Importance of Noncrystalline Hydroxide Phases in Sequential Extractions to Fractionate Antimony in Acid Soils     

《Communications in Soil Science and Plant Analysis》2012,43(11-12):1487-1501

Abstract

Sequential extraction techniques have been used to make inferences about speciation of phosphorus (P) and to a lesser extent arsenic (As) in soils. However, sequential extraction studies on the less‐abundant group V element, antimony (Sb), are limited. In this work, a widely used P sequential extraction scheme was modified and used to extract P, As, and Sb from two acidic soils from the Macleay River floodplain, NSW, that were enriched with Sb (26.9 and 23.0 mg kg^?1). An ammonium oxalate–oxalic acid step was included in the extraction sequence to dissolve the noncrystalline iron (Fe) and aluminium (Al) hydroxide phase. It extracted 30 to 47% of Sb, indicating the importance of this fraction, which may be mobilized in the floodplain by acid sulfate soil processes and periodic waterlogging. The original method overestimated P, As, and Sb in the residual fraction (30–71%). Relative efficiency values of extracts for P, As, and Sb were compared, and inferences about phase distributions were made. The results suggest some potential in using extractions to assess bioavailability of Sb in soil.  相似文献   

土壤总砷测定前处理方法探讨   总被引：2，自引：0，他引：2  

邹强  刘芳  龚世龙  杨剑虹 《土壤通报》2011,(6):1341-1344

采用加标回收方法比较研究了5种土壤总砷测定的前处理方法(分别为浓HNO3-浓H2SO4-HC1O4法、王水法、浓HNO3-浓H2SO4-V2O5法、浓HNO3-浓H2SO4-V2O5Ⅰ法和浓HNO3-浓H2SO4-V2O5Ⅱ法),结果表明,5种前处理方法的加标回收率在89.9%～102%之间,变异系数在0.56%～5.27%之间。其中,浓HNO3-浓H2SO4-V2O5Ⅰ法处理,土壤所用消解时间40min左右,其回收率较高,在98.5%～99.1%之间,变异系数较小,在0.56%～0.85%之间;该前处理方法具有消解时间最短、加标回收率和精密度高及重现性最好的特点,优于其他4种前处理方法,可作为推荐方法应用。  相似文献   

河北沧州果品主产区土壤砷空间变异性研究     

刘福顺  刘会玲  张毅功 《土壤通报》2011,(6)

采用GIS技术和地统计学相结合的方法对河北沧州果品主产区献县、泊头、沧县3个县表层土壤(0～20 cm)砷的空间分异特征进行了分析。结果表明:3个县表层土壤砷的平均值为12.46 mg kg-1,砷污染存在的风险较低。土壤砷最优理论模型为指数模型,空间结构上具有中等程度空间相关性,说明其空间变异主要是由母质、地形、土壤类型等结构性因素引起的。各向异性分析表明地质背景、河流和飘尘可能影响着土壤砷的分布。Kriging插图结果直观的反映出研究区内土壤砷的空间变异特征。调查结果显示含砷污水的农田灌溉,含砷煤燃烧产生的大气降尘,含砷农药、化肥的使用等是影响土壤砷分布的人为因素。  相似文献   

六价铬污染土壤后形态变化及其对土壤脲酶活性的影响     

蔡少华  ;和文祥  ;梁艳茹  ;潘宝钧 《农业环境保护》2009,(2):251-255

采用室内模拟方法较为系统地研究了六价水溶态铬和总铬对土壤脲酶活性的影响。结果表明,六价铬进入土壤后,水溶态含量迅速降低,降幅随培养时间延长而减缓;水溶态铬含量与外源总铬的变化呈极显著正相关;六价铬抑制土壤脲酶活性,且脲酶活性与六价水溶态铬达到极显著负相关,揭示脲酶活性可作为土壤铬污染程度的指标之一;从土壤脲酶角度获得的红壤轻度和中度污染时临界浓度,土壤总铬和水溶态铬含量分别为17．07、85．37mg·kg-1和0．78、3．88mg·kg-1;随土壤肥力降低,土壤脲酶的ED10和ED50递减。  相似文献   

不同种植年限大棚菜田土壤水溶性盐分的变化特征   总被引：12，自引：0，他引：12  

陈碧华  杨和连  李亚灵  李新峥  周俊国 《水土保持学报》2012,26(1):241-245

采集新乡市不同种植年限大棚菜田、露天菜田及大田土壤共计160个样品,调查分析水溶性盐总量、各盐分离子的变化及土壤pH值。结果表明,大棚土壤在连续种植不同年限后,水溶性盐总量上升幅度与种植年限呈极显著相关(r=0.92**);K+、Na+、Cl-、NO2-、NO3-、SO24-含量与种植年限呈正相关,而Ca2+、Mg2+、HCO3-含量变化与种植年限呈负相关;土壤pH值降低幅度与种植年限呈极显著相关;K+、Na+、Cl-、NO3-、SO42-的含量均与土壤水溶性盐总量呈极显著相关。新乡市大棚菜田土壤中Cl-、NO2-、NO3-含量与pH值变化存在极显著负相关;SO42-含量与pH值变化存在显著负相关;HCO3-与土壤pH值变化存在极显著正相关。新乡市大棚菜田阳离子以K+、Na+为主,阴离子主要以Cl-、NO2-、NO3-、SO42-为主;不同种植年限对大棚土壤盐渍化和酸化有极显著影响,K+、Na+、Cl-、NO2-、NO3-、SO42-则是造成土壤盐渍化的重要原因,Cl-、NO2-、NO3-、SO42-是造成土壤酸化的重要原因。  相似文献   

适于轻度Cd、As污染土壤种植的水稻品种筛选     

叶新新  周艳丽  孙波 《农业环境保护》2012,(6):1082-1088

对重金属具有高耐性、低富集的水稻品种可用于轻度重金属污染的水稻土。采用温室盆栽试验研究2种水稻土（红泥田和黄泥田）中Cd、As污染对9种水稻生长的影响,分析不同水稻品种对Cd、As富集能力的差异。结果表明,As污染处理下所有水稻品种的生物量均显著降低,在红泥田上,水稻生物量降低幅度为29.4%～54.3%;在黄泥田上,降低幅度为29.5～53.3%。不同水稻品种对As耐性有显著差异（P〈0.05）,晚粳9707（粳稻）生物量降幅较小,耐性较高;浙1500（籼稻）降幅较大,耐性较低。对于Cd污染处理,在2种类型土壤上9种水稻对Cd耐性差异不显著。不同水稻品种对土壤Cd、As的富集能力有显著差异（P〈0.05）。在2种类型土壤上,德农2000（杂交稻）和浙1500（籼稻）分别对As、Cd的富集系数最高,对As、Cd污染敏感;南粳32（粳稻）对Cd、As的富集系数均较低,对Cd、As污染不敏感。在9个水稻品种中,南粳32对Cd、As的富集能力最低,并且对As耐性较高,适合在Cd、As轻度污染的水稻土上种植。  相似文献   

Changes in the microbial community structure in soils treated with a mixture of glucose and peptone with reference to the respiratory quinone profile     

Arata Katayama  Hong-Ying Hu  Mamie Nozawa  Sayuri Takahashi  Koichi Fujie 《Soil Science and Plant Nutrition》2013,59(6):841-846

Based on the respiratory quinone profile, changes in the structure of microbial communities in the soil samples from Nagoya University Farm were monitored after the treatment with 1% of a mixture of glucose and peptone. Samples of two soils differing in the fertilization history were examined: CF-soil with the application of only chemical fertilizers and FYM-soil with the application of only farmyard manure at a high rate. In the CF-soil, the amount of water-soluble organic carbon (WOC), indicator of the mixture of glucose and peptone, decreased to the original level after 14 d. After 7 d, the soil pH reached the maximum level, then decreased gradually. Changes in the inorganic nitrogen levels in the water extract also reflected the 14-d period of mineralization. The amount of respiratory quinones reached maximum levels after 7 d and gradually decreased, reflecting the changes in the microbial biomass. The quinone composition significantly changed during the 14-d period and returned to a profile similar to the original one after 28 d. Diversity of quinones significantly decreased during the 14-d period due to the predominance of ubiquinone with 9 isoprenoid units. In the FYM-soil, the amount of WOC decreased to the original level after 1 d, and the pH and inorganic nitrogen levels in the water extract reflected the one-day mineralization period, and nitrification started after 3 d. Although the amount of quinones indicated an increase in the microbial biomass for 14 d, the quinone composition did not change. These findings suggested that long-term application of farmyard manure resulted in stable microbial communities in response to the incorporation of organic matter in soil.  相似文献   

铅锌尾矿中砷代谢功能基因的多样性     

LI Xiaofang  Philip L. BOND  Longbin HUANG 《土壤圈》2017,27(3):630-637

Microbial activities impact arsenic (As) transformation in mine tailings substantially,yet little is understood on the functional diversity of As metabolism genes.This study explored this issue using a metagenomic approach coupled by a local BLASTN procedure established in our recent studies.An assembled metagenome,recovered from hypersaline and sulfidic mine tailings,was screened for As metabolism genes aioA,arrA,arsC and arsM.This was done using a local BLASTN procedure against databases of the As metabolism genes built in this study.Putative As metabolism genes detected in the assembled metagenome included 11 arsM,20 arsC and 1 arrA full-length sequences.Together with the rRNA-based phylogenetic profiling results,a picture depicting microbial As cycling in the tailings to the genus level was obtained.It was found that most of the dominant genera in the tailings potentially harboured the genes for As reduction and/or methylation.In particular,a typical pyrite-eater present in the tailings,Thioalkalivibrio sp.,was found to harbour not only arsC and arsM,but also arrA.These results highlight the unexpected diversity of As metabolism genes in the tailings,especially considering the extremely low species diversity therein.The microbial As cycling picture established here has potential use for guiding the purposeful manipulation of As biogeochemistry in the tailings.  相似文献   

铁改性生物炭促进土壤砷形态转化抑制植物砷吸收   总被引：10，自引：6，他引：10  

董双快  徐万里  吴福飞  闫翠侠  李典鹏  贾宏涛 《农业工程学报》2016,32(15):204-212

通过盆栽试验研究了不同砷污染水平(10、20、40和80 mg/kg)下,添加不同量(10、20和40 g/kg)改性前后的生物炭对土壤砷形态及植物吸收砷规律的影响。该文以棉花秸秆生物炭及改性生物炭(棉花秸秆生物炭与Fe Cl3?6H2O按质量比为20∶1)为试材,小白菜为供试植物。结果表明:生物炭(10~40 g/kg)和改性生物炭(10 g/kg)能促进小白菜的生长,在添加量分别为20和10 g/kg时生物量最大,其最大值分别为8.26和6.68 g/盆,改性生物炭在添加量为10 g/kg时高于对照组和等量未改性生物炭处理组。在砷质量分数为10和20 mg/kg的基础上,添加生物炭(10~40 g/kg)后,土壤中砷主要以残渣态形式存在;水溶态砷分别增加了0.22%~3.36%和0.96%~3.70%;改性生物炭添加对土壤砷质量分数为10 mg/kg时水溶态砷无明显影响,土壤砷质量分数为20 mg/kg时,添加改性生物炭(10~40 g/kg)后水溶态砷减少了0.12%~0.58%。在高浓度(40和80 mg/kg)砷土壤中,水溶态砷含量随着土壤中砷含量的增加而增大;添加生物炭(10~40 g/kg)后,土壤中水溶态砷分别增加了0.21%~1.56%和2.11%~8.94%,但砷主要以铝形砷形式存在,残渣态砷次之。各处理组小白菜可食部分和根部砷质量分数在添加10~40 g/kg生物炭后的变化规律不尽相同,等量的改性生物炭添加后,可食部分由18.28 mg/kg显著降低至2.66 mg/kg(P0.05),根部从133.99 mg/kg显著降低至20.21 mg/kg(P0.05)。改性生物炭与未改性生物炭相比,改性生物炭能降低土壤中水溶态砷的含量及对小白菜吸收砷有显著的抑制作用。因此,该研究可为改性生物炭在含砷土壤的修复应用中提供数据支撑与理论基础。  相似文献   

市售茶叶中重金属含量特征及其分析     

张亚莉  耿丽平  张春楠  孙洪欣  赵全利  张明明  刘文菊 《中国农学通报》2017,33(28):151-157

为了解市售主要茶叶中重金属的含量情况,采集市售主要茶叶种类,采用高压密闭消解系统、电感耦合等离子质谱法(ICP-MS)和原子荧光光谱法测定茶叶中的铅(Pb)、镉(Cd)、汞(Hg)、砷(As)的含量,并根据《食品中污染物限量》(GB 2762—2012)、《茶叶中铬、镉、汞、砷及氟化物限量》(NY 659—2003)以及《绿色食品-代用茶中华人民共和国农业行业标准》(NY/T 2140—2012)分析了市售茶叶中Pb、Cd、Hg、As的含量特征。结果显示,茶叶中Pb、Cd、Hg、As含量范围分别为0.1~1.67、0.0006~0.085、0.00021~0.022、0.00~0.78 mg/kg,所有茶叶样品Pb、Cd、Hg均符合相关标准。但1.9%茶叶样品中As含量超过国内《绿色食品-代用茶》中As的标准(As≤0.5 mg/kg),超标样品为散装黑茶。茶叶中Pb、Cd、Hg、As含量具有一定的相关性,Pb与As、Hg、Cd元素之间,Cd与As元素之间存在极显著相关。对市场中茶叶进行选择时,建议选择定型包装茶叶,产于广西的定型包装的茉莉花茶较安全;而市场中黑茶和散装茶质量差异较大,在选择相关茶叶商品时应根据其原产地、包装类型及单价分辨其质量的高低。  相似文献