Source of and potential bio-indicator for the heavy metal pollution in Ny-lesund,Arctic

Three kinds of tundra plant samples including Dicranum angustum(a type of boreal bryophyte),Puccinellia phryganodes(a type of fringy plant),Salix polaris(a type of vascular plant) and surface soil were samples in 200 at Ny-lesund of the Arctic.The levels of eight heavy metal elements(Hg,Pb,Cd,Cu,Zn,Ni,Fe and Mn) and three metal-like elements(As,Se,Sr) in the plant and soil samples of the areas within previous coal mining activities are significantly higher than those of other areas.The relative accumulation of these elements in these tundra plant samples is consistent with the one in the soil samples,especially in the areas affected by previous coal-mining activities.Thus,the pollution is apparently from local coal mining activity.Dicranum angustum has the highest concentrations among those elements,and it can be a good bio-indicator for heavy metal pollution in Ny-lesund.Though Ny-lesund is less polluted by heavy metal than nearby Northern European human living areas,but much more than the tundras of the Alaska,Greenland and the Antarctic.     

Transport patterns and numerical simulation of heavy metal pollutants in soils of lead–zinc ore mines

Exploring transport patterns of soil contaminants is essential for solving the problem of heavy metal contamination in mine soils. In this study, contamination of Pb, Zn, and Cd in the mountain soils of the lead–zinc ore mines in Ganxi Township, Hengdong County, Hunan Province, China was investigated, and their transport patterns were further explored using a soil-column model and numerical simulation techniques. In total, 111 mine soil samples were collected and placed into six experimental soil columns. By controlling the water flow, a control soil column group(CK), two mixed soil columns X_1 with daily water flows of 1 and 5 L, and three mixed soil columns X_3 with daily water flows of 2, 3, and 4 L were evaluated. The results showed that the residual fraction of Pb accounted for 71.93 % of the content on average, whereas the exchangeable fractions of Zn, Cd, and Fe-Mn oxide-bound fractions of Zn and Cd accounted for 28.60%, 31.07%, and 43.2% and 53.54% of the content, respectively. Pb, Zn, and Cd in the soils of the CK, X_1, and X_3 groups mainly were accumulated at a depth from approximately 0 to 20 cm, and the content at this depth accounted for 60.09% of that at a 0～40 cm depth. The soil at a depth range of 0～10 cm was most seriously contaminated, and the proportion of content was 32.39% of that at a 0～40 cm depth. Numerical simulation showed that on the 5 th day, the pollutant transport range was 0～24 cm, and on the 9 th day, the pollutant transport range exceeded 40 cm. On the 15 th day, the transport capacity of pollutants at depths of 0～40 cm was close to the stable state, but the soil at a depth of 0～10 cm was still heavily polluted. These results reflect the transport pattern of heavy metal pollutants in the soil of lead–zinc ore mines and may provide a reliable scientific support for the prevention of heavy metal contamination in mine environments.     

Evaluation on environmental quality for heavy metal elements of Xihe soil

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.     

Characteristics of the active-layer under the China-Russia Crude Oil pipeline

Active layer is a key component for permafrost environment studies as many subsurface biological,biogeochemical,ecological,and pedogenic activities prevail in this layer.This study focuses on active layer temperature monitoring in an area with sporadic permafrost at two adjacent sites along China-Russia Crude Oil Pipeline(CRCOP),NorthEast China.Site T1 is located in disturbed ground on the right-of-way(on-ROW)2 m away from the center of the oil pipeline.T2 is located in a natural and undisturbed site,around 16.6 m off-ROW.Our objective was to study seasonal variability of the active layer depth and thermal regime from October 2017 to September 2018.The monitoring sites consist of soil temperature probes arranged in a vertical array at different depths at both sites.The following parameters were computed:number of isothermal days(ID),freezing days(FD),thawing days(TD),freezing degree days(FDD),thawing degree days(TDD),number of freeze-thaw days(FTD).The mean air temperature in the monitoring period reached-3.2℃.The temperature profile indicates that the maximum active layer thickness observed during the study period was 10 m at T1 and 2 m at T2.The majority of the soil temperatures were above or close to 0℃,resulting in great values of TDD,especially in the first 4 m depth.TDD for T1 were predominant and ranged between 600-1160℃·days(0-4 m depth)reflecting the influence of oil temperature from the pipeline.In T2 borehole FDD were predominant for all the soil layer depths resulting in less permafrost degradation.This comparison emphasizes the significant influence of vegetation removal and the dispersed heat from the pipeline on the active layer thickness.     

STUDY ON FLUXES OF CH4 EMISSION FROM PADDY FIELDS IN CHANGCHUN AREA

CH4 is a kind of important greenhouse gases in atmosphere. The current atmospheric concentration of CH4 is about 1.7ppmv and is increasing at almost 2％ per year. The sources of CH4 include paddies, wetland and tundra, insects, the digestive tracts of ruminants, coal mining, biomass burning, and the leakage of natural gas. The total input to the atmosphere lies in the range 300－ 550Tg per year. CH4 from paddy fields is about 10％ － 20％ of total source of atmospheric CH4 (DING, 1997). …     

Soil Organic Matter Fractions under Different Vegetation Types in Permafrost Regions along the Qinghai-Tibet Highway,North of Kunlun Mountains,China

As a key attribute of soil quality, soil organic matter(SOM) and its different fractions play an important role in regulating soil nutrient cycling and soil properties.This study evaluated the soil carbon(C) and nitrogen(N) concentrations in different SOM fractions(light– and heavy fractions,microbial biomass) under different vegetation types and analyzed their influencing factors in continuous permafrost regions along the Qinghai-Tibet Highway in the North of Kunlun Mountains, China.Soil samples were collected in pits under four vegetation types — Alpine swamp meadow(ASM), Alpine meadow(AM), Alpine steppe(AS) and Alpine desert(AD) — at the depth of 0-50 cm.The vegetation coverage was the highest at ASM and AM, followed byAS and AD.The results indicated that the concentrations of light fraction carbon(LFC) and nitrogen(LFN), and microbial biomass carbon(MBC)and nitrogen(MBN) decreased as follows: ASM AM AS AD, with the relatively stronger decrease of LFC,whereas the heavy fraction carbon(HFC) and nitrogen(HFN) concentrations were lower in AS soils than in the AD soils.The relatively higher proportions of LFC/SOC and MBC/SOC in the 0-10 cm depth under the ASM soils are mainly resulted from its higher substrate input and soil moisture content.Correlation analysis demonstrated that aboveground biomass, soil moisture content, soil organic carbon(SOC) and total nitrogen(TN) positively correlated to LFC, LFN, HFC, HFN, MBC and MBN, while p H negatively correlated to LFC, LFN, HFC, HFN, MBC and MBN.There was no relationship between active layer thickness and SOM fractions, except for the LFC.Results suggested that vegetation cover, soil moisture content, and SOC and TN concentrations were significantly correlated with the amount and availability of SOM fractions, while permafrost had less impact on SOM fractions in permafrost regions of the central Qinghai–Tibet Plateau.     

Acid Volatile Sulfide and Simultaneously Extracted Metals in Tidal Flat Sediments of Jiaozhou Bay, China

It is well known that acid-volatile sulfide （AVS） plays an important role in influencing the toxicity of divalent cationic metals within anoxic sediments. In studying sediment core samples collected from tidal flats within the Jiaozhou Bay, China, we found that the AVS concentration gradually increases with depth and decreases from high tidal flat to low tidal flat areas. We evaluated the chemical activity and bioavailability of heavy metals in the tidal flat based on the molar ratio of simultaneously extracted metals （SEM） and AVS. The value of SEM/AVS is generally less than 1 in this area except for the surface layer, which suggests that the heavy metals only have chemical activity in the surface layer. SEM is most highly concentrated at the boundary of the redox layer SEM have similar depth distributions throughout the tidal flat. The aeration of low tidal flat sediment indicates that SEM gradually move to deeper sites via interstitial water.     

A quantification of the effects of erosion on the productivity of purple soils

Research on the effects of soil erosion on soil productivity has attracted increasing attention.Purple soil is one of the main soil types in China and plays an important role in the national economy.However,the relationship between erosion and the productivity of purple soils has not been well studied.The purpose of this research was to determine if soil depth,which is dependent on the rate of erosion,has an influence on crop yield and growth.Plot and pot experiments at different soil depths were performed.Results indicate that soils from different parental materials had different growth features and crop yields due to the differential fertility of the derived soils.The yield reduction rate increases exponentially with the depth of eroded soil(level of erosion).The yield reduction rate per unit eroded soil horizon(10 cm) is approximately 10.5% for maize and wheat.     

The influence of seasonal snow on soil thermal and water dynamics under different vegetation covers in a permafrost region

Seasonal snow is one of the most important influences on the development and distribution of permafrost and the hydrothermal regime in surface soil. Alpine meadow, which constitutes the main land type in permafrost regions of the Qinghai-Tibet Plateau, was selected to study the influence of seasonal snow on the temperature and moisture in active soil layers under different vegetation coverage. Monitoring sites for soil moisture and temperature were constructed to observe the hydrothermal processes in active soil layers under different vegetation cover with seasonal snow cover variation for three years from 2010 to 2012. Differences in soil temperature and moisture in areas of diverse vegetation coverage with varying levels of snow cover were analyzed using active soil layer water and temperature indices. The results indicated that snow cover greatly influenced the hydrothermal dynamics of the active soil layer in alpine meadows. In the snow manipulation experiment with a snow depth greater than 15 cm, the snow cover postponed both the freeze-fall and thawrise onset times of soil temperature and moisture in alpine LC （lower vegetation coverage） meadows and of soil moisture in alpine HC （higher vegetation coverage） meadows; however, the opposite response occurred for soil temperatures of alpine HC meadows,where the entire melting period was extended by advancing the thaw-rise and delaying the freeze-fall onset time of the soil temperature. Snow cover resulted in a decreased amplitude and rate of variation in soil temperature, for both alpine HC meadows and alpine LC meadows, whereas the distinct influence of snow cover on the amplitude and rate of soil moisture variation occurred at different soil layers with different vegetation coverages. Snow cover increased the soil moisture of alpine grasslands during thawing periods. The results confirmed that the annual hydrothermal dynamics of active layers in permafrost were subject to the synergistic actions of both snow cover and vegetation coverage.     

STUDY ON THE RELATIONSHIP BETWEEN SPECIATION OF HEAVY METALS AND THEIR ECOTOXICITY——I. TOXICITY OF Cu, Cd , Pb AND Zn IN SEAWATER TO THREE MARINE ALGAE IN THE PRESENCE OF DIFFERENT COMPLEXATION AGENTS

Heavy metal is a main pollutant in the marine ecosystem . so study on the effect of heavy metal on phytoplankton is important . Algae (Chaetoceros sp . , Dunaliella sp . ., Dicrateria zhanjiangenis Hu . var . sp .) were laboratory cultured to observe the effect of heavy metals on their growth . The effect of different metal ion concentration , the detoxication effect of complexation agents and the growth of algae in different media and different nutrition levels were studied to evaluate the effect of metal speciation . It is proved that trace amount of heavy metals can stimulate the growth of algae cells but that high concentration is lethal . The sequence of toxicity is Cd2+>Zn2+>Pb2+ . In ordinary nutrition conditions , the detoxication sequence of complexation agents to Chaetoceros sp . is EDTA > sodium salicylate > sodium oxalate > sodium citrate > sulfanilic acid > O-phenanthroline . This is in good conformity with the stability constant sequence of these agents with copper and good evidence that t     

SPATIAL-TEMPORAL VARIATION OF HEAVY METAL ELEMENTS CONTENT IN COVERING SOIL OF RECLAMATION AREA IN FUSHUN COAL MINE

Grid method is employed for sampling covering soil at the test field, which is reclamation area filled bycoal mining wastes for cropland in the Fushun coal mine, Liaoning Province, the Northeast China. The soil samples aretaken at different locations, including three kinds of covering soil, three different depths of soil layers and four differentcovering ages of covering soil. The spatial-temporal variation of heavy metal element content in reclamation soil is studied. The results indicate that the content of heavy metal elements is decreasing year after year; the determinant reasonwhy the content of heavy metal elements at 60cm depth layer is higher than that at 30em depth layer and surface is fertilizer and manure apphcation; the metal elements mainly come from external environment; there is no metal pollution comingfrom mother material (coal mining wastes) in plough layer of covering soil.     

大柳塔采煤塌陷区土壤含水量的空间变异特征分析

通过研究采煤塌陷区土壤水空间分布及动态变化特征,查明了采煤塌陷对土壤含水量的影响,这对矿区生态环境保护、塌陷区土地复垦等具有重要指导意义。以大柳塔双沟采煤塌陷区为试验区,利用传统统计学和地统计学方法分析了采煤塌陷条件下的包气带土壤水空间变异特征。研究结果表明:由于采煤塌陷造成塌陷区土壤层位在垂向上倒置、重组,引起土壤粒度、容重、孔隙度等土壤物理特性的改变,使塌陷区土壤含水量比非塌陷区显著降低,在不同深度层（0~60 cm）分别减少14.2%~21.9%;在垂向分布上塌陷区土壤水分也表现出较强的变异性,其离散系数在不同深度（0~60 cm）与非塌陷区的差值在19.2%~50%之间。根据试验区0 cm、20 cm、40 cm、60 cm四个层面土壤含水量的Kriging插值等值线图显示,土壤含水量低值区均位于塌陷区内的塌陷坑部位,证明地表的地裂缝、塌陷坑、塌陷洞等塌陷形态对土壤持水能力的影响颇为显著。采煤塌陷区土壤含水量降低、空间变异性增强直接导致了地表植被生存环境的恶化,地表景观被严重破坏。     

Source of and potential bio-indicator for the heavy metal pollution in Ny-(A)lesund, Arctic

Three kinds of tundra plant samples including Dicranum angnstum(a type of boreal bryophyte) , PuccineUia phryganodes (a type of fringy p/ant),Salix polaris (a type of vascular plant) and surface soil were samples in 200 at Ny-Alesund of the Arctic.The levels of eight heavy metal elements (Hg, Pb, Cd, Cu, Zn, Ni, Fe and Mn) and three metal-like dements (As, Se, Sr) in the plant and soil samples of the areas within previous coal mining activities are significantly higher than those of other areas.The relative accumulation of these elements in these tundra plant samples is consistent with the one in the soft samples, especially in the areas affected by previous coal-mining activities.Thus, the pollution is apparently from local coal mining activity.Dicranum angustum has the highest concentrations among those elements, and it can be a good bio-indicator for heavy metal pollution in Ny(A)lesund.Though Ny(A)lesund is less polluted by heavy metal than nearby Northern European human living areas, but much more than the tundras of the Alaska, Greenland and the Antarctic.     

资江河口区农田土壤重金属污染评价及来源分析

资江是洞庭湖的第二大支流，其中上游锑(Sb)矿采矿冶炼工业发达，给资江下游及洞庭湖区带来了严重的重金属污染风险。以资江河口区为研究区，采集了132个农田土壤样品及7个资江水样，综合采用多种污染评价方法、空间分析、多元统计分析方法对研究区重金属进行了污染评价及来源分析。结果表明，研究区农田土壤重金属平均质量分数表现为Zn>Cr>Ni>Pb>Cu>As>Sb>Cd，旱田土壤重金属平均质量分数除Pb外均高于水田。Sb、As、Cd为主要污染元素，Sb达到了中等污染和中等生态风险的程度，总体处于轻微-中等生态风险程度。资江水体Sb质量浓度较高，平均为10.51 μg/L。Sb主要来源于中上游的锑矿工业，受高锑质量浓度地表水灌溉、垃圾填埋场以及燃煤等人为活动的控制；Cd主要来源于农药化肥、生活垃圾和城镇废水等人为活动；Cr主要来源于成土母质，而Cu、Zn、As、Ni、Pb受成土母质和人为活动的双重控制。      

滨州海岸带土壤和海底沉积物重金属空间分布特征

通过对滨州近海海域海底沉积物测试数据及海岸带陆域土壤地球化学分析,对滨州海岸带陆域土壤和海底沉积物中7种重金属(Hg,Cd,Pb,Cu,Zn,Cr,Ni)的空间分布特征进行了研究,并绘制了各指标含量陆海联合分区图。分析结果表明,滨州市海岸带重金属元素含量基本上均低于国标规定的海洋一类沉积物的最高标准,仅有个别元素含量超过一级标准值,表明局部存在一定的重金属污染。从滨州海岸带重金属含量空间分布上来看,除Hg元素外,其余重金属元素含量呈现一定的规律,基本上陆域含量高于海域含量,且大部分元素都呈现出陆域城镇值高,郊区值低的态势。区内化工企业较发达,Ni,Cr属于中度变异区,Cd,Hg,Pb属于高度变异,受人为影响因素较大,考虑区内土壤及海底沉积物重金属富集主要来源于工业"三废"。     

Effect of Wetland Reclamation on Soil Organic Carbon Stability in Peat Mire Soil Around Xingkai Lake in Northeast China

Content and density of soil organic carbon(SOC) and labile and stable SOC fractions in peat mire soil in wetland, soybean field and rice paddy field reclaimed from the wetland around Xingkai Lake in Northeast China were studied. Studies were designed to investigate the impact of reclamation of wetland for soybean and rice farming on stability of SOC. After reclamation, SOC content and density in the top 0–30 cm soil layer decreased, and SOC content and density in soybean field were higher than that in paddy field. Content and density of labile SOC fractions also decreased, and density of labile SOC fractions and their ratios with SOC in soybean field were lower than that observed in paddy field. In the 0–30 cm soil layer, densities of labile SOC fractions, namely, dissolved organic carbon(DOC), microbial biomass carbon(MBC), readily oxidized carbon(ROC) and readily mineralized carbon(RMC), in both soybean field and paddy field were all found to be lower than those in wetland by 34.00% and 13.83%, 51.74% and 35.13%, 62.24% and 59.00%, and 64.24% and 17.86%, respectively. After reclamation, SOC density of micro-aggregates( 0.25 mm) as a stable SOC fraction and its ratio with SOC in 0–5, 5–10, 10–20 and 20–30 cm soil layers increased. SOC density of micro-aggregates in the 0–30 cm soil layer in soybean field was 50.83% higher than that in paddy field. Due to reclamation, SOC density and labile SOC fraction density decreased, but after reclamation, most SOC was stored in a more complex and stable form. Soybean farming is more friendly for sustainable SOC residence in the soils than rice farming.     

郑州东北郊污水灌区重金属元素对土壤的污染

根据郑州市东北郊不同污水灌区、不同深度的土壤采样分析结果,计算了重金属元素在土壤中的概率分布类型及环境背景值,论述了重金属元素对土壤的污染特点及其对农作物生长的影响,并指出了汞污染土壤的普遍性和对粮食及蔬菜质量所造成的危害。     

煤矸石堆附近耕作层土壤中重金属污染状况与评价——以鲁西南煤炭基地为例

通过对鲁西南煤炭基地若干混堆的煤矸石山周围耕作层土壤的实际调查及分析测试资料,研究了煤矸石堆附近耕作层土壤中重金属污染状况。结果表明,土壤局部已经受到Cd、Ni的污染,但未出现多金属复合污染状况。煤矸石堆附近土壤已经受到采矿等人类活动的影响,其中Cd,Hg的人为影响最大。从8种重金属元素含量随深度的变化曲线形态来看,Hg,Cd 2种元素与Cr,Ni,Cu,Zn,Pb,As 6种元素曲线形态显示差异性,Hg,Cd元素在土壤中赋存、迁移等应具特殊性,有待进一步研究。     

Response of Soil Moisture to Rainfall Event in Black Locust Plantations at Different Stages of Restoration in Hilly-gully Area of the Loess Plateau,China

Precipitation plays an important role in the water supplies that support ecological restoration by sustaining large-scale artificial plantations in arid and semiarid regions, especially black locust(Robinia pseudoacacia) plantations(RP plantations), which are widely planted due to R. pseudoacacia being an excellent pioneer species. Characterizing the response of soil moisture to rainfall events at different stages of restoration is important for assessing the sustainability of restoration in RP plantations. In this study, we quantified the response of soil moisture to rainfall events at different years of restoration(15, 20 and 30 yr) representing different restoration stages in RP plantations in a typical hilly-gully area, i.e., the Yangjuangou Catchment, of the Loess Plateau, China. Over the growing season(June to September) of 2017, smart probes were placed at nine depths(10, 20, 40, 60, 80, 100, 120, 150, and 180 cm below the soil surface) to obtain volumetric soil water information at 30-min intervals in the three RP plantations. The advance of the wetting front was depicted, and the total cumulative water infiltration was measured. Soil moisture was mainly replenished by eight heavy rainfall events(mean rainfall amount = 46.3 mm), accounting for 88.7% of the rainfall during the growing season. The mean soil moisture content profiles of RP plantations at the three restoration stages were ordered as 30-yr(14.07%) 20-yr(10.12%) 15-yr(8.03%), and this relationship displayed temporal stability. Soil moisture was primarily replenished by rainfall at the 0-60 cm soil depth, and soil moisture remained stable below the 100-cm soil depth. The rainfall regime influenced the advancement of the wetting front. Here, a single rainfall event of 30 mm was the rainfall threshold for infiltration into the 60-cm soil layer. The total infiltration time ranged from 310.5-322.0 h, but no significant differences were found among RP plantations at different restoration stages. Young and old RP plantations had more total infiltration(more than 228.2 mm) and deeper infiltration depths(80-100 cm) than middle-aged plantations. The RP plantation at the intermediate restoration stage exhibited minimal total infiltration(174.2 mm) and a shallow infiltration depth(60 cm) due to the soil physical structure of the plot, which may have limited rain infiltration. More stand conditions that may affect infiltration should be considered for priority afforestation areas.     

章丘区北部土壤重金属地球化学特征及潜在生态风险

以山东省济南市章丘区北部表层土壤中As等8种重金属元素为研究对象,利用多元统计进行重金属来源分析,采用污染负荷指数法及潜在生态危害指数法进行污染评价,结果表明:研究区表层土壤重金属元素含量低于济南市土壤背景值,Cd和Hg元素含量为强度变异,在表层土壤产生一定的富集;不同土地利用类型下重金属元素含量具有差异性。土壤中Cr,Cu,Ni和Zn来源于土壤母质,Cd和Pb元素来源于人类活动,As元素来源复杂。土壤综合污染以轻度污染为主,重金属元素污染程度大小为AsNiPbZnCrCuCdHg。综合潜在生态风险以轻微和中度为主,潜在生态风险强弱程度为HgCdAsCuPbNiCrZn,建议防范Hg和Cd元素污染及生态风险。