[Objective] To study the remediation efficiency of red mud on Pb, Zn and Cd in the heavy metal contaminated paddy soil of mine area, to clarify its remediation mechanism and fertilizer efficiency on heavy metal contam...[Objective] To study the remediation efficiency of red mud on Pb, Zn and Cd in the heavy metal contaminated paddy soil of mine area, to clarify its remediation mechanism and fertilizer efficiency on heavy metal contaminated soil. [Method] The soil incubation experiment was conducted to study the effect of red mud on the pH values and electrical conductivity （EC）, and the remediation efficiency of red mud on lead （Pb）, zinc （Zn） and cadmium （Cd） in heavy metal contaminated soil. [Result] Red mud addition reduced the content of exchangeable Pb, Zn and Cd in the soil significantly. Compared with the control, when incubated for 30, 60 and 90 d with the red mud dosage of 4% （W/W）, the exchangeable Pb content was decreased by 39.25%, 41.38% and 50.19%; exchangeable Zn content was decreased by 49.26%, 57.32% and 47.16%; and exchangeable Cd content was decreased by 19.53%, 24.06% and 25.70%, respectively. The application of red mud had significant impact on the share of Pb, Zn and Cd contents in five forms, and different amounts of red mud application all reduced the proportion of exchangeable Pb, Zn and Cd to the total Pb, Zn and Cd. In addition, the proportion of exchangeable Pb, Zn and Cd to total Pb, Zn and Cd decreased with the increasing amount of red mud addition. [Conclusion] The study provided references for reasonable application of red mud and reduction of heavy metal pollution in paddy soil.展开更多
Gibbs free binding energy and adsorption energy between cations and charged soil particles were used to evaluate the interactions between ions and soil particles. The distribution of Gibbs free adsorption energies cou...Gibbs free binding energy and adsorption energy between cations and charged soil particles were used to evaluate the interactions between ions and soil particles. The distribution of Gibbs free adsorption energies could not be determined experimentally before the development of Wien effect measurements in dilute soil suspensions. In the current study, energy relationships between heavy metal ions and particles of Hapli-Udic Argosol （Alfisol） and Ferri-Udic Argosol were inferred from Wien effect measurements in dilute suspensions of homoionic soil particles （〈 2 μm） of the two soils, which were saturated with ions of five heavy metals, in deionized water. The mean Gibbs free binding energies of the heavy metal ions with Hapli-Udic Argosol and Ferri-Udic Argosol particles diminished in the order of Pb^2＋ 〉 Cd^2＋ 〉 Cu^2＋ 〉 Zn^2＋ 〉 Cr^3＋, where the range of binding energies for Hapli-Udic Argosol （7.25-9.32 kJ mol^-1） was similar to that for Ferri-Udic Argosol （7.43-9.35 kJ mol^-1）. The electrical field-dependent mean Gibbs free adsorption energies of these heavy metal ions for Hapli-Udic Argosol and for Ferri-Udic Argosol descended in the order： Cu^2＋ 〉 Cd2^＋ 〉 Pb^2＋ 〉 Zn^2＋ 〉 Cr^3＋, and Cd^2＋ 〉 Cu^2＋ 〉 Pb^2＋ 〉 Zn^2＋ 〉 Cr^3＋, respectively. The mean Gibbs free adsorption energies of Cu^2＋, Zn^2＋, Cd^2＋, Pb^2＋, and Cr^3＋ at a field strength of 200 kV cm^-1, for example, were in the range of 0.8-3.2 kJ mo1^-1 for the two soils.展开更多
Concentration of heavy metals in blood and urine of rabbit after inhaling three different kinds of cigarette was studied through the animal passive smoking pattern. The samples were prepared by nitric acid solution di...Concentration of heavy metals in blood and urine of rabbit after inhaling three different kinds of cigarette was studied through the animal passive smoking pattern. The samples were prepared by nitric acid solution digestion and determination of seven kinds of heavy metals including Hg, Se, Sn, Pb, Cd, Ni and Cr was performed by inductively coupled plasma-atomic emission spectrometry （ICP-AES）. The ICP-AES method was established with good precision and accuracy, relative standard deviation （n=6） was between 2.9% and 5.9%, and the recovery was in the range of 95.0%-104.2%. Concentration of six heavy metals increases in some extent in blood and urine after period of smoking and the increasing of heavy metals in blood and urine all shows time dependence. Significantly higher heavy metal levels are observed in the blood and urine of the cigarette inhaling rabbits in the exposed group. The concentration of six kinds of heavy metals in the blood of the rabbit increases after 16 weeks exposing to cigarette smoking. Three times of rig, ten times of Se and trace amount ofPb, Cd, Ni and Cr are detected in the blood after 16 weeks of smoking. For urine samples, about three times of Hg, two times of Se, five times of Pb and trace amount of Cd are detected after 16 weeks of inhalation of cigarette. Comparatively, higher concentration of heavy metals are detected after inhaling of Nise cigarette.展开更多
An anomalous isotope effect exists in many heavy element isotope systems （e.g., Sr, Gd, Zn, U）. This effect used to be called the ＂odd--even isotope effect＂ because the odd mass number isotopes behave differently ...An anomalous isotope effect exists in many heavy element isotope systems （e.g., Sr, Gd, Zn, U）. This effect used to be called the ＂odd--even isotope effect＂ because the odd mass number isotopes behave differently from the even mass number isotopes. This mass-indepen- dent isotope fractionation driving force, which originates from the difference in the ground-state electronic energies caused by differences in nuclear size and shape, is cur- rently denoted as the nuclear field shift effect （NFSE）. It is found that the NFSE can drive isotope fractionation of some heavy elements （e.g., Hg, T1, U） to an astonishing degree, far more than the magnitude caused by the con- ventional mass-dependent effect （MDE）. For light ele- ments, the MDE is the dominant factor in isotope fractionation, while the NFSE is neglectable. Furthermore, the MDE and the NFSE both decrease as temperatures increase, though at different rates. The MDE decreases rapidly with a factor of 1/T2, while the NFSE decreases slowly with a factor of 1/T. As a result, even at high temperatures, the NFSE is still significant for many heavy element isotope systems. In this review paper, we begin with an introduction of the basic concept of the NSFE, including its history and recent progress, and follow with the potential implications of the inclusion of the NFSE into the kinetic isotope fractionation effect （KIE） and heavy isotope geochronology.展开更多
基金Supported by the National Natural Science Foundation of China(50874046)the National High-tech Research and Develop Program of China(863 Program)(2010AA065203)the Science and Technology Project of Education Bureau of Hunan Province,China(08A032)~~
文摘[Objective] To study the remediation efficiency of red mud on Pb, Zn and Cd in the heavy metal contaminated paddy soil of mine area, to clarify its remediation mechanism and fertilizer efficiency on heavy metal contaminated soil. [Method] The soil incubation experiment was conducted to study the effect of red mud on the pH values and electrical conductivity （EC）, and the remediation efficiency of red mud on lead （Pb）, zinc （Zn） and cadmium （Cd） in heavy metal contaminated soil. [Result] Red mud addition reduced the content of exchangeable Pb, Zn and Cd in the soil significantly. Compared with the control, when incubated for 30, 60 and 90 d with the red mud dosage of 4% （W/W）, the exchangeable Pb content was decreased by 39.25%, 41.38% and 50.19%; exchangeable Zn content was decreased by 49.26%, 57.32% and 47.16%; and exchangeable Cd content was decreased by 19.53%, 24.06% and 25.70%, respectively. The application of red mud had significant impact on the share of Pb, Zn and Cd contents in five forms, and different amounts of red mud application all reduced the proportion of exchangeable Pb, Zn and Cd to the total Pb, Zn and Cd. In addition, the proportion of exchangeable Pb, Zn and Cd to total Pb, Zn and Cd decreased with the increasing amount of red mud addition. [Conclusion] The study provided references for reasonable application of red mud and reduction of heavy metal pollution in paddy soil.
基金Project supported by the National Natural Science Foundation of China(Nos.40401030 and 20577054).
文摘Gibbs free binding energy and adsorption energy between cations and charged soil particles were used to evaluate the interactions between ions and soil particles. The distribution of Gibbs free adsorption energies could not be determined experimentally before the development of Wien effect measurements in dilute soil suspensions. In the current study, energy relationships between heavy metal ions and particles of Hapli-Udic Argosol （Alfisol） and Ferri-Udic Argosol were inferred from Wien effect measurements in dilute suspensions of homoionic soil particles （〈 2 μm） of the two soils, which were saturated with ions of five heavy metals, in deionized water. The mean Gibbs free binding energies of the heavy metal ions with Hapli-Udic Argosol and Ferri-Udic Argosol particles diminished in the order of Pb^2＋ 〉 Cd^2＋ 〉 Cu^2＋ 〉 Zn^2＋ 〉 Cr^3＋, where the range of binding energies for Hapli-Udic Argosol （7.25-9.32 kJ mol^-1） was similar to that for Ferri-Udic Argosol （7.43-9.35 kJ mol^-1）. The electrical field-dependent mean Gibbs free adsorption energies of these heavy metal ions for Hapli-Udic Argosol and for Ferri-Udic Argosol descended in the order： Cu^2＋ 〉 Cd2^＋ 〉 Pb^2＋ 〉 Zn^2＋ 〉 Cr^3＋, and Cd^2＋ 〉 Cu^2＋ 〉 Pb^2＋ 〉 Zn^2＋ 〉 Cr^3＋, respectively. The mean Gibbs free adsorption energies of Cu^2＋, Zn^2＋, Cd^2＋, Pb^2＋, and Cr^3＋ at a field strength of 200 kV cm^-1, for example, were in the range of 0.8-3.2 kJ mo1^-1 for the two soils.
基金Project(11JJ5053) supported by the Provincial Natural Science Foundation of Hunan Province,China
文摘Concentration of heavy metals in blood and urine of rabbit after inhaling three different kinds of cigarette was studied through the animal passive smoking pattern. The samples were prepared by nitric acid solution digestion and determination of seven kinds of heavy metals including Hg, Se, Sn, Pb, Cd, Ni and Cr was performed by inductively coupled plasma-atomic emission spectrometry （ICP-AES）. The ICP-AES method was established with good precision and accuracy, relative standard deviation （n=6） was between 2.9% and 5.9%, and the recovery was in the range of 95.0%-104.2%. Concentration of six heavy metals increases in some extent in blood and urine after period of smoking and the increasing of heavy metals in blood and urine all shows time dependence. Significantly higher heavy metal levels are observed in the blood and urine of the cigarette inhaling rabbits in the exposed group. The concentration of six kinds of heavy metals in the blood of the rabbit increases after 16 weeks exposing to cigarette smoking. Three times of rig, ten times of Se and trace amount ofPb, Cd, Ni and Cr are detected in the blood after 16 weeks of smoking. For urine samples, about three times of Hg, two times of Se, five times of Pb and trace amount of Cd are detected after 16 weeks of inhalation of cigarette. Comparatively, higher concentration of heavy metals are detected after inhaling of Nise cigarette.
基金funding support from the973 Program(2014CB440904)Chinese NSF projects(41225012,41490635,41530210)
文摘An anomalous isotope effect exists in many heavy element isotope systems （e.g., Sr, Gd, Zn, U）. This effect used to be called the ＂odd--even isotope effect＂ because the odd mass number isotopes behave differently from the even mass number isotopes. This mass-indepen- dent isotope fractionation driving force, which originates from the difference in the ground-state electronic energies caused by differences in nuclear size and shape, is cur- rently denoted as the nuclear field shift effect （NFSE）. It is found that the NFSE can drive isotope fractionation of some heavy elements （e.g., Hg, T1, U） to an astonishing degree, far more than the magnitude caused by the con- ventional mass-dependent effect （MDE）. For light ele- ments, the MDE is the dominant factor in isotope fractionation, while the NFSE is neglectable. Furthermore, the MDE and the NFSE both decrease as temperatures increase, though at different rates. The MDE decreases rapidly with a factor of 1/T2, while the NFSE decreases slowly with a factor of 1/T. As a result, even at high temperatures, the NFSE is still significant for many heavy element isotope systems. In this review paper, we begin with an introduction of the basic concept of the NSFE, including its history and recent progress, and follow with the potential implications of the inclusion of the NFSE into the kinetic isotope fractionation effect （KIE） and heavy isotope geochronology.
