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Metaschoepite (UO3·2H2O) is a product of the corrosion of depleted uranium munition and is commonly found in former war zones and at military test sites. Understanding metaschoepite transformation and uranium (U) mobility is important for the sustainable operation of U-containing test-firing and nuclear waste disposal sites. In the present study, the stabilization effects of Mn(II)-salts on metaschoepite in soil under different water regimes (saturation and flooding) were investigated. Results indicated that the dissolution and transformation of metaschoepite were controlled by water regimes and redox processes in the soil system. The concentrations of water-extractable U in the metaschoepite-amended soils after 270 days of incubation for the saturation and flooding groups were 299 and 173 mg kg–1, respectively. The addition of Mn(II)-salts significantly retarded the release of U(VI) in the metaschoepite-amended soils. The U stabilization efficiency of Mn(II) was persistently > 90% during the 270 days of incubation, irrespective of water regimes. The X-ray photoelectron spectroscopy results showed no detectable reduction of liberated U(VI) in the “open waterlogged” soil system, while the X-ray diffraction analyses confirmed the transformation of metaschoepite with signals of schoepites disappearing over the course of the experiment. The study highlights the potential for the use of Mn(II)-salts in practical applications for in situ stabilization of U-contaminated sites and nuclear waste disposal.
Fuyu Guo; Georgio Proctor; Steven L. Larson; John H. Ballard; Heather M. Knotek-Smith; Dongmei Cao; Ruyi Yang; Xingxiang Wang; Fengxiang Han. Stabilization Effects of Mn(II)-Salts on Metaschoepite in Soil under Different Water Regimes. ACS Earth and Space Chemistry 2021, 5, 2160 -2168.
AMA StyleFuyu Guo, Georgio Proctor, Steven L. Larson, John H. Ballard, Heather M. Knotek-Smith, Dongmei Cao, Ruyi Yang, Xingxiang Wang, Fengxiang Han. Stabilization Effects of Mn(II)-Salts on Metaschoepite in Soil under Different Water Regimes. ACS Earth and Space Chemistry. 2021; 5 (8):2160-2168.
Chicago/Turabian StyleFuyu Guo; Georgio Proctor; Steven L. Larson; John H. Ballard; Heather M. Knotek-Smith; Dongmei Cao; Ruyi Yang; Xingxiang Wang; Fengxiang Han. 2021. "Stabilization Effects of Mn(II)-Salts on Metaschoepite in Soil under Different Water Regimes." ACS Earth and Space Chemistry 5, no. 8: 2160-2168.
Heavy metal pollution in soil and water has been of worldwide concern due to their biotoxicity/ecotoxicity in the ecosystem, accumulation in the food chain, and persistence in the environment. Microbially induced carbonate precipitation (MICP) is known as an efficient and cost-effective biogeochemical process for the remediation of heavy metals in contaminated environment. This study reviews the mechanisms of biomineralization of urease-producing microorganisms and their biogeochemical process with various heavy metals and trace elements. Biogeochemical factors affecting the formation of carbonate biominerals were discussed. These factors included the growth and urease activity of microorganisms, calcium concentration and coexisted cations/anions, dissolved inorganic carbon, pH, redox potential, etc. In addition, the mechanisms of the biomineral morphology and its controlling factors such as medium types, microbial species, and extracellular polymeric substance were analyzed as well. Finally, the challenge and current knowledge gap on further application of MICP in remediation of heavy metal–, trace element–, and U-polluted soils and water were presented.
Xue Chen; Dan Zhang; Steven L. Larson; John H. Ballard; Heather M. Knotek-Smith; Jing Nie; Nan Hu; Dexin Ding; Fengxiang X. Han. Microbially Induced Carbonate Precipitation Techniques for the Remediation of Heavy Metal and Trace Element–Polluted Soils and Water. Water, Air, & Soil Pollution 2021, 232, 1 -15.
AMA StyleXue Chen, Dan Zhang, Steven L. Larson, John H. Ballard, Heather M. Knotek-Smith, Jing Nie, Nan Hu, Dexin Ding, Fengxiang X. Han. Microbially Induced Carbonate Precipitation Techniques for the Remediation of Heavy Metal and Trace Element–Polluted Soils and Water. Water, Air, & Soil Pollution. 2021; 232 (7):1-15.
Chicago/Turabian StyleXue Chen; Dan Zhang; Steven L. Larson; John H. Ballard; Heather M. Knotek-Smith; Jing Nie; Nan Hu; Dexin Ding; Fengxiang X. Han. 2021. "Microbially Induced Carbonate Precipitation Techniques for the Remediation of Heavy Metal and Trace Element–Polluted Soils and Water." Water, Air, & Soil Pollution 232, no. 7: 1-15.
Though Pb(II) adsorption onto HA has been extensively studied, its kinetic and thermodynamic features are not fully understood. This work investigated the kinetic processes and isotherms of Pb(II) adsorption onto a humic acid (HA) derived from leonardite in an aqueous solution. The basic properties of the HA were determined by standard methods, and Fourier transform infrared spectroscopic (FTIR) technique. Adsorption kinetic experiments were conducted at 120 mg Pb/L at 288, 298, 308, and 318 K. The adsorption data were best fitted into the pseudo-second-order model, suggesting the chemisorption nature of Pb(II) adsorption. Batch adsorption experiments were conducted at 0–200 mg Pb/L, and the data fit the Freundlich and Temkin models well. Pb(II) adsorption onto HA initially increased, then decreased, with rising temperature. Thermodynamic parameters showed that Pb(II) adsorption was exothermic and spontaneous. Though Cu(II), Zn(II), or Cd(II) could compete with Pb(II) for adsorption, the low cost and high adsorption capacity of leonardite-derived HA determined that it was an excellent adsorbent to remove Pb(II) from an aqueous solution. The optimized experimental conditions derived from the central composite design (CCD) were 20 mg HA, pH 5.0, 4-h react time, and 80 mg Pb/L.
Fande Meng; Yuwei Zhang; Yongbing Cai; Guodong Yuan; Feng X. Han. Kinetic and Thermodynamic Features of Pb(II) Removal From Aqueous Solution by Leonardite-Derived Humic Acid. Water, Air, & Soil Pollution 2021, 232, 1 -12.
AMA StyleFande Meng, Yuwei Zhang, Yongbing Cai, Guodong Yuan, Feng X. Han. Kinetic and Thermodynamic Features of Pb(II) Removal From Aqueous Solution by Leonardite-Derived Humic Acid. Water, Air, & Soil Pollution. 2021; 232 (7):1-12.
Chicago/Turabian StyleFande Meng; Yuwei Zhang; Yongbing Cai; Guodong Yuan; Feng X. Han. 2021. "Kinetic and Thermodynamic Features of Pb(II) Removal From Aqueous Solution by Leonardite-Derived Humic Acid." Water, Air, & Soil Pollution 232, no. 7: 1-12.
A modification method of clay mineral surface was developed to improve its adsorption capacity of uranium. Uranium is a radionuclide with high toxicity and extremely long half-life, which can pollute the environment and endanger human health. This study proposes a new method of activation of clay mineral surface with phosphoric acid for rapid adsorption of uranium from aqueous solution. Compared with other modification methods, this method has the advantages of availability of raw materials, simple operation and good adsorption effects. It provides a cost-effective material to capture uranium ions from water. The essences of this new development are as following: • Activation and changes of clay minerals’ surface functionalities with the treatment of phosphoric acid • Controlled modifications of the surface properties of the clay towards the enhancement of U adsorption capacity • Rapid removal of uranium from water
Li Bao; Fuyu Guo; Hanrui Wang; Steven L. Larson; John H. Ballard; Heather M. Knotek-Smith; Qinku Zhang; Jing Nie; Ahmet Celik; Saiful M. Islam; Shalom Dasari; Naiming Zhang; Fengxiang Han. Functionalization of clay surface for the removal of uranium from water. MethodsX 2021, 8, 101275 .
AMA StyleLi Bao, Fuyu Guo, Hanrui Wang, Steven L. Larson, John H. Ballard, Heather M. Knotek-Smith, Qinku Zhang, Jing Nie, Ahmet Celik, Saiful M. Islam, Shalom Dasari, Naiming Zhang, Fengxiang Han. Functionalization of clay surface for the removal of uranium from water. MethodsX. 2021; 8 ():101275.
Chicago/Turabian StyleLi Bao; Fuyu Guo; Hanrui Wang; Steven L. Larson; John H. Ballard; Heather M. Knotek-Smith; Qinku Zhang; Jing Nie; Ahmet Celik; Saiful M. Islam; Shalom Dasari; Naiming Zhang; Fengxiang Han. 2021. "Functionalization of clay surface for the removal of uranium from water." MethodsX 8, no. : 101275.
Uranium is a chemically toxic and radioactive heavy metal. Depleted uranium (DU) is the byproduct of the uranium enrichment process, with a majority of U as uranium-238, and a lower content of the fissile isotope uranium-235 than natural uranium. Uranium-235 is mainly used in nuclear reactors and in the manufacture of nuclear weapons. Exposure is likely to have an impact on humans or the ecosystem where military operations have used DU. Yuma Proving Ground in Arizona, USA has been using depleted uranium ballistics for 36 years. At a contaminated site in the Proving Grounds, soil samples were collected from the flat, open field and lower elevated trenches that typically collect summer runoff. Spatial distribution and fractionation of uranium in the fields were analyzed with total acid digestion and selective sequential dissolution with eight operationally defined solid-phase fractions. In addition to uranium, other trace elements (As, Ba, Co, Cr, Cu, Hg, Mo, Nb, Pd, Pb, V, Zn, Zr) were also assessed. Results show that the trench area in the testing site had a higher accumulation of total U (12.4%) compared to the open-field soil with 279 mg/kg U. Among the eight solid-phase components in the open-field samples, U demonstrated stronger affinities for the amorphous iron-oxide bound, followed by the carbonate bound, and the residual fractions. However, U in the trench area had a stronger binding to the easily reducible oxide bound fraction, followed by the carbonate-bound and amorphous iron-oxide-bound fractions. Among other trace elements, Nb, As, and Zr exhibited the strongest correlations with U distribution among solid-phase components. This study indicates a significant spatial variation of U distribution in the shooting range site. Fe/Mn oxides and carbonate were the major solid-phase components for binding U in the weapon test site.
Joseph A. Kazery; Georgio Proctor; Steve L. Larson; John H. Ballard; Heather M. Knotek-Smith; Qinku Zhang; Ahmet Celik; Shaloam Dasari; Saiful M. Islam; Paul B. Tchounwou; Fengxiang X. Han. Distribution and Fractionation of Uranium in Weapon Tested Range Soils. ACS Earth and Space Chemistry 2021, 5, 356 -364.
AMA StyleJoseph A. Kazery, Georgio Proctor, Steve L. Larson, John H. Ballard, Heather M. Knotek-Smith, Qinku Zhang, Ahmet Celik, Shaloam Dasari, Saiful M. Islam, Paul B. Tchounwou, Fengxiang X. Han. Distribution and Fractionation of Uranium in Weapon Tested Range Soils. ACS Earth and Space Chemistry. 2021; 5 (2):356-364.
Chicago/Turabian StyleJoseph A. Kazery; Georgio Proctor; Steve L. Larson; John H. Ballard; Heather M. Knotek-Smith; Qinku Zhang; Ahmet Celik; Shaloam Dasari; Saiful M. Islam; Paul B. Tchounwou; Fengxiang X. Han. 2021. "Distribution and Fractionation of Uranium in Weapon Tested Range Soils." ACS Earth and Space Chemistry 5, no. 2: 356-364.
Anthropogenic activities involving uranium mining, nuclear fuel processing, nuclear weapon production, or nuclear power plant accidents have polluted soil and groundwater. As a byproduct of the uranium enrichment process for nuclear energy production, depleted uranium metal is available for use in a number of non-energy applications. Many of these uses cause a distribution of uranium metal, soluble uranium species, and oxides in the environment. A number of restoration techniques have been developed. One remedial approach is in situ biomineralization of U to form highly stable and insoluble U mineral products in soils and sediments. This review covers the current research status of uranium biomineralization using phosphate. The biogeochemical processes, biomineralization mechanisms, and biogeochemical conditions associated with the formation of uranium phosphate minerals were reviewed. This overview may be used to facilitate the further development and optimization of in situ bioremediation strategies for uranium in environmental systems.
Dan Zhang; Xue Chen; Steven L. Larson; John H. Ballard; Heather M. Knotek-Smith; Dexin Ding; Nan Hu; Fengxiang X. Han. Uranium Biomineralization with Phosphate—Biogeochemical Process and Its Application. ACS Earth and Space Chemistry 2020, 4, 2205 -2214.
AMA StyleDan Zhang, Xue Chen, Steven L. Larson, John H. Ballard, Heather M. Knotek-Smith, Dexin Ding, Nan Hu, Fengxiang X. Han. Uranium Biomineralization with Phosphate—Biogeochemical Process and Its Application. ACS Earth and Space Chemistry. 2020; 4 (12):2205-2214.
Chicago/Turabian StyleDan Zhang; Xue Chen; Steven L. Larson; John H. Ballard; Heather M. Knotek-Smith; Dexin Ding; Nan Hu; Fengxiang X. Han. 2020. "Uranium Biomineralization with Phosphate—Biogeochemical Process and Its Application." ACS Earth and Space Chemistry 4, no. 12: 2205-2214.
Depleted uranium (DU) munitions have a potential impact on the environment. However, the characterization and horizontal migration of DU corrosion products over a continuous period time in different soil moisture regimes were not well studied. X-ray Power Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier-transform Infrared Spectroscopy (FT-IR), Raman spectra and Inductively Coupled Plasma Mass Spectrometry (ICP-MS)/X-ray Fluorescence spectroscopy (XRF) were used to characterize the corrosion products, the rates of formation of uranium oxides and the distribution of uranium in soil. UO2.8 and UO3 appeared in the DU metallic fragment/soil systems under the saturated soil regime in 4 weeks. UO3 was observed in the soil with the field capacity moisture regime in 16 weeks, but not in the air dry soil. Corrosion started at angled cracks, small pits and edges. DU metal corrosion rates decreased following the trend: Saturated soil > Field capacity soil > Air dry soil. Under the sequential extraction of the soil fractions, the percentage of uranium bound to the carbonate fraction was more than 41.5%. This study demonstrates that soil moisture content plays a role in DU metal corrosion and migration.
Qinku Zhang; Steven L. Larson; John H. Ballard; Xianchun Zhu; Heather M. Knotek-Smith; Fengxiang X. Han. Uranium metal corrosion in soils with different soil moisture regimes. Corrosion Science 2020, 179, 109138 .
AMA StyleQinku Zhang, Steven L. Larson, John H. Ballard, Xianchun Zhu, Heather M. Knotek-Smith, Fengxiang X. Han. Uranium metal corrosion in soils with different soil moisture regimes. Corrosion Science. 2020; 179 ():109138.
Chicago/Turabian StyleQinku Zhang; Steven L. Larson; John H. Ballard; Xianchun Zhu; Heather M. Knotek-Smith; Fengxiang X. Han. 2020. "Uranium metal corrosion in soils with different soil moisture regimes." Corrosion Science 179, no. : 109138.
Inorganic lead halide perovskite materials (e.g., CsPbI3) have a great potential to be used in light-emitting diodes (LEDs). However, poor stability of CsPbI3 has limited its application. In this work, CsPbI3 nanocrystals (NCs) show excellent stability (up to 60 days) under ambient and heating conditions (100 oC). Moreover, the performance of the tetra-n-butylammonium iodide (TBAI)-assisted CsPbI3 NCs obtained under different reaction times is also investigated and compared, suggesting 15 s is the optimum reaction time for NC synthesis. Furthermore, a mechanism of stability enhancement is also proposed, indicating TBAI is very critical to retard phase transition from cubic to orthorhombic structure. This study provides important insights into the synthesis of perovskite CsPbI3 NCs with high stability toward LED applications.
Li Pan; Lin Zhang; Yifang Qi; Keonna Conkle; Fengxiang X Han; Xianchun Zhu; Dream Box; Tigran V. Shahbazyan; Qilin Dai. Stable CsPbI3 Nanocrystals Modified by Tetra-n-butylammonium Iodide for Light-Emitting Diodes. ACS Applied Nano Materials 2020, 3, 9260 -9267.
AMA StyleLi Pan, Lin Zhang, Yifang Qi, Keonna Conkle, Fengxiang X Han, Xianchun Zhu, Dream Box, Tigran V. Shahbazyan, Qilin Dai. Stable CsPbI3 Nanocrystals Modified by Tetra-n-butylammonium Iodide for Light-Emitting Diodes. ACS Applied Nano Materials. 2020; 3 (9):9260-9267.
Chicago/Turabian StyleLi Pan; Lin Zhang; Yifang Qi; Keonna Conkle; Fengxiang X Han; Xianchun Zhu; Dream Box; Tigran V. Shahbazyan; Qilin Dai. 2020. "Stable CsPbI3 Nanocrystals Modified by Tetra-n-butylammonium Iodide for Light-Emitting Diodes." ACS Applied Nano Materials 3, no. 9: 9260-9267.
Biochar is a stable carbon rich by-product synthesized through pyrolysis of plant and animal based biomass, and nano-biochar material has gained increasing attention due to its unique properties for environmental applications. In the present study, a simple cost-effective method for the synthesis of biochar nanoparticles through hydrothermally using agricultural residuals and by-products was developed. Both soybean straw and cattle manure were selected as the feedstock to produce the bulk-biochar. The synthesis procedure involved the digestion of the bulk-biochar with concentrated nitric acid and sulfuric acid in a high pressure condition using a hydrothermal reactor. The suspension was isolated using vacuum filtration with 0.22-μm membrane followed by drying at 65 °C in an oven. Scanning electron microscopy results revealed that both of the biochars had a well-developed porous structure following pyrolysis. Both transmission electron microscopy and the dynamic light scattering results of the hydrothermally treated biochar indicated that the soybean straw and cattle manure biochar nanodots had an average of 5-nm and 4-nm in size, respectively. Overall two raw materials produced 8.5–10% biochar nanodots. The present method presents a simple, quick and cost-effective method for synthesis of biochar nanodots. The method provided a useful tool discovering the applicability biochar nanodots for environmental applications. • Nano-biochar formation from bulk-biochar using hydrothermal reactor • Evaluate nano-biochar's environmental fate and behavior in soil and water • Synthesize multifunctional adsorbent using nano-biochar as primary material
Fuyu Guo; Li Bao; Hanrui Wang; Steven L. Larson; John H. Ballard; Heather M. Knotek-Smith; Qinku Zhang; Yi Su; Xingxiang Wang; Fengxiang Han. A simple method for the synthesis of biochar nanodots using hydrothermal reactor. MethodsX 2020, 7, 101022 .
AMA StyleFuyu Guo, Li Bao, Hanrui Wang, Steven L. Larson, John H. Ballard, Heather M. Knotek-Smith, Qinku Zhang, Yi Su, Xingxiang Wang, Fengxiang Han. A simple method for the synthesis of biochar nanodots using hydrothermal reactor. MethodsX. 2020; 7 ():101022.
Chicago/Turabian StyleFuyu Guo; Li Bao; Hanrui Wang; Steven L. Larson; John H. Ballard; Heather M. Knotek-Smith; Qinku Zhang; Yi Su; Xingxiang Wang; Fengxiang Han. 2020. "A simple method for the synthesis of biochar nanodots using hydrothermal reactor." MethodsX 7, no. : 101022.
Depleted uranium armor penetrating munitions are used on testing and training ranges leading to elevated concentrations of U in range soils. To prevent exposure on secure areas contaminated with depleted uranium (DU) hotspots, easy and rapid screening methods are needed. This study explores the feasibility of field portable X-ray fluorescence (FPXRF) spectrometry as a fast screening tool for locating hotspots of DU in the field. Direct comparisons of results were made for U concentrations in soil obtained using a FPXRF spectrometry and measurement of U using ICP-MS after acid digestion. The environmental samples included both field range contaminated soils collected at a munition testing facility and soils spiked with uranium dioxide, uranium trioxide and uranyl nitrate. Using U concentrations measured with ICP-MS from split samples, FPXRF operating procedures and conditions such as analysis time, soil moisture content, sample amount, and sample packing factors were optimized. Results showed that the FPXRF technique yielded similar U concentrations as ICPMS measurements after acid digestion in both standard soil (NIST) samples and DU contaminated range soils. In field contaminated soils, U values with FPXRF were 88.8% of the measurements with ICPMS with a significant correlation (R2: 0.98, n=8). Sample preparation affected the uranium concentration measurements made with FPXRF in the laboratory and in the field. A loose packing of the samples in the sample containers, higher sample occupancy as well as low soil moisture yielded significantly high U concentrations by 4-5%, 15-50% and 43%, respectively. The measured soil U concentrations were not affected by the variation of the sample analysis time. This study suggests that FPXRF is a promising fast screening tool for field DU hotspots as well as detection/location of penetrators in the fields that can increase the ability to rapidly and inexpensively manage DU on ranges and help ensure sustainable use of DU munitions on testing and training ranges.
Georgio Proctor; Hanrui Wang; Steven L. Larson; John H. Ballard; Heather Knotek-Smith; Charles Waggonor; Ron Unz; Jiangxia Li; Jackeline McComb; Decheng Jin; Zikri Arslan; Fengxiang X Han. Rapid Screening for Uranium in Soils Using Field-Portable X-ray Fluorescence Spectrometer: A Comparative Study. ACS Earth and Space Chemistry 2020, 4, 211 -217.
AMA StyleGeorgio Proctor, Hanrui Wang, Steven L. Larson, John H. Ballard, Heather Knotek-Smith, Charles Waggonor, Ron Unz, Jiangxia Li, Jackeline McComb, Decheng Jin, Zikri Arslan, Fengxiang X Han. Rapid Screening for Uranium in Soils Using Field-Portable X-ray Fluorescence Spectrometer: A Comparative Study. ACS Earth and Space Chemistry. 2020; 4 (2):211-217.
Chicago/Turabian StyleGeorgio Proctor; Hanrui Wang; Steven L. Larson; John H. Ballard; Heather Knotek-Smith; Charles Waggonor; Ron Unz; Jiangxia Li; Jackeline McComb; Decheng Jin; Zikri Arslan; Fengxiang X Han. 2020. "Rapid Screening for Uranium in Soils Using Field-Portable X-ray Fluorescence Spectrometer: A Comparative Study." ACS Earth and Space Chemistry 4, no. 2: 211-217.
A novel laboratory simulation system has been developed for the study of the corrosion of uranium metal in soils. Corrosion and transportation of depleted uranium (DU) as the metal undergoes weathering as a buried material within the soil environment. The corrosion of uranium metal in soil was not well understood due to the gas-liquid-solid phase of the soil. This study presents a novel method to investigate the change of uranium species during the process of process of oxidation of metallic uranium in these environments. Compared with other techniques used for the study of environmental corrosion of metals in soils, this method has the advantage of low secondary uranium pollution, no energy consumption, and ease of operation. The simulation system has been used for the following studies:
Qinku Zhang; Steven L. Larson; John H. Ballard; Pohlee Cheah; Xianchun Zhu; Heather M. Knotek-Smith; Fengxiang X. Han. Laboratory simulation of uranium metal corrosion in different soil moisture regimes. MethodsX 2020, 7, 100789 .
AMA StyleQinku Zhang, Steven L. Larson, John H. Ballard, Pohlee Cheah, Xianchun Zhu, Heather M. Knotek-Smith, Fengxiang X. Han. Laboratory simulation of uranium metal corrosion in different soil moisture regimes. MethodsX. 2020; 7 ():100789.
Chicago/Turabian StyleQinku Zhang; Steven L. Larson; John H. Ballard; Pohlee Cheah; Xianchun Zhu; Heather M. Knotek-Smith; Fengxiang X. Han. 2020. "Laboratory simulation of uranium metal corrosion in different soil moisture regimes." MethodsX 7, no. : 100789.
After depleted uranium (DU) is deposited in the environment, it corrodes producing mobile uranium species. The upward transport mechanism in a desert landscape is associated with the dissolution/precipitation of uranium minerals that vary in composition and solubility in soil pore water. The objective of this study is to develop the laboratory column simulation to investigate the upward transport mechanism with cyclic capillary wetting and drying moisture regimes. Results showed that evaporation driven upward transport occurred even during the first 2 months of wetting-drying regimes. Evaporation driven upward transport may control the U movement in the soil profile in an arid climate. The new system did not generate any uranium-containing wastewater.
Qinku Zhang; Steven L. Larson; John H. Ballard; Pohlee Cheah; Joseph A. Kazery; Heather M. Knotek-Smith; Fengxiang X. Han. A novel laboratory simulation system to uncover the mechanisms of uranium upward transport in a desert landscape. MethodsX 2019, 7, 100758 .
AMA StyleQinku Zhang, Steven L. Larson, John H. Ballard, Pohlee Cheah, Joseph A. Kazery, Heather M. Knotek-Smith, Fengxiang X. Han. A novel laboratory simulation system to uncover the mechanisms of uranium upward transport in a desert landscape. MethodsX. 2019; 7 ():100758.
Chicago/Turabian StyleQinku Zhang; Steven L. Larson; John H. Ballard; Pohlee Cheah; Joseph A. Kazery; Heather M. Knotek-Smith; Fengxiang X. Han. 2019. "A novel laboratory simulation system to uncover the mechanisms of uranium upward transport in a desert landscape." MethodsX 7, no. : 100758.
Metal(loid) pollution in vegetable field soils has become increasingly severe and affects the safety of vegetable crops. Research in China has mainly focused on greenhouse vegetables (GV), while open field vegetables (OV) and the spatial distribution patterns of metal(loid)s in the surrounding soils have rarely been assessed. In the present study, spatial analysis methods combining Geographic Information Systems (GIS) and Moran’s I were applied to analyze the effects of vegetable fields on metal(loid) accumulation in soils. Overall, vegetable fields affected the spatial distribution of metal(loid)s in soils. In long-term vegetable production, the use of large amounts of organic fertilizer led to the bioconcentration of cadmium (Cd) and mercury (Hg), and long-term fertilization resulted in a significant pH decrease and consequent transformation and migration of chromium (Cr), lead (Pb), and arsenic (As). Thus, OV fields with a long history of planting had lower average pH and Cd, and higher average As, Cr, Hg, and Pb than GV fields, reached 0.93%, 10.1%, 5.8%, 3.0%, 80.8%, and 0.43% respectively. Due to the migration and transformation of metal(loid)s in OV soils, these should be further investigated regarding their abilities to reduce the accumulation of metal(loid)s in soils and protect the quality of the cultivated land.
Qiang Wang; Shanlian Yang; Menglei Zheng; Fengxiang Han; Youhua Ma. Effects of Vegetable Fields on the Spatial Distribution Patterns of Metal(loid)s in Soils Based on GIS and Moran’s I. International Journal of Environmental Research and Public Health 2019, 16, 4095 .
AMA StyleQiang Wang, Shanlian Yang, Menglei Zheng, Fengxiang Han, Youhua Ma. Effects of Vegetable Fields on the Spatial Distribution Patterns of Metal(loid)s in Soils Based on GIS and Moran’s I. International Journal of Environmental Research and Public Health. 2019; 16 (21):4095.
Chicago/Turabian StyleQiang Wang; Shanlian Yang; Menglei Zheng; Fengxiang Han; Youhua Ma. 2019. "Effects of Vegetable Fields on the Spatial Distribution Patterns of Metal(loid)s in Soils Based on GIS and Moran’s I." International Journal of Environmental Research and Public Health 16, no. 21: 4095.
Selection of rice varieties and application of amendments are effective measures to ensure food safety. Here we report that in the non-Cd area, the grain quality of all rice varieties met the Chinese National Grain Safety Standards (CNGSS). In the high-Cd area, rice varieties showed significant different bioaccumulation of Cd with lower rice yields than those in non-Cd area with the average decrease of 31.1%. There was a negative correlation between grain Cd content and yields. A total of 19 rice varieties were selected as low Cd accumulating rice varieties and their Cd content met CNGSS in the low-Cd area. Six of them met CNGSS in the high-Cd area. The application of amendments significantly reduced Cd content in rice grains by 1.0-84.7% with an average of 52.6% and 13 of varieties met CNGSS. The amendments reduced available Cd content in soils by 1.1-75.8% but had no significant effects on rice yields. Therefore, the current study implied that proper agronomic management with selection of rice varieties and soil amendments was essential in controlling Cd accumulation in rice grains.
Liangmei Chen; Wenge Wu; Fengxiang Han; Jiangxia Li; Wenling Ye; Huanhuan Fu; Yonghua Yan; Youhua Ma; Qiang Wang. Agronomic Management and Rice Varieties Controlling Cd Bioaccumulation in Rice. International Journal of Environmental Research and Public Health 2019, 16, 2376 .
AMA StyleLiangmei Chen, Wenge Wu, Fengxiang Han, Jiangxia Li, Wenling Ye, Huanhuan Fu, Yonghua Yan, Youhua Ma, Qiang Wang. Agronomic Management and Rice Varieties Controlling Cd Bioaccumulation in Rice. International Journal of Environmental Research and Public Health. 2019; 16 (13):2376.
Chicago/Turabian StyleLiangmei Chen; Wenge Wu; Fengxiang Han; Jiangxia Li; Wenling Ye; Huanhuan Fu; Yonghua Yan; Youhua Ma; Qiang Wang. 2019. "Agronomic Management and Rice Varieties Controlling Cd Bioaccumulation in Rice." International Journal of Environmental Research and Public Health 16, no. 13: 2376.
Electrokinetic-enhanced phytoremediation is an effective technology to decontaminate heavy metal contaminated soil. In this study, we examined the effects of electrokinetic treatments on plant uptake and bioaccumulation of U from soils with various U sources. Redistribution of uranium in soils as affected by planting and electrokinetic treatments was investigated. The soil was spiked with 100 mg kg–1 UO2, UO3, and UO2(NO3)2. After sunflower and Indian mustard grew for 60 days, 1 voltage of direct-current was applied across the soils for 9 days. The results indicated that U uptake in both plants were significantly enhanced by electrokinetic treatments from soil with UO3 and UO2(NO3)2. U was more accumulated in roots than in shoots. Electrokinetic treatments were effective on lowering soil pH near the anode region. Overall, uranium (U) removal efficiency reached 3.4–4.3% from soils with UO3 and uranyl with both plants while that from soil with UO2 was 0.7–0.8%. Electrokinetic remediation treatment significantly enhanced the U removal efficiency (5–6%) from soils with UO3 and uranyl but it was 0.8–1.3% from soil with UO2, indicating significant effects of U species and electrokinetic enhancement on U bioaccumulation. This study implies the potential feasibility of electrokinetic-enhanced phytoremediation of U soils with sunflower and Indian mustard.
Jiangxia Li; Jun Zhang; Steven L. Larson; John H. Ballard; Kai Guo; Zikri Arslan; Youhua Ma; Charles A. Waggoner; Jeremy R. White; Fengxiang X. Han. Electrokinetic-enhanced phytoremediation of uranium-contaminated soil using sunflower and Indian mustard. International Journal of Phytoremediation 2019, 21, 1197 -1204.
AMA StyleJiangxia Li, Jun Zhang, Steven L. Larson, John H. Ballard, Kai Guo, Zikri Arslan, Youhua Ma, Charles A. Waggoner, Jeremy R. White, Fengxiang X. Han. Electrokinetic-enhanced phytoremediation of uranium-contaminated soil using sunflower and Indian mustard. International Journal of Phytoremediation. 2019; 21 (12):1197-1204.
Chicago/Turabian StyleJiangxia Li; Jun Zhang; Steven L. Larson; John H. Ballard; Kai Guo; Zikri Arslan; Youhua Ma; Charles A. Waggoner; Jeremy R. White; Fengxiang X. Han. 2019. "Electrokinetic-enhanced phytoremediation of uranium-contaminated soil using sunflower and Indian mustard." International Journal of Phytoremediation 21, no. 12: 1197-1204.
Humic acid (HA) is well known as an inexpensive and effective adsorbent for heavy metal ions. However, the thermodynamics of uranium (U) adsorption onto HA is not fully understood. This study aimed to understand the kinetics and isotherms of U(VI) adsorption onto HA under different temperatures from acidic water. A leonardite-derived HA was characterized for its ash content, elemental compositions, and acidic functional groups, and used for the removal of U (VI) from acidic aqueous solutions via batch experiments at initial concentrations of 0–100 mg·L−1 at 298, 308 and 318 K. ICP-MS was used to determine the U(VI) concentrations in solutions before and after reacting with the HA. The rate and capacity of HA adsorbing U(VI) increased with the temperature. Adsorption kinetic data was best fitted to the pseudo second-order model. This, together with FTIR spectra, indicated a chemisorption of U(VI) by HA. Equilibrium adsorption data was best fitted to the Langmuir and Temkin models. Thermodynamic parameters such as equilibrium constant (K0), standard Gibbs free energy (ΔG0), standard enthalpy change (ΔH0), and standard entropy change (ΔS0), indicated that U(VI) adsorption onto HA was endothermic and spontaneous. The co-existence of cations (Cu2+, Co2+, Cd2+ and Pb2+) and anions (HPO42− and SO42−) reduced U(VI) adsorption. The high propensity and capacity of leonardite-derived HA adsorbing U(VI) suggests that it has the potential for cost-effective removal of U(VI) from acidic contaminated waters.
Fande Meng; Guodong Yuan; Steven L. Larson; John H. Ballard; Jeremy R. White; Zikri Arslan; Fengxiang X. Han. Kinetics and Thermodynamics of Uranium (VI) Adsorption onto Humic Acid Derived from Leonardite. International Journal of Environmental Research and Public Health 2019, 16, 1552 .
AMA StyleFande Meng, Guodong Yuan, Steven L. Larson, John H. Ballard, Jeremy R. White, Zikri Arslan, Fengxiang X. Han. Kinetics and Thermodynamics of Uranium (VI) Adsorption onto Humic Acid Derived from Leonardite. International Journal of Environmental Research and Public Health. 2019; 16 (9):1552.
Chicago/Turabian StyleFande Meng; Guodong Yuan; Steven L. Larson; John H. Ballard; Jeremy R. White; Zikri Arslan; Fengxiang X. Han. 2019. "Kinetics and Thermodynamics of Uranium (VI) Adsorption onto Humic Acid Derived from Leonardite." International Journal of Environmental Research and Public Health 16, no. 9: 1552.
Laboratory studies using metal spiked soils are challenging due to soil heterogeneity. This work provides an easy, quick, precise, and accurate technique for the preparation of spiked soils for laboratory research. The process described spiking soil with various uranium species and other heavy metals for laboratory scale pilot experiments under various biogeochemical conditions. The procedure involves grinding both dry soil and metal chemicals into the fine powder. The spiked soil mixture was further homogenized through a modified splitting and combining of the sample by diagonal flipping using plastic sheeting. Comparison of measured concentrations with theoretical values were obtained with <20% precision and accuracy. However, tradition spiking method with metal solution often yielded high heterogeneous spiked soils due to strong metal adsorption in soils. Re-drying and re-grinding of soils were required following the spiking in order to homogenize treated soils, generating inhalable particulates. Thus appropriate personal protective equipment and practices are required for the safety concern. The present method with metal salt powder proved a safe, useful, quick, accurate and precise, and homogenized soil spiking method.
Liangmei Chen; Steven L. Larson; John H. Ballard; Youhua Ma; Qinku Zhang; Jiangxia Li; Linchun Wu; Zikri Arslan; Fengxiang X. Han. Laboratory spiking process of soil with various uranium and other heavy metals. MethodsX 2019, 6, 734 -739.
AMA StyleLiangmei Chen, Steven L. Larson, John H. Ballard, Youhua Ma, Qinku Zhang, Jiangxia Li, Linchun Wu, Zikri Arslan, Fengxiang X. Han. Laboratory spiking process of soil with various uranium and other heavy metals. MethodsX. 2019; 6 ():734-739.
Chicago/Turabian StyleLiangmei Chen; Steven L. Larson; John H. Ballard; Youhua Ma; Qinku Zhang; Jiangxia Li; Linchun Wu; Zikri Arslan; Fengxiang X. Han. 2019. "Laboratory spiking process of soil with various uranium and other heavy metals." MethodsX 6, no. : 734-739.
Reactive oxygen species (ROS) such as the free radicals (e.g. hydroxyl, nitric acid, superoxide) cause damage to lipids, proteins and DNA. Increased production of ROS occurs from pollution. Process of removal or neutralization of ROS is achieved through antioxidants enzyme defense systems and provide homeostasis within biological systems. Aerobic organisms have complex antioxidant systems using enzymatic and non-enzymatic antioxidants to prevent overproduction of ROS. This study examined the toxic effects of arsenic and zinc on Eastern oysters, their interaction and resulting enzymatic responses. Cellular damage as indicated with lipid peroxidation and antioxidant defensive enzyme activities (superoxide dismutase, SOD; glutathione peroxidase, GPX and catalase, CAT) were measured in the hepatopancreas of Eastern oysters exposed to single and combined treatments of arsenic and zinc for 30 days. The results showed either arsenic or zinc exposure significantly increased the lipid peroxidation and triggered antioxidant defenses. Activities of antioxidant enzymes (SOD, GPX and CAT) were markedly elevated upon expose of As or Zn. However, at the presence of Zn, As toxicity expressed as lipid oxidation significantly decreased as well as accordingly decreased activities of antioxidant enzymes. This revealed that the presence of Zn showed a significantly antagonistic effect on arsenic toxicity in Eastern oysters from Northern Gulf of Mexico.
Turquoise C. Alexander; Fengxiang X. Han; Zikri Arslan; Paul B. Tchounwou. Toxicity of As in Crassostrea virginica (Gmelin, 1791) from the Northern Gulf of Mexico at the presence of Zn and its antioxidant defense mechanisms. Ecotoxicology and Environmental Safety 2019, 172, 514 -522.
AMA StyleTurquoise C. Alexander, Fengxiang X. Han, Zikri Arslan, Paul B. Tchounwou. Toxicity of As in Crassostrea virginica (Gmelin, 1791) from the Northern Gulf of Mexico at the presence of Zn and its antioxidant defense mechanisms. Ecotoxicology and Environmental Safety. 2019; 172 ():514-522.
Chicago/Turabian StyleTurquoise C. Alexander; Fengxiang X. Han; Zikri Arslan; Paul B. Tchounwou. 2019. "Toxicity of As in Crassostrea virginica (Gmelin, 1791) from the Northern Gulf of Mexico at the presence of Zn and its antioxidant defense mechanisms." Ecotoxicology and Environmental Safety 172, no. : 514-522.
Anthropogenic activities, such as ore mining and processing, nuclear power generation, and weapon tests, have generated uranium (U) contamination to soils and waters. The mobility and bioavailability of U are influenced by its sources, speciation, and plant species. Phytoremediation has emerged as an environmentally friendly, cost-effective green technology to remediate radioisotope- and metal-contaminated soils. The main objective of this study was to explore the feasibility using sunflower (Helianthus annuus) and Indian mustard (Brassica juncea) in cleaning up soils with UO2, UO3, and UO2(NO3)2. Uranium was found to be bioaccumulated in plant roots more than plant shoots. Uranium uptake by both plant species was significantly higher from the UO3- and uranyl-contaminated soils than from UO2-contaminated soils. UO3- and UO2(NO3)2-contaminated soils showed higher exchangeable, weak acid extractable, and labile U than the UO2-contaminated soils. After a growing season, three U forms decreased as redistribution/transformation of U resulted in U species with lower extractability. This study indicates the importance of U speciation in soil with regard to the potential use of sunflower and Indian mustard for phytoremediation of U-contaminated soils.
Fande Meng; Decheng Jin; Kai Guo; Steven L. Larson; John H. Ballard; Liangmei Chen; Zikri Arslan; Guodong Yuan; Jeremy R. White; Lixiang Zhou; Youhua Ma; Charles A. Waggoner; Fengxiang X. Han. Influences of U Sources and Forms on Its Bioaccumulation in Indian Mustard and Sunflower. Water, Air, & Soil Pollution 2018, 229, 369 .
AMA StyleFande Meng, Decheng Jin, Kai Guo, Steven L. Larson, John H. Ballard, Liangmei Chen, Zikri Arslan, Guodong Yuan, Jeremy R. White, Lixiang Zhou, Youhua Ma, Charles A. Waggoner, Fengxiang X. Han. Influences of U Sources and Forms on Its Bioaccumulation in Indian Mustard and Sunflower. Water, Air, & Soil Pollution. 2018; 229 (11):369.
Chicago/Turabian StyleFande Meng; Decheng Jin; Kai Guo; Steven L. Larson; John H. Ballard; Liangmei Chen; Zikri Arslan; Guodong Yuan; Jeremy R. White; Lixiang Zhou; Youhua Ma; Charles A. Waggoner; Fengxiang X. Han. 2018. "Influences of U Sources and Forms on Its Bioaccumulation in Indian Mustard and Sunflower." Water, Air, & Soil Pollution 229, no. 11: 369.
Lead and mercury are two of the most toxic heavy metals in environments. Mesosilicate-templated magnetic nanocarbons with ascorbic acid as carbon precursor were developed through nanocasting processes. The nanocarbon showed effective magnetic separation and the maximum adsorption capacity of 80.6 and 66.3 mg/g for Hg and Pb, respectively. Langmuir model well described adsorption processes of both Hg and Pb from water. Magnetic nanocarbon could be easily separated and incinerated, reducing the volume requiring the disposal. This study indicates that mesosilicate-templated nanocarbons with easy disposal potentials may be good candidates for cleansing Hg and Pb from contaminated water.
Kai Guo; Steven L. Larson; John H. Ballard; Zikri Arslan; Rong Zhang; Yong Ran; Yi Su; Fengxiang X. Han. Novel Magnetic Nanocarbon and Its Adsorption of Hg and Pb from Water. Water, Air, & Soil Pollution 2018, 229, 122 .
AMA StyleKai Guo, Steven L. Larson, John H. Ballard, Zikri Arslan, Rong Zhang, Yong Ran, Yi Su, Fengxiang X. Han. Novel Magnetic Nanocarbon and Its Adsorption of Hg and Pb from Water. Water, Air, & Soil Pollution. 2018; 229 (4):122.
Chicago/Turabian StyleKai Guo; Steven L. Larson; John H. Ballard; Zikri Arslan; Rong Zhang; Yong Ran; Yi Su; Fengxiang X. Han. 2018. "Novel Magnetic Nanocarbon and Its Adsorption of Hg and Pb from Water." Water, Air, & Soil Pollution 229, no. 4: 122.