This work focused on determining the physico-chemical characteristics (pH, carbon and nitrogen) and trace metal elements (TMEs) content (As, Sb, Cd, Hg, Ni, Pb, Cr, Zn) of soils in the Brazzaville city. Soil samples w...This work focused on determining the physico-chemical characteristics (pH, carbon and nitrogen) and trace metal elements (TMEs) content (As, Sb, Cd, Hg, Ni, Pb, Cr, Zn) of soils in the Brazzaville city. Soil samples were taken from a depth of 0 to 20 cm using a hand auger on both banks of five tributaries of the Congo River (Djoué, Mfilou, Mfoa, Tsiémé, Djiri) that flow through the city of Brazzaville. 90 sampling points were defined, with 3 points 250 m apart on the banks and located, for each river, at three sites: upstream, midstream and downstream. Finally, 15 composite samples representative of the study area were taken. The average pH values of the water varied between 6.5 and 7.5. These pH values show that the soils studied are neutral. Total carbon content varied between 0.7% (Djiri) and 1.6% (Djoué). Total nitrogen content ranged from 0.08% (Djiri) to 0.12% (Djoué). TMEs contents varied from 0.5 to 1.8 mg/kg for Sb, from 0.5 to 2.5 mg/kg for As, from 0.1 to 0.18 mg/kg for Cd, from 4.2 to 11.3 mg/kg for Cr, from 0.07 to 0.27 mg/kg for Hg, from 0.7 to 2.4 mg/kg for Ni, from 0 to 158 mg/kg for Pb and from 16 to 105 mg/kg for Zn. The lowest TMEs levels were observed in the soils of the Djiri river, while the highest levels were observed in the soils of the Djoué and Tsiémé rivers. The ANOVA and Bonferroni test did not show significant differences in the means of the parameters measured (p > 0.05). The TMEs levels were below the accepted standards (NF U44-041), with the exception of Pb, which had high levels downstream of the Djoué. According to the pollution index values calculated using soil TME content, the soils on the banks of the Djoué river are considered polluted, while those on the banks of the Tsiémé river are moderately polluted, those on the banks of the Mfoa and Mfilou rivers are slightly polluted, and the soils on the banks of Djiri river are unpolluted.展开更多
Atmospheric metal pollution is a significant environmental issue in China.Understanding the microscopic characteristics of metallic elements are crucial for investigating their sources and health effects,but this info...Atmospheric metal pollution is a significant environmental issue in China.Understanding the microscopic characteristics of metallic elements are crucial for investigating their sources and health effects,but this information is still limited.In this study,transmission electron microscopy(TEM)combined with bulk analysis method were employed to investigate the microscopic characteristics and mass concentrations of atmospheric metallic elements at a village site and an urban site located in North China Plain during wintertime.Our results reveal that the total mass concentrations of 16 metallic elements(including nine toxic heavy metallic elements)in PM_(2.5)were 3439.18±1101.24 ng/m^(3)(1129.6±376.85 ng/m^(3))at the village site and 3555.1±916.71 ng/m^(3)(1295.26±446.39 ng/m^(3))at urban site,accounting for 2.23%and 2.76%of PM_(2.5),respectively.We found that K,Ca,and Fe were the dominant elements,constituting over 75%of total metal mass.TEM analysis indicates that these metallic elements were mainly enriched in six types of individual particles,including K-rich,mineral,fly ash,Fe-rich,Zn-rich,and Pb-rich particles.Mineral particles were predominant in all individual metal particles at urban site,while K-rich particles became the dominant metal particles influenced by residential biomass burning at village site.Moreover,we found toxic metal particles(Fe-rich,Zn-rich,Pb-rich,and fly ash)presented smaller mean sizes(243 nm)in village air compared to urban air(337 nm),suggesting that metal particles in village air might pose a higher health risk to the residents.These results emphasize that atmospheric metal pollution in the village areas need more attentions in the future.展开更多
Metals and biogenic elements were analyzed from surface sediments of sixteen stations and a 32 cm core collected from Zhifu Bay in July 2009.High concentrations of biogenic silica（BSi）reflected the high diatom produ...Metals and biogenic elements were analyzed from surface sediments of sixteen stations and a 32 cm core collected from Zhifu Bay in July 2009.High concentrations of biogenic silica（BSi）reflected the high diatom productivity in the Bay.Meanwhile,total organic carbon（TOC）in Zhifu Bay was mainly from terrestrial sources.All metals were lower than the marine sediment quality guidelines.Based on the vertical profiles of biogenic elements,there was a clear increase of TOC,total nitrogen（TN）,and total phosphate（TP）between1985 and 2000.TN concentrations decreased after the start of the operation of the sewage treatment plant in 1998;however TOC and BSi remained at high levels.Metal concentrations showed a general increase from the bottom to the top of the core.Most anthropogenic metals reached a maximum during 1996 and 2000,and decreased after the startup of the sewage plant;however,they have increased again recently.The results from correlation analysis and principal component analysis show that industrial pollution is the main source of Cd,Cr,Cu,Ni,Pb and Zn contamination in Zhifu Bay,and Yantai Port and ship transportation also contribute a lot to Cd,Cu,Hg,and Pb pollution.展开更多
Cementitious gangue-fly ash backfill(CGB)is used as a green mining technology worldwide.However,under the coupled effects of geological stress and groundwater,the metal elements in the CGB tend to migrate into nearby ...Cementitious gangue-fly ash backfill(CGB)is used as a green mining technology worldwide.However,under the coupled effects of geological stress and groundwater,the metal elements in the CGB tend to migrate into nearby strata,which can consequently result in pollution of the groundwater environment.In this paper,the influence of initial pH and stress damage on the migration behavior of metal elements in CGB is quantitatively studied through the multi-physical field coupling model of stress-permeability-con centration.The enhanced Nemerow index evaluation method is used to comprehensively evaluate the impact of these metal elements migration behaviors on the groundwater environment.The research results show that:(1)When the stress damage of the CGB increases from 0.76 to 0.95,the Darcy velocity at the bottom of the CGB first increases,then decreases,and finally stabilizes at 2.01×10^(-7)m/s.The longest time to reach the maximum Darcy velocity is 3 a.(2)When the damage of the CGB is 0.95,the farthest migration distances of Al,Cr,Mn,Fe,Ba,and Pb are 40.5,34.0,29.8,32.9,38.8 and 32.1 m,respectively.(3)The alkaline environment stimulates the migration of Al,Cr,Fe,Mn,and Pb,whereas Ba migrates farther under acidic conditions.The farthest migration distance of Ba is 31.6 m under pH 3.(4)The enhanced Nemerow index indicates that when stress damage increases from 0.76 to 0.95,the areas with poor water quality increase from 0 to 1.71%,and no area is classified as very poor grade.When the initial pH changes from 3 to 11,100%of the region is classified as fair or above.The initial pH of the CGB has a relatively slight influence on the groundwater environment.This study provides experimental data and theoretical basis for the environmental evaluation of CGB.展开更多
Lithium halide solid-state electrolytes,with the general formula of Li_(3±m)M_(n)X_(6),are regarded as the promising families of electrolyte material for all solid-state lithium-ion batteries because of the relat...Lithium halide solid-state electrolytes,with the general formula of Li_(3±m)M_(n)X_(6),are regarded as the promising families of electrolyte material for all solid-state lithium-ion batteries because of the relatively good ionic conductivity,high oxidative stability against high-voltage oxide cathodes,and broad electrochemical stability window[1].Here,M stands for one or multiple metal elements and X for one or multiple halogen elements.展开更多
[Objectives]To detect content of Pb,Cd,Hg,As,Cu,Zn,and Cr in Lysimachia christinae,and to analyze the pollution level.[Methods]Seven kinds of elements in L.christinae were determined by Inductively coupled plasma mass...[Objectives]To detect content of Pb,Cd,Hg,As,Cu,Zn,and Cr in Lysimachia christinae,and to analyze the pollution level.[Methods]Seven kinds of elements in L.christinae were determined by Inductively coupled plasma mass spectrometry and analyzed by single index and comprehensive index.[Results]The seven heavy metal elements showed good linearity in their respective concentration ranges.The recoveries of the samples were 84.5%-109.5%,and the RSD values were 2.30%-5.10%.Comparing the measured results of heavy metal elements with the limit values stipulated in the 2020 edition of the Chinese Pharmacopoeia and other standards,the Cr element in 19 batches of samples exceeded the standard,and the Zn element in 7 batches of samples exceeded the standard.The exceeding rates were 100.0%and 36.8%,respectively;the content of other heavy metal elements did not exceed the standard.The order of individual index from large to small was Cr,Zn,Cd,Hg,Cu,As,and Pb,and the average comprehensive pollution level was mild pollution and above.[Conclusions]L.christinae was mainly polluted by Cr,followed by Zn;this study can provide basic data for drafting of the limit standard for heavy metal elements in L.christinae.展开更多
The objective of this study was to investigate the concentration and spatial distribu- tion patterns of 9 potentially toxic heavy metal elements （As, Cd, Co, Cr, Pb, Cu, Z.n, Mn, and Ni） in road dust in the Bayan Ob...The objective of this study was to investigate the concentration and spatial distribu- tion patterns of 9 potentially toxic heavy metal elements （As, Cd, Co, Cr, Pb, Cu, Z.n, Mn, and Ni） in road dust in the Bayan Obo Mining Region in Inner Mongolia, China. Contamination levels were evaluated using the geoaccumulation index and the enrichment factor. Human health risks for each heavy metal element were assessed using a human exposure model. Results showed that the dust contained significantly elevated heavy metal elements concen- trations compared with the background soil. The spatial distribution pattern of all tested met- als except for As coincided with the locations of industrial areas while the spatial distribution of As was associated with domestic sources. The contamination evaluation indicated that Cd, Pb, and Mn in road dust mainly originated from anthropogenic sources with a rating of ＂heav- ily polluted＂ to ＂extremely polluted,＂ whereas the remaining metals originated from both natural and anthropogenic sources with a level of ＂moderately polluted＂. The non-cancer health risk assessment showed that ingestion was the primary exposure route for all metals in the road dust and that Mn, Cr, Pb, and As were the main contributors to non-cancer risks in both children and adults. Higher HI values were calculated for children （H1=1.89）, indicating that children will likely experience higher health risks compared with adults （H1=0.23）. The cancer risk assessment showed that Cr was the main contributor, with cancer risks which were 2-3 orders of magnitude higher than those for other metals. Taken in concert, the non-cancer risks posed by all studied heavy metal elements and the cancer risks posed by As Co, Cr, Cd, and Ni to both children and adults in Bayan Obo Mining Region fell within the acceptable range.展开更多
Total of 23 bench samples were taken from the No. 7 Coal of Iqe Coalfield, Qinghai Province, China, following Chinese Standard Method GB/T 482-2008 （2008）. These samples were analyzed by powder X-ray diffraction （...Total of 23 bench samples were taken from the No. 7 Coal of Iqe Coalfield, Qinghai Province, China, following Chinese Standard Method GB/T 482-2008 （2008）. These samples were analyzed by powder X-ray diffraction （XRD）, inductively coupled plasma mass spectrometry （ICP- MS） and X-ray fluorescence （XRF）. The results indicate that the No. 7 Coal belongs to a low rank （Ro.ran =0.659%） and high-ash coal （40.54%）. Compared to common Chinese and world low-rank coals, the lqe coal contains anomalous concentrations of rare metal elements, rare-scattered （dispersed） elements and rare earth elements. The highest contents of Rb, Cs, Ga and REY reach to 180, 26, 37, and 397 ppm, respectively. Their average contents of these elements are 10.9, 15, 4.8 and 3.5 times higher than those of world coals, respectively. Minerals in the coal include kaolinite, quartz, muscovite, siderite, and traces of rutile, and brookite. Kaolinite could be main host minerals of Rb, Cs, Ga and REY. The anomalous rare element Rb and Cs accumulation in the Iqe coal is related to both organic and inorganic matter. The REY concentrations may be related to circulation of thermal solutions, contained or sorbed by clayey particles, and organic matter as well.展开更多
Grid method is employed for sampling covering soil at the test field,whic h is reclamation area filled by coal mining wastes for cropland in th e Fushun coal mine,Liaoning Province,the Northeast China.The soil samp le...Grid method is employed for sampling covering soil at the test field,whic h is reclamation area filled by coal mining wastes for cropland in th e Fushun coal mine,Liaoning Province,the Northeast China.The soil samp les are taken at different locations,inclu ding three kinds of covering soil,th ree different depths of soil layers a nd four different covering ages of covering soil.The s patial-temporal variation of heavy metal element content in reclamatio n soil is stud-ied.The results indicate that the co ntent of heavy metal elements is decreasing year after year;the determin ant reason why the content of heavy metal elemen ts at 60cm depth layer is higher than t hat at 30cm depth layer and surface is fertiliz-er and manure application;the metal elements mainly come from external environment;there is no metal pollut ion coming from mother material(coal mining wastes)in plough layer of covering soil.展开更多
In the current study, we determined concentrations and transfer rates of Ag, Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, P, Rb, Sr and Zn to Brown Birch Scaber Stalks （Leccinum scabrum） mushrooms emerged ...In the current study, we determined concentrations and transfer rates of Ag, Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, P, Rb, Sr and Zn to Brown Birch Scaber Stalks （Leccinum scabrum） mushrooms emerged in the area of Sudety Mountains （Sudetes） in Poland. Fruiting bodies and topsoil samples beneath L. scabrum were collected form the Ktodzka Dale. The trace elements were determined using validated method and inductively coupled plasma - atomic emission spectroscopy （ICP-AES） for final measurement. Mushrooms contained Ag, Cr, Hg, Co, Ni and Sr at 〈 1.0μg/g dry weight; Ba and Pb at -1.0μg/g dw; Cd at 〈 5μPg/g dw; Cu and Mn at 〉 10 μg/g dw; Al and Ca at -100μg/g dw; Fe, Na, Rb and Zn at lOO to 500μg/g dw, Mg at -1.000μg/g dw; P at -5,000 μg/g dw and K at -30,000 μg/g dw. Ca, Mn and Ni were nearly equally distributed between stipes and caps; stipes compared to caps were enriched in Ba, Na and Sr, while caps were enriched in Ag, Al, Cd, Co, Cr, Cu, Fe, K, P, Pb, Rb and Zn. The values of bioconcentration factor （BCF） varied highly depending on chemical element and were 〉1 for Ag, Cd, Cu, K, Mg, Na, P, Rb and Zn, while 〈1 for A1, Ba, Ca, Co, Cr, Fe, Mn, Ni, Pb and Sr. Topsoil showed elevated content of lead and mean concentration was 99 ± 32 μg/g dw, while cadmium was at 0.41 ± 0.15 and those two highly toxic to human elements occurred in edible caps of L. scabrum at 4.5 ± 2.2 and 2.9 ± 2.0 μg/g dw, respectively.展开更多
: By means of kerogen purification, the proton induced X-ray emission (PIXE) and instrumental neutron activation analysis (INAA), the authors have studied the organic/inorganic occurrence modes of the metallic element...: By means of kerogen purification, the proton induced X-ray emission (PIXE) and instrumental neutron activation analysis (INAA), the authors have studied the organic/inorganic occurrence modes of the metallic elements of the Baiguoyuan silver-vanadium deposit hosted in black shale in Hubei Province, China. The result shows that Au, Hg and Ta have a strong tendency to occur organically, with more than 70% of these elements being associated organically. Se, Ga, Ag and Hf are partly associated with organic matter, with more than 20% of them occurring organically. Compared with the above elements, Zn, Cu, As and Sb are weakly associated organically, and tend to be enriched in kerogen. However, Mn, Th, U, V, Co, Cr, AI, Fe and Sc usually occur inorganically. Of the rare earth elements (REE), La, Ce, Tb, Dy, Yb and Lu have stronger ability to be associated with organic matter than Sm and Eu.展开更多
A newly developed approach for trace metal elements detection for aqueous samples analysis is presented in this paper. The idea of this approach is to improve ablation efficiency by transforming the liquid sample into...A newly developed approach for trace metal elements detection for aqueous samples analysis is presented in this paper. The idea of this approach is to improve ablation efficiency by transforming the liquid sample into a dense cloud of droplets using an ultrasonic nebulizer. The resulting droplets are then subjected to analysis by laser induced breakdown spectroscopy （LIBS）. A purpose-built ultrasonic nebulizer assisted LIBS （UN-LIBS） system has been applied to the analysis of aqueous samples at trace levels of concentration. Experimental investigations of solution samples were carried out with various dissolved trace metal elements （Mn, Zn, Cu, Pb, Fe, Mg and Na） using this approach. The characteristics of UN-LIBS signal of the elements were investigated regarding the lifetime and S/B ratio and the calibration curves for trace metal elements analyses. The obtained LODs are comparable or much better than the LODS of the reported signal enhancement approaches when the laser pulse energy was as low as 30 mJ. The good linearity of calibration curves and the low LODs shows the potential ability of this method for metal elements analysis application. The density of the electrons was calculated by measuring the Stark width of the line of Ha. The possible mechanism of the LIBS signal enhancement of this approach was briefly discussed.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
A series of selective dissolution experunents were conducted on the hydrogeinc ferromanganese crusts collected near Line Island to study the geochemistry of Mn, Fe, Cu, Co, Ni and Ti. Despite of the fact that the very...A series of selective dissolution experunents were conducted on the hydrogeinc ferromanganese crusts collected near Line Island to study the geochemistry of Mn, Fe, Cu, Co, Ni and Ti. Despite of the fact that the very close intergrowth between amorphous ferric oxyhydroxides and 6-MnO2 exists in the hydrogenic ferromanganese crusts, there is no isomorphous substitution between iron and manganese. This is because the two elements in oxides have different crystal chemistry and geochemistry, such assertion bemg in agreement with the results of selective dissolution experiments. Transitional metal elements such as Cu, Co, Ni and Ti are enriched in different phases, i.e. Ni and Co are incorporated into 6-MnO2 while Cu and Ti are incorporated into ferric oxyhy- droxides. The distributions of the elements in amorphous ferric oxyhydroxides and δ-MnO2 are controlled by the existing states of the elements in the seawater and the crystal chemistry and geochemistry of these elements/inns in oxides.展开更多
Electrocatalytic N_(2) reduction under ambient-condition is considered to be the most appealing strategy to the conventional Haber-Bosch process for synthetic ammonia to alleviate greenhouse emissions and reduce envir...Electrocatalytic N_(2) reduction under ambient-condition is considered to be the most appealing strategy to the conventional Haber-Bosch process for synthetic ammonia to alleviate greenhouse emissions and reduce environmental pollution, mainly powered by renewable energy. Recent years, rapid advances have been gained in this attractive research field, and numerous electrocatalysts have been exploited. However, its conversion efficiency is still far behind the requirement of industrial applications owing to the breakage of the N≡N triple bond, which is an energetically challenging kinetically complex multistep reaction and the strong competing reaction of hydrogen evolution reaction. Recently, main group metal-based catalysts have been demonstrated promising application prospect for ammonia production, significantly boosting their further application in this field. However, a comprehensive review of main group metal-based catalysts towards electrochemical ammonia production applications is still lacking. In this review, the fundamentals of N_(2) reduction, such as the reaction pathways, the reaction potential and the challenges of N_(2) reduction have been comprehensively discussed. And then, the role, mechanism, and effect of each main group element-based catalysts used for N_(2) reduction (Li, K, Al, Ga, Sn, Sb, Bi, and their compounds) are systematically summarized. Finally, several state-of-the-art strategies to promote their NRR catalytic performance, as well as the existing problems and prospects are put forward. This review is expected to guide the design and establishment of more efficient electrocatalytic N_(2) reduction systems based on main group metal elements in the future.展开更多
[Objectives]The effects of metal elements in irrigation water in the tobacco areas of southern Anhui on the coke sweet aroma of tobacco leaves was determined.[Methods]53 representative areas for tobacco planting in so...[Objectives]The effects of metal elements in irrigation water in the tobacco areas of southern Anhui on the coke sweet aroma of tobacco leaves was determined.[Methods]53 representative areas for tobacco planting in southern Anhui were selected,and the quality of irrigation water,especially the content of metal elements,was investigated.[Results]The contents of micro(medium)elements in the irrigation water were too low to have a significant effect on the formation of the coke sweet aroma style of tobacco leaves.The contents of Mg,Ca and Zn were 0.7-8.0,<40 and 0.002-0.029 mg/L,respectively.The heavy metal contents of the irrigation water and other basic control items all met corresponding national standards.Furthermore,the tobacco planting experiment under controlled irrigation using paddy soil in the greenhouse proved that Zn was a negative correlation factor for forming the coke sweet aroma style of tobacco and the threshold value was≥10 mg/L in the irrigation water.Meanwhile,Mg was a positive correlation factor and the content of Mg to promote the coke sweet aroma style should be maintained at 40-90 mg/L.Ca and Mg had a synergistic effect,which was mainly appropriate for acid paddy soils.[Conclusions]This study improves the quality and yield of the coke sweet aroma of tobacco leaves,and has important theoretical and practical value for the formation of a popular agronomic control method.展开更多
Anatase（TiO_2） has been widely used in photocatalysis. However, it can only absorb near-ultraviolet light with a wavelength below approximately 388 nm due to a wide band gap. Therefore a modification should be made ...Anatase（TiO_2） has been widely used in photocatalysis. However, it can only absorb near-ultraviolet light with a wavelength below approximately 388 nm due to a wide band gap. Therefore a modification should be made for anatase to increase its capability in utilizing more abundant visible light. We investigated the doped anatase with the most promising 3d transition metal elements, and the results showed that the visible light absorption intensity was increased significantly due to the reduced band gap and the cavitation effects. As compared to other 3d transition metals, Cu was found to be the most effective one in improving anatase photocatalytic effects. In addition, greater Cu concentration doped in the anatase increased the photocatalysis effects but reduced the anatase stability, therefore, an optimized Cu concentration should be considered to optimize the anatase photocatalysis activity.展开更多
[Objectives]To study the impact of heavy metal pollution of soil and plants during the process of reclaimed water for irrigation of green land in arid areas and the potential health risks to humans during use.[Methods...[Objectives]To study the impact of heavy metal pollution of soil and plants during the process of reclaimed water for irrigation of green land in arid areas and the potential health risks to humans during use.[Methods]Taking Zhongwei City in Ningxia,a typical arid area,as the research area,the irrigation water,soil and green grass in the reclaimed water irrigation region and the original green water irrigation region were sampled,the heavy elements Hg,As,Zn,Pb,Cd,Cr were detected,and the Nemerow method,biological absorption coefficient,and health risk assessment were employed to evaluate the degree of soil pollution,plant absorption capacity,and human health risks.[Results]Compared with the original green water,the Hg,Cd,and Cr pollution of the reclaimed water irrigated green land was higher,the As,Zn,Pb pollution was lower,and the content of Hg and Cd was higher than the environmental background values of soil in Ningxia;the Cr content exceeded the risk intervention values of the first type of land in the Soil Environmental Quality—Risk Control Standard for Soil Contamination of Development Land(GB 36600-2018).Compared with the original green water irrigation region,it is found that the reclaimed water irrigation reduced the heavy metal pollution of the soil to a certain extent.The heavy metal content of tall fescue grass(Festuca arundinacea)in the reclaimed water irrigation region was Zn,Cr,Pb,As,Cd,and Hg from high to low;the order of the biological absorption coefficient was Cd>As>Zn>Pb>Hg>Cr;irrigation water exerted a certain effect on the content of heavy metals in plants and the biological absorption coefficient through the soil.Using the health risk assessment method recommended by Environmental Protection Agency of the United States of America(USEPA),it was found that the reclaimed water has the highest risk through the inhalation route,and the occupational population has a higher risk of skin contact with soil and plants.[Conclusions]This study is intended to provide data support and theoretical basis for the environmental safety risk research of the application of reclaimed water in arid areas to urban greening.展开更多
According to "Environmental quality standard for soil" and using As,Cd,Cr,Cu,Hg,Ni,Pb,Zn elements as evaluation index,the author evaluated soil environmental quality in Xihe area of Shenyang.The results show...According to "Environmental quality standard for soil" and using As,Cd,Cr,Cu,Hg,Ni,Pb,Zn elements as evaluation index,the author evaluated soil environmental quality in Xihe area of Shenyang.The results show that the soil in Xihe area is polluted rifely by heavy metal elements.The polluted areas are mainly distributed near the upstreams of Xihe River,Shenxin River and Shenliao irrigation canal.There exist large distinctions among the heavy metal elements to the pollution degree.Cd pollution area is the biggest and the most serious in pollution degree.展开更多
Accumulation and releasing of trace metal elements on aluminum containing sediments of inner drinking water pipe is discussed,as studied from five variations effecting:raw water quality,chemical reagents,solution pH a...Accumulation and releasing of trace metal elements on aluminum containing sediments of inner drinking water pipe is discussed,as studied from five variations effecting:raw water quality,chemical reagents,solution pH and drinking water flow condition.In order to decrease the release of trace metal elements,and to ensure the pipe operation and human safety,water quality adjustment is suggested to avoid aluminum containing sediments formation in drinking distribution system.The maximum amounts of accumulation of common trace metal elements are given.Future trends of development in this field are also proposed.展开更多
文摘This work focused on determining the physico-chemical characteristics (pH, carbon and nitrogen) and trace metal elements (TMEs) content (As, Sb, Cd, Hg, Ni, Pb, Cr, Zn) of soils in the Brazzaville city. Soil samples were taken from a depth of 0 to 20 cm using a hand auger on both banks of five tributaries of the Congo River (Djoué, Mfilou, Mfoa, Tsiémé, Djiri) that flow through the city of Brazzaville. 90 sampling points were defined, with 3 points 250 m apart on the banks and located, for each river, at three sites: upstream, midstream and downstream. Finally, 15 composite samples representative of the study area were taken. The average pH values of the water varied between 6.5 and 7.5. These pH values show that the soils studied are neutral. Total carbon content varied between 0.7% (Djiri) and 1.6% (Djoué). Total nitrogen content ranged from 0.08% (Djiri) to 0.12% (Djoué). TMEs contents varied from 0.5 to 1.8 mg/kg for Sb, from 0.5 to 2.5 mg/kg for As, from 0.1 to 0.18 mg/kg for Cd, from 4.2 to 11.3 mg/kg for Cr, from 0.07 to 0.27 mg/kg for Hg, from 0.7 to 2.4 mg/kg for Ni, from 0 to 158 mg/kg for Pb and from 16 to 105 mg/kg for Zn. The lowest TMEs levels were observed in the soils of the Djiri river, while the highest levels were observed in the soils of the Djoué and Tsiémé rivers. The ANOVA and Bonferroni test did not show significant differences in the means of the parameters measured (p > 0.05). The TMEs levels were below the accepted standards (NF U44-041), with the exception of Pb, which had high levels downstream of the Djoué. According to the pollution index values calculated using soil TME content, the soils on the banks of the Djoué river are considered polluted, while those on the banks of the Tsiémé river are moderately polluted, those on the banks of the Mfoa and Mfilou rivers are slightly polluted, and the soils on the banks of Djiri river are unpolluted.
基金supported by the National Natural Science Foundation of China(Nos.42307143,42307127,and 42307141)Shandong Provincial Natural Science Foundation(Nos.ZR2023QD151,ZR2024QD160,and ZR2023QD094)+2 种基金Zhejiang Province Basic Public Welfare Research Program Project(No.LGC22B050009)the Ph.D.Research Startup Foundation of Shandong University of Aeronautics(No.2022Y19)LAC/CMA(No.2023B10)。
文摘Atmospheric metal pollution is a significant environmental issue in China.Understanding the microscopic characteristics of metallic elements are crucial for investigating their sources and health effects,but this information is still limited.In this study,transmission electron microscopy(TEM)combined with bulk analysis method were employed to investigate the microscopic characteristics and mass concentrations of atmospheric metallic elements at a village site and an urban site located in North China Plain during wintertime.Our results reveal that the total mass concentrations of 16 metallic elements(including nine toxic heavy metallic elements)in PM_(2.5)were 3439.18±1101.24 ng/m^(3)(1129.6±376.85 ng/m^(3))at the village site and 3555.1±916.71 ng/m^(3)(1295.26±446.39 ng/m^(3))at urban site,accounting for 2.23%and 2.76%of PM_(2.5),respectively.We found that K,Ca,and Fe were the dominant elements,constituting over 75%of total metal mass.TEM analysis indicates that these metallic elements were mainly enriched in six types of individual particles,including K-rich,mineral,fly ash,Fe-rich,Zn-rich,and Pb-rich particles.Mineral particles were predominant in all individual metal particles at urban site,while K-rich particles became the dominant metal particles influenced by residential biomass burning at village site.Moreover,we found toxic metal particles(Fe-rich,Zn-rich,Pb-rich,and fly ash)presented smaller mean sizes(243 nm)in village air compared to urban air(337 nm),suggesting that metal particles in village air might pose a higher health risk to the residents.These results emphasize that atmospheric metal pollution in the village areas need more attentions in the future.
基金supported by the National Natural Science Foundation of China(Nos.41476132,41276154)
文摘Metals and biogenic elements were analyzed from surface sediments of sixteen stations and a 32 cm core collected from Zhifu Bay in July 2009.High concentrations of biogenic silica（BSi）reflected the high diatom productivity in the Bay.Meanwhile,total organic carbon（TOC）in Zhifu Bay was mainly from terrestrial sources.All metals were lower than the marine sediment quality guidelines.Based on the vertical profiles of biogenic elements,there was a clear increase of TOC,total nitrogen（TN）,and total phosphate（TP）between1985 and 2000.TN concentrations decreased after the start of the operation of the sewage treatment plant in 1998;however TOC and BSi remained at high levels.Metal concentrations showed a general increase from the bottom to the top of the core.Most anthropogenic metals reached a maximum during 1996 and 2000,and decreased after the startup of the sewage plant;however,they have increased again recently.The results from correlation analysis and principal component analysis show that industrial pollution is the main source of Cd,Cr,Cu,Ni,Pb and Zn contamination in Zhifu Bay,and Yantai Port and ship transportation also contribute a lot to Cd,Cu,Hg,and Pb pollution.
基金supported by the National Natural Science Foundation of China(Nos.52274149 and 52474162)the Fundamental Research Funds for the Central Universities(Nos.2024JCCXNY04 and 2023YQTD02)+1 种基金the Ph.D.Top Innovative Talents Fund of CUMTB(No.BBJ2024013)the Yue Qi Young Scholar Project(No.2020QN03)。
文摘Cementitious gangue-fly ash backfill(CGB)is used as a green mining technology worldwide.However,under the coupled effects of geological stress and groundwater,the metal elements in the CGB tend to migrate into nearby strata,which can consequently result in pollution of the groundwater environment.In this paper,the influence of initial pH and stress damage on the migration behavior of metal elements in CGB is quantitatively studied through the multi-physical field coupling model of stress-permeability-con centration.The enhanced Nemerow index evaluation method is used to comprehensively evaluate the impact of these metal elements migration behaviors on the groundwater environment.The research results show that:(1)When the stress damage of the CGB increases from 0.76 to 0.95,the Darcy velocity at the bottom of the CGB first increases,then decreases,and finally stabilizes at 2.01×10^(-7)m/s.The longest time to reach the maximum Darcy velocity is 3 a.(2)When the damage of the CGB is 0.95,the farthest migration distances of Al,Cr,Mn,Fe,Ba,and Pb are 40.5,34.0,29.8,32.9,38.8 and 32.1 m,respectively.(3)The alkaline environment stimulates the migration of Al,Cr,Fe,Mn,and Pb,whereas Ba migrates farther under acidic conditions.The farthest migration distance of Ba is 31.6 m under pH 3.(4)The enhanced Nemerow index indicates that when stress damage increases from 0.76 to 0.95,the areas with poor water quality increase from 0 to 1.71%,and no area is classified as very poor grade.When the initial pH changes from 3 to 11,100%of the region is classified as fair or above.The initial pH of the CGB has a relatively slight influence on the groundwater environment.This study provides experimental data and theoretical basis for the environmental evaluation of CGB.
文摘Lithium halide solid-state electrolytes,with the general formula of Li_(3±m)M_(n)X_(6),are regarded as the promising families of electrolyte material for all solid-state lithium-ion batteries because of the relatively good ionic conductivity,high oxidative stability against high-voltage oxide cathodes,and broad electrochemical stability window[1].Here,M stands for one or multiple metal elements and X for one or multiple halogen elements.
基金Supported by Risk Monitoring Task Project of Chongqing Drug Administration in 2020。
文摘[Objectives]To detect content of Pb,Cd,Hg,As,Cu,Zn,and Cr in Lysimachia christinae,and to analyze the pollution level.[Methods]Seven kinds of elements in L.christinae were determined by Inductively coupled plasma mass spectrometry and analyzed by single index and comprehensive index.[Results]The seven heavy metal elements showed good linearity in their respective concentration ranges.The recoveries of the samples were 84.5%-109.5%,and the RSD values were 2.30%-5.10%.Comparing the measured results of heavy metal elements with the limit values stipulated in the 2020 edition of the Chinese Pharmacopoeia and other standards,the Cr element in 19 batches of samples exceeded the standard,and the Zn element in 7 batches of samples exceeded the standard.The exceeding rates were 100.0%and 36.8%,respectively;the content of other heavy metal elements did not exceed the standard.The order of individual index from large to small was Cr,Zn,Cd,Hg,Cu,As,and Pb,and the average comprehensive pollution level was mild pollution and above.[Conclusions]L.christinae was mainly polluted by Cr,followed by Zn;this study can provide basic data for drafting of the limit standard for heavy metal elements in L.christinae.
基金National Natural Scientific Foundation of China,No.41571473,No.41401591
文摘The objective of this study was to investigate the concentration and spatial distribu- tion patterns of 9 potentially toxic heavy metal elements （As, Cd, Co, Cr, Pb, Cu, Z.n, Mn, and Ni） in road dust in the Bayan Obo Mining Region in Inner Mongolia, China. Contamination levels were evaluated using the geoaccumulation index and the enrichment factor. Human health risks for each heavy metal element were assessed using a human exposure model. Results showed that the dust contained significantly elevated heavy metal elements concen- trations compared with the background soil. The spatial distribution pattern of all tested met- als except for As coincided with the locations of industrial areas while the spatial distribution of As was associated with domestic sources. The contamination evaluation indicated that Cd, Pb, and Mn in road dust mainly originated from anthropogenic sources with a rating of ＂heav- ily polluted＂ to ＂extremely polluted,＂ whereas the remaining metals originated from both natural and anthropogenic sources with a level of ＂moderately polluted＂. The non-cancer health risk assessment showed that ingestion was the primary exposure route for all metals in the road dust and that Mn, Cr, Pb, and As were the main contributors to non-cancer risks in both children and adults. Higher HI values were calculated for children （H1=1.89）, indicating that children will likely experience higher health risks compared with adults （H1=0.23）. The cancer risk assessment showed that Cr was the main contributor, with cancer risks which were 2-3 orders of magnitude higher than those for other metals. Taken in concert, the non-cancer risks posed by all studied heavy metal elements and the cancer risks posed by As Co, Cr, Cd, and Ni to both children and adults in Bayan Obo Mining Region fell within the acceptable range.
基金supported by the China geological survey project"Qaidam Basin Oil and Gas Resources Evaluation"(Nr:([2013]4-(3),001-008)National Natural Science Foundation of China(No.41330317)
文摘Total of 23 bench samples were taken from the No. 7 Coal of Iqe Coalfield, Qinghai Province, China, following Chinese Standard Method GB/T 482-2008 （2008）. These samples were analyzed by powder X-ray diffraction （XRD）, inductively coupled plasma mass spectrometry （ICP- MS） and X-ray fluorescence （XRF）. The results indicate that the No. 7 Coal belongs to a low rank （Ro.ran =0.659%） and high-ash coal （40.54%）. Compared to common Chinese and world low-rank coals, the lqe coal contains anomalous concentrations of rare metal elements, rare-scattered （dispersed） elements and rare earth elements. The highest contents of Rb, Cs, Ga and REY reach to 180, 26, 37, and 397 ppm, respectively. Their average contents of these elements are 10.9, 15, 4.8 and 3.5 times higher than those of world coals, respectively. Minerals in the coal include kaolinite, quartz, muscovite, siderite, and traces of rutile, and brookite. Kaolinite could be main host minerals of Rb, Cs, Ga and REY. The anomalous rare element Rb and Cs accumulation in the Iqe coal is related to both organic and inorganic matter. The REY concentrations may be related to circulation of thermal solutions, contained or sorbed by clayey particles, and organic matter as well.
文摘Grid method is employed for sampling covering soil at the test field,whic h is reclamation area filled by coal mining wastes for cropland in th e Fushun coal mine,Liaoning Province,the Northeast China.The soil samp les are taken at different locations,inclu ding three kinds of covering soil,th ree different depths of soil layers a nd four different covering ages of covering soil.The s patial-temporal variation of heavy metal element content in reclamatio n soil is stud-ied.The results indicate that the co ntent of heavy metal elements is decreasing year after year;the determin ant reason why the content of heavy metal elemen ts at 60cm depth layer is higher than t hat at 30cm depth layer and surface is fertiliz-er and manure application;the metal elements mainly come from external environment;there is no metal pollut ion coming from mother material(coal mining wastes)in plough layer of covering soil.
基金supported in part by the National Science Centre(NCN) of Poland under Grant PRELUDIUM project NoUMO-2011/03/N/NZ9/04136the Chinese Academy of Science(Project No 2010T1Z26)
文摘In the current study, we determined concentrations and transfer rates of Ag, Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, P, Rb, Sr and Zn to Brown Birch Scaber Stalks （Leccinum scabrum） mushrooms emerged in the area of Sudety Mountains （Sudetes） in Poland. Fruiting bodies and topsoil samples beneath L. scabrum were collected form the Ktodzka Dale. The trace elements were determined using validated method and inductively coupled plasma - atomic emission spectroscopy （ICP-AES） for final measurement. Mushrooms contained Ag, Cr, Hg, Co, Ni and Sr at 〈 1.0μg/g dry weight; Ba and Pb at -1.0μg/g dw; Cd at 〈 5μPg/g dw; Cu and Mn at 〉 10 μg/g dw; Al and Ca at -100μg/g dw; Fe, Na, Rb and Zn at lOO to 500μg/g dw, Mg at -1.000μg/g dw; P at -5,000 μg/g dw and K at -30,000 μg/g dw. Ca, Mn and Ni were nearly equally distributed between stipes and caps; stipes compared to caps were enriched in Ba, Na and Sr, while caps were enriched in Ag, Al, Cd, Co, Cr, Cu, Fe, K, P, Pb, Rb and Zn. The values of bioconcentration factor （BCF） varied highly depending on chemical element and were 〉1 for Ag, Cd, Cu, K, Mg, Na, P, Rb and Zn, while 〈1 for A1, Ba, Ca, Co, Cr, Fe, Mn, Ni, Pb and Sr. Topsoil showed elevated content of lead and mean concentration was 99 ± 32 μg/g dw, while cadmium was at 0.41 ± 0.15 and those two highly toxic to human elements occurred in edible caps of L. scabrum at 4.5 ± 2.2 and 2.9 ± 2.0 μg/g dw, respectively.
文摘: By means of kerogen purification, the proton induced X-ray emission (PIXE) and instrumental neutron activation analysis (INAA), the authors have studied the organic/inorganic occurrence modes of the metallic elements of the Baiguoyuan silver-vanadium deposit hosted in black shale in Hubei Province, China. The result shows that Au, Hg and Ta have a strong tendency to occur organically, with more than 70% of these elements being associated organically. Se, Ga, Ag and Hf are partly associated with organic matter, with more than 20% of them occurring organically. Compared with the above elements, Zn, Cu, As and Sb are weakly associated organically, and tend to be enriched in kerogen. However, Mn, Th, U, V, Co, Cr, AI, Fe and Sc usually occur inorganically. Of the rare earth elements (REE), La, Ce, Tb, Dy, Yb and Lu have stronger ability to be associated with organic matter than Sm and Eu.
基金supported by National Natural Science Foundation of China(No.11104153)
文摘A newly developed approach for trace metal elements detection for aqueous samples analysis is presented in this paper. The idea of this approach is to improve ablation efficiency by transforming the liquid sample into a dense cloud of droplets using an ultrasonic nebulizer. The resulting droplets are then subjected to analysis by laser induced breakdown spectroscopy （LIBS）. A purpose-built ultrasonic nebulizer assisted LIBS （UN-LIBS） system has been applied to the analysis of aqueous samples at trace levels of concentration. Experimental investigations of solution samples were carried out with various dissolved trace metal elements （Mn, Zn, Cu, Pb, Fe, Mg and Na） using this approach. The characteristics of UN-LIBS signal of the elements were investigated regarding the lifetime and S/B ratio and the calibration curves for trace metal elements analyses. The obtained LODs are comparable or much better than the LODS of the reported signal enhancement approaches when the laser pulse energy was as low as 30 mJ. The good linearity of calibration curves and the low LODs shows the potential ability of this method for metal elements analysis application. The density of the electrons was calculated by measuring the Stark width of the line of Ha. The possible mechanism of the LIBS signal enhancement of this approach was briefly discussed.
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supported by China Ocean Mineral Resources Research and Development Association (COMRA) (DY105-05-01-05)China Ministry of Education (205089)China National Natural Science Foundation (40076015).
文摘A series of selective dissolution experunents were conducted on the hydrogeinc ferromanganese crusts collected near Line Island to study the geochemistry of Mn, Fe, Cu, Co, Ni and Ti. Despite of the fact that the very close intergrowth between amorphous ferric oxyhydroxides and 6-MnO2 exists in the hydrogenic ferromanganese crusts, there is no isomorphous substitution between iron and manganese. This is because the two elements in oxides have different crystal chemistry and geochemistry, such assertion bemg in agreement with the results of selective dissolution experiments. Transitional metal elements such as Cu, Co, Ni and Ti are enriched in different phases, i.e. Ni and Co are incorporated into 6-MnO2 while Cu and Ti are incorporated into ferric oxyhy- droxides. The distributions of the elements in amorphous ferric oxyhydroxides and δ-MnO2 are controlled by the existing states of the elements in the seawater and the crystal chemistry and geochemistry of these elements/inns in oxides.
基金This work was supported by the National Natural Science Foundation of China(No.52071171)the Liaoning Revitalization Talents Program-Pan Deng Scholars(XLYC1802005)+4 种基金the Liaoning Bai-QianWan Talents Program(LNBQW2018B0048)the National Science Fund of Liaoning Province for Excellent Young Scholars(2019-YQ-04)the Key Project of Scientific Research of the Education Department of Liaoning Province(LZD201902)the Department of Education of Liaoning Province(LQN201903 and LQN202008)the Foundation for Young Scholars of Liaoning University(LDQN2019007).
文摘Electrocatalytic N_(2) reduction under ambient-condition is considered to be the most appealing strategy to the conventional Haber-Bosch process for synthetic ammonia to alleviate greenhouse emissions and reduce environmental pollution, mainly powered by renewable energy. Recent years, rapid advances have been gained in this attractive research field, and numerous electrocatalysts have been exploited. However, its conversion efficiency is still far behind the requirement of industrial applications owing to the breakage of the N≡N triple bond, which is an energetically challenging kinetically complex multistep reaction and the strong competing reaction of hydrogen evolution reaction. Recently, main group metal-based catalysts have been demonstrated promising application prospect for ammonia production, significantly boosting their further application in this field. However, a comprehensive review of main group metal-based catalysts towards electrochemical ammonia production applications is still lacking. In this review, the fundamentals of N_(2) reduction, such as the reaction pathways, the reaction potential and the challenges of N_(2) reduction have been comprehensively discussed. And then, the role, mechanism, and effect of each main group element-based catalysts used for N_(2) reduction (Li, K, Al, Ga, Sn, Sb, Bi, and their compounds) are systematically summarized. Finally, several state-of-the-art strategies to promote their NRR catalytic performance, as well as the existing problems and prospects are put forward. This review is expected to guide the design and establishment of more efficient electrocatalytic N_(2) reduction systems based on main group metal elements in the future.
文摘[Objectives]The effects of metal elements in irrigation water in the tobacco areas of southern Anhui on the coke sweet aroma of tobacco leaves was determined.[Methods]53 representative areas for tobacco planting in southern Anhui were selected,and the quality of irrigation water,especially the content of metal elements,was investigated.[Results]The contents of micro(medium)elements in the irrigation water were too low to have a significant effect on the formation of the coke sweet aroma style of tobacco leaves.The contents of Mg,Ca and Zn were 0.7-8.0,<40 and 0.002-0.029 mg/L,respectively.The heavy metal contents of the irrigation water and other basic control items all met corresponding national standards.Furthermore,the tobacco planting experiment under controlled irrigation using paddy soil in the greenhouse proved that Zn was a negative correlation factor for forming the coke sweet aroma style of tobacco and the threshold value was≥10 mg/L in the irrigation water.Meanwhile,Mg was a positive correlation factor and the content of Mg to promote the coke sweet aroma style should be maintained at 40-90 mg/L.Ca and Mg had a synergistic effect,which was mainly appropriate for acid paddy soils.[Conclusions]This study improves the quality and yield of the coke sweet aroma of tobacco leaves,and has important theoretical and practical value for the formation of a popular agronomic control method.
基金Funded by the National Natural Science Foundation of China(Nos.51604205 and 51774223)the Natural Science Foundation of Hubei Province(No.2016CFB268)+1 种基金the Fundamental Research Funds for the Central Universities(WUT:2016IVA046 and 2017IVB018)the Open Fund from Hubei Key Laboratory of Indust rial Fume and Dust Pollution Control(HBIK2015-02)
文摘Anatase（TiO_2） has been widely used in photocatalysis. However, it can only absorb near-ultraviolet light with a wavelength below approximately 388 nm due to a wide band gap. Therefore a modification should be made for anatase to increase its capability in utilizing more abundant visible light. We investigated the doped anatase with the most promising 3d transition metal elements, and the results showed that the visible light absorption intensity was increased significantly due to the reduced band gap and the cavitation effects. As compared to other 3d transition metals, Cu was found to be the most effective one in improving anatase photocatalytic effects. In addition, greater Cu concentration doped in the anatase increased the photocatalysis effects but reduced the anatase stability, therefore, an optimized Cu concentration should be considered to optimize the anatase photocatalysis activity.
基金Supported by Research and Development and Demonstration Project of Domestic Reclaimed Water Reuse Technology(2018YFC0408104)First-rate Discipline Project of Colleges and Universities in Ningxia(NXYLXK2017A03)Key Research and Development Plan Project of Ningxia Hui Autonomous Region(2018BEG03008).
文摘[Objectives]To study the impact of heavy metal pollution of soil and plants during the process of reclaimed water for irrigation of green land in arid areas and the potential health risks to humans during use.[Methods]Taking Zhongwei City in Ningxia,a typical arid area,as the research area,the irrigation water,soil and green grass in the reclaimed water irrigation region and the original green water irrigation region were sampled,the heavy elements Hg,As,Zn,Pb,Cd,Cr were detected,and the Nemerow method,biological absorption coefficient,and health risk assessment were employed to evaluate the degree of soil pollution,plant absorption capacity,and human health risks.[Results]Compared with the original green water,the Hg,Cd,and Cr pollution of the reclaimed water irrigated green land was higher,the As,Zn,Pb pollution was lower,and the content of Hg and Cd was higher than the environmental background values of soil in Ningxia;the Cr content exceeded the risk intervention values of the first type of land in the Soil Environmental Quality—Risk Control Standard for Soil Contamination of Development Land(GB 36600-2018).Compared with the original green water irrigation region,it is found that the reclaimed water irrigation reduced the heavy metal pollution of the soil to a certain extent.The heavy metal content of tall fescue grass(Festuca arundinacea)in the reclaimed water irrigation region was Zn,Cr,Pb,As,Cd,and Hg from high to low;the order of the biological absorption coefficient was Cd>As>Zn>Pb>Hg>Cr;irrigation water exerted a certain effect on the content of heavy metals in plants and the biological absorption coefficient through the soil.Using the health risk assessment method recommended by Environmental Protection Agency of the United States of America(USEPA),it was found that the reclaimed water has the highest risk through the inhalation route,and the occupational population has a higher risk of skin contact with soil and plants.[Conclusions]This study is intended to provide data support and theoretical basis for the environmental safety risk research of the application of reclaimed water in arid areas to urban greening.
基金Supported by Project of China Geological Survey(No.1212010511209)
文摘According to "Environmental quality standard for soil" and using As,Cd,Cr,Cu,Hg,Ni,Pb,Zn elements as evaluation index,the author evaluated soil environmental quality in Xihe area of Shenyang.The results show that the soil in Xihe area is polluted rifely by heavy metal elements.The polluted areas are mainly distributed near the upstreams of Xihe River,Shenxin River and Shenliao irrigation canal.There exist large distinctions among the heavy metal elements to the pollution degree.Cd pollution area is the biggest and the most serious in pollution degree.
基金This work was supported by City Collage of Science and Technology.Chongqing University and Chongqing HaiRun institute of energy saving research。
文摘Accumulation and releasing of trace metal elements on aluminum containing sediments of inner drinking water pipe is discussed,as studied from five variations effecting:raw water quality,chemical reagents,solution pH and drinking water flow condition.In order to decrease the release of trace metal elements,and to ensure the pipe operation and human safety,water quality adjustment is suggested to avoid aluminum containing sediments formation in drinking distribution system.The maximum amounts of accumulation of common trace metal elements are given.Future trends of development in this field are also proposed.
