[Objective] The aim was to study the damage and the mechanism of combined pollution of Pb and Cd on rice growth,yield and quality of rice. [Method]Effects of combined pollution of Pb and Cd on the growth and yield of ...[Objective] The aim was to study the damage and the mechanism of combined pollution of Pb and Cd on rice growth,yield and quality of rice. [Method]Effects of combined pollution of Pb and Cd on the growth and yield of rice were studied by pot experiment with cultivating rice. [Result] Pb and Cd could promote rice growth at low concentration while inhibit plant height at high concentration; Pb and Cd stress reduced the number of rice tillers significantly,with the increasing of stress concentration,the decrease amplitude of the number of tillers was greater; the panicle per pot,seed setting rate,1 000-grain weight and yield of rice were reduced significantly by Pb and Cd stress,the grain number per panicle decreased significantly under low concentration of Pb and Cd but increased significantly under high concentration; the brown rice rate and milled rice rate increased significantly under low concentration of Pb and Cd while at high concentration of Pb and Cd,the both two reduced significantly,the head milled rice rate reduced significantly with the decreasing of concentration; The Pb and Cd content of grains were significantly positively related to the concentrations of Pb and Cd content in soil,it had excessively exceeded hygienic standard when the concentrations of Pb and Cd in soil were medium-high and the unqualified rate reached 333% and 122%. [Conclusion]The study had provided basis for the establishment of rice cultivation system in pollution areas.展开更多
A series of column experiments were performed to investigate the mechanisms of silicon （Si） and heavy metals （HM） interaction in the soil. The column experiments were conducted with Gray Forest Soil treated by var...A series of column experiments were performed to investigate the mechanisms of silicon （Si） and heavy metals （HM） interaction in the soil. The column experiments were conducted with Gray Forest Soil treated by various forms of active Si （diatomaceous earth, zeolite, amorphous silicon dioxide and concentrated monosilicic acid） in environment polluted conditions with soluble salts of Cd, Cu, Ni and Pb. All Si-rich substances used in the test were analyzed with electron scan microscope. The results of HM immobilization in soil by Si-rich materials showed that diatomaceous earth and concentrated monosilicic acid immobilized HM better than zeolite and amorphous silicon dioxide. The reductions in HM mobility were re- alized by the reaction between monosilicic acid and HM in soil solution and by adsorption of HM on Si-rich surface. The intensity of HM movement through soil depended on the type of HM. The maximum reduction of HM mobility with application of Si-rich substances was obtained for Cd and Ni and less effect was observed for Cu and Pb.展开更多
[Objective] This study aimed to investigate the characteristics of Pb and Cd uptake and accumulation in Osmanthus fragrans（Thunb.） Lour.under single and combined stress of Pb and Cd.[Method] Pot experiment was adopt...[Objective] This study aimed to investigate the characteristics of Pb and Cd uptake and accumulation in Osmanthus fragrans（Thunb.） Lour.under single and combined stress of Pb and Cd.[Method] Pot experiment was adopted with O.fragrans seedlings as experimental materials to investigate the effect of single and combined stresses of Pb and Cd on the growth of O.fragrans seedlings under 0,50,100,500,1 000 and 2 000 mg/kg of Pb and 0,1,10,50,100 and 200 mg/kg of Cd.[Result] Under the experimental conditions,the growth of O.fragrans seedlings was significantly inhibited under moderate Pb stress（500 mg/kg） and high Cd stress（100 mg/kg）;the decreasing order of Pb uptake rate of different O.fragrans tissues was root stem leaf;the decreasing order of Cd content of different O.fragrans tissues was root stem leaf,while the decreasing order of Cd uptake rate of different O.fragrans tissues was stem root leaf.[Conclusion] Under combined stress,low concentrations of Pb and Cd can mutually promote the uptake and accumulation,while high concentrations of Pb and Cd can mutually inhibit the uptake and accumulation.展开更多
Biochar(BC) derived from waste products is a cost-effective sorbent for remediation of metal-contaminated soils.We studied the kinetics and adsorption mechanisms for removal of metal ions,such as lead(Pb^(2+)) and cad...Biochar(BC) derived from waste products is a cost-effective sorbent for remediation of metal-contaminated soils.We studied the kinetics and adsorption mechanisms for removal of metal ions,such as lead(Pb^(2+)) and cadmium(Cd^(2+)) with biochar.The adsorption capacities of BC for Pb^(2+) and Cd^(2+) increased after alkaline treatment.The highest sorption capacities were 175.53 and 68.08 mg g^(–1),for Pb and Cd,respectively.The Langmuir adsorption isotherm and pseudo second kinetic equation could well fit the adsorption processes,revealing that the sorption mechanisms of Pb^(2+) and Cd^(2+) by BC are complex and predominantly controlled by chemisorption.BC has a higher affinity for Pb than Cd,due to easy hydrolysis of Pb at low pH.Furthermore,precipitation as carbonate minerals(2PbCO_3·Pb(OH)_2 and CdCO_3) and complexation with functional groups(carboxyl and hydroxyl) were also important for adsorption of Pb and Cd by BC.展开更多
Metal oxides(Fe, Mn oxides) in natural surface coatings(biofilms and associated minerals) are believed to play a significant role in the fate and transport of trace metal in aquatic environments. Seasonal variation of...Metal oxides(Fe, Mn oxides) in natural surface coatings(biofilms and associated minerals) are believed to play a significant role in the fate and transport of trace metal in aquatic environments. Seasonal variation of Fe, Mn oxides and organic materials in surface coatings, which were developed periodically on glass slides in Nanhu Lake, Jilin Province, China over the time frame of three seasons, was investigated in order to understand the influence of metal oxides on Pb and Cd adsorption to heterogeneous surface coating materials(biofilm). Pb and Cd adsorption was measured under controlled laboratory conditions(mineral salts solution with defined speciation, ionic strength 0 05 mol/L, 25℃ and pH 6 0). The classical Langmuir adsorption isotherm was applied to estimate equilibrium coefficients of Pb and Cd adsorption to the surface coatings. In general, components in the surface coatings varied greatly with seasons altering and obtained higher concentrations in summer while the content of iron oxides always exceeded that of manganese oxides. Correlation analyses between the maximum adsorption of Pb and Cd and components in the surface coatings developed periodically indicated that Pb phase association with Mn oxides and Cd phase association with Fe oxides as well as Mn oxides were statistically significant. Effect of Mn oxides on Cd adsorption was confirmed in view of its higher content in the surface coatings. The importance of ferromanganese oxides for Pb and Cd adsorption to the natural surface coatings developed in different seasons was evidenced.展开更多
Surface coatings and surficial sediments were obtained in four natural waters in Xianghai Wetland in China to study the role of surface coatings and surficial sediments in controlling the transporting and cycling of h...Surface coatings and surficial sediments were obtained in four natural waters in Xianghai Wetland in China to study the role of surface coatings and surficial sediments in controlling the transporting and cycling of heavy metals in aquatic environments. Pb and Cd adsorption to the surface coatings and surficial sediments were measured under controlled laboratory conditions(mineral salts solution with defined speciation, ionic strength 0 05 mol/L, 25℃ and pH 6 0 for surface coatings; and 0 005 mol/L CaCl 2 solution, 25℃ and pH 6 0 for surficial sediments). The Langmuir adsorption isotherm was applied to estimate equilibrium coefficients of Pb and Cd adsorption to the surface coatings and surficial sediments, and the component analyses of surface coatings and surficial sediments were also carried out. Correlation analyses between the maximum adsorption of Pb and Cd(Г max ) and the components in the surface coatings and surficial sediments suggested that there was a statistically significant trend for Pb and Cd adsorption(Г max ) to the surface coatings to increase with increasing in contents of Fe and Mn oxides in the surface coatings and surficial sediments. And the metal adsorption abilities of surface coatings were much stronger than those of surficial sediments, highlighting that in the same water, i.e. at the same pH and initial metal concentrations, the metals(such as lead and cadmium) in supernatant were feasible to be adsorbed by surface coatings than surficial sediments. The more importance of surface coatings than surficial sediments for adsorbing and cycling of heavy metals in aquatic environments was evidenced.展开更多
基金Supported by the Program of Ministry of Environmental Protection(200809093 )the Significant Science Planning Program of Guangdong Province (2008A080800028)~~
文摘[Objective] The aim was to study the damage and the mechanism of combined pollution of Pb and Cd on rice growth,yield and quality of rice. [Method]Effects of combined pollution of Pb and Cd on the growth and yield of rice were studied by pot experiment with cultivating rice. [Result] Pb and Cd could promote rice growth at low concentration while inhibit plant height at high concentration; Pb and Cd stress reduced the number of rice tillers significantly,with the increasing of stress concentration,the decrease amplitude of the number of tillers was greater; the panicle per pot,seed setting rate,1 000-grain weight and yield of rice were reduced significantly by Pb and Cd stress,the grain number per panicle decreased significantly under low concentration of Pb and Cd but increased significantly under high concentration; the brown rice rate and milled rice rate increased significantly under low concentration of Pb and Cd while at high concentration of Pb and Cd,the both two reduced significantly,the head milled rice rate reduced significantly with the decreasing of concentration; The Pb and Cd content of grains were significantly positively related to the concentrations of Pb and Cd content in soil,it had excessively exceeded hygienic standard when the concentrations of Pb and Cd in soil were medium-high and the unqualified rate reached 333% and 122%. [Conclusion]The study had provided basis for the establishment of rice cultivation system in pollution areas.
基金Supported by the Science and Technology Cooperation Project of China and Russia during 2013-2014 for Control of Farmland Soil Pollution in Dongting Lake Area(CR1605)the General Fund from China Hunan Provincial Science and Technology Department for Technology Introduction and Experimental Study for Control of Farmland Soil Pollution in Dongting Lake Area(2013WK4011)~~
文摘A series of column experiments were performed to investigate the mechanisms of silicon （Si） and heavy metals （HM） interaction in the soil. The column experiments were conducted with Gray Forest Soil treated by various forms of active Si （diatomaceous earth, zeolite, amorphous silicon dioxide and concentrated monosilicic acid） in environment polluted conditions with soluble salts of Cd, Cu, Ni and Pb. All Si-rich substances used in the test were analyzed with electron scan microscope. The results of HM immobilization in soil by Si-rich materials showed that diatomaceous earth and concentrated monosilicic acid immobilized HM better than zeolite and amorphous silicon dioxide. The reductions in HM mobility were re- alized by the reaction between monosilicic acid and HM in soil solution and by adsorption of HM on Si-rich surface. The intensity of HM movement through soil depended on the type of HM. The maximum reduction of HM mobility with application of Si-rich substances was obtained for Cd and Ni and less effect was observed for Cu and Pb.
基金Supported by Major Science and Technology Program for Water Pollution Control and Treatment in the National Eleventh Five-Year Plan(2009ZX07104-003)Major Science and Technology Program for Water Pollution Control and Treatment in the National Twelfth Five-Year Plan(2012ZX07104-002-04)the Outstanding Youth Innovative Team Plan Project of Hubei Province(No:T200703)~~
文摘[Objective] This study aimed to investigate the characteristics of Pb and Cd uptake and accumulation in Osmanthus fragrans（Thunb.） Lour.under single and combined stress of Pb and Cd.[Method] Pot experiment was adopted with O.fragrans seedlings as experimental materials to investigate the effect of single and combined stresses of Pb and Cd on the growth of O.fragrans seedlings under 0,50,100,500,1 000 and 2 000 mg/kg of Pb and 0,1,10,50,100 and 200 mg/kg of Cd.[Result] Under the experimental conditions,the growth of O.fragrans seedlings was significantly inhibited under moderate Pb stress（500 mg/kg） and high Cd stress（100 mg/kg）;the decreasing order of Pb uptake rate of different O.fragrans tissues was root stem leaf;the decreasing order of Cd content of different O.fragrans tissues was root stem leaf,while the decreasing order of Cd uptake rate of different O.fragrans tissues was stem root leaf.[Conclusion] Under combined stress,low concentrations of Pb and Cd can mutually promote the uptake and accumulation,while high concentrations of Pb and Cd can mutually inhibit the uptake and accumulation.
基金the National Key R&D Program of China (2017YFD0801300)the Guangdong Technology Program of China (2017B020203001)+1 种基金the Guangdong Natural Science Foundation of China (2017A030313245)the Guangzhou Technology Program of China (201607010393,2016201604030017 and 201707010484) for financial support
文摘Biochar(BC) derived from waste products is a cost-effective sorbent for remediation of metal-contaminated soils.We studied the kinetics and adsorption mechanisms for removal of metal ions,such as lead(Pb^(2+)) and cadmium(Cd^(2+)) with biochar.The adsorption capacities of BC for Pb^(2+) and Cd^(2+) increased after alkaline treatment.The highest sorption capacities were 175.53 and 68.08 mg g^(–1),for Pb and Cd,respectively.The Langmuir adsorption isotherm and pseudo second kinetic equation could well fit the adsorption processes,revealing that the sorption mechanisms of Pb^(2+) and Cd^(2+) by BC are complex and predominantly controlled by chemisorption.BC has a higher affinity for Pb than Cd,due to easy hydrolysis of Pb at low pH.Furthermore,precipitation as carbonate minerals(2PbCO_3·Pb(OH)_2 and CdCO_3) and complexation with functional groups(carboxyl and hydroxyl) were also important for adsorption of Pb and Cd by BC.
文摘Metal oxides(Fe, Mn oxides) in natural surface coatings(biofilms and associated minerals) are believed to play a significant role in the fate and transport of trace metal in aquatic environments. Seasonal variation of Fe, Mn oxides and organic materials in surface coatings, which were developed periodically on glass slides in Nanhu Lake, Jilin Province, China over the time frame of three seasons, was investigated in order to understand the influence of metal oxides on Pb and Cd adsorption to heterogeneous surface coating materials(biofilm). Pb and Cd adsorption was measured under controlled laboratory conditions(mineral salts solution with defined speciation, ionic strength 0 05 mol/L, 25℃ and pH 6 0). The classical Langmuir adsorption isotherm was applied to estimate equilibrium coefficients of Pb and Cd adsorption to the surface coatings. In general, components in the surface coatings varied greatly with seasons altering and obtained higher concentrations in summer while the content of iron oxides always exceeded that of manganese oxides. Correlation analyses between the maximum adsorption of Pb and Cd and components in the surface coatings developed periodically indicated that Pb phase association with Mn oxides and Cd phase association with Fe oxides as well as Mn oxides were statistically significant. Effect of Mn oxides on Cd adsorption was confirmed in view of its higher content in the surface coatings. The importance of ferromanganese oxides for Pb and Cd adsorption to the natural surface coatings developed in different seasons was evidenced.
文摘Surface coatings and surficial sediments were obtained in four natural waters in Xianghai Wetland in China to study the role of surface coatings and surficial sediments in controlling the transporting and cycling of heavy metals in aquatic environments. Pb and Cd adsorption to the surface coatings and surficial sediments were measured under controlled laboratory conditions(mineral salts solution with defined speciation, ionic strength 0 05 mol/L, 25℃ and pH 6 0 for surface coatings; and 0 005 mol/L CaCl 2 solution, 25℃ and pH 6 0 for surficial sediments). The Langmuir adsorption isotherm was applied to estimate equilibrium coefficients of Pb and Cd adsorption to the surface coatings and surficial sediments, and the component analyses of surface coatings and surficial sediments were also carried out. Correlation analyses between the maximum adsorption of Pb and Cd(Г max ) and the components in the surface coatings and surficial sediments suggested that there was a statistically significant trend for Pb and Cd adsorption(Г max ) to the surface coatings to increase with increasing in contents of Fe and Mn oxides in the surface coatings and surficial sediments. And the metal adsorption abilities of surface coatings were much stronger than those of surficial sediments, highlighting that in the same water, i.e. at the same pH and initial metal concentrations, the metals(such as lead and cadmium) in supernatant were feasible to be adsorbed by surface coatings than surficial sediments. The more importance of surface coatings than surficial sediments for adsorbing and cycling of heavy metals in aquatic environments was evidenced.
