现代黄河三角洲土壤特性对多氯联苯分布的影响规律

对现代黄河三角洲22个表层土壤样品中类二噁英类多氯联苯(PCBs)进行双毛细管柱GC-ECD结合MS测试,并使用相关数学统计学分析方法-相关性研究方法研究了现代黄河三角洲地区土壤特性对PCBs分布的影响,结果表明:土壤有机质量分数与其类二噁英类PCBs的总质量浓度呈弱的正相关关系。土壤粒径组成中粘粒质量分数与其类二噁英类PCBs的总质量浓度呈相关性关系,且达到极显著的水平;粉砂粒的质量分数与类二噁英类PCBs的总质量浓度无相关关系;砂粒质量分数与类二噁英类PCBs的质量浓度呈负相关关系,达到显著相关的水平。土壤溶解盐质量分数及pH值与类二噁英类PCBs的总量没有明显的相关性。可见,土壤中有机质、土壤颗粒组成中粘粒和砂粒质量分数是影响现代黄河三角洲地区土壤中PCBs分布的主要因素。     

多氯联苯在土壤中的吸附规律及其影响因素研究

为了建立定量描述土壤中多氯联苯（PCBs）迁移规律的数学模型,以采自现代黄河三角洲地区的土壤为研究对象,针对类二噁英类多氯联苯PCB81及阻转类多氯联苯PCB95在土壤中的吸附行为进行了研究,获得了其吸附等温方程并分析了土壤有机质含量、颗粒组成、pH、矿物质含量等特性参数对吸附量的影响。结果表明,PCBs在土壤中的吸附行为符合Langmuir吸附等温方程;PCBs的吸附量与土壤中有机质含量和土壤粘粒含量呈正相关关系,与土壤pH值及土壤矿物质含量无明显相关关系。     

不同类型植物篱对长江上游坡耕地土壤养分含量及坡面分布的影响

在调查分析长江上游现有坡耕地植物篱的配置方式、生长状况和室内分析植物篱-坡耕地系统中土壤养分含量和颗粒组成的基础上,对3种坡耕地-植物篱系统中土壤养分含量及其分布特征进行了研究,结果表明：在坡耕地-植物篱系统中,植物篱能显著改善和提高植物篱带内表层土壤的养分含量,不同植物篱带内土壤有机质、全氮、水解氮、全磷、速效磷、全钾、速效钾平均质量分数比带间坡耕地土壤分别提高了59.1%、83.5%、56.2%、83.3%、149.6%、14.0%、153.1%,植物篱带内土壤阳离子交换量比带间坡耕地土壤提高了21.6%。植物篱带内比带间坡耕地土壤沙粒质量分数减小了9.4%,粘粒质量分数增加了21.6%,在植物篱系统中土壤粘粒质量分数与土壤养分含量在3种植物篱系统内表现出一致的规律性,自篱间坡耕地至植物篱带呈增加的趋势,至植物篱带下土壤粘粒和土壤养分含量减小。     

广东坡地红壤颗粒组成状况的研究──Ⅲ.土壤颗粒组成与土壤理化性质的关系

根据所收集的土壤理化分析资料，探讨了广东坡地红壤类颗粒组成对土壤理化性质的影响．研究结果表明，土壤＜0．01mm物理性粘粒或是＜0．001mm粘粒含量与土壤结构系数、＜0．005mm孔隙度、土壤持水量、土壤阳离子代换量、土壤有机质、土壤N和P含量均呈显著正相关；＜0．001mm颗粒含量与土壤有效持水量呈显著指数相关。由此可见，土壤颗粒组成是影响土壤肥力的重要因素。     

土壤性质对土壤中汞赋存形态的影响

土壤是一个复杂的生态系统，典型相关分析表明，土壤的组成性状对土壤中汞的形态分布影响较大，影响因子主要有ＦＡ，ＨＡ，有机质和碳酸盐含量，土壤粘粒作用较小，土壤有机质表现出很强的表面络合能力。     

广州郊区农业土壤重金属含量与土壤性质的关系

研究了广州郊区农业土壤性质和土壤中的重金属含量,并对2者的相关关系进行了分析。结果表明:广州郊区农业土壤中壤土占样品总数的70.5%,土壤pH值平均为5.93,土壤有机质平均含量为31 7g·kg-1,土壤阳离子交换量不高,且各区之间变幅较大;Cu、Pb、Zn、Ni、Cd、As和Hg有效态含量在3种土壤中顺序为菜园土>水稻土>赤红壤;土壤重金属和土壤理化性质间的关系复杂,如有效态Cu、Zn、Ni与土壤有机质含量呈极显著相关,Cd与土壤有机质含量和土壤粘粒含量呈极显著相关,As除与有机质含量和粘粒含量有关,与pH、阳离子交换量也有极显著相关关系。     

干旱区土壤小麦根系界面Cd行为的环境影响研究——以甘肃省白银市区耕作灰钙土为例

通过大田环境-土壤-作物系统Cd行为的环境影响研究，初步发现，共存元素Cd、Cu、Ni、Pb、Zn对Cd元素在土壤-作物根系界面行为的影响表现为正效应，其影响顺序为Cd>Pb>Cu>Zn>Ni；pH值、粘粒、粗粉粒含量与根系Cd含量呈负相关；磷和砂粒含量与根系Cd含量呈正相关；细粉粒、粗粘粒、有机质和CEC     

PCB138在土壤中的吸附特征及土壤特性对其吸附的影响

为研究六氯联苯PCB138在土壤组分中的吸附特征及土壤特性对其吸附的影响,选取红壤和有机质含量较高的黑土作为供试土壤,提取土壤有机质组分中的胡敏酸和胡敏素,采用振荡平衡法研究了PCB138在原供试土壤、胡敏酸和胡敏素中的吸附特征。结果表明,PCB138在两种土壤组分中的吸附是一个快速吸附过程,240 min即可达到吸附平衡。PCB138在土壤组分中吸附速率和吸附量表现为:胡敏酸﹥原土壤﹥胡敏素,准一级动力学方程能更好地描述其吸附过程。PCB138在黑土中的吸附速率和吸附量略大于其在红壤中的相应数值。PCB138在两种土壤中的吸附过程可用Freundlich吸附等温方程描述。Pearson相关性分析结果表明,PCB138在两种土壤组分中的吸附量与土壤中有机质量分数和2μm粒径质量分数呈显著相关(P0.05)。吸附速率与土壤中有机质质量分数呈极显著相关(P0.01)。实验条件下,土壤中有机质质量分数和2μm粒径质量分数可能是影响PCB138在土壤组分中的吸附行为的主要土壤特性因素。本研究可为揭示PCBs的环境行为与污染控制提供依据。     

典型烧结厂周边土壤多氯联苯的环境污染特征

本文以唐山某典型烧结厂为研究对象,对铁矿石烧结厂排放的烟气及周边土壤样品进行采集,应用同位素稀释高分辨气相色谱-高分辨质谱联用法(HRGC/HRMS)测定了多氯联苯(PCBs)的含量,并研究了PCBs的同类物分布特征.其中烟气样品中类二英PCBs(dl-PCBs)总浓度为1.04—1.77ng·m~(-3),毒性当量值为8.99—19.32pg·WHO-TEQ·m~(-3).烧结厂周边土壤样品中dl-PCBs的总浓度为8.81—403.59pg·g~(-1),毒性当量值为0.05—0.65pg·WHO-TEQ·g~(-1),是背景土壤样品的(0.035pg·WHO-TEQ·g~(-1))的1—19倍.可以看出,该烧结厂周边环境土壤受到了企业所排放PCBs等有毒污染物的影响.大部分土壤样品的同类物分布特征相似;CB-118对土壤dl-PCBs浓度贡献率最大,贡献率为31.74%.CB-101对土壤指示性PCBs浓度贡献率最大,贡献率为52.82%.将土壤样品和烟气样品的同类物分布进行比较发现二者略有不同.尽管都是以低氯代同类物为主,但是烟气样品中最高的同类物是TrCBs,且随着氯代数的增加,浓度呈现明显下降的趋势;而土壤样品PeCBs浓度最高,PeCBs前后都呈现逐级下降的趋势.唐山市此烧结厂周边土壤无论是TEQ值,指示性PCBs总浓度,PCBs总浓度与其它研究相比都处于较高水平.     

北京市西三环地区大气中多氯联苯的污染特征和气粒分配

以北京市西三环地区北京工商大学作为采样点,在2017年3—5月共采集气相、颗粒相(PM_(2.5)、PM_(10)、TSP)样品54个,对样品中28种PCBs单体进行定性定量分析,研究大气中多氯联苯(PCBs)的污染特征、在不同粒径颗粒物(PM_(2.5)、PM_(10)、TSP)中的分布规律和气粒分配行为.结果表明,北京市西三环地区大气中PCBs总浓度为144—859 pg·m~(-3),在国内外处于中等水平.其中,气相样品中PCBs浓度为131—814 pg·m~(-3),平均浓度为495 pg·m~(-3),占大气中PCBs总浓度的94.95%;颗粒相样品中PCBs浓度为12.3—48.9 pg·m~(-3),平均浓度为26.3 pg·m~(-3),占大气中PCBs总浓度的5.05%.低氯代PCBs更多地分布在气相上,高氯代PCBs更多地分布在颗粒相上.对不同粒径颗粒物(≤2.5μm、2.5—10μm、10μm)中PCBs的分析表明,PCBs主要分布在≤2.5μm的颗粒物中.不同粒径颗粒物中所含PCBs同系物的组成比例接近,以三氯至七氯为主,占颗粒物中PCBs总含量的88%以上.用过冷饱和蒸气压P0L(Pa)和分配系数Kp来描述PCBs的气粒分配行为,lg Kp-lg P0L的斜率为-0.3653,说明北京西三环地区大气中PCBs的气粒分配未达到平衡状态,在气粒分配过程中以吸收机制为主.     

蕉园土壤因子与香蕉枯萎病发病的相关性研究

香蕉枯萎病（Fusarium oysporum f.cubense）是当前严重威胁我国华南地区香蕉生产的重要土传病害,目前尚未找到有效的防治方法。于2010年采集了3个典型香蕉枯萎病患病样地（尖峰、冲坡、十月田）和2个健康样地（临高、广州）的根际与非根际土壤样品共46份,采用常规分析方法测定了19项土壤理化指标含量。旨在从农艺措施的角度考虑香蕉枯萎病的防治提供理论依据。结果表明：健康蕉园的大多理化性状和养分含量高于患病蕉园。尤以土壤粘粒、有机质、CEC、全N、全P、有效P、有效Cu、有效Fe、有效B和交换性Ca含量表现更为明显,其在健康蕉园中的含量均为患病蕉园的1.5倍以上。同一患病蕉园根际土壤中的pH值随植株感病级别增加而上升,而有效P和有效B含量随植株感病级别增加而降低。由此可以推论,在蕉园适当增施P肥和B肥有助于抑制香蕉枯萎病发生。     

The correlation of total and extractable heavy metals from soil and domestic sewage sludge and their transfer to maize ( Zea mays L.) plants

A study to understand the mobility and transport of heavy metals (HMs) from soil and soil amended with sewage sludge to maize plants was carried out. The total and ethylenediaminetetraaceticacid (EDTA)-extractable HMs in agricultural soil and untreated domestic sewage sludge samples, and the correlation between the total and extractable metals in soil and sewage sludge were carried out. Pot experiments were performed to study the transfer of HMs to maize grains, grown in soil (control) and in soil amended with sewage sludge (test samples). The total and extractable HMs in soil, sewage sludge, and maize grains were analysed by FAAS/ETAAS (flame atomic absorption spectrometer/electrothermal atomic absorption spectrometer) after digestion in microwave oven. Statistically significant correlations were obtained between the total contents of Cu, Cd, As and their respective extractable fractions in soil, while in domestic wastewater sludge (DWS) the better correlation was observed only for Ni and Cd. The edible part of maize plants (grains) from test samples presented high concentration of Zn, Pb, Ni, Cd, Cu, As, and Cr concentrations (80.7–85.6, 3.8–3.95, 2.35–2.5, 0.75–0.82, 3.21–3.29, 0.23–0.27, and 0.22–0.29?mg?kg^?1, respectively). Good correlations were found between metals in exchangeable fractions of both soil and DWS and total metals in control and test samples of maize grains. The transfer factor of all HMs from DWS to maize grains was also determined.     

Estimation of the daily soil/dust (SD) ingestion rate of children from Gansu Province,China via hand-to-mouth contact using tracer elements

A total of 60 children (31 males and 29 females) between the ages of 3 and 12 years were randomly selected from Lanzhou City in Gansu Province, northwest China. Hand (soil/dust) SD samples from these children were collected using hand wipes. We determined the approximate amounts of hand SD and the concentrations of three tracer soil elements (Ce, Y, and V) in these samples. The approximate amounts of hand SD ranged from 42.28 to 173.76 mg, with a median value of 85.42 mg. In addition, the mean amounts of hand SD estimated using the concentrations of Ce, Y, and V in the samples were 4.63, 3.43, and 3.42 mg, respectively. The amount of hand SD varied greatly among the age groups: primary school children had more hand SD than kindergarten children, males had more hand SD than females, and children from rural areas had more hand SD than those from urban areas. The rates of daily ingestion of hand SD for kindergarten and primary school children were estimated to be 7.73 and 6.61 mg/day, respectively.     

蔬菜地土壤磷提取及模拟径流中磷素潜在流失的影响

蔬菜地磷素流失是一种典型农业非点源污染类型。通过观测地表径流中溶解态反应磷(DRP)、生物可利用磷(BAP)可以监测土壤磷素流失程度。受到各种客观条件的限制,这两个指标比较难于获取,而土壤中的总磷(TP)、Olsen(OP)、Mehlich-1(M-1P)和水溶性磷(Pw)可以通过常规分析手段获取。本文选取27个典型蔬菜样地,分析测定各样地土壤中的总磷(TP)、Olsen(OP)、Mehlich-1(M-1P)和水溶性磷(Pw)四个磷提取变量,采用了经典方法计算土壤磷流失潜能指标——磷吸持饱和度(DPS)。同时采用模拟径流实验得出典型蔬菜样地地表径流样中溶解态反应磷(DRP)、生物可利用磷(BAP)。结果表明:M-1P、Pw与DPS呈极显著正相关,相关系数分别达到了0.85和0.74(p<0.01);而M-1P、Pw与DRP浓度相关系数(r2=0.843和0.786,p<0.01)大于TP、OP与DRP浓度的相关系数(r2=0.554和0.722,p<0.01)。结论认为,通过测定M-1P、Pw和计算DPS能比较准确、便捷地预测土壤径流磷素流失风险程度。     

Heavy metals from soil and domestic sewage sludge and their transfer to Sorghum plants

We studied the mobility and transport of heavy metals such as Cu, Zn, As, Cd, Cr, Ni, and Pb, from soil and soil amended with sewage sludge to sorghum plants. The total and ethylenediaminetetraacetic acid (EDTA) extractable heavy metals in agricultural soil and untreated domestic sewage sludge (DWS) samples were determined. The correlation between the total and extractable metals in soil and sewage sludge was investigated. The total and extractable heavy metals in soil, sewage sludge and sorghum grain were analysed by flame and electro thermal atomic absorption spectrometer (FAAS/ETAAS), after digestion in microwave oven. Statistically good correlations were obtained between the total contents of all heavy metals and their respective extractable fractions in soil and domestic wastewater sludge. Transfer factors of all heavy metals from domestic sewage sludge to sorghum grains were determined.     

The relationship between soil geochemistry and the bioaccessibility of trace elements in playground soil

A total of 32 samples of surficial soil were collected from 16 playground areas in Madrid (Spain), in order to investigate the importance of the geochemistry of the soil on subsequent bioaccessibility of trace elements. The in vitro bioaccessibility of As, Co, Cr, Cu, Ni, Pb and Zn was evaluated by means of two extraction processes that simulate the gastric environment and one that reproduces a gastric?+?intestinal digestion sequence. The results of the in vitro bioaccessibility were compared against aqua regia extractions (“total” concentration), and it was found that total concentrations of As, Cu, Pb and Zn were double those of bioaccessible values, whilst that of Cr was ten times higher. Whereas the results of the gastric?+?intestinal extraction were affected by a high uncertainty, both gastric methods offered very similar and consistent results, with bioaccessibilities following the order: As?=?Cu?=?Pb?=?Zn?>?Co?>?Ni?>?Cr, and ranging from 63 to 7?%. Selected soil properties including pH, organic matter, Fe and CaCO₃ content were determined to assess their influence on trace element bioaccessibility, and it was found that Cu, Pb and Zn were predominantly bound to organic matter and, to a lesser extent, Fe oxides. The former fraction was readily accessible in the gastric solution, whereas Fe oxides seemed to recapture negatively charged chloride complexes of these elements in the gastric solution, lowering their bioaccessibility. The homogeneous pH of the playground soils included in the study does not influence trace element bioaccessibility to any significant extent except for Cr, where the very low gastric accessibility seems to be related to the strongly pH-dependent formation of complexes with organic matter. The results for As, which have been previously described and discussed in detail in Mingot et al. (Chemosphere 84: 1386–1391, 2011), indicate a high gastric bioaccessibility for this element as a consequence of its strong association with calcium carbonate and the ease with which these bonds are broken in the gastric solution. The calculation of risk assessments are therefore dependant on the methodology used and the specific environment they address. This has impacts on management strategies formulated to ensure that the most vulnerable of society, children, can live and play without adverse consequences to their health.     

Metal distribution in urban soil around steel industry beside Queen Alia Airport,Jordan

The objective of this study was to assess the extent and severity of metal contamination in urban soil around Queen Alia Airport, Jordan. Thirty-two soil samples were collected around steel manufacturing plants located in the Al-Jiza area, south Jordan, around the Queen Alia Airport. The samples were obtained at two depths, 0–10 and 10–20 cm, and were analyzed by atomic absorption spectrophotometry for lead (Pb), zinc (Zn), cadmium (Cd), iron (Fe), copper (Cu) and chromium (Cr) levels. The physicochemical factors believed to affect the mobility of metals in the soil of the study area were also examined, including pH, electrical conductivity, total organic matter, calcium carbonate (CaCO₃) content and cation exchange capacity. The high concentrations of Pb, Zn and Cd in the soil samples were found to be related to anthropogenic sources, such as the steel manufacturing plants, agriculture and traffic emissions, with the highest concentrations of these metals close to the site of the steel plants; in contrast the concentration of Cr was low in the soil sampled close to the steel plants. The metals were concentrated in the surface soil, and concentrations decreased with increasing depth, reflecting the physical properties of the soil and its alkaline pH. The mineralogical composition of the topsoil, identified by X-ray diffraction, was predominantly quartz, calcite, dolomite and minor minerals, such as gypsum and clay minerals. Metal concentrations were compared using one-way analysis of variance (ANOVA) to compute the statistical significance of the mean. The results of the ANOVA showed significant differences between sites for Pb, Cd and Cu, but no significant differences for the remaining metals tested. Factor analysis revealed that polluted soil occurs predominantly at sites around the steel plants and that there is no significant variation in the characteristics of the unpolluted soil, which are uniform in the study area.     

Sequential extraction of cadmium in different soil phases and plant parts from a former industrialized area

Cd concentrations in mobile phases of soil are more representative than total Cd concentration for estimating Cd bioavailability, physicochemical reactivity and mobility. In this study, selective sequential extraction procedures were used to determine Cd in different soil phases. Soil samples and plants grown in these soils were collected from a serpentine and copper-mining area in Maden-Elazig-Turkey. The extracted fractions were exchangeable/carbonate, reducible-iron/manganese oxides, oxidizable-organic matter and sulfides, and residual phases except silicates. Concentrations of Cd in soils and plant samples were determined by flame atomic absorption spectrometry and inductively coupled plasma-mass spectrometry. We found that Cd concentrations in the EDTA and NH₂OH·HCl extracts are higher in most soil samples compared to the other extracts. We conclude that Cd levels in mobile phases are unexpectedly high. The observed Cd concentrations are in ranges of 0.03–3.4 mg kg⁻¹ for soil and 0.02–2.5 mg kg⁻¹ for plant parts. The percentages of cadmium up to 56% in exchangeable and carbonates fractions were observed to be significantly higher than in those values less than 2% reported in literature. This study has shown that the modified extraction method can be usefully applied to determine Cd concentrations in potentially mobile phase of soil. Furthermore, it was concluded that Brassicasea and Rumex leaves can be used as hyperaccumulator plants because their translocation factor and/or enrichment coefficient values were found to be higher than 1.0.     

土壤与酸的反应时间对土壤酸度及土壤溶液中铝离子形态分布的影响

用两种土壤研究土壤与酸的反应时间对土壤酸度及土壤溶液中铝离子形态分布的影响。结果表明，土壤溶液pH随反应时间增加而增加，安徽红壤pH的增幅大于江西红壤。在pH3.0的HNO3溶液中，土壤溶液中的总铝及Al3 均随反应时间增加而减少，而在pH3．5的HNO3溶液中，土壤溶液中总铝及Al－F络合物先随反应时间的增加而减小．然后又有所增加。