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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.
Soil salinity and its associated soil compaction and low fertility is a big problem for land management in the arid region or coastal zone. Here, a low-cost and potassium (K)-rich biochar of reed (phragmites communis) was demonstrated effective in alleviating the problem in wheat-maize rotation in the Yellow River Delta region. Adding the biochar at 0, 3, 6, and 12 t ha–1 to a soil with a 2.8‰ salt content via rotary tillage with straw returning, with or without fertilizers, reduced soil bulk density (BD) and increased saturated hydraulic conductivity (Ks). At 12 t ha–1 dose and by wheat and maize harvests, respectively, biochar lowered soil BD by 9.1% and 14.5%, increased Ks by 82.7% and 91.2%, and reduced sodium adsorption ratio (SAR) by 64.9% and 92.8% in comparison with the control (CK). Further, in comparison with conventional fertilization (CF: 375 kg ha–1 for each crop), biochar use (6 and 12 t ha–1), together with 75% of CF, enhanced the nitrogen use efficiency (NUE) by 20.5%–31.4% for wheat and 15.9%–30.9% for maize. It raised the yields of wheat by 11.3%–17.1% and maize by 9.7%–14.8%. By reducing BD, increasing Ks, and decreasing SAR, biochar alleviated soil compaction and salt stress and increased NUE and crop yields. This outcome suggests that the conversion of local bio-waste into biochar as a soil amendment is of agronomic and environmental benefits.
Liang Xiao; Guodong Yuan; Lirong Feng; Dongxue Bi; Jing Wei. Soil properties and the growth of wheat (Triticum aestivum L.) and maize (Zea mays L.) in response to reed (phragmites communis) biochar use in a salt-affected soil in the Yellow River Delta. Agriculture, Ecosystems & Environment 2020, 303, 107124 .
AMA StyleLiang Xiao, Guodong Yuan, Lirong Feng, Dongxue Bi, Jing Wei. Soil properties and the growth of wheat (Triticum aestivum L.) and maize (Zea mays L.) in response to reed (phragmites communis) biochar use in a salt-affected soil in the Yellow River Delta. Agriculture, Ecosystems & Environment. 2020; 303 ():107124.
Chicago/Turabian StyleLiang Xiao; Guodong Yuan; Lirong Feng; Dongxue Bi; Jing Wei. 2020. "Soil properties and the growth of wheat (Triticum aestivum L.) and maize (Zea mays L.) in response to reed (phragmites communis) biochar use in a salt-affected soil in the Yellow River Delta." Agriculture, Ecosystems & Environment 303, no. : 107124.
A bulky waste, oyster shell (OS), was calcinated at 400–800°C to produce Ca-rich products (OS400–OS800) to reduce the human health risk of soil cadmium (Cd) and arsenic (As). Thermogravimetric analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), and BET method were used to characterize OS and its calcined products. OS and OS400–OS700 removed little Cd and As from water, whereas OS800 removed 1508 mg Cd or 514 mg As per kg of OS800 from solutions of 1032 mg Cd/L or 257 mg As/L via adsorption and precipitation. Adding OS800 at a 2% dose to a Cd- and As-contaminated soil lowered its exchangeable Cd from 60% to 27%, and reduced Cd content in the edible part of vegetable Bok Choy from 2.80 to 0.048 mg/kg and As from 1.73 to 0.47 mg/kg. Converting OS to soil amendment has the dual benefits to soil remediation and sustainable oyster aquaculture.
Dongxue Bi; Guodong Yuan; Jing Wei; Liang Xiao; Lirong Feng. Conversion of Oyster Shell Waste to Amendment for Immobilising Cadmium and Arsenic in Agricultural Soil. Bulletin of Environmental Contamination and Toxicology 2020, 105, 277 -282.
AMA StyleDongxue Bi, Guodong Yuan, Jing Wei, Liang Xiao, Lirong Feng. Conversion of Oyster Shell Waste to Amendment for Immobilising Cadmium and Arsenic in Agricultural Soil. Bulletin of Environmental Contamination and Toxicology. 2020; 105 (2):277-282.
Chicago/Turabian StyleDongxue Bi; Guodong Yuan; Jing Wei; Liang Xiao; Lirong Feng. 2020. "Conversion of Oyster Shell Waste to Amendment for Immobilising Cadmium and Arsenic in Agricultural Soil." Bulletin of Environmental Contamination and Toxicology 105, no. 2: 277-282.
The effects of microbial colonization and biofilm formation on microplastics in the marine and coastal environments have aroused global concern recently. However, the simultaneous influences of exposure time and depth on biofilm formation, and subsequently on the properties variations of microplastics is less studied. In this study, polyethylene (PE) film was exposed at three depths (2 m, 6 m, and 12 m) for three time periods (30 days, 75 days, and 135 days) in the coastal seawater of Yellow Sea, China. The results show that the total amount of biofilms markedly increased with exposure time, but decreased with water depth. Typical morphologies and compositions of biofilms such as coccus-, rod-, disc-shaped bacteria and filaments, as well as a dense layer of extracellular polymeric substances were observed on the surfaces of the PE microplastics. Biofilm formation could decrease the hydrophobicity of PE microplastics, and increase the abundances of hydrophilic C−O and CO groups on the surface of PE. Alphaproteobacteria, Gammaproteobacteria and Bacteroidia were identified as the core microbiome of the PE associated biofilms, while the dominant bacteria families vary from the early to the late phases of the biofilm formation. Our results indicate that microplastics associated biofilms could affect the environmental processes and fates of microplastics in the marine and coastal environment.
Chen Tu; Tao Chen; Qian Zhou; Ying Liu; Jing Wei; Joanna J. Waniek; Yongming Luo. Biofilm formation and its influences on the properties of microplastics as affected by exposure time and depth in the seawater. Science of The Total Environment 2020, 734, 139237 .
AMA StyleChen Tu, Tao Chen, Qian Zhou, Ying Liu, Jing Wei, Joanna J. Waniek, Yongming Luo. Biofilm formation and its influences on the properties of microplastics as affected by exposure time and depth in the seawater. Science of The Total Environment. 2020; 734 ():139237.
Chicago/Turabian StyleChen Tu; Tao Chen; Qian Zhou; Ying Liu; Jing Wei; Joanna J. Waniek; Yongming Luo. 2020. "Biofilm formation and its influences on the properties of microplastics as affected by exposure time and depth in the seawater." Science of The Total Environment 734, no. : 139237.
Being carbon-rich and porous, biochar has the potential to improve soil physical properties, so does conventional farming practice. Here, a field trial was conducted to investigate the combined effects of biochar use and farming practice on the physical properties of a salt-affected compact soil for wheat–maize rotation in the Yellow River Delta region. Salix fragilis L. was used as feedstock to produce biochar in the field via aerobic carbonization at an average temperature of 502 °C, terminated by a water mist spray, for use as a soil amendment at 0, 1, 2, and 4 g kg−1 doses (CK, T1, T2, and T3, respectively). Farming practices included rotary tillage/straw returning for wheat sowing, spring irrigation, no-tillage seeding of maize, and autumn irrigation. Both cutting ring and composite samples of the soil were collected at four stages of wheat–maize rotation (22, 238, 321, and 382 d after the benchmark date of land preparation for wheat sowing) for the determination of soil properties by established methods. Rotary tillage/straw returning reduced soil bulk density (BD) from 1.48 to 1.27 g cm−3 (CK) and 1.14 g cm−3 (T3) and increased saturated hydraulic conductivity (Ks) from 0.05 × 10−5 to 0.75 × 10−5 cm s−1 (CK) and 1.25 × 10−5 cm s−1 (T3). This tillage effect on BD and Ks gradually disappeared due to the disturbance from the subsequent farming practice. Biochar use lessened the disturbance. At maize harvest, BD was 1.47 (CK) vs. 1.34 g cm−3 (T3), and Ks was 0.06 × 10−5 (CK) vs. 0.28 × 10−5 cm s−1(T3); in comparison with CK, T3 increased Na+ leaching by 65%, Cl− leaching by 98%, organic carbon content by 40.3%, and water-stable aggregates (0.25–2 mm) by 38%, indicating an improvement in soil properties. Biochar use and rotary tillage improved soil physical properties (BD, Ks) and favored soil aeration, water filtration, and salt leaching, which further helped the accumulation of soil organic carbon, the formation of water-stable aggregates, and the amelioration of salt-affected compact soil.
Liang Xiao; Guodong Yuan; Lirong Feng; Dongxue Bi; Jing Wei; Guanhua Shen; Zhaohui Liu. Coupled effects of biochar use and farming practice on physical properties of a salt-affected soil with wheat–maize rotation. Journal of Soils and Sediments 2020, 20, 3053 -3061.
AMA StyleLiang Xiao, Guodong Yuan, Lirong Feng, Dongxue Bi, Jing Wei, Guanhua Shen, Zhaohui Liu. Coupled effects of biochar use and farming practice on physical properties of a salt-affected soil with wheat–maize rotation. Journal of Soils and Sediments. 2020; 20 (8):3053-3061.
Chicago/Turabian StyleLiang Xiao; Guodong Yuan; Lirong Feng; Dongxue Bi; Jing Wei; Guanhua Shen; Zhaohui Liu. 2020. "Coupled effects of biochar use and farming practice on physical properties of a salt-affected soil with wheat–maize rotation." Journal of Soils and Sediments 20, no. 8: 3053-3061.
Biochar has limited capacity to adsorb oxytetracycline (OTC). Here we have used bamboo willow biochar (BC) as a carrier to produce nMnO2-loaded biochars (MBC) by a co-precipitation method. Their chemical compositions, morphological features, specific surface area, and surface functional groups were observed or determined. Batch experiments were conducted to assess the effects of reaction time, initial OTC concentrations, pH, salt concentrations, and natural organic matter (NOM) on OTC removal. Kinetics and isotherms indicated that OTC was mainly adsorbed via chemical interactions, and mono- and multi-layer adsorption occurred on the surface. MBC removed 19–25 times more OTC than BC, and the removal was highest at near-neutral pH, not influenced by NaCl (2, 10 mM), slighted reduced by NOM (0–20 mg L−1), and enhanced by NaHCO3 (2, 10 mM). Besides being an adsorbent, MBC acted as an oxidant and degraded 58.5% of OTC at 24 h.
Lirong Feng; Guodong Yuan; Liang Xiao; Jing Wei; Dongxue Bi. Biochar Modified by Nano-manganese Dioxide as Adsorbent and Oxidant for Oxytetracycline. Bulletin of Environmental Contamination and Toxicology 2020, 107, 269 -275.
AMA StyleLirong Feng, Guodong Yuan, Liang Xiao, Jing Wei, Dongxue Bi. Biochar Modified by Nano-manganese Dioxide as Adsorbent and Oxidant for Oxytetracycline. Bulletin of Environmental Contamination and Toxicology. 2020; 107 (2):269-275.
Chicago/Turabian StyleLirong Feng; Guodong Yuan; Liang Xiao; Jing Wei; Dongxue Bi. 2020. "Biochar Modified by Nano-manganese Dioxide as Adsorbent and Oxidant for Oxytetracycline." Bulletin of Environmental Contamination and Toxicology 107, no. 2: 269-275.
With abundant oxygen-containing functional groups, a humic substance (HS) has a high potential to remediate soils contaminated by heavy metals. Here, HS was first extracted from a leonardite and analyzed for its chemical compositions and spectroscopic characteristics. Then it was assessed for its ability as a washing agent to remove Cd and As from three types of soils (red soil, black soil, and fluvo-aquic soil) that were spiked with those contaminants (Cd: 40.5–49.1 mg/kg; As: 451–584 mg/kg). The operational washing conditions, including the pH and concentration of the HS, washing time and cycles, and liquid–soil ratio, were assessed for Cd and As removal efficiency. At pH 7, with an HS concentration (3672 mg C/L) higher than its critical micelle concentration and a liquid–soil ratio of 30, a single washing for 6–12 h removed 41.9 mg Cd/kg and 199.3 mg As/kg from red soil, 33.5 mg Cd/kg and 291.5 mg As/kg from black soil, and 30.4 mg Cd/kg and 325.5 mg As/kg from fluvo-aquic soil. The removal of Cd and As from the contaminated soils involved the complexation of Cd and As with the carboxyl and phenolic groups of HS. Outcomes from this research could be used to develop a tailor-made HS washing agent for the remediation of Cd- and As-contaminated soils with different properties.
Dongxue Bi; Guodong Yuan; Jing Wei; Liang Xiao; Lirong Feng; Fande Meng; Jie Wang. A Soluble Humic Substance for the Simultaneous Removal of Cadmium and Arsenic from Contaminated Soils. International Journal of Environmental Research and Public Health 2019, 16, 4999 .
AMA StyleDongxue Bi, Guodong Yuan, Jing Wei, Liang Xiao, Lirong Feng, Fande Meng, Jie Wang. A Soluble Humic Substance for the Simultaneous Removal of Cadmium and Arsenic from Contaminated Soils. International Journal of Environmental Research and Public Health. 2019; 16 (24):4999.
Chicago/Turabian StyleDongxue Bi; Guodong Yuan; Jing Wei; Liang Xiao; Lirong Feng; Fande Meng; Jie Wang. 2019. "A Soluble Humic Substance for the Simultaneous Removal of Cadmium and Arsenic from Contaminated Soils." International Journal of Environmental Research and Public Health 16, no. 24: 4999.
Biochar has been intensively investigated for carbon sequestration, soil fertility enhancement, and immobilization of heavy metals and organic pollutants. Large-scale use of biochar in agricultural production and environmental remediation, however, has been constrained by its high cost. Here, we demonstrated the production of low-cost biochar ($20/ton) in the field from Robinia pseudoacacia biowaste via a combined aerobic and oxygen-limited carbonization process and a fire-water-coupled method. It involved aerobic combustion at the outer side of biomass, oxygen-limited pyrolysis in the inner core of biomass, and the termination of the carbonization by water spray. The properties of biochar thus produced were greatly affected by exposure time (the gap between a burning char fell to the ground and being extinguished by water spray). Biochar formed by zero exposure time showed a larger specific surface area (155.77 m2/g), a higher carbon content (67.45%), a lower ash content (15.38%), and a higher content of carboxyl and phenolic-hydroxyl groups (1.74 and 0.86 mol/kg, respectively) than biochars formed with longer exposure times (5–30 min). Fourier-transform infrared spectroscopic (FTIR) spectra indicated that oxygen-containing functional groups of biochar played a role in Cd and oxytetracycline sorption though a quantitative relationship could not be established as the relative contribution of carbon and ash moieties of biochar to the sorption was unknown. Outcomes from this research provide an option for inexpensive production of biochar to support its use as a soil amendment in developing countries.
Liang Xiao; Lirong Feng; Guodong Yuan; Jing Wei. Low-cost field production of biochars and their properties. Environmental Geochemistry and Health 2019, 42, 1569 -1578.
AMA StyleLiang Xiao, Lirong Feng, Guodong Yuan, Jing Wei. Low-cost field production of biochars and their properties. Environmental Geochemistry and Health. 2019; 42 (6):1569-1578.
Chicago/Turabian StyleLiang Xiao; Lirong Feng; Guodong Yuan; Jing Wei. 2019. "Low-cost field production of biochars and their properties." Environmental Geochemistry and Health 42, no. 6: 1569-1578.
Multiple spectroscopic technologies and chemometric analyses were combined to explore the compositional characteristics and Cu binding performance of biochar-derived dissolved organic matter (DOM). The DOM samples were extracted from biochars produced from lignocellulose-rich rapeseed cake (RSC) by pyrolysis at 300, 500, and 700 °C (i.e., RSC300, RSC500, RSC700). Fourier transform infrared spectroscopy (FTIR) and carbon K-edge near-edge X-ray absorption fine structure spectroscopy (NEXAFS) analyses were combined to elucidate the molecular-level C species in the DOM. With the increasing pyrolysis temperature, DOM aromaticity increased, whereas the proportion of metal complexing sites (e.g., carboxyl and phenolic groups) decreased. Fluorescence excitation-emission matrix (EEM) spectroscopy with parallel factor analysis (PARAFAC) indicated that biochar DOM, irrespective of pyrolysis temperature, was mostly composed of three types of humic-like components (C1–C3), and a small amount of a protein-like component (C4). As charring temperature increased, DOM concentrations decreased substantially, but the humic-like C3 with abundant aromatic structures became predominant. Fluorescence quenching experiment and two-dimensional correlation spectroscopy (2D-COS) analysis suggested that the preferential Cu(II) binding fractions of the DOM were the humic-like substances. Moreover, the quenching curve fitting results for individual components indicated that despite the Cu(II) binding affinity was slightly enhanced as the pyrolysis temperature increased, the binding capacities of the four components decreased. In general, the DOM components from RSC biochar exhibited limited Cu(II) binding capacities (2.18–17.7 μmol L−1). Results from this study improved understanding of the mechanisms by which biochar DOM interacts with Cu, and provided tools for fast screening of biochars to reduce their environmental risks.
Jing Wei; Chen Tu; Guodong Yuan; Yongqiang Zhou; Hailong Wang; Jian Lu. Limited Cu(II) binding to biochar DOM: Evidence from C K-edge NEXAFS and EEM-PARAFAC combined with two-dimensional correlation analysis. Science of The Total Environment 2019, 701, 134919 .
AMA StyleJing Wei, Chen Tu, Guodong Yuan, Yongqiang Zhou, Hailong Wang, Jian Lu. Limited Cu(II) binding to biochar DOM: Evidence from C K-edge NEXAFS and EEM-PARAFAC combined with two-dimensional correlation analysis. Science of The Total Environment. 2019; 701 ():134919.
Chicago/Turabian StyleJing Wei; Chen Tu; Guodong Yuan; Yongqiang Zhou; Hailong Wang; Jian Lu. 2019. "Limited Cu(II) binding to biochar DOM: Evidence from C K-edge NEXAFS and EEM-PARAFAC combined with two-dimensional correlation analysis." Science of The Total Environment 701, no. : 134919.
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.
The capacity of biochar to take up heavy metals from contaminated soil and water is influenced by the pyrolysis temperature. We have prepared three biochar samples from Jerusalem artichoke stalks (JAS) by pyrolysis at 300, 500 and 700 °C, denoted as JAS300, JAS500, and JAS700, respectively. A variety of synchrotron-based techniques were used to assess the effect of pyrolysis temperature on the molecular properties and copper (Cu) sorption capacity of the samples. The content of oxygen-containing functional groups in the biochar samples decreased, while that of aromatic structures and alkaline mineral components increased, with a rise in pyrolysis temperature. Scanning transmission X-ray microscopy indicated that sorbed Cu(II) was partially reduced to Cu(I), but this process was more evident with JAS300 and JAS700 than with JAS500. Carbon K-edge X-ray absorption near edge structure spectroscopy indicated that Cu(II) cations were sorbed to biochar via complexation and Cu-π bonding. With rising pyrolysis temperature, Cu(II)-complexation weakened while Cu-π bonding was enhanced. In addition, the relatively high ash content and pH of JAS500 and JAS700 facilitated Cu precipitation and the formation of langite on the surface of biochar. The results of this investigation will aid the conversion of halophyte waste to useable biochar for the effective remediation of Cu-contaminated soil and water.
Jing Wei; Chen Tu; Guodong Yuan; Ying Liu; Dongxue Bi; Liang Xiao; Jian Lu; Benny K.G. Theng; Hailong Wang; Lijuan Zhang; Xiangzhi Zhang. Assessing the effect of pyrolysis temperature on the molecular properties and copper sorption capacity of a halophyte biochar. Environmental Pollution 2019, 251, 56 -65.
AMA StyleJing Wei, Chen Tu, Guodong Yuan, Ying Liu, Dongxue Bi, Liang Xiao, Jian Lu, Benny K.G. Theng, Hailong Wang, Lijuan Zhang, Xiangzhi Zhang. Assessing the effect of pyrolysis temperature on the molecular properties and copper sorption capacity of a halophyte biochar. Environmental Pollution. 2019; 251 ():56-65.
Chicago/Turabian StyleJing Wei; Chen Tu; Guodong Yuan; Ying Liu; Dongxue Bi; Liang Xiao; Jian Lu; Benny K.G. Theng; Hailong Wang; Lijuan Zhang; Xiangzhi Zhang. 2019. "Assessing the effect of pyrolysis temperature on the molecular properties and copper sorption capacity of a halophyte biochar." Environmental Pollution 251, no. : 56-65.
A carbon-coated montmorillonite nanocomposite (CMt), obtained by hydrothermal carbonization of montmorillonite suspension in glucose, was used to remove Cr(VI) from aqueous solutions. The distribution and speciation of Cr immobilized by CMt were assessed by transmission electron microscopy with energy-dispersive X-ray analysis, X-ray absorption near edge structure (XANES), and scanning transmission soft X-ray microscopy (STXM). The variation in the functional groups and molecular structures of CMt was also investigated. The capacity of CMt for adsorbing Cr(VI) was markedly superior to that of the parent montmorillonite, showing maximum uptake of 100 and 12.4 mg g-1 at pH 2 and 8, respectively. The Cr K-edge XANES and STXM analyses indicated that Cr(VI) was reduced to Cr(III) under both acidic and alkaline conditions, while a Cr(OH)3 precipitate and Cr(III)-acetate complex were the predominant species present on the CMt surface. The Fourier transform infrared spectroscopy and C K-edge XANES further suggested that the phenolic groups in CMt could serve as electron donors, facilitating Cr(VI) reduction. The combined results indicate that electrostatic attraction, Cr(VI) reduction, complexation, and precipitation are involved in the removal of Cr(VI) by CMt.
Jing Wei; Chen Tu; Guodong Yuan; Dongxue Bi; Liang Xiao; Benny K.G. Theng; Hailong Wang; Yong Sik Ok. Carbon-coated montmorillonite nanocomposite for the removal of chromium(VI) from aqueous solutions. Journal of Hazardous Materials 2019, 368, 541 -549.
AMA StyleJing Wei, Chen Tu, Guodong Yuan, Dongxue Bi, Liang Xiao, Benny K.G. Theng, Hailong Wang, Yong Sik Ok. Carbon-coated montmorillonite nanocomposite for the removal of chromium(VI) from aqueous solutions. Journal of Hazardous Materials. 2019; 368 ():541-549.
Chicago/Turabian StyleJing Wei; Chen Tu; Guodong Yuan; Dongxue Bi; Liang Xiao; Benny K.G. Theng; Hailong Wang; Yong Sik Ok. 2019. "Carbon-coated montmorillonite nanocomposite for the removal of chromium(VI) from aqueous solutions." Journal of Hazardous Materials 368, no. : 541-549.
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.
The fate and transport of antibiotics in the aquatic environment are usually influenced by the combined effects of environmental factors. In this study, batch-type experiments were conducted to investigate the combined effects of phosphate and salinity on oxytetracycline (OTC) adsorption on, and desorption from, two marine sediments. Pseudo-second-order kinetic model fitted the kinetic data better than pseudo-first-order model. The pseudo-second-order kinetic rate (k2) of OTC increased significantly with increasing phosphate concentrations. Sorption isotherms of OTC can be well described by both the Langmuir and Freundlich models. Compared with the control experiments (without phosphate addition), Freundlich distribution coefficients (KF) after addition of 50 mg L−1 phosphate decreased from 24.9 to 17.9 L kg−1 on sediments collected from Laizhou Bay, and from 52.2 to 31.3 L kg−1 on sediments collected from Bohai Bay, which indicated that phosphate could inhibit adsorption of OTC on marine sediments. Furthermore, phosphate had a stronger inhibitory effect on OTC adsorption at low salinity level than at high salinity level. The effects of phosphate on OTC adsorption can be explained by ion exchange, change of sediment surface charge, and electrostatic repulsion mechanisms. Desorption experiments showed that phosphate can enhance the total desorption percentage of OTC from marine sediments. Overall, the presence of phosphate in marine system may enhance OTC’s long-term transport.
Jia Li; Hua Zhang; Guodong Yuan. Phosphate affects adsorption and desorption of oxytetracycline in the seawater-sediment systems. Environmental Science and Pollution Research 2018, 25, 28160 -28168.
AMA StyleJia Li, Hua Zhang, Guodong Yuan. Phosphate affects adsorption and desorption of oxytetracycline in the seawater-sediment systems. Environmental Science and Pollution Research. 2018; 25 (28):28160-28168.
Chicago/Turabian StyleJia Li; Hua Zhang; Guodong Yuan. 2018. "Phosphate affects adsorption and desorption of oxytetracycline in the seawater-sediment systems." Environmental Science and Pollution Research 25, no. 28: 28160-28168.
The dissolved organic matter (DOM) samples from biochars produced from Jerusalem artichoke stalks by pyrolysis at 300, 500, and 700 °C were characterized using a combination of spectroscopic techniques. Additionally, the binding affinities (long KM) and the complexation capacities (CL) of the DOM samples with Cu(II) were calculated to assess their Cu binding properties. The biochar-borne DOM contained mainly humic-like components (C1–C3) with a small amount of a protein-like component (C4). As the charring temperature increased, the concentrations of released DOM decreased. The low temperature biochar-borne DOM was found to have more carboxyl groups than its high temperature counterparts, and thus it had larger CL values. In contrast, the high temperature biochar-borne DOM had larger long KM values. Low temperature biochars, if applied in a large quantity, would alter copper mobility in the environment because of their high DOM contents and large copper binding capacities.
Jing Wei; Chen Tu; Guodong Yuan; Dongxue Bi; Hailong Wang; Lijuan Zhang; Benny K. G. Theng. Pyrolysis Temperature-Dependent Changes in the Characteristics of Biochar-Borne Dissolved Organic Matter and Its Copper Binding Properties. Bulletin of Environmental Contamination and Toxicology 2018, 103, 169 -174.
AMA StyleJing Wei, Chen Tu, Guodong Yuan, Dongxue Bi, Hailong Wang, Lijuan Zhang, Benny K. G. Theng. Pyrolysis Temperature-Dependent Changes in the Characteristics of Biochar-Borne Dissolved Organic Matter and Its Copper Binding Properties. Bulletin of Environmental Contamination and Toxicology. 2018; 103 (1):169-174.
Chicago/Turabian StyleJing Wei; Chen Tu; Guodong Yuan; Dongxue Bi; Hailong Wang; Lijuan Zhang; Benny K. G. Theng. 2018. "Pyrolysis Temperature-Dependent Changes in the Characteristics of Biochar-Borne Dissolved Organic Matter and Its Copper Binding Properties." Bulletin of Environmental Contamination and Toxicology 103, no. 1: 169-174.
In recent years, soil contamination has become a global environmental problem. Biochar is a porous and carbon-rich material produced from pyrolysis of biomass residues from agricultural and forestry production. It can be used to immobilize heavy metals and organic pollutants in soil through adsorption. Here we report results obtained from our recent studies focusing on the interactions between biochar and soil contaminants. Incubation and pot experiments were carried out to investigate the effect of biochar type, application rate, and particle size on soil properties, bioavailability, mobility, and redistribution of the heavy metals in soil and the accumulation of heavy metals in the plants. Batch equilibration method was used to explore the effect of biochar type, aging process, dosage, and soil organic carbon content on adsorption and desorption of organic pollutants (e.g., phthalic acid esters, or PAEs) in soil. Incubation and pot trials were conducted to evaluate the impact of biochar on the degradation and bioavailability of PAEs in soils. Our results demonstrate that biochar can potentially be used as soil amendment for remediation of soils contaminated with heavy metals and organic pollutants. The efficacy of biochar application on immobilization of contaminants varies with the type, application rate, and particle size of biochars, soil properties, and contaminant types.
Hailong Wang; Xing Yang; Lizhi He; Kouping Lu; Karin Muller; Kim McGrouther; Song Xu; Xiaokai Zhang; Jianwu Li; Huagang Huang; Guodong Yuan; Guotao Hu; Xingyuan Liu. Using Biochar for Remediation of Contaminated Soils. Twenty Years of Research and Development on Soil Pollution and Remediation in China 2018, 763 -783.
AMA StyleHailong Wang, Xing Yang, Lizhi He, Kouping Lu, Karin Muller, Kim McGrouther, Song Xu, Xiaokai Zhang, Jianwu Li, Huagang Huang, Guodong Yuan, Guotao Hu, Xingyuan Liu. Using Biochar for Remediation of Contaminated Soils. Twenty Years of Research and Development on Soil Pollution and Remediation in China. 2018; ():763-783.
Chicago/Turabian StyleHailong Wang; Xing Yang; Lizhi He; Kouping Lu; Karin Muller; Kim McGrouther; Song Xu; Xiaokai Zhang; Jianwu Li; Huagang Huang; Guodong Yuan; Guotao Hu; Xingyuan Liu. 2018. "Using Biochar for Remediation of Contaminated Soils." Twenty Years of Research and Development on Soil Pollution and Remediation in China , no. : 763-783.
The occurrence of uranium (U) and depleted uranium (DU)-contaminated wastes from anthropogenic activities is an important environmental problem. Insoluble humic acid derived from leonardite (L-HA) was investigated as a potential adsorbent for immobilizing U in the environment. The effect of initial pH, contact time, U concentration, and temperature on U(VI) adsorption onto L-HA was assessed. The U(VI) adsorption was pH-dependent and achieved equilibrium in 2 h. It could be well described with pseudo-second-order model, indicating that U(VI) adsorption onto L-HA involved chemisorption. The U(VI) adsorption mass increased with increasing temperature with maximum adsorption capacities of 91, 112 and 120 mg g at 298, 308 and 318 K, respectively. The adsorption reaction was spontaneous and endothermic. We explored the processes of U(VI) desorption from the L-HA-U complex through batch desorption experiments in 1 mM NaNO and in artificial seawater. The desorption process could be well described by pseudo-first-order model and reached equilibrium in 3 h. L-HA possessed a high propensity to adsorb U(VI). Once adsorbed, the release of U(VI) from L-HA-U complex was minimal in both 1 mM NaNOand artificial seawater (0.06% and 0.40%, respectively). Being abundant, inexpensive, and safe, L-HA has good potential for use as a U adsorbent from aqueous solution or immobilizing U in soils.
Fande Meng; Guodong Yuan; Steven L. Larson; John H. Ballard; Charles A. Waggoner; Zikri Arslan; Fengxiang X. Han. Removing uranium (VI) from aqueous solution with insoluble humic acid derived from leonardite. Journal of Environmental Radioactivity 2017, 180, 1 -8.
AMA StyleFande Meng, Guodong Yuan, Steven L. Larson, John H. Ballard, Charles A. Waggoner, Zikri Arslan, Fengxiang X. Han. Removing uranium (VI) from aqueous solution with insoluble humic acid derived from leonardite. Journal of Environmental Radioactivity. 2017; 180 ():1-8.
Chicago/Turabian StyleFande Meng; Guodong Yuan; Steven L. Larson; John H. Ballard; Charles A. Waggoner; Zikri Arslan; Fengxiang X. Han. 2017. "Removing uranium (VI) from aqueous solution with insoluble humic acid derived from leonardite." Journal of Environmental Radioactivity 180, no. : 1-8.
Yongbing Cai; Hua Zhang; Guodong Yuan; Feiyue Li. Sources, speciation and transformation of arsenic in the gold mining impacted Jiehe River, China. Applied Geochemistry 2017, 84, 254 -261.
AMA StyleYongbing Cai, Hua Zhang, Guodong Yuan, Feiyue Li. Sources, speciation and transformation of arsenic in the gold mining impacted Jiehe River, China. Applied Geochemistry. 2017; 84 ():254-261.
Chicago/Turabian StyleYongbing Cai; Hua Zhang; Guodong Yuan; Feiyue Li. 2017. "Sources, speciation and transformation of arsenic in the gold mining impacted Jiehe River, China." Applied Geochemistry 84, no. : 254-261.
Adsorption is an important mechanism to immobilize cadmium (Cd) in soil, for which humic substances have a potential. However, commercial humic substances are either very acidic (pH = 2) or alkaline/Na+-enriched, making them less suitable for use in acid and saline soils. Here, we used leonardite to produce humic adsorbents HA (pH = 4.02), Ca-HA (pH = 10.9), and Ca-CPAM-HA (pH = 9.62) by using HCl, CaCl2, or CaCl2-polyacrylamide as a flocculant. Their elemental compositions, acidity, and spectroscopic properties were determined, and their Cd adsorption characteristics were assessed by batch kinetic and thermodynamic experiments at environmentally relevant concentrations. Further, HA was mixed with Cd-contaminated soils and incubated for a month to assess its effect on Cd immobilization. Good fitting of kinetic adsorption data into pseudo-second-order model, together with FTIR spectroscopic data, suggested the chemisorption mechanism by forming Cd(II)-carboxyl complexes. The maximum adsorption capacity derived from the Langmuir equation was 129, 114, and 110 mg Cd(II)/g for HA, Ca-HA, and Ca-CPAM-HA, respectively. These values are almost the same on carbon-normalized basis. HA reduced acetic acid extractable Cd by 31% or more. Besides their high propensity for Cd adsorption, humic adsorbents are inexpensive, safe, and beneficial to soil quality.
Fande Meng; Guodong Yuan; Jing Wei; Dongxue Bi; Hailong Wang. Leonardite-derived humic substances are great adsorbents for cadmium. Environmental Science and Pollution Research 2017, 24, 23006 -23014.
AMA StyleFande Meng, Guodong Yuan, Jing Wei, Dongxue Bi, Hailong Wang. Leonardite-derived humic substances are great adsorbents for cadmium. Environmental Science and Pollution Research. 2017; 24 (29):23006-23014.
Chicago/Turabian StyleFande Meng; Guodong Yuan; Jing Wei; Dongxue Bi; Hailong Wang. 2017. "Leonardite-derived humic substances are great adsorbents for cadmium." Environmental Science and Pollution Research 24, no. 29: 23006-23014.
Cost-effective and eco-friendly washing agents are in demand for Cd contaminated soils. Here, we used leonardite-derived humic substances to wash different types of Cd-contaminated soils, namely, a silty loam (Soil 1), a silty clay loam (Soil 2), and a sandy loam (Soil 3). Washing conditions were investigated for their effects on Cd removal efficiency. Cadmium removal was enhanced by a high humic substance concentration, long washing time, near neutral pH, and large solution/soil ratio. Based on the tradeoff between efficiency and cost, an optimum working condition was established as follows: humic substance concentration (3150 mg C/L), solution pH (6.0), washing time (2 h) and a washing solution/soil ratio (5). A single washing removed 0.55 mg Cd/kg from Soil 1 (1.33 mg Cd/kg), 2.32 mg Cd/kg from Soil 2 (6.57 mg Cd/kg), and 1.97 mg Cd/kg from Soil 3 (2.63 mg Cd/kg). Cd in effluents was effectively treated by adding a small dose of calcium hydroxide, reducing its concentration below the discharge limit of 0.1 mg/L in China. Being cost-effective and safe, humic substances have a great potential to replace common washing agents for the remediation of Cd-contaminated soils. Besides being environmentally benign, humic substances can improve soil physical, chemical, and biological properties.
Fande Meng; Guodong Yuan; Jing Wei; Dongxue Bi; Yong Sik Ok; Hailong Wang. Humic substances as a washing agent for Cd-contaminated soils. Chemosphere 2017, 181, 461 -467.
AMA StyleFande Meng, Guodong Yuan, Jing Wei, Dongxue Bi, Yong Sik Ok, Hailong Wang. Humic substances as a washing agent for Cd-contaminated soils. Chemosphere. 2017; 181 ():461-467.
Chicago/Turabian StyleFande Meng; Guodong Yuan; Jing Wei; Dongxue Bi; Yong Sik Ok; Hailong Wang. 2017. "Humic substances as a washing agent for Cd-contaminated soils." Chemosphere 181, no. : 461-467.