环保疏浚底泥改良用于绿化种植土技术研究

为有效解决环保疏浚底泥资源化利用难题,以武汉某湖泊环保疏浚底泥为研究对象,现场取样测试分析了其主要理化性质,以脱硫石膏及有机肥作为改良物料,配制了3种底泥改良用于绿化种植土的改良剂。通过淋溶试验,分析了淋溶量对改良底泥理化性质的影响规律。淋溶试验结果表明,添加了合适的改良剂并经过淋溶的环保疏浚底泥,其理化指标得到了明显改善,有机质、有效磷、速效钾等营养元素含量显著提升,满足绿化种植土相关技术要求。通过盆栽试验,研究了不同改良剂对供试植物生长状况的影响。盆栽种植试验结果显示,供试植物在改良底泥中生长良好,其中有机质含量最高的改良物料改良效果最佳,验证了环保疏浚底泥改良用于绿化种植土的可行性。     

Effects of the peat acid digestion protocol on geochemically and morphologically diverse tephra deposits

Tephra shards for electron probe microanalysis are most efficiently extracted from peat using acid digestion, which removes organic material that hinders density separation methods. However, strong acids are known to alter glass chemical compositions, and several studies have examined how acid digestion affects rhyolitic volcanic glass. The focus on rhyolitic tephra in these studies leaves considerable uncertainty, as the dissolution rates of natural glasses (including tephra) are determined by the chemical composition and surface area/volume ratio, both of which vary in tephra deposits. Here, we use duplicate samples of basaltic, trachydacitic and rhyolitic tephra to examine physical and geochemical alteration following acid digestion. Scanning electron microscope imagery reveals no discernible degradation of glass surfaces, and electron probe microanalysis results from duplicate samples are statistically indistinguishable. These findings suggest the acid digestion protocol for organic peats does not significantly alter glass geochemistry regardless of shard morphologies or geochemical compositions.     

有机污染物在长江三角洲城市群典型沉积物中的迁移行为

长江三角洲城市群地区是中国沉积类型种类相对多、岩性类型复杂的地质区域。改革开放以来该地区化工企业快速发展, 使有机化工产品泄漏到土壤和沉积物中的风险加大, 对环境构成了较大的安全隐患, 因此, 掌握污染物在土壤和沉积物中的迁移转化规律对后续开发利用具有实用意义。采集并分析了长江三角洲城市群4种代表性的沉积物, 以邻氯甲苯为代表开展了有机污染物在沉积物中迁移行为的研究, 并利用SPSS软件建立邻氯甲苯吸附量与沉积物理化性质之间的相关方程。研究结果表明: 长江三角洲城市群湖积相、湖沼积相、冲湖积相和冲积相沉积物的有机质含量直接控制其对邻氯甲苯的吸附阻滞能力, 土壤的pH、矿物成分、阳离子交换量对邻氯甲苯的吸附能力影响不大, 苏州的湖积和湖沼积沉积物中有机质含量较高(7~63 g/kg), 其对邻氯甲苯的吸附阻滞能力较强, 而南京、镇江等地的冲积沉积物和常州、江阴南部的冲湖积沉积物中有机质含量较低(4~15 g/kg), 对邻氯甲苯的吸附能力较弱, 使污染物更易迁移; Freundlich模型能够较好地拟合不同种类沉积物对邻氯甲苯的等温吸附过程, 表征吸附强度的系数KF与沉积物的有机质含量呈显著正相关, 有机质含量越大, KF值越大, 沉积物对邻氯甲苯的吸附强度越强, 邻氯甲苯的等温吸附过程线性程度越高。研究成果将有利于预测有机污染物在长江三角洲城市群地区不同种类沉积物中的吸附行为, 为治理污染和调整工业布局提供理论依据。     

Geostatistical and multi‐elemental analysis of soils to interpret land‐use history in the Hebrides,Scotland

In the absence of documentary evidence about settlement form and agricultural practice in northwest Scotland before the mid‐18th century, a geoarchaeological approach to reconstructing medieval land use and settlement form is presented here. This study applies multielemental analysis to soils previously collected from a settlement site in the Hebrides and highlights the importance of a detailed knowledge of the local soil environment and the cultural context. Geostatistical methods were used to analyze the spatial variability and distribution of a range of soil properties typically associated with geoarchaeological investigations. Semivariograms were produced to determine the spatial dependence of soil properties, and ordinary kriging was undertaken to produce prediction maps of the spatial distribution of these soil properties and enable interpolation over nonsampled locations in an attempt to more fully elucidate former land‐use activity and settlement patterns. The importance of identifying the spatial covariance of elements and the need for several lines of physical and chemical evidence is highlighted. For many townships in the Hebrides, whose precise location and layout prior to extensive land reorganization in the late 18th–early 19th century is not recoverable through plans, multi‐elemental analysis of soils can offer a valuable prospective and diagnostic tool. © 2007 Wiley Periodicals, Inc.     

祁连山青海云杉(Picea crassifolia)林土壤有机碳与化学性质的相互关系

通过对祁连山大野口流域的青海云杉林大样地进行土壤剖面取样, 分析了样地土壤有机碳与pH值、养分和阳离子交换量等基本化学性质的变化规律及其相互关系. 结果表明: 随土层深度不断增加, 土壤有机碳含量逐渐减小, 在20～30 cm以下趋于稳定(P > 0.05); 土壤pH值不断增大, 仅在0～10 cm与10～20 cm差异显著(P<0.05); 土壤全氮、速效氮、全磷和阳离子交换量不断减小, 全氮含量在30～40 cm以下趋于稳定(P > 0.05), 速效氮含量变化剧烈(P<0.05), 全磷含量差异性不显著(P > 0.05), 阳离子交换量与有机碳含量变化规律相同; 土壤速效磷、全钾和速效钾含量没有明显的变化规律, 速效磷和全钾含量差异性不显著(P > 0.05), 速效钾含量仅在0～10 cm与10～20 cm差异显著(P<0.05). 土壤有机碳与全氮、速效氮、全磷、速效磷、速效钾和阳离子交换量之间呈极显著和显著正相关, 与土壤pH值和全钾含量之间呈极显著和显著负相关. 土壤有机碳与其他基本化学性质的回归方程具有较高精度(R²=0.793), 影响土壤有机碳含量的主要化学因子依次为土壤阳离子交换量、速效钾和全磷含量.     

疏浚污泥资源化处理试验研究

疏浚污泥的处理与处置是世界性的环保难题,资源化处理技术的研究有重要的工程应用价值。通过化学处理技术,在疏浚污泥中加入磷酸,将其中的重金属转变成难溶的金属磷酸盐固化在处理产物中,加入FeCl3试剂与水作用,改善处理后污泥的物理力学性质;通过热处理技术大大降低有机物的含量,使固体残留物无害化。研究了不同磷酸含量和不同FeCl3含量对其物理力学和热学性质的影响。试验结果表明,处理后的疏浚污泥污染物活动性降低,并有可能用作建筑材料。     

基于DGT技术对土壤硒生物有效性及其影响因素的分析

硒是生态环境中重要的微量元素之一,如何准确评估其生物有效性一直存在争议。在四川省广安市邻水县采集了60套农作物及其根系土样品,分析其Se含量和理化性质。同时基于梯度扩散膜技术对土壤有效Se含量进行分析,并对土壤有效Se含量的影响因素进行探究。结果表明,研究区土壤Se含量为0.15~2.42 mg/kg,均值为0.48 mg/kg,不同类型土壤Se含量差异明显,石灰土(1.06 mg/kg)>黄壤(0.78 mg/kg)>紫色土(0.28 mg/kg)>水稻土(0.27 mg/kg)。石灰土和黄壤有机质含量和总铁(TFe₂O₃)含量明显高于其他类型土壤。研究区内不同类型土壤的DGT-Se明显不同,与土壤Se含量分布相反。相关性分析表明土壤DGT-Se与Se含量、TFe₂O₃含量、S含量、有机质含量、pH值、Al₂O₃含量显著相关,受理化性质影响导致不同类型土壤中DGT-Se的差异。水稻根系土壤DGT-Se与水稻籽实Se含量显著正相关,用DGT可以较好地表达水稻-根系土系统中土壤Se的生物有效性。基于DGT技术评估预测区域尺度农业土壤有效Se含量时,需充分考虑土壤类型及其理化性质。     

Quantitative determination of cerussite (lead carbonate) by X-ray powder diffraction and inferences for lead speciation and transport in stream sediments from a former lead mining area in Scotland

Most current investigations of sites contaminated with heavy metals (e.g. Pb, Zn, Cu) emphasise the importance of determining the amounts of physical and chemical forms of metals rather than just the total amounts present. Chemical extraction techniques used for this purpose are inevitably operationally defined. A more direct approach to the identification of crystalline forms can be made by mineralogical techniques such as X-ray powder diffraction (XRPD), but quantitative determination of a particular form is not often attempted. Recent advances in methods of analysis and sample preparation for XRPD mean that it is now a relatively simple matter to obtain quantitative XRPD data. Here, it is applied to the quantitative determination of the forms of Pb in different size-fractions of stream sediment samples from Leadhills/Wanlockhead, SW Scotland, an historic Pb mining area. Comparison of the XRPD analyses with determinations of Pb by atomic absorption spectrophotometry demonstrates that a large proportion of the Pb present in the stream sediments is in the form of cerussite (PbCO₃). Furthermore, the cerussite tends to be concentrated in the silt fraction and is even a minor component of the clay-size fraction. However, quantitative analysis of fractions <6 μm indicates that cerussite alone cannot account for all the Pb in this size range. Indirectly, this result suggests that Pb adsorbed to clay minerals, organic matter and/or amorphous Fe and Mn oxides may be proportionally more important for the <6 μm materials. Sediment in this size range, however, typically accounts for no more than 1% by weight of the total stream bed sediment samples collected in the study area. In relation to its size distribution, the mobility of Pb within the wider environment is most likely to occur principally through physical transport of fine particles.     

Characterisation and evaluation of reference materials for black carbon analysis using elemental composition, colour, BET surface area and C NMR spectroscopy

A recent comparative exercise found that different black carbon (BC) quantification methods produced widely varying results for a set of BC reference materials that included three laboratory-produced BC-rich materials, five environmental BC matrices and four samples of non-BC organic matter. This variation was attributed to a range of physical and chemical properties of the samples that could, in various ways, result in the over- or under-detection of BC in some or all of the techniques. Here the most pertinent chemical and physical characteristics of the samples are presented, including elemental analysis, lightness measurements, BET surface area measurements and ¹³C NMR analysis. Amongst the BC-rich materials, soot and char could be distinguished from one another mainly on the basis of H/C and O/C ratios, NMR observability and BET surface area. The results indicate that the aromatic structures in the soot are more highly condensed, and this explains why some BC quantification techniques detect these two materials differently. The non-BC potentially interfering materials were shown to share properties with the BC-rich materials (high C content, low lightness values and high aromaticity) that are used for certain BC quantification methods. This may lead to overestimation of BC unless these interfering materials are removed during pre-treatment. The environmental matrices were found to have relatively high amounts of metal oxides that have the potential to catalyse or inhibit thermal and chemical reactions during BC analysis.     

几种土壤的细沟侵蚀过程及其影响因素

通过间隔为11h的二次人工模拟降雨和冲蚀槽试验研究了10种土壤的侵蚀过程,发现在第2次降雨中大多数土壤出现了细沟侵蚀形式。采样微形态观察发现,在第1次降雨中形成结皮的土壤在第2次降雨中出现了细沟侵蚀;产流产沙观测发现所有出现细沟侵蚀的土壤在第1次降雨中径流含沙量逐渐减少,而第2次降雨中有一个先剧增后减少的过程。土壤理化分析及多元逐步回归分析结果表明,土壤颗粒组成、有机质含量、铁铝含量等因素对细沟侵蚀的影响表现不明显,而与土壤团聚体有关结构指标、细沟侵蚀、产流产沙速率及总量呈显著相关关系。分析表明,团聚体分散度、崩解速率与渗透系数之比两个指标能较好地预测细沟侵蚀发生的可能性,同时也能很好地预测侵蚀产沙量。     

A formalized approach to analysis of geoarchaeological sediment samples: The location of the early punic Harbor at Carthage,Tunisia

This article concerns, first, the development of an approach to data analysis of sedimentological, micro- and macrofaunal, and artifactual data obtained from analysis of geoarchaeological sediment core samples and, second, an algorithmic ordering of resulting sediment groups to arrive at a definitive stratigraphic sequence. Correspondence analysis (CA) was the principal data analysis technique applied, and the algorithmic ordering is one developed for discrete sampling sequences such as core transects. From a methodological standpoint, this approach allows an assessment of the usefulness of different types of analytical information pertaining to a paleoenvironmental reconstruction of a coastal archaeological site. In terms of the geoarchaeological problem that initiated the study, the results permit a possible reconstruction of the location and nature of the first Punic port at Carthage, Tunisia.     

利用化学方法消除氯干扰的土壤中有机碳测定方法

在高锰酸钾外加热法测试土壤中有机碳的过程中,常遇到高含量氯离子对测试结果的正干扰,为解决此问题,本文提出了利用化学方法消除较高含量氯离子对测定土壤有机碳的干扰消除方法。在称取样品时,加入0. 15 g硫酸汞,消除样品中氯的干扰,通过对部分国家土壤、水系沉积物标准样品的分析测试,验证其方法准确度良好,方法的精密度为:5. 83%,可满足地质行业相关标准要求。     

小秦岭金矿区土壤重金属生物有效性与影响因素

土壤中重金属生物有效性与影响因素分析是土壤重金属风险管控的关键问题。通过实地调查、现场采样、实验测试、综合分析等方法,分析了研究区100km2内Hg、Pb、Cd、Cr、As、Cu、Zn七种重金属元素的有效态含量特征,研究了这些重金属有效态含量之间、有效态含量与全量、有效态与土壤pH、有机质含量、粒度等基本理化参数之间的相关性,分析了重金属污染来源。结果表明,土壤中Hg、Pb、Cd、Cr、As、Cu、Zn七种重金属有效态的平均含量分别为2.29mg/kg、594mg/kg、2.52mg/kg、6.30mg/kg、2.16mg/kg、48.14mg/kg、50.21mg/kg,其变异系数大小为：Hg＞Pb＞Cu＞Zn＞Cd＞As＞Cr。Hg的变异系数最大,是由于金矿选矿活动采用混汞法提金排放的尾矿堆（库）分布不均。Hg、Pb、Cd、Cu、Zn有效态量与全量之间均存在显著的相关性;土壤有机质与重金属有效态之间存在显著的相关性;土壤pH与有效态重金属之间存在显著的负相关性;土壤粒度对重金属有效态的累积影响不明显。     

小秦岭金矿区土壤重金属生物有效性与影响因素

土壤中重金属生物有效性与影响因素分析是土壤重金属风险管控的关键问题。通过实地调查、现场采样、实验测试、综合分析等方法,分析了研究区100km2内Hg、Pb、Cd、Cr、As、Cu、Zn七种重金属元素的有效态含量特征,研究了这些重金属有效态含量之间、有效态含量与全量、有效态与土壤pH、有机质含量、粒度等基本理化参数之间的相关性,分析了重金属污染来源。结果表明,土壤中Hg、Pb、Cd、Cr、As、Cu、Zn七种重金属有效态的平均含量分别为2.29mg/kg、594mg/kg、2.52mg/kg、6.30mg/kg、2.16mg/kg、48.14mg/kg、50.21mg/kg,其变异系数大小为:HgPbCuZnCdAsCr。Hg的变异系数最大,是由于金矿选矿活动采用混汞法提金排放的尾矿堆(库)分布不均。Hg、Pb、Cd、Cu、Zn有效态量与全量之间均存在显著的相关性;土壤有机质与重金属有效态之间存在显著的相关性;土壤pH与有效态重金属之间存在显著的负相关性;土壤粒度对重金属有效态的累积影响不明显。     

Comparison of metal homogeneity in grab,quartered, and crushed — sieved portions of stream sediments and metal content change resulting from crushing — sieving activity

Restricted grain size sediment samples were collected along two streams. Metal content in some samples may have been influenced by landfill emissions. Each sample was divided into a grab portion, a quartered portion, and a portion crushed and sieved to a smaller size and then quartered. A duplicate sample from each of these portions was extracted. The Cu, Pb, Zn, Co, Ba, Fe, Mn, and Ca quantities were determined for each duplicate sample. Relative standard deviation was used to reflect homogeneity of metal content. Metal occurrence represented speciated metals or major components of chemical phases. Results indicated that variation of metal content among portions was uniform and did not vary as a function of absolute metal quantity. Homogeneity was similar in the same size grab and quartered samples. A more homogeneous metal state was displayed by the crushed and sieved sediments. However, this activity enriched softer chemical phases and associated speciated metals. It was concluded that sediments need not be quartered to obtain a better homogeneity of metal distribution and that field samples should not be crushed and sieved prior to chemical analyses. Assessment of sediments affected by metal emission sources must include a knowledge of metal homogeneity in individual samples.     

福建龙海市土壤营养元素全量特征及有效量预测

以福建龙海市为研究区,在不同地质背景、土地利用方式、土壤类型和土壤成因类型条件下进行样品采集,共采集56件土壤样品,测定pH值、有机质含量（SOM）、阳离子交换量（CEC）、营养元素全量及有效量。利用相关分析、线性回归分析等统计手段,探究土壤中营养元素有效量的影响因素,建立并验证了研究区土壤中营养元素有效量的预测模型,以此深入了解区内土壤养分状况,为该区土地的合理利用及治理提供科学依据。结果表明：龙海市土壤呈酸性—强酸性,有机质含量较低,阳离子交换量偏低;土壤中N、P、K、Mo、Zn元素全量相对富集;元素全量、有效量及其有效度变异性较强;土壤中B、Cu、K、Mn等营养元素全量与有效量相关性较好,土壤pH值对K、Mo、Si的有效度有一定影响,CEC与Si的有效度呈显著正相关,SOM增加有利于提高Cu、Fe、Mn、P、Zn等元素有效量。通过土壤全量分析数据及土壤理化指标建立的线性模型,可以预测表层土壤中Cu、Fe、Mo、Mo、P、S、Si等营养元素的有效量,若引入更多影响因子,将有利于进一步提高模型的拟合效果,使得预测更准确。     

Terrestrial organic matter controlling gas hydrate formation in the Nankai Trough accretionary prism, offshore Shikoku, Japan

Sediment core samples from Sites 1175, 1176, and 1178, ODP Leg 190, Nankai Trough were analyzed for sedimentary organic matter and inorganic elemental compositions to clarify geochemical conditions for the formation of gas hydrate. Low chloride concentrations and anomalously low core temperature infer the existence of gas hydrate at Site 1178. Trace amounts of gas hydrate are also suggested for Site 1176. Site 1175 does not have any significant evidence of gas hydrate, although all the three sites are within the gas hydrate stability zone. The sediment from Site 1178 is characterized by abundant terrigenous organic matter, older geologic ages, and comparatively higher maturity levels, suggesting high rates of CO₂ generation during diagenesis. The CO₂ generation potential of sediment may be one of the crucial conditions for the formation of gas hydrate.     

1∶5万地球化学普查中样品分析配套方案和质量监控体系

介绍了1∶5万地球化学普查中土壤及水系沉积物样品的分析配套方案、方法检出限以及准确度、精密度;对分析方法的质量控制,包括准确度和精密度的控制、报出率的控制、平行样和异常点样品的重复性检验,对分析流程的质量评估.此方法已应用于大规模土壤及水系沉积物样品的分析测试,提供了巨量的基础数据,取得了良好的应用效果.     

Anthropogenic influences on Zuni agricultural soils

Farmers in the Zuni area of the semiarid American Southwest have successfully cultivated maize and other crops for over three millennia without using artificial fertilizers. Zuni agricultural fields are among the oldest, more or less continuously cultivated areas in the United States. Traditional Zuni agriculture is based on runoff farming, a system whereby runoff and organic‐rich sediment generated in small watersheds are captured and directed onto fields for crop use. We conducted a study to compare soil properties associated with paired and unpaired cultivated, abandoned, and uncultivated fields to evaluate the long‐term effects of cultivation on soil quality. Sampling and analytical methods of this research are especially applicable to geoarchaeological studies of anthropogenic effects on soil fertility and agricultural sustainability in ancient and traditional historical farming systems. Results of the Zuni soil study indicate that cultivation has altered some soil properties, including bulk density, organic carbon, total nitrogen, and C:N ratios in paired fields, but there is no indication that agricultural soils are degraded. This assessment supports the perception of Zuni farmers that long‐term cultivation has not caused a decline in agricultural productivity. © 2005 Wiley Periodicals, Inc.     

Geochemical,mineralogical and microbiological characteristics of sediment from a naturally reduced zone in a uranium-contaminated aquifer

Localized zones or lenses of naturally reduced sediments have the potential to play a significant role in the fate and transport of redox-sensitive metals and metalloids in aquifers. To assess the mineralogy, microbiology and redox processes that occur in these zones, several cores from a region of naturally occurring reducing conditions in a U-contaminated aquifer (Rifle, CO) were examined. Sediment samples from a transect of cores ranging from oxic/suboxic Rifle aquifer sediment to naturally reduced sediment were analyzed for U and Fe content, oxidation state, and mineralogy; reduced S phases; and solid-phase organic C content using a suite of analytical and spectroscopic techniques on bulk sediment and size fractions. Solid-phase U concentrations were higher in the naturally reduced zone, with a high proportion of the U present as U(IV). The sediments were also elevated in reduced S phases and Fe(II), indicating it is very likely that U(VI), Fe(III), and SO₄ reduction has occurred or is occurring in the sediment. The microbial community was assessed using lipid- and DNA-based techniques, and statistical redundancy analysis was performed to determine correlations between the microbial community and the geochemistry. Increased concentrations of solid-phase organic C and biomass in the naturally reduced sediment suggests that natural bioreduction is stimulated by a zone of increased organic C concentration associated with fine-grained material and lower permeability to groundwater flow. Characterization of the naturally bioreduced sediment provides an understanding of the natural processes that occur in the sediment under reducing conditions and how they may impact natural attenuation of radionuclides and other redox sensitive materials. Results also suggest the importance of recalcitrant organic C for maintaining reducing conditions and U immobilization.