[Objectives] The research was conducted to study characteristics of bioavailable levels pollution of heavy metals in the surface soil of the lead-zinc mine in Changhua.[Methods] A total of 56 surface samples were coll...[Objectives] The research was conducted to study characteristics of bioavailable levels pollution of heavy metals in the surface soil of the lead-zinc mine in Changhua.[Methods] A total of 56 surface samples were collected from the 3 study zones （peripheral zone, reclamation zone and tailing zone） located at the lead-zine mine in Changhua. Based on total and bioavailable heavy metals （Pb, Zn, Cu and Cd） in soils, the correlation of total content with bioavailable content was analyzed, and their pollution characteristics were assessed by methods of single factor pollution index, Nemerow pollution index, geological accumulation index and potential ecological risk index.[Results] （i） The surface soils were polluted by Pb, Zn, Cu, Cd in different degrees, and the overall trend of the contents of the 4 heavy metals was in order of Cd 〉 Pb 〉 Zn 〉 Cu. The average excess multiple of heavy metals of total and bioavailable content in soils were in the order of peripheral zone 〉 tailing zone 〉 reclaimed zone, and their pollution degrees were tailing zone 〉 peripheral zone 〉 reclaimed zone. （ii） In general, the total and bioavailable contents of Pb, Zn, Cu, Cd showed a significant correlation, but were not correlated in each study zone. （iii） Pollution degrees of the study zones were in the order of tailing zone 〉 peripheral zone 〉 reclamation zone. The pollutions of heavy metals Pb and Cd were more serious, especially Cd reached high levels of pollution degree, and the pollution degrees of Zn, Cu were lighter. Contributors of ecological risk were mainly Cd, Pb and Cu, and the contribution of Cd achieved more than 90 %, making it the main source of pollution.[Conclusions] The results not only revealed the pollution status of heavy metals in the surface soil of the abandoned coal mine, but also could provide scientific guidance for reasonable utilization and ecological recovery of the land.展开更多
The local structure of an alternative Pb（Zn1/3Nb2/3）O3-based perovskite ceramic is investigated. The 0.07BaTiO33-0.93Pb（Zn1/3Nb2/3）O3 ceramic is synthesized using a combination of Zn3Nb2O8 B-site precursor and BaT...The local structure of an alternative Pb（Zn1/3Nb2/3）O3-based perovskite ceramic is investigated. The 0.07BaTiO33-0.93Pb（Zn1/3Nb2/3）O3 ceramic is synthesized using a combination of Zn3Nb2O8 B-site precursor and BaTiO33 perovskite phase stabilizer. Then, x-ray absorption spectroscopy and density functional theory are employed to calculate the local structure configuration and formation energy of the prepared samples. Ba2＋ is found to replace Pb2＋ in AA-site with Zn2＋ occupying BB-site in Pb（Zn1/3Nb2/3）O3, while in the neighboring structure, Ti4＋4＋ replaces Nb5＋5＋ in BB-site with Pb2＋2＋ occupying AA-site. With the substitution of BaTiO33 in Pb（Zn1/3Nb2/3）O3, the bond length between Zn2＋ and Pb2＋ is longer than that of the typical perovskite phase of Pb（Zn1/3Nb2/3）O3. This indicates the key role of BaTiO33 in decreasing the steric hindrance of Pb2＋ lone pair, and the mutual interactions between Pb2＋ lone pair and Zn2＋ and the formation energy is seen to decrease. This finding of the formation energy and local structure configuration relationship can further extend a fundamental understanding of the role of BaTiO33 in stabilizing the perovskite phase in PbZn13Nb23O3-based materials, which in turn will lead to an improved preparation technique for desired electrical properties.展开更多
The paper discusses the tectonic setting of the fortnation of the Dexing giant copper-gold-lead-zinc deposit and its geological features and demonstrates in detail the polygenetic compound mechanism of its formation.
This work was to study composition characteristics and the subsequent effect on the lead(Pb) binding properties of dissolved organic matter(DOM) derived from seaweed-based(SWOF) and chicken manure organic fertilizers(...This work was to study composition characteristics and the subsequent effect on the lead(Pb) binding properties of dissolved organic matter(DOM) derived from seaweed-based(SWOF) and chicken manure organic fertilizers(CMOF) during a one-year field incubation experiment using the excitation-emission matrix-parallel factor(EEM-PARAFAC) and twodimensional correlation spectroscopy(2DCOS) analysis. Results showed that high aromatic and hydrophobic fluorescent substances were enriched in CMOF-derived DOM and SWOFderived DOM and enhanced over time. And phenolic groups in the fulvic-like substances for SWOF-derived DOM and carboxyl groups in the humic-like substances for CMOF-derived DOM had the fastest responses over time, respectively. Moreover, both non-fluorescent polysaccharides and fluorescent humic-like substances or fulvic-like substances with aromatic(C=C) groups first participated in the binding process of Pb to SWOF-derived DOM on day 0 and 180 during the lead binding process. In contrast, humic-like substances associated with aromatic(C=C) and phenolic groups gave a faster response to Pb binding on day 360. Regarding CMOF-derived DOM, the fulvic-like substances associated with aromatic(C=C) and carboxylic groups displayed a faster response to Pb ions on day 0. Nonetheless,polysaccharides and humic-like associated with phenolic groups had a faster response on days 180 and 360. It is noteworthy that the polysaccharides, which participated in Pb binding to CMOF-derived DOM, posed a higher risk of Pb in the environment after 360 days. Therefore, these findings gave new insights into the long-term applications of commercial organic fertilizers for the amendment of soil.展开更多
The Mengya’a Lead–zinc deposit is a large skarn deposit in the north of the eastern segment of Gangdese metallogenic belt.The garnet is the main altered mineral in the Mengya’a area.The color of the garnet varies f...The Mengya’a Lead–zinc deposit is a large skarn deposit in the north of the eastern segment of Gangdese metallogenic belt.The garnet is the main altered mineral in the Mengya’a area.The color of the garnet varies from chartreuse to dark yellow brown and to russet.The brown garnet(Grt1)is related to pyrrhotite and chalcopyrite,and the green garnet(Grt2)is associated with lead–zinc mineralization.LA-ICP-MS is the induced coupled plasma mass spectrometry.This paper has used this technique to investigate Grt1 and Grt2.Grt1 develops core–rim textures with strong oscillation zone occurring in rim,whereas Grt2lacks core–rim textures and featured by oscillation zone.LA–ICP–MS analysis shows that garnets of Mengya’a are rich in CaO(29.90–37.52%)and FeO(21.17–33.35%),but low in Al_(2)O_(3)(0.05–4.85%).The calculated end members belong to grandite(grossular–andradite)garnets andradite.The negative Al(IV)versus Fe^(3+),positive Al(IV)versus total Al stoichiometric number,the positive Al(IV)versus Fe^(3+),and the negative Al(IV)versus total REE,all indicate that the substitution of REEs in garnets is controlled by YAG.All Garnets are depleted in large lithophile elements(e.g.,Rb=0.00–4.01 ppm,Sr=0.03–8.56 ppm).The total REE in Grt1 core is high(ΣREE=233–625 ppm),with HREE enriched pattern(LREE/HREE=0.33–1.69)and weak negative Eu anomalies(δEu=0.21–0.47).In contrast,the total REEs in the Grt1 rim and Grt2 are low(ΣREE=12.4–354 ppm;ΣREE=21.0–65.3 ppm),with LREE enriched pattern(LREE/HREE=0.54–34.4;LREE/HREE=11.4–682)and positive Eu anomalies(δEu=0.35–27.2;δEu=1.02–30.7).After data compilation of garnet chemicals,we found that the early fluid responsible for the core of Grt1 was a relatively closed and chloride-depleted fluid system.It was close-to-neutral,with a low water–rock ratio.The core of garnet was formed by fluid diffusion in metasomatic processes.The fluid was changed into a relatively open system with reduced,chloride-rich,and weakacid fluid.It was fluid infiltration and metasomatism that resulted in the formation of Grt1 rim and Grt2.展开更多
基金Supported by the Natural Science Foundation of Hainan Province(411102)the Scientific Research Innovation Project for College Graduates of Hainan Normal University(Hsyx2015-33)the College Students Science and Technology Innovation Project in Hainan Province(cxcyxj2017016)
文摘[Objectives] The research was conducted to study characteristics of bioavailable levels pollution of heavy metals in the surface soil of the lead-zinc mine in Changhua.[Methods] A total of 56 surface samples were collected from the 3 study zones （peripheral zone, reclamation zone and tailing zone） located at the lead-zine mine in Changhua. Based on total and bioavailable heavy metals （Pb, Zn, Cu and Cd） in soils, the correlation of total content with bioavailable content was analyzed, and their pollution characteristics were assessed by methods of single factor pollution index, Nemerow pollution index, geological accumulation index and potential ecological risk index.[Results] （i） The surface soils were polluted by Pb, Zn, Cu, Cd in different degrees, and the overall trend of the contents of the 4 heavy metals was in order of Cd 〉 Pb 〉 Zn 〉 Cu. The average excess multiple of heavy metals of total and bioavailable content in soils were in the order of peripheral zone 〉 tailing zone 〉 reclaimed zone, and their pollution degrees were tailing zone 〉 peripheral zone 〉 reclaimed zone. （ii） In general, the total and bioavailable contents of Pb, Zn, Cu, Cd showed a significant correlation, but were not correlated in each study zone. （iii） Pollution degrees of the study zones were in the order of tailing zone 〉 peripheral zone 〉 reclamation zone. The pollutions of heavy metals Pb and Cd were more serious, especially Cd reached high levels of pollution degree, and the pollution degrees of Zn, Cu were lighter. Contributors of ecological risk were mainly Cd, Pb and Cu, and the contribution of Cd achieved more than 90 %, making it the main source of pollution.[Conclusions] The results not only revealed the pollution status of heavy metals in the surface soil of the abandoned coal mine, but also could provide scientific guidance for reasonable utilization and ecological recovery of the land.
基金Supported by the Thailand Research Fund under Grant No TRG5880097
文摘The local structure of an alternative Pb（Zn1/3Nb2/3）O3-based perovskite ceramic is investigated. The 0.07BaTiO33-0.93Pb（Zn1/3Nb2/3）O3 ceramic is synthesized using a combination of Zn3Nb2O8 B-site precursor and BaTiO33 perovskite phase stabilizer. Then, x-ray absorption spectroscopy and density functional theory are employed to calculate the local structure configuration and formation energy of the prepared samples. Ba2＋ is found to replace Pb2＋ in AA-site with Zn2＋ occupying BB-site in Pb（Zn1/3Nb2/3）O3, while in the neighboring structure, Ti4＋4＋ replaces Nb5＋5＋ in BB-site with Pb2＋2＋ occupying AA-site. With the substitution of BaTiO33 in Pb（Zn1/3Nb2/3）O3, the bond length between Zn2＋ and Pb2＋ is longer than that of the typical perovskite phase of Pb（Zn1/3Nb2/3）O3. This indicates the key role of BaTiO33 in decreasing the steric hindrance of Pb2＋ lone pair, and the mutual interactions between Pb2＋ lone pair and Zn2＋ and the formation energy is seen to decrease. This finding of the formation energy and local structure configuration relationship can further extend a fundamental understanding of the role of BaTiO33 in stabilizing the perovskite phase in PbZn13Nb23O3-based materials, which in turn will lead to an improved preparation technique for desired electrical properties.
文摘The paper discusses the tectonic setting of the fortnation of the Dexing giant copper-gold-lead-zinc deposit and its geological features and demonstrates in detail the polygenetic compound mechanism of its formation.
基金supported by the Natural Science Foundation for High-level Talents from Basic and Applied Basic Research Programs of Hainan Province (No. 2019RC022)the National Natural Science Foundation of China (Nos. 41807326 and 21866013)。
文摘This work was to study composition characteristics and the subsequent effect on the lead(Pb) binding properties of dissolved organic matter(DOM) derived from seaweed-based(SWOF) and chicken manure organic fertilizers(CMOF) during a one-year field incubation experiment using the excitation-emission matrix-parallel factor(EEM-PARAFAC) and twodimensional correlation spectroscopy(2DCOS) analysis. Results showed that high aromatic and hydrophobic fluorescent substances were enriched in CMOF-derived DOM and SWOFderived DOM and enhanced over time. And phenolic groups in the fulvic-like substances for SWOF-derived DOM and carboxyl groups in the humic-like substances for CMOF-derived DOM had the fastest responses over time, respectively. Moreover, both non-fluorescent polysaccharides and fluorescent humic-like substances or fulvic-like substances with aromatic(C=C) groups first participated in the binding process of Pb to SWOF-derived DOM on day 0 and 180 during the lead binding process. In contrast, humic-like substances associated with aromatic(C=C) and phenolic groups gave a faster response to Pb binding on day 360. Regarding CMOF-derived DOM, the fulvic-like substances associated with aromatic(C=C) and carboxylic groups displayed a faster response to Pb ions on day 0. Nonetheless,polysaccharides and humic-like associated with phenolic groups had a faster response on days 180 and 360. It is noteworthy that the polysaccharides, which participated in Pb binding to CMOF-derived DOM, posed a higher risk of Pb in the environment after 360 days. Therefore, these findings gave new insights into the long-term applications of commercial organic fertilizers for the amendment of soil.
基金funded by the Surface Project of National Natural Science Foundation of China (41372093)。
文摘The Mengya’a Lead–zinc deposit is a large skarn deposit in the north of the eastern segment of Gangdese metallogenic belt.The garnet is the main altered mineral in the Mengya’a area.The color of the garnet varies from chartreuse to dark yellow brown and to russet.The brown garnet(Grt1)is related to pyrrhotite and chalcopyrite,and the green garnet(Grt2)is associated with lead–zinc mineralization.LA-ICP-MS is the induced coupled plasma mass spectrometry.This paper has used this technique to investigate Grt1 and Grt2.Grt1 develops core–rim textures with strong oscillation zone occurring in rim,whereas Grt2lacks core–rim textures and featured by oscillation zone.LA–ICP–MS analysis shows that garnets of Mengya’a are rich in CaO(29.90–37.52%)and FeO(21.17–33.35%),but low in Al_(2)O_(3)(0.05–4.85%).The calculated end members belong to grandite(grossular–andradite)garnets andradite.The negative Al(IV)versus Fe^(3+),positive Al(IV)versus total Al stoichiometric number,the positive Al(IV)versus Fe^(3+),and the negative Al(IV)versus total REE,all indicate that the substitution of REEs in garnets is controlled by YAG.All Garnets are depleted in large lithophile elements(e.g.,Rb=0.00–4.01 ppm,Sr=0.03–8.56 ppm).The total REE in Grt1 core is high(ΣREE=233–625 ppm),with HREE enriched pattern(LREE/HREE=0.33–1.69)and weak negative Eu anomalies(δEu=0.21–0.47).In contrast,the total REEs in the Grt1 rim and Grt2 are low(ΣREE=12.4–354 ppm;ΣREE=21.0–65.3 ppm),with LREE enriched pattern(LREE/HREE=0.54–34.4;LREE/HREE=11.4–682)and positive Eu anomalies(δEu=0.35–27.2;δEu=1.02–30.7).After data compilation of garnet chemicals,we found that the early fluid responsible for the core of Grt1 was a relatively closed and chloride-depleted fluid system.It was close-to-neutral,with a low water–rock ratio.The core of garnet was formed by fluid diffusion in metasomatic processes.The fluid was changed into a relatively open system with reduced,chloride-rich,and weakacid fluid.It was fluid infiltration and metasomatism that resulted in the formation of Grt1 rim and Grt2.
