponin has a removal rate of 87.7% and 76.2% of cadmium and phenanthrene, respectively, from the combined contaminated soil. The removals of cadmium and phenanthrene from the soils were not obviously constrained each other. Thus, saponin has the potential for the removal of heavy metal and PAHs from the combined contaminated soils. - Saponin has great potential for the simultaneous removal of cadmium and phenanthrene from the combined contaminated soils

Simultaneous removal of phenanthrene and cadmium from contaminated soils by saponin, a plant-derived biosurfactant

Energy Technology Data Exchange (ETDEWEB)

Song Saisai [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Zhu Lizhong [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China)], E-mail: zlz@zju.edu.cn; Zhou Wenjun [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China)

2008-12-15

Batch experiments were conducted to evaluate the performance of saponin, a plant-derived biosurfactant, for simultaneously removing phenanthrene and cadmium from the combined contaminated soils. Results showed that phenanthrene was desorbed from the contaminated soils by saponin with the partition of phenanthrene into surfactant micelle, meanwhile cadmium was effectively removed from the contaminated soils by the complexation of cadmium with the external carboxyl groups of saponin micelle. The efficiencies of saponin for the removal of phenanthrene and cadmium from the contaminated soils were greater than that of Triton X100 and citric acid, respectively. At concentration of 3750 mg/L, saponin has a removal rate of 87.7% and 76.2% of cadmium and phenanthrene, respectively, from the combined contaminated soil. The removals of cadmium and phenanthrene from the soils were not obviously constrained each other. Thus, saponin has the potential for the removal of heavy metal and PAHs from the combined contaminated soils. - Saponin has great potential for the simultaneous removal of cadmium and phenanthrene from the combined contaminated soils.

Using synthetic polymers to reduce soil erosion after forest fires in Mediterranean soils

Science.gov (United States)

Lado, Marcos; Ben-Hur, Meni; Inbar, Assaf

2010-05-01

Forest fires are a major environmental problem in the Mediterranean region because they result in a loss of vegetation cover, changes in biodiversity, increases in greenhouse gasses emission and a potential increase of runoff and soil erosion. The large increases in runoff and sediment yields after high severity fires have been attributed to several factors, among them: increase in soil water repellency; soil sealing by detached particles and by ash particles, and the loss of a surface cover. The presence of a surface cover increases infiltration, and decreases runoff and erosion by several mechanisms which include: rainfall interception, plant evapotranspiration, preservation of soil structure by increasing soil organic matter, and increasing surface roughness. The loss of vegetation cover as a result of fire leaves the surface of the soil exposed to the direct impact of the raindrops, and therefore the sensitivity of the soil to runoff generation and soil loss increases. In this work, we propose a new method to protect soils against post-fire erosion based on the application of synthetic polymers to the soil. Laboratory rainfall simulations and field runoff plots were used to analyze the suitability of the application of synthetic polymers to reduce soil erosion and stabilize soil structure in Mediterranean soils. The combination of these two processes will potentially favor a faster recovery of the vegetation structure. This method has been successfully applied in arable land, however it has not been tested in burnt forests. The outcome of this study may provide important managerial tools for forest management following fires.

In vitro suppression of fungi caused by combinations of apparently non-antagonistic soil bacteria

NARCIS (Netherlands)

De Boer, W.; Wagenaar, A.M.; Klein Gunnewiek, P.J.A.; Van Veen, J.A.

2007-01-01

We hypothesized that apparently non-antagonistic soil bacteria may contribute to suppression of fungi during competitive interactions with other bacteria. Four soil bacteria (Brevundimonas sp., Luteibacter sp., Pedobacter sp. and Pseudomonas sp.) that exhibited little or no visible antifungal

Soil and worm: on eating as relating

NARCIS (Netherlands)

Bertoni, F.

2013-01-01

Earthworms and soil combine in an ecotoxicological experiment in the Vrije Universiteit in Amsterdam. To determine the effects of a toxic compound produced by genetically modified broccoli, ecotoxicologists use the earthworm in a standardized test to understand the conditions of the soil. In the

Linking soil systems to societal value systems

Science.gov (United States)

Helming, Katharina; Daedlow, Katrin; Techen, Anja; Kaiser, David Brian

2017-04-01

Sustainable management of soils is needed to avoid soil degradation and to maintain soil functions. This requires the assessment of how human activities drive soil management, how soil management affect soil functions and soil degradation, which trade-offs occur and how they compromise sustainable development targets. In the frame of the German research programme "Soils as a sustainable resource for the bio-economy - BonaRes", we developed an enhanced approach of the DPSIR (driver-pressure-state-impact-response) cycle which helps to assess these interrelations. Because not all soil functions can be maximized simultaneously in space and time and trade-offs are inevitable, it depends on the societal value system to decide which management practices and respective soil functional performances are valued sustainably. We analysed the applicability of three valuation concepts being prominent in research about social-ecological systems, namely resource efficiency, ecosystem services, and ethics and equity. The concept of resource efficiency is based in the life-cycle thinking and is often applied at the level of the farming systems and in the context of bio-economy strategies. It covers the use of natural (water, energy, nutrients, land) and economic resources. At the landscape level, the concept of ecosystem services is prominent. Here, the contribution of soils to the provisioning, regulating and cultural services of the natural ecosystems is considered. Ethical considerations include the intrinsic values of nature as well as issues of local and global equity between different societal groups, generations, and localities. The three concepts cover different problem dimensions and complexity levels of soil management and decision making. Alone, none of them are capable to discover complex questions of sustainable soil management and development. Rather, the exact spatial and temporal framing of the sustainability problem at stake determines which combination of the value

Effect of soil solarization on soil-borne pathogens

International Nuclear Information System (INIS)

Sobh, Hana

1995-01-01

Author.Soil solarization was conducted at three locations on the Lebanese coast. Maximum soil temperatures recorded were 53 and 48 celsius degrees at Jiyeh, 48.9, 46 and 43 celsius degrees at Naameh and 48, 45 and 43.5 celsius degrees at Khaldeh at 5, 15 and 25cm soil depths respectively. Mean soil temperatures recorded at 3pm were at Jiyeh 51.6, 47 and 46 celsius degrees compared to Naameh 47, 45 and 41 celsius degrees and Khaldeh 44, 42 and 41 celsius degrees at 5, 15 and 25 cm respectively. The mean temperature in solarized soils were 7.3 to 15 celsius degrees higher than those of the nonsolarized soils indicating a sustained increase of soil temperature in the solarized soils. The effect of soil solarization on artificially introduced fungal pathogens in the soil at Khaldeh, resulted in complete destruction of sclerotia of Sclerotinia spp. at three depths studied. However, with respect to the two other pathogens tested, solarization resulted in reduction of the viability of microsclerotia of Verticillium spp. by 99-79% and of Fusarium oxysporum f. sp. melonis inoculum by 88-54% at 5 and 15 cm respectively, but only by 45% and 14% reduction at 25 cm. This level of control is significant when it is compared to the percentage of control where the level of reduction of inoculum viability did not exceed 10% at any soil depth. As there were contradicting reports in the literature on nematodes, two field trials in greenhouses were conducted to study the possibility of integrating 2 methods for management on nematodes. Soil solarization alone or in combination with biological control of nematodes using Arthrobotrys spp. and Dactyl ella brocophaga to control the root-knot nematodes on two crops, tomato at Naameh and cucumber at Jiyeh were compared to Methyl Bromide treatment. It was evident that, even on a very susceptible crop like cucumber, the integration of biological control and soil solarization gave a good level of control similar to methyl bromide. Neither root

Soil analysis. Modern instrumental technique

International Nuclear Information System (INIS)

Smith, K.A.

1993-01-01

This book covers traditional methods of analysis and specialist monographs on individual instrumental techniques, which are usually not written with soil or plant analysis specifically in mind. The principles of the techniques are combined with discussions of sample preparation and matrix problems, and critical reviews of applications in soil science and related disciplines. Individual chapters are processed separately for inclusion in the appropriate data bases

The combined effects of urea application and simulated acid rain on soil acidification and microbial community structure.

Science.gov (United States)

Liu, Xingmei; Zhou, Jian; Li, Wanlu; Xu, Jianming; Brookes, Philip C

2014-05-01

Our aim was to test the effects of simulated acid rain (SAR) at different pHs, when applied to fertilized and unfertilized soils, on the leaching of soil cations (K, Ca, Mg, Na) and Al. Their effects on soil pH, exchangeable H(+) and Al(3+) and microbial community structure were also determined. A Paleudalfs soil was incubated for 30 days, with and without an initial application of urea (200 mg N kg(-1)soil) as nitrogen (N) fertilizer. The soil was held in columns and leached with SAR at three pH levels. Six treatments were tested: SAR of pH 2.5, 4.0 and 5.6 leaching on unfertilized soil (T1, T2 and T3), and on soils fertilized with urea (T4, T5 and T6). Increasing acid inputs proportionally increased cation leaching in both unfertilized and fertilized soils. Urea application increased the initial Ca and Mg leaching, but had no effect on the total concentrations of Ca, Mg and K leached. There was no significant difference for the amount of Na leached between the different treatments. The SAR pH and urea application had significant effects on soil pH, exchangeable H(+) and Al(3+). Urea application, SAR treated with various pH, and the interactions between them all had significant impacts on total phospholipid fatty acids (PLFAs). The highest concentration of total PLFAs occurred in fertilized soils with SAR pH5.6 and the lowest in soils leached with the lowest SAR pH. Soils pretreated with urea then leached with SARs of pH 4.0 and 5.6 had larger total PLFA concentrations than soil without urea. Bacterial, fungal, actinomycete, Gram-negative and Gram-positive bacterial PLFAs had generally similar trends to total PLFAs.

Assessing the dynamics of the upper soil layer relative to soil management practices

Science.gov (United States)

Hatfield, J.; Wacha, K.; Dold, C.

2017-12-01

The upper layer of the soil is the critical interface between the soil and the atmosphere and is the most dynamic in response to management practices. One of the soil properties most reflective to changes in management is the stability of the aggregates because this property controls infiltration of water and exchange of gases. An aggregation model has been developed based on the factors that control how aggregates form and the forces which degrade aggregates. One of the major factors for this model is the storage of carbon into the soil and the interaction with the soil biological component. To increase soil biology requires a stable microclimate that provides food, water, shelter, and oxygen which in turn facilitates the incorporation of organic material into forms that can be combined with soil particles to create stable aggregates. The processes that increase aggregate size and stability are directly linked the continual functioning of the biological component which in turn changes the physical and chemical properties of the soil. Soil aggregates begin to degrade as soon as there is no longer a supply of organic material into the soil. These processes can range from removal of organic material and excessive tillage. To increase aggregation of the upper soil layer requires a continual supply of organic material and the biological activity that incorporates organic material into substances that create a stable aggregate. Soils that exhibit stable soil aggregates at the surface have a prolonged infiltration rate with less runoff and a gas exchange that ensures adequate oxygen for maximum biological activity. Quantifying the dynamics of the soil surface layer provides a quantitative understanding of how management practices affect aggregate stability.

Electrodialytic decontamination of heavy metal polluted soil

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Hansen, Henrik K.; Karlsmose, Bodil

1996-01-01

Electrodialytic remediation of heavy metal polluted soil is a newly developed method, which combines the electrokinetic mevement of ions in soil with the principle of electrodialytis. The method has been proven to work in laboratory scale and at present two types of pilot plant tests are made....

Application of manures to mitigate the harmful effects of electrokinetic remediation of heavy metals on soil microbial properties in polluted soils.

Science.gov (United States)

Tahmasbian, Iman; Safari Sinegani, Ali Akbar; Nguyen, Thi Thu Nhan; Che, Rongxiao; Phan, Thuc D; Hosseini Bai, Shahla

2017-12-01

Ethylenediaminetetraacetic acid (EDTA) used with electrokinetic (EK) to remediate heavy metal-polluted soils is a toxic chelate for soil microorganisms. Therefore, this study aimed to evaluate the effects of alternative organic chelates to EDTA on improving the microbial properties of a heavy metal-polluted soil subjected to EK. Cow manure extract (CME), poultry manure extract (PME) and EDTA were applied to a lead (Pb) and zinc (Zn)-polluted calcareous soil which were subjected to two electric intensities (1.1 and 3.3 v/cm). Soil carbon pools, microbial activity, microbial abundance (e.g., fungal, actinomycetes and bacterial abundances) and diethylenetriaminepentaacetic acid (DTPA)-extractable Pb and Zn (available forms) were assessed in both cathodic and anodic soils. Applying the EK to soil decreased all the microbial variables in the cathodic and anodic soils in the absence or presence of chelates. Both CME and PME applied with two electric intensities decreased the negative effect of EK on soil microbial variables. The lowest values of soil microbial variables were observed when EK was combined with EDTA. The following order was observed in values of soil microbial variables after treating with EK and chelates: EK + CME or EK + PME > EK > EK + EDTA. The CME and PME could increase the concentrations of available Pb and Zn, although the increase was less than that of EDTA. Overall, despite increasing soil available Pb and Zn, the combination of EK with manures (CME or PME) mitigated the negative effects of using EK on soil microbial properties. This study suggested that the synthetic chelates such as EDTA could be replaced with manures to alleviate the environmental risks of EK application.

Bioremediation potential of diesel-contaminated Libyan soil.

Science.gov (United States)

Koshlaf, Eman; Shahsavari, Esmaeil; Aburto-Medina, Arturo; Taha, Mohamed; Haleyur, Nagalakshmi; Makadia, Tanvi H; Morrison, Paul D; Ball, Andrew S

2016-11-01

Bioremediation is a broadly applied environmentally friendly and economical treatment for the clean-up of sites contaminated by petroleum hydrocarbons. However, the application of this technology to contaminated soil in Libya has not been fully exploited. In this study, the efficacy of different bioremediation processes (necrophytoremediation using pea straw, bioaugmentation and a combination of both treatments) together with natural attenuation were assessed in diesel contaminated Libyan soils. The addition of pea straw was found to be the best bioremediation treatment for cleaning up diesel contaminated Libyan soil after 12 weeks. The greatest TPH degradation, 96.1% (18,239.6mgkg(-1)) and 95% (17,991.14mgkg(-1)) were obtained when the soil was amended with pea straw alone and in combination with a hydrocarbonoclastic consortium respectively. In contrast, natural attenuation resulted in a significantly lower TPH reduction of 76% (14,444.5mgkg(-1)). The presence of pea straw also led to a significant increased recovery of hydrocarbon degraders; 5.7log CFU g(-1) dry soil, compared to 4.4log CFUg(-1) dry soil for the untreated (natural attenuation) soil. DGGE and Illumina 16S metagenomic analyses confirm shifts in bacterial communities compared with original soil after 12 weeks incubation. In addition, metagenomic analysis showed that original soil contained hydrocarbon degraders (e.g. Pseudoxanthomonas spp. and Alcanivorax spp.). However, they require a biostimulant (in this case pea straw) to become active. This study is the first to report successful oil bioremediation with pea straw in Libya. It demonstrates the effectiveness of pea straw in enhancing bioremediation of the diesel-contaminated Libyan soil. Copyright © 2016 Elsevier Inc. All rights reserved.

Electronic Nose Technology to Measure Soil Microbial Activity and Classify Soil Metabolic Status

OpenAIRE

Fabrizio De Cesare; Elena Di Mattia; Simone Pantalei; Emiliano Zampetti; Vittorio Vinciguerra; Antonella Macagnano

2011-01-01

The electronic nose (E-nose) is a sensing technology that has been widely used to monitor environments in the last decade. In the present study, the capability of an E-nose, in combination with biochemical and microbiological techniques, of both detecting the microbial activity and estimating the metabolic status of soil ecosystems, was tested by measuring on one side respiration, enzyme activities and growth of bacteria in natural but simplified soil ecosystems over 23 days of incubation thr...

Integrating soil conservation practices and glyphosate-resistant crops: impacts on soil.

Science.gov (United States)

Locke, Martin A; Zablotowicz, Robert M; Reddy, Krishna N

2008-04-01

Conservation practices often associated with glyphosate-resistant crops, e.g. limited tillage and crop cover, improve soil conditions, but only limited research has evaluated their effects on soil in combination with glyphosate-resistant crops. It is assumed that conservation practices have similar benefits to soil whether or not glyphosate-resistant crops are used. This paper reviews the impact on soil of conservation practices and glyphosate-resistant crops, and presents data from a Mississippi field trial comparing glyphosate-resistant and non-glyphosate-resistant maize (Zea mays L.) and cotton (Gossypium hirsutum L.) under limited tillage management. Results from the reduced-tillage study indicate differences in soil biological and chemical properties owing to glyphosate-resistant crops. Under continuous glyphosate-resistant maize, soils maintained greater soil organic carbon and nitrogen as compared with continuous non-glyphosate-resistant maize, but no differences were measured in continuous cotton or in cotton rotated with maize. Soil microbial community structure based on total fatty acid methyl ester analysis indicated a significant effect of glyphosate-resistant crop following 5 years of continuous glyphosate-resistant crop as compared with the non-glyphosate-resistant crop system. Results from this study, as well as the literature review, indicate differences attributable to the interaction of conservation practices and glyphosate-resistant crop, but many are transient and benign for the soil ecosystem. Glyphosate use may result in minor effects on soil biological/chemical properties. However, enhanced organic carbon and plant residues in surface soils under conservation practices may buffer potential effects of glyphosate. Long-term field research established under various cropping systems and ecological regions is needed for critical assessment of glyphosate-resistant crop and conservation practice interactions. Copyright (c) 2008 by John Wiley & Sons

Evaluating the new soil erosion map of Hungary

Science.gov (United States)

Waltner, István; Centeri, Csaba; Takács, Katalin; Pirkó, Béla; Koós, Sándor; László, Péter; Pásztor, László

2017-04-01

With growing concerns on the effects of climate change and land use practices on our soil resources, soil erosion by water is becoming a significant issue internationally. Since the 1964 publication of the first soil erosion map of Hungary, there have been several attempts to provide a countrywide assessment of erosion susceptibility. However, there has been no up-to-date map produced in the last decade. In 2016, a new, 1:100 000 scale soil erosion map was published, based on available soil, elevation, land use and meteorological data for the extremely wet year of 2010. The map utilized combined outputs for two spatially explicit methods: the widely used empirical Universal Soil Loss Equation (USLE) and the process-based Pan-European Soil Erosion Risk Assessment (PESERA) models. The present study aims to provide a detailed analysis of the model results. In lieu of available national monitoring data, information from other sources were used. The Soil Degradation Subsystem (TDR) of the National Environmental Information System (OKIR) is a digital database based on a soil survey and farm dairy data collected from representative farms in Hungary. During the survey all kind of degradation forms - including soil erosion - were considered. Agricultural and demographic data was obtained from the Hungarian Central Statistical Office (KSH). Data from an interview-based survey was also used in an attempt to assess public awareness of soil erosion risks. Point-based evaluation of the model results was complemented with cross-regional assessment of soil erosion estimates. This, combined with available demographic information provides us with an opportunity to address soil erosion on a community level, with the identification of regions with the highest risk of being affected by soil erosion.

Chlorination and dechlorination rates in a forest soil — A combined modelling and experimental approach

Energy Technology Data Exchange (ETDEWEB)

Montelius, Malin, E-mail: malin.montelius@liu.se [Department of Thematic Studies — Environmental Change, Linköping University, 581 83 Linköping (Sweden); Svensson, Teresia [Department of Thematic Studies — Environmental Change, Linköping University, 581 83 Linköping (Sweden); Lourino-Cabana, Beatriz [EDF, Laboratoire National d' Hydraulique et Environnement, 78401 Chatou (France); Thiry, Yves [Andra, Research and Development Division, Parc de la Croix Blanche, 1/7 rue Jean Monnet, 92298 Châtenay-Malabry Cedex (France); Bastviken, David [Department of Thematic Studies — Environmental Change, Linköping University, 581 83 Linköping (Sweden)

2016-06-01

Much of the total pool of chlorine (Cl) in soil consists of naturally produced organic chlorine (Cl{sub org}). The chlorination of bulk organic matter at substantial rates has been experimentally confirmed in various soil types. The subsequent fates of Cl{sub org} are important for ecosystem Cl cycling and residence times. As most previous research into dechlorination in soils has examined either single substances or specific groups of compounds, we lack information about overall bulk dechlorination rates. Here we assessed bulk organic matter chlorination and dechlorination rates in coniferous forest soil based on a radiotracer experiment conducted under various environmental conditions (additional water, labile organic matter, and ammonium nitrate). Experiment results were used to develop a model to estimate specific chlorination (i.e., fraction of Cl{sup −} transformed to Cl{sub org} per time unit) and specific dechlorination (i.e., fraction of Cl{sub org} transformed to Cl{sup −} per time unit) rates. The results indicate that chlorination and dechlorination occurred simultaneously under all tested environmental conditions. Specific chlorination rates ranged from 0.0005 to 0.01 d{sup −1} and were hampered by nitrogen fertilization but were otherwise similar among the treatments. Specific dechlorination rates were 0.01–0.03 d{sup −1} and were similar among all treatments. This study finds that soil Cl{sub org} levels result from a dynamic equilibrium between the chlorination and rapid dechlorination of some Cl{sub org} compounds, while another Cl{sub org} pool is dechlorinated more slowly. Altogether, this study demonstrates a highly active Cl cycling in soils. - Highlights: • Chlorination and dechlorination rates in soil were revealed by a radiotracer method. • Chlorination was hampered by nitrogen addition. • Both Cl{sup −} and many Cl{sub org} compounds are highly reactive in soils. • Some formed Cl{sub org} seem to be refractory.

Soil washing: From characterization to implementation

International Nuclear Information System (INIS)

Corden, F.L.; Groenendijk, E.

1995-01-01

Only recently has soil washing begun to be applied to remediation of contaminated soils in the US. The experience gained during full-scale and large pilot-scale projects points to the importance of soil and site characterization in correctly evaluating the applicability of soil washing to a site and determining accurate cost estimates for its implementation. This paper will discuss actual case studies of various treatability and pilot study approaches that led to successful evaluation and implementation of soil washing remedies. Soil washing is applicable to a broad variety of chemical contaminants. Target contaminants include metals, radionuclides, pesticides, polychlorinated biphenyls, polynuclear aromatic hydrocarbons and petroleum hydrocarbons, as well as combinations of these contaminants. Because the contaminants noted above are deposited in the soils in a variety of forms, the unit operations necessary to treat the soil vary. It is the diversity of the available treatment alternatives, and the ability to use the units in a variety of process flow configurations that result in a very broad definition of soil washing

Comparing and combining terrestrial laser scanning with ground-and UAV-based imaging for national-level assessment of soil erosion

Science.gov (United States)

McShane, Gareth; James, Mike R.; Quinton, John; Anderson, Karen; DeBell, Leon; Evans, Martin; Farrow, Luke; Glendell, Miriam; Jones, Lee; Kirkham, Matthew; Lark, Murray; Rawlins, Barry; Rickson, Jane; Quine, Tim; Wetherelt, Andy; Brazier, Richard

2014-05-01

3D topographic or surface models are increasingly being utilised for a wide range of applications and are established tools in geomorphological research. In this pilot study 'a cost effective framework for monitoring soil erosion in England and Wales', funded by the UK Department for Environment, Food and Rural Affairs (Defra), we compare methods of collecting topographic measurements via remote sensing for detailed studies of dynamic processes such as erosion and mass movement. The techniques assessed are terrestrial laser scanning (TLS), and unmanned aerial vehicle (UAV) photography and ground-based photography, processed using structure-from-motion (SfM) 3D reconstruction software. The methods will be applied in regions of different land use, including arable and horticultural, upland and semi natural habitats, and grassland, to quantify visible erosion pathways at the site scale. Volumetric estimates of soil loss will be quantified using the digital surface models (DSMs) provided by each technique and a modelled pre-erosion surface. Visible erosion and severity will be independently established through each technique, with their results compared and combined effectiveness assessed. A fixed delta-wing UAV (QuestUAV, http://www.questuav.com/) captures photos from a range of altitudes and angles over the study area, with automated SfM-based processing enabling rapid orthophoto production to support ground-based data acquisition. At sites with suitable scale erosion features, UAV data will also provide a DSM for volume loss measurement. Terrestrial laser scanning will provide detailed, accurate, high density measurements of the ground surface over long (100s m) distances. Ground-based photography is anticipated to be most useful for characterising small and difficult to view features. By using a consumer-grade digital camera and an SfM-based approach (using Agisoft Photoscan version 1.0.0, http://www.agisoft.ru/products/photoscan/), less expertise and fewer control

Case studies: Soil mapping using multiple methods

Science.gov (United States)

Petersen, Hauke; Wunderlich, Tina; Hagrey, Said A. Al; Rabbel, Wolfgang; Stümpel, Harald

2010-05-01

Soil is a non-renewable resource with fundamental functions like filtering (e.g. water), storing (e.g. carbon), transforming (e.g. nutrients) and buffering (e.g. contamination). Degradation of soils is meanwhile not only to scientists a well known fact, also decision makers in politics have accepted this as a serious problem for several environmental aspects. National and international authorities have already worked out preservation and restoration strategies for soil degradation, though it is still work of active research how to put these strategies into real practice. But common to all strategies the description of soil state and dynamics is required as a base step. This includes collecting information from soils with methods ranging from direct soil sampling to remote applications. In an intermediate scale mobile geophysical methods are applied with the advantage of fast working progress but disadvantage of site specific calibration and interpretation issues. In the framework of the iSOIL project we present here some case studies for soil mapping performed using multiple geophysical methods. We will present examples of combined field measurements with EMI-, GPR-, magnetic and gammaspectrometric techniques carried out with the mobile multi-sensor-system of Kiel University (GER). Depending on soil type and actual environmental conditions, different methods show a different quality of information. With application of diverse methods we want to figure out, which methods or combination of methods will give the most reliable information concerning soil state and properties. To investigate the influence of varying material we performed mapping campaigns on field sites with sandy, loamy and loessy soils. Classification of measured or derived attributes show not only the lateral variability but also gives hints to a variation in the vertical distribution of soil material. For all soils of course soil water content can be a critical factor concerning a succesful

Assessing the nutritional potential of sodium in combination with ...

African Journals Online (AJOL)

The role of sodium (Na) in combination with potassium (K) in the growth and yield of tomato (Lycopersicon esculentum L.) was studied in soil culture. Sodium was applied at 0, 5, 10, 20 mg / kg soil as NaCl and K at 0, 20, 40, 80 mg / kg soil as KCl. Records of components of growth and mineral nutrient uptake and ...

The combined effect of the Lymphatic Filariasis Elimination Programme and the Schistosomiasis and Soil-transmitted Helminthiasis Control Programme on soil-transmitted helminthiasis in schoolchildren in Tanzania.

Science.gov (United States)

Massa, Khalid; Magnussen, Pascal; Sheshe, Amir; Ntakamulenga, Robert; Ndawi, Benedict; Olsen, Annette

2009-01-01

The combined effect of the Lymphatic Filariasis Elimination Programme (LFEP) and the National Schistosomiasis and Soil-transmitted Helminthiasis Control Programme (NSSCP) on soil-transmitted helminthiasis (STH) was evaluated. In September 2004, before mass drug administration (MDA) with ivermectin and albendazole by the LFEP in October, the prevalence and intensity of STH were recorded in 228 pupils in one primary school. After 8 months, all available pupils were re-examined, and the prevalence of Ascaris lumbricoides, Trichuris trichiura and hookworm had decreased from 0.9 to 0.7% (P=0.84), from 4.8 to 0.7% (P=0.004) and from 45.6 to 11.9% (P<0.001), respectively. Overall, 81.2% of the schoolchildren stated that they were treated by the LFEP in October 2004. After the 8 months follow-up, pupils were treated with praziquantel and albendazole by the present project (substitute for the NSSCP). After another 4 months (at 12 months follow-up), the prevalence of hookworm infection was reduced to 4.8% (P=0.003), while the prevalence of T. trichiura was reduced to 0.3% (P=0.54) and the prevalence of A. lumbricoides remained unchanged. Mass co-administration of ivermectin and albendazole by the LFEP had a significant effect on STH, which was further amplified by treatment with praziquantel and albendazole 4 months later.

Soil precompression stress, penetration resistance and crop yields in relation to differently-trafficked, temperate-region sandy loam soils

DEFF Research Database (Denmark)

Schjønning, Per; Lamandé, Mathieu; Munkholm, Lars Juhl

2016-01-01

. Undisturbed soil cores were used for quantifying the precompression stress (spc) of non-compacted soil. Tractor-trailer combinations for slurry application with wheel loads of 3, 6 and 8 Mg (treatments M3, M6, M8) were used for the experimental traffic in the spring at field-capacity. For one additional...

In-situ remediation system for groundwater and soils

Science.gov (United States)

Corey, John C.; Kaback, Dawn S.; Looney, Brian B.

1993-01-01

A method and system for in-situ remediation of contaminated groundwater and soil where the contaminants, such as toxic metals, are carried in a subsurface plume. The method comprises selection and injection into the soil of a fluid that will cause the contaminants to form stable, non-toxic compounds either directly by combining with the contaminants or indirectly by creating conditions in the soil or changing the conditions of the soil so that the formation of stable, non-toxic compounds between the contaminants and existing substances in the soil are more favorable. In the case of non-toxic metal contaminants, sulfides or sulfates are injected so that metal sulfides or sulfates are formed. Alternatively, an inert gas may be injected to stimulate microorganisms in the soil to produce sulfides which, in turn, react with the metal contaminants. Preferably, two wells are used, one to inject the fluid and one to extract the unused portion of the fluid. The two wells work in combination to create a flow of the fluid across the plume to achieve better, more rapid mixing of the fluid and the contaminants.

Combined use of alkane-degrading and plant growth-promoting bacteria enhanced phytoremediation of diesel contaminated soil.

Science.gov (United States)

Tara, Nain; Afzal, Muhammad; Ansari, Tariq M; Tahseen, Razia; Iqbal, Samina; Khan, Qaiser M

2014-01-01

Inoculation of plants with pollutant-degrading and plant growth-promoting microorganisms is a simple strategy to enhance phytoremediation activity. The objective of this study was to determine the effect of inoculation of different bacterial strains, possessing alkane-degradation and 1-amino-cyclopropane-1 -carboxylic acid (ACC) deaminase activity, on plant growth and phytoremediation activity. Carpet grass (Axonopus affinis) was planted in soil spiked with diesel (1% w/w) for 90 days and inoculated with different bacterial strains, Pseudomonas sp. ITRH25, Pantoea sp. BTRH79 and Burkholderia sp. PsJN, individually and in combination. Generally, bacterial application increased total numbers of culturable hydrocarbon-degrading bacteria in the rhizosphere ofcarpet grass, plant biomass production, hydrocarbon degradation and reduced genotoxicity. Bacterial strains possessing different beneficial traits affect plant growth and phytoremediation activity in different ways. Maximum bacterial population, plant biomass production and hydrocarbon degradation were achieved when carpet grass was inoculated with a consortium of three strains. Enhanced plant biomass production and hydrocarbon degradation were associated with increased numbers of culturable hydrocarbon-degrading bacteria in the rhizosphere of carpet grass. The present study revealed that the combined use of different bacterial strains, exhibiting different beneficial traits, is a highly effective strategy to improve plant growth and phytoremediation activity.

Alkanes as Components of Soil Hydrocarbon Status: Behavior and Indication Significance

Science.gov (United States)

Gennadiev, A. N.; Zavgorodnyaya, Yu. A.; Pikovskii, Yu. I.; Smirnova, M. A.

2018-01-01

Studies of soils on three key plots with different climatic conditions and technogenic impacts in Volgograd, Moscow, and Arkhangelsk oblasts have showed that alkanes in the soil exchange complex have some indication potential for the identification of soil processes. The following combinations of soil-forming factors and processes have been studied: (a) self-purification of soil after oil pollution; (b) accumulation of hydrocarbons coming from the atmosphere to soils of different land use patterns; and (c) changes in the soil hydrocarbon complex beyond the zone of technogenic impact due to the input of free hydrocarbon-containing gases. At the injection input of hydrocarbon pollutants, changes in the composition and proportions of alkanes allow tracing the degradation trend of pollutants in the soil from their initial content to the final stage of soil self-purification, when the background concentrations of hydrocarbons are reached. Upon atmospheric deposition of hydrocarbons onto the soil, from the composition and mass distribution of alkanes, conclusions can be drawn about the effect of toxicants on biogeochemical processes in the soil, including their manifestation under different land uses. Composition analysis of soil alkanes in natural landscapes can reveal signs of hydrocarbon emanation fluxes in soils. The indication potentials of alkanes in combination with polycyclic aromatic hydrocarbons and other components of soil hydrocarbon complex can also be used for the solution of other soil-geochemical problems.

Uncertainty in soil carbon accounting due to unrecognized soil erosion.

Science.gov (United States)

Sanderman, Jonathan; Chappell, Adrian

2013-01-01

The movement of soil organic carbon (SOC) during erosion and deposition events represents a major perturbation to the terrestrial carbon cycle. Despite the recognized impact soil redistribution can have on the carbon cycle, few major carbon accounting models currently allow for soil mass flux. Here, we modified a commonly used SOC model to include a soil redistribution term and then applied it to scenarios which explore the implications of unrecognized erosion and deposition for SOC accounting. We show that models that assume a static landscape may be calibrated incorrectly as erosion of SOC is hidden within the decay constants. This implicit inclusion of erosion then limits the predictive capacity of these models when applied to sites with different soil redistribution histories. Decay constants were found to be 15-50% slower when an erosion rate of 15 t soil ha(-1)  yr(-1) was explicitly included in the SOC model calibration. Static models cannot account for SOC change resulting from agricultural management practices focused on reducing erosion rates. Without accounting for soil redistribution, a soil sampling scheme which uses a fixed depth to support model development can create large errors in actual and relative changes in SOC stocks. When modest levels of erosion were ignored, the combined uncertainty in carbon sequestration rates was 0.3-1.0 t CO2  ha(-1)  yr(-1) . This range is similar to expected sequestration rates for many management options aimed at increasing SOC levels. It is evident from these analyses that explicit recognition of soil redistribution is critical to the success of a carbon monitoring or trading scheme which seeks to credit agricultural activities. © 2012 Blackwell Publishing Ltd.

The solonetzic process in surface soils and buried paleosols and its reflection in the mineralogical soil memory

Science.gov (United States)

Chizhikova, N. P.; Kovda, I. V.; Borisov, A. V.; Shishlina, N. I.

2009-10-01

The development of the solonetzic process in paleosols buried under kurgans and in the modern surface soils has been studied on the basis of the analysis of the clay (memory“ of the solid-phase soil components. The mineralogical characteristics show that the solonetzic process in the modern background soil is more developed. The mineralogical approach allows us to reveal the long-term changes in the soil status; it is less useful for studying the effect of short-term bioclimatic fluctuations. In the latter case, more labile soil characteristics should be used. The mineralogical method, combined with other methods, becomes more informative upon the study of soil chronosequences. Our studies have shown that the data on the clay minerals in the buried paleosols may contain specific information useful for paleoreconstructions that is not provided by other methods.

Combination of a Fast Cleanup Procedure and a DR-CALUX® Bioassay for Dioxin Surveillance in Taiwanese Soils

Science.gov (United States)

Lin, Ding-Yan; Lee, Yi-Pin; Li, Chiu-Ping; Chi, Kai-Hsien; Liang, Bo-Wei P.; Liu, Wen-Yao; Wang, Chih-Cheng; Lin, Susana; Chen, Ting-Chien; Yeh, Kuei-Jyum C.; Hsu, Ping-Chi; Hsu, Yi-Chyun; Chao, How-Ran; Tsou, Tsui-Chun

2014-01-01

Our goal was to determine dioxin levels in 800 soil samples collected from Taiwan. An in vitro DR-CALUX® assay was carried out with the help of an automated Soxhlet system and fast cleanup column. The mean dioxin level of 800 soil samples was 36.0 pg-bioanalytical equivalents (BEQs)/g dry weight (d.w.). Soil dioxin-BEQs were higher in northern Taiwan (61.8 pg-BEQ/g d.w.) than in central, southern, and eastern Taiwan (22.2, 24.9, and 7.80 pg-BEQ/g d.w., respectively). Analysis of multiple linear regression models identified four major predictors of dioxin-BEQs including soil sampling location (β = 0.097, p contamination. Soil samples collected in northern Taiwan, and especially in Bade City, soils near industrial areas, and soils with darker color may contain higher dioxin-BEQ levels. PMID:24806195

Combined effect of microwave and activated carbon on the remediation of polychlorinated biphenyl-contaminated soil.

Science.gov (United States)

Liu, Xitao; Yu, Gang

2006-04-01

The application of microwave and activated carbon for the treatment of polychlorinated biphenyl (PCB) contaminated soil was explored in this study with a model compound of 2,4,5-trichlorobiphenyl (PCB29). PCB-contaminated soil was treated in a quartz reactor by microwave irradiation at 2450MHz with the addition of granular activated carbon (GAC). In this procedure, GAC acted as microwave absorbent for reaching high temperature and reductant for dechlorination. A sheltered type-K thermocouple was applied to record the temperature rising courses. It was shown that the addition of GAC could effectively promote the temperature rising courses. The determination of PCB residues in soil by gas chromatography (GC) revealed that rates of PCB removal were highly dependent on microwave power, soil moisture content, and the amount of GAC added. GC with mass spectrum (MS) detector and ion chromatography were employed for the analysis of degradation intermediates and chlorine ions, respectively. It was suggested that microwave irradiation with the assistance of activated carbon might be a potential technology for the remediation of PCB-contaminated soil.

Impact of monovalent cations on soil structure. Part II. Results of two Swiss soils

Science.gov (United States)

Farahani, Elham; Emami, Hojat; Keller, Thomas

2018-01-01

In this study, we investigated the impact of adding solutions with different potassium and sodium concentrations on dispersible clay, water retention characteristics, air permeability, and soil shrinkage behaviour using two agricultural soils from Switzerland with different clay content but similar organic carbon to clay ratio. Three different solutions (including only Na, only K, and the combination of both) were added to soil samples at three different cation ratio of soil structural stability levels, and the soil samples were incubated for one month. Our findings showed that the amount of readily dispersible clay increased with increasing Na concentrations and with increasing cation ratio of soil structural stability. The treatment with the maximum Na concentration resulted in the highest water retention and in the lowest shrinkage capacity. This was was associated with high amounts of readily dispersible clay. Air permeability generally increased during incubation due to moderate wetting and drying cycles, but the increase was negatively correlated with readily dispersible clay. Readily dispersible clay decreased with increasing K, while readily dispersible clay increased with increasing K in Iranian soil (Part I of our study). This can be attributed to the different clay mineralogy of the studied soils (muscovite in Part I and illite in Part II).