Spatially Disaggregated Inventories of Soil NO and N2O Emissions for Great Britain

Estimates of soil N₂O and NOemissions at regional and country scales arehighly uncertain, because the most widely usedmethodologies are based on few data, they do notinclude all sources and do not account forspatial and seasonal variability. To improveunderstanding of the spatial distribution of soilNO and N₂O emissions we have developedsimple multi-linear regression models based onpublished field studies from temperate climates.The models were applied to create spatialinventories at the 5 km² scale of soil NOand N₂O emissions for Great Britain. The N₂O regression model described soilN₂O emissions as a function of soil N input,soil water content, soil temperature and land useand provided an annual N₂O emission of 128 kt N₂O-N yr^-1. Emission rates largerthan 12 kg N₂O-N ha^-1 yr^-1 werecalculated for the high rainfall grassland areasin the west of Great Britain.Soil NO emissions were calculated using tworegression models, which described NO emissionsas a function of soil N input with and without afunction for the water filled pore space. Thetotal annual emissions from both methods, 66 and7 kt NO-N yr^-1, respectively, span the rangeof previous estimates for Great Britain.     

Bioavailability of metals and As from acidified multicontaminated soils: Use of white lupin to validate several extraction methods

White lupin is an annual crop that has been used for phytostabilization of acidified multicontaminated (heavy metals and As) soils from the Aznalcóllar spill-affected area, Southern Spain. One of the most important factors for successful phytostabilization is monitoring the pollutant bioavailability in the soil. The aim of this work was to determine the best-suited method for assessing the bioavailability of heavy metals together with As in the Aznalcóllar spill-affected area, by means of a systematic comparison between different extraction methods (Ammonium bicarbonate-diethylenetriamine pentaacetic acid (AB-DTPA), CaCl₂, NaNO₃, BCR, (NH₄)₂SO₄ and rhizo). Both AB-DTPA and the first step of the BCR method were found to be unsuitable for assessing the bioavailability of heavy metals and As to plants growing in acidic soils. However, CaCl₂-extractable As, Cu, and Zn and NaNO₃-extractable As and Zn were well correlated with their concentrations in plant organs. Rhizo and (NH₄)₂SO₄, with the highest determination coefficients, were the most recommended simple extraction methods to assess the bioavailability of As, Cu, Fe, Mn, and Zn in acidified multicontaminated soils using white lupin as an excluder model plant.     

Some characteristics of the distribution of heavy metals in urban topsoil of Xuzhou,China

An assessment is presented of distribution characteristics of heavy metals in the urban topsoil from the city of Xuzhou. The concentrations of Ag, Al, As, Au, Ba, Be, Bi, Cd, Co, Cr, Cu, Fe, Ga, Hg, Li, Mn, Mo, Ni, Pb, Pd, Pt, Sb, Sc, Se, Sn, V and Zn have been determined from 21 soil samples. Examination of lognormal distribution plots indicates that the diagrams of Al, Be, Fe, Ga, Li, and V are almost linear suggesting that these metals are almost unaffected by anthropogenic activities while the plots for As, Cd, Cu, Pb, Pd, Pt, Se, Zn and others are not linear probably due to anthropogenic activities from which these metals are delivered to the soils. Al is used for mineralogical normalization of these data. An evaluation of background values for topsoil is also carried out by means of lognormal distribution plots. The results show our background values obtained from the lognormal distribution plots are comparable to those values of uncontaminated soils of Xuzhou obtained by previous work except for Cd and Hg. At present, no explanation for the exceptions Cd and Hg can be given.     

Accumulation of metallic elements by Amanita muscaria from rural lowland and industrial upland regions

ABSTRACT

This study was carried out on the accumulation and occurrence of Ag, Al, Ba, Ca, Cd, Co, Cu, Fe, Hg, K, Mg, Mn, Na, Rb, Sr and Zn in the mushroom Amanita muscaria and forest topsoil from two lowland sites in the Tuchola Pinewoods in the north-central region and an upland site in the ?wietokrzyskie Mountains in the south-central region of Poland. Topsoil from the upland location showed Ag, Al, Ba, Ca, Cd, Co, Cu, Fe, Hg, Na and Zn at significantly higher concentration levels (pseudo-total fraction and often also the labile or extractable fraction) than at both lowland locations, where topsoil was richer in Mg, and similar in Rb. Amanita muscaria from the upland region differed from individuals collected in the lowland sites by higher concentration levels of Cd, Cu, Hg and Mn in caps. This could be related to higher concentration levels of the metallic elements in topsoil in the upland region. On other side, A. muscaria from the upland site was poorer in Co and Fe in caps, and in Ca, Co, Fe and Sr in stipes. In spite of the differences in content of the geogenic metallic elements in topsoil between the lowland and upland locations, A. muscaria from both regions was able to regulate uptake and accumulation of Ag, Al, Ba, Ca, K, Mg, Na, Rb and Zn, which were at similar concentration levels in caps but not necessarily in stipes.     

Mercury transportation in soil via using gypsum from flue gas desulfurization unit in coal-fired power plant

The mercury flux in soils was investigated, which were amended by gypsums from flue gas desulphurization (FGD) units of coal- fired power plants. Studies have been carried out in confined greenhouses using FGD gypsum treated soils. Major research focus is uptakes of mercury by plants, and emission of mercury into the atmosphere under varying application rates of FGD gypsum, simulating rainfall irrigations, soils, and plants types. Higher FGD gypsum application rates generally led to higher mercury concentrations in the soils, the increased mercury emissions into the atmosphere, and the increased mercury contents in plants (especially in roots and leaves). Soil properties and plant species can play important roles in mercury transports. Some plants, such as tall fescue, were able to prevent mercury from atmospheric emission and infiltration in the soil. Mercury concentration in the stem of plants was found to be increased and then leveled off upon increasing FGD gypsum application. However, mercury in roots and leaves was generally increased upon increasing FGD gypsum application rates. Some mercury was likely absorbed by leaves of plants from emitted mercury in the atmosphere.     

Watering techniques and zero-valent iron biochar pH effects on As and Cd concentrations in rice rhizosphere soils, tissues and yield

Zero-valent iron amended biochar (ZVIB) has been proposed as a promising material in immobilizing heavy metals in paddy fields. In this study, the impacts of pH of ZVIB (pH 6.3 and pH 9.7) and watering management techniques (watering amount in the order of CON (control, 5/72)>3/72>1–3/72>3/100>1/72, with 5/72, for example, representing irrigation given to 5 cm above soil surface in 72 hr regular interval) on As and Cd bioavailability for rice and its grain yield (Yield_BR) were investigated in a pot experiment. Brown rice As (As_BR) content was irrelative to the watering treatments, while significantly decreased (>50%) with the addition of both ZVIB materials. The diminutions of brown rice Cd (Cd_BR) content as well as the Yield_BR were highly dependent on both the soil amendment materials’ pH and watering amount. Among all the watering treatments, 3/72 treatment (15% less irrigation water than the CON) with ZVIB 6.3 amendment was the optimum fit for simultaneous reduction of As_BR (50%) and Cd_BR contents (19%) as well as for significant increment (12%) of the Yield_BR. Although high pH (9.7) ZVIB application could also efficiently decrease As and Cd contents in brown rice, it might risk grain yield lost if appropriate (e.g. 3/72 in our study) watering management technique was not chosen. Therefore, ZVIB would be an environmentally friendly option as an amendment material with proper selection of watering management technique to utilize As and Cd co-contaminated arable soils safely for paddy cultivation.     

三峡库区澎溪河流域消落带土壤有机磷生物有效性研究

选取了澎溪河流域六个点位消落带土壤和岸边土壤,以NaOH-EDTA提取土壤中有机磷,并采用酶水解技术表征有机磷生物有效性。结果表明：①消落带土壤NaOH-EDTA提取液中总磷含量为74.55～140.54 mg/kg,无机磷含量为49.91～104.23 mg/kg,有机磷含量为14.61～36.31 mg/kg。消落带土壤有机磷含量低于岸边土壤。②消落带土壤有机磷中总可酶解有机磷（EHP）含量均值为6.23 mg/kg,占土壤有机磷含量的26.7%。消落带土壤EHP含量与有机磷含量呈极显著正相关（n=6,p<0.01）。③消落带土壤EHP含量、活性单酯磷含量与土壤有机质含量呈显著正相关（n=6,p<0.01）,土壤有机质含量是影响有机磷生物有效性的重要因素。④消落带土壤与岸边土壤EHP组分特征相同,含量由高到低依次为类植酸磷、活性单酯磷、二酯磷,但消落带土壤EHP含量显著低于岸边土壤。周期性的干湿交替会造成消落带土壤有机磷向库区水体释放,消落带土壤有机磷地球化学循环对库区水体的潜在影响不容忽视。     

贵阳市某蔬菜地养殖废水污灌土壤重金属、抗生素复合污染研究

养殖废水灌溉农田易造成重金属、抗生素复合污染,从而引发环境健康风险.对贵阳市乌当区长期污灌蔬菜地土壤进行调查研究,探究长期污灌条件下土壤重金属、抗生素复合污染状况.同时,采用电感耦合等离子体质谱仪(ICP-MS)对Zn、Cd、Pb、As和Cr含量进行测定,采用超声波提取,固相萃取-高效液相色谱-串联质谱分析的方法对抗生素进行测定.结果表明,与对照组比较,污灌土壤Cd呈积累趋势,Zn、Pb、As含量降低,Cr含量变化不大.Zn、Cd、Pb、As和Cr的污染指数分别为0.59、2.20、0.21、0.86、0.27,Cd达到中度污染水平.污灌土壤Cd、Pb以可还原态为主,Zn、As、Cr以残渣态为主,与对照相比,污灌土壤可还原态重金属普遍升高,其中,可还原态Cd从5.56%增加至57.2%,可还原态Pb从34.5%增加至52.3%.污灌土壤中四环素类、磺胺类和喹诺酮类抗生素含量明显增加,总量范围分别为0.14~15.8、0.26~8.03、0.31~32.8μg·kg~(-1),未污灌对照土壤的四环素类、磺胺类未检出,喹诺酮类含量为0.77~1.13μg·kg~(-1).相关分析结果显示,重金属Pb和Zn与3类抗生素呈正相关关系,存在复合污染现象,而Cd、As和Cr与抗生素之间没有显著的相关关系.     

Characteristics of biomass ashes from different materials and their ameliorative effects on acid soils

The chemical characteristics, element contents, mineral compositions, and the ameliorative effects on acid soils of five biomass ashes from different materials were analyzed. The chemical properties of the ashes varied depending on the source biomass material. An increase in the concrete shuttering contents in the biomass materials led to higher alkalinity, and higher Ca and Mg levels in biomass ashes, which made them particularly good at ameliorating effects on soil acidity. However, heavy metal contents, such as Cr, Cu, and Zn in the ashes, were relatively high. The incorporation of all ashes increased soil pH, exchangeable base cations, and available phosphorus, but decreased soil exchangeable acidity. The application of the ashes from biomass materials with a high concrete shuttering content increased the soil available heavy metal contents. Therefore, the biomass ashes from wood and crop residues with low concrete contents were the better acid soil amendments.     

准东煤炭产业区周边土壤重金属污染与健康风险的空间分布特征

以新疆准东煤炭产业区周边土壤重金属为研究对象,土壤按照0~10 cm、10~20 cm、20~30 cm分层取样,共采集156个土壤样品,测定了Zn、Cu、Cr、Pb、Hg和As共6种重金属含量,采用污染负荷指数（PLI）和美国环保署的健康风险模型评价了不同土壤深度重金属污染程度和对人体的健康风险,进一步利用多元统计分析、地统计分析和GIS技术研究了评价结果的差异显著性、空间变异结构和分布格局,并利用交叉验证方法检验了预测精度. 结果表明,Zn、Cu、Pb的含量范围为46.06~48.00、18.37~19.271、11.30~13.29 mg·kg^-1,与新疆背景值相比均未超标;Cr、Hg、As的含量范围为80.29~85.42、0.06~0.07、30.64~31.52 mg·kg^-1,与新疆背景值相比均超标,且超标率为60%以上;研究区土壤污染负荷（PLI）大小顺序为PLI_{0~10 cm}（1.35）> PLI_{20~30 cm}（1.28）> PLI_{10~20 cm}（1.25）,属于轻度污染;非致癌风险（HI）大小顺序为HI_{0~10 cm}（2.53E-01））> HI_{20~30 cm}（2.48E-01）> HI_{10~20 cm}（2.43E-01）,不存在非致癌健康风险;致癌风险（TCR）大小顺序为TCR_{0~10 cm}（2.81E-05）> TCR_{20~30 cm}（2.80E-05）> TCR_{10~20 cm}（2.74E-05）,存在可接受的致癌风险;方差分析得出不同土壤深度PLI、HI和TCR显著性水平分别为0.863、0.134、0.056,表明差异不显著;地统计分析表明,0~10 cm土壤深度Zn、Cu和As含量高值区位于产业区附近及其北部,Pb含量高值区组合成明显的“V”形高值带,Hg含量高值区位于中南部,Cr含量高值区以各产业区为中心向四周辐射状递减;PLI、HI和TCR高值区均位于研究区西北和东北方向,PLI随土壤深度增加中度污染区域逐渐减小,HI和TCR随深度增加高值区面积无明显变化. 总之,人口聚集的6个产业区附近及北部为重金属污染程度和人体健康风险高值区,特别是Cr、Hg、As污染程度较严重,As对人体健康风险贡献率最大,应当引起重视.