We have developed specialized equipment based on hydrogen mini-MDM sensors and the WSN telecommunication technology for long-term monitoring of hydrogen content in the environment.Unlike existing methods,the developed...We have developed specialized equipment based on hydrogen mini-MDM sensors and the WSN telecommunication technology for long-term monitoring of hydrogen content in the environment.Unlike existing methods,the developed equipment makes it possible to carry out measurements directly in the explosion zone with high discreteness in time.This equipment was tested at a large rare-earth deposit of the Lovozero alkaline pluton Karnasurt in the underground mining tunnel.We observed a short time impulse very high concentration of hydrogen in the atmosphere(more than 3 orders of normal atmosphere concentration).This discovery is very important because at the time of the explosion one can create abnormally high concentrations of explosive mixtures of hydrocarbon gases that can leaded to accidents.The high resolving power of the our measurement equipment makes it possible in the first time in practical to determine the shape of the anomaly hydrogen of such a concentration and to calculate the volumes of hydrogen released from the rocks,at first time in the practice.The shape of the anomaly usually consists of 2-3 additional peaks of the shape-“dragon-head”like.We make an first attempt is made to explain this form of anomaly in the article.The aim of the work the estimate hydrogen emission in mining ore deposit of rare earth elements.展开更多
Industrial and agricultural activities lead to the release of rare earth elements(REEs)in wastewater and aquatic ecosystems,and their accumulation in soils.However,the behavior of REEs in soils remains somewhat unclea...Industrial and agricultural activities lead to the release of rare earth elements(REEs)in wastewater and aquatic ecosystems,and their accumulation in soils.However,the behavior of REEs in soils remains somewhat unclear.In the present work the fractionation and fixation of REEs in soddy-podzolic and chernozem soils spiked with La,Ce,and Nd chlorides were studied using dynamic(continuous flow)extraction,which allows natural conditions to be mimicked and artefacts to be minimised.The eluents applied are aimed to dissolve exchangeable,specifically sorbed,bound to Mn oxides,bound to metal-organic complexes,and bound to amorphous and poorly ordered Fe/Al oxides fractions extractable by 0.05 mol/L Ca(NO_(3))2,0.43 mol/L CH_(3)COOH,0.1 mol/L NH_(2)OH·HCl,0.1 mol/L K_(4)P_(2)O_(7) at pH 11,and 0.1 mol/L(NH4)_(2)C_(2)O_(4) at pH 3.2,respectively.It is found that the fixations of added La,Ce,and Nd in the form of metal-organic complexes is predominant for both types of soils:35%-38%in soddy-podzolic soil and 50%-79%in chernozem.The fixation of added elements in the first three fractions(exchangeable,specifically sorbed,and bound to Mn oxides)is significant for soddy-podzolic soil(5%-25%).For chernozem,the relative contents of added Ce and Nd in these fractions are nearly negligible.Only the content of exchangeable La is notable,about 5%.Adding any of three elements(La,Ce,or Nd)at the level of100 mg/kg to an initial sample results in changing the fractionation and bioaccessibility of other REEs present in soil.Their contents increase in the first three fractions and decrease in fifth(oxalate extractable)fraction for both soddy-podzolic soil and chernozem.The main difference is the behavior of REEs in pyrophosphate extractable fraction.For soddy-podzolic soil,adding La,Ce,or Nd results in decreasing the contents of other REEs associated with organic matter.For chernozem,on the contrary,the contents of REEs in the form of metal-organic complexes slightly increase.These processes may be attributed to competitive binding of elements and soil properties;they must be taken into account when assessing the environmental risks of soil pollution with REEs.展开更多
基金program“Basic research for the development of the Russian Arctic”(I32П)of the Presidium of the RAS and partly State contract No 0226-2019-0051 of GI KSC RAS..
文摘We have developed specialized equipment based on hydrogen mini-MDM sensors and the WSN telecommunication technology for long-term monitoring of hydrogen content in the environment.Unlike existing methods,the developed equipment makes it possible to carry out measurements directly in the explosion zone with high discreteness in time.This equipment was tested at a large rare-earth deposit of the Lovozero alkaline pluton Karnasurt in the underground mining tunnel.We observed a short time impulse very high concentration of hydrogen in the atmosphere(more than 3 orders of normal atmosphere concentration).This discovery is very important because at the time of the explosion one can create abnormally high concentrations of explosive mixtures of hydrocarbon gases that can leaded to accidents.The high resolving power of the our measurement equipment makes it possible in the first time in practical to determine the shape of the anomaly hydrogen of such a concentration and to calculate the volumes of hydrogen released from the rocks,at first time in the practice.The shape of the anomaly usually consists of 2-3 additional peaks of the shape-“dragon-head”like.We make an first attempt is made to explain this form of anomaly in the article.The aim of the work the estimate hydrogen emission in mining ore deposit of rare earth elements.
基金Project supported by the Russian Science Foundation(16-13-10417)the Russian Foundation for Basic Research(19-05-50016)+1 种基金Ministry of Science and Higher Education of the Russian Federation(K1-2014-026,K2-2020-003)Vernadsky Institute of Geochemistry and Analytical Chemistry,Russian Academy of Sciences(0116-2019-0010)。
文摘Industrial and agricultural activities lead to the release of rare earth elements(REEs)in wastewater and aquatic ecosystems,and their accumulation in soils.However,the behavior of REEs in soils remains somewhat unclear.In the present work the fractionation and fixation of REEs in soddy-podzolic and chernozem soils spiked with La,Ce,and Nd chlorides were studied using dynamic(continuous flow)extraction,which allows natural conditions to be mimicked and artefacts to be minimised.The eluents applied are aimed to dissolve exchangeable,specifically sorbed,bound to Mn oxides,bound to metal-organic complexes,and bound to amorphous and poorly ordered Fe/Al oxides fractions extractable by 0.05 mol/L Ca(NO_(3))2,0.43 mol/L CH_(3)COOH,0.1 mol/L NH_(2)OH·HCl,0.1 mol/L K_(4)P_(2)O_(7) at pH 11,and 0.1 mol/L(NH4)_(2)C_(2)O_(4) at pH 3.2,respectively.It is found that the fixations of added La,Ce,and Nd in the form of metal-organic complexes is predominant for both types of soils:35%-38%in soddy-podzolic soil and 50%-79%in chernozem.The fixation of added elements in the first three fractions(exchangeable,specifically sorbed,and bound to Mn oxides)is significant for soddy-podzolic soil(5%-25%).For chernozem,the relative contents of added Ce and Nd in these fractions are nearly negligible.Only the content of exchangeable La is notable,about 5%.Adding any of three elements(La,Ce,or Nd)at the level of100 mg/kg to an initial sample results in changing the fractionation and bioaccessibility of other REEs present in soil.Their contents increase in the first three fractions and decrease in fifth(oxalate extractable)fraction for both soddy-podzolic soil and chernozem.The main difference is the behavior of REEs in pyrophosphate extractable fraction.For soddy-podzolic soil,adding La,Ce,or Nd results in decreasing the contents of other REEs associated with organic matter.For chernozem,on the contrary,the contents of REEs in the form of metal-organic complexes slightly increase.These processes may be attributed to competitive binding of elements and soil properties;they must be taken into account when assessing the environmental risks of soil pollution with REEs.
