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1.
农田土壤–蔬菜体系中残留和滋生的多种抗生素抗性致病细菌已对人体健康和生态环境安全造成较严重的隐患,因此开展针对性的风险管控技术研究十分迫切。生物质炭阻控与农业噬菌体疗法联用靶向灭活土壤–蔬菜体系中抗生素抗性致病细菌,为解决此类污染土壤问题提供了全新途径。本研究以自主制备的抗生素抗性致病细菌(携带四环素抗性基因tet W的大肠杆菌K12,携带氯霉素抗性基因amp C的铜绿假单胞菌PAO1)污染农田土壤为盆栽用土,开展生菜土培试验60d。设置单独或同时添加生物质炭和接种广宿主型噬菌体(YSZ 5K)的不同处理,以土壤–生菜体系中K12、PAO1数量变化及tet W、amp C丰度消减程度表征联合修复的效果。结果表明,针对土壤–生菜体系中残留K12、PAO1和tet W、amp C消减程度变化,判断不同处理效果,依次为:BP(生物质炭与噬菌体联用) B(单独施用生物质炭)P(单独接种噬菌体)CK(对照),其中BP处理条件下,K12与PAO1在土壤和生菜叶片中数量较之对照处理下降了2.1~3.1个数量级,tet W和amp C丰度较之对照处理下降了2.2~3.3个数量级。此外,在BP处理条件下,生菜收获后,土壤微生物群落结构与功能多样性和稳定性指数也得到显著提升,证明该联合治理方式是一种较为环境友好的修复技术。本研究结果可为降低土壤–蔬菜体系中抗性致病细菌的残留风险提供科学的理论依据和有效的管控技术。  相似文献   

2.
叶茂  孙明明  黄丹  张忠云  赵远超  胡锋  蒋新 《土壤》2020,52(2):213-222
由致病细菌导致的新型生物污染土壤问题,已给人体健康和生态环境造成了较严重的安全隐患,开展针对性的风险管控和修复技术研究十分必要。噬菌体疗法作为一种可以高效靶向追踪灭活土壤体系中致病细菌的有效手段,越来越受到关注。本文将从噬菌体疗法定义的内涵及外延、噬菌体疗法在土壤系统中灭活致病细菌的应用及对土壤生态功能影响的角度,综述近年来国内外关于噬菌体疗法在土壤环境系统中靶向灭活致病细菌的研究进展,并提出现有研究不足及未来发展趋势,以期为噬菌体疗法在我国致病细菌污染土壤的治理应用提供科学参考和理论依据。  相似文献   

3.
5个蓖麻品种对土壤中镉富集的差异   总被引:1,自引:0,他引:1  
为了评价能源作物蓖麻对污染农田中重金属镉(Cd)的富集修复能力,本研究以5个蓖麻品种为试验材料,通过大田试验对比了不同蓖麻品种在Cd污染农田中的生长情况、对Cd的富集和转运能力以及对Cd污染土壤的修复能力。结果表明,5个蓖麻品种在Cd污染农田中生长良好,其中滇蓖2号的株高、茎粗及单株产量显著高于其他品种,分别为440.78 cm、5.04 cm以及338.85 g。5个蓖麻品种根、茎、叶及果实的Cd含量、Cd积累量和富集系数均存在显著差异,其中经作蓖麻1号根、茎和果实的Cd含量最高,分别为1.40、1.14和0.33 mg·kg-1。污染修复能力方面,滇蓖2号Cd的积累量达3.38 mg/株,提取率为5.34%,显著高于其他品种。经作蓖麻1号尽管富集能力最强,但由于其生物量最小,其Cd积累量及年提取效率均最低。综上可知,蓖麻对土壤中重金属Cd的富集能力较强,可用于修复云南个旧地区的Cd污染土壤,且种植滇蓖2号可以获得较好的修复效果。本研究结果为云南Cd污染土壤治理提供了理论基础和参考依据。  相似文献   

4.
随着我国农田土壤重金属污染的加剧,传统的物理、化学和生物修复方法不能完全满足农田土壤修复的要求,亟待寻找高效稳定、成本低廉且无二次污染的农田土壤修复技术。地球化学工程技术即是遵循这一理念的修复技术之一。本文就地球化学工程技术在农田土壤修复中的应用现状与阶段性成果进行了回顾,着重概述了地球化学材料固定与钝化,地球化学工程阻隔,地球化学转化、吸收与浓集以及地球化学自然降解与衰减等4类技术在土壤修复中的研究进展和实践成果。并在此基础上讨论了应用地球化学工程技术进行农田土壤修复的优势和不足,展望了地球化学工程技术修复农田土壤的应用前景和发展趋势,提出注重多种修复技术的联合使用、开发功能化纳米材料与磁性纳米复合材料进行修复及加快土壤修复理论成果转化的研究方向。  相似文献   

5.
目前,我国农田污染严重,国家已经出台有关法律法规,并投入大量资金,推动农田土壤修复产业的发展。基于此,在归纳总结农田土壤修复产业现状的基础上,针对农田污染修复技术尚未成熟的实际情况,尝试提出农田土壤修复行业的发展趋势,以期为农田土壤修复行业的良性发展提供参考意见。  相似文献   

6.
镉(Cd)污染农田土壤的修复是环境质量领域关注的热点,原位钝化修复技术是一项较为经济且实用的解决方案,其技术关键在于钝化材料。本文对各类钝化材料原位钝化Cd的修复效果进行了综合比较分析,综述了钝化材料应用优劣情况、研究趋势、成本效益及其潜在修复机理,以期为Cd污染农田土壤原位钝化修复材料应用提供参考。  相似文献   

7.
中碱性镉污染农田原位钝化修复材料研究进展   总被引:5,自引:1,他引:4  
农田土壤重金属污染威胁人类健康,其修复成为环境领域的研究热点。钝化修复因具有修复速率快、成本低、操作简单、不影响农业生产等特点,广泛应用于大面积重金属污染农田尤其是酸性农田修复治理中。相应,针对酸性重金属污染土壤的钝化修复材料也得到了广泛研究,然而,针对中碱性重金属污染土壤的钝化材料研究相对较少。从无机类、有机类以及复合型3种类型的修复材料概述了钝化修复材料在中碱性Cd污染土壤中的研究进展。总结了中碱性重金属污染土壤钝化修复材料以选用复合型材料为宜,且以钙镁磷肥、椰壳生物炭、油菜秸秆生物炭、腐殖酸形成有机-无机复合效果较好且经济环保。其次,从钝化剂的合理施用、风险评估等方面提出展望,以期为中碱性农田土壤重金属污染修复提供参考。  相似文献   

8.
土壤中存在能够威胁植物、动物和人体健康的病原细菌,消减这类土壤生物污染是一体化健康(One Health)的重要任务。因具有宿主细菌专一性强、侵染效率高、环境扰动性小等特性,噬菌体成为生态消减土壤病原细菌生物污染的重要手段。然而,由于土壤生物和非生物环境的复杂性,提升噬菌体消减土壤生物污染的效果和稳定性仍是当前的重大挑战。本文从噬菌体在土壤中的生存以及与病原细菌互作等过程着手,分析总结影响噬菌体阻控土壤生物污染效果和稳定性的主要因素:1)噬菌体的宿主细菌谱和种群数量,2)土壤病原细菌的多态性,3)影响噬菌体与土壤病原细菌互作的环境因素。通过构建高效噬菌体鸡尾酒、改善噬菌体产品形式和优化噬菌体施用技术等措施,建立提升阻控土壤生物污染效果和稳定性的策略,为完善土壤生物污染噬菌体疗法提供科学支撑。  相似文献   

9.
贵州铅锌冶炼区农田土壤镉铅有效性评价与预测模型研究   总被引:3,自引:1,他引:2  
张厦  宋静  高慧  张强  刘赣 《土壤》2017,49(2):328-336
农田土壤重金属的不同活性库分布和土壤-溶液分配模型能够提供重金属的生物有效性和浸出能力等信息,因而在风险评价和修复实践中非常重要。本研究采集毕节铅锌冶炼区30个历史污染农田土壤,同时在贵州省范围内采集5种类型背景土壤制成不同浓度Pb/Cd单一污染土壤;经3个月老化,分别测定由0.43 mol/L HNO_3、0.1 mol/L HCl和0.005 mol/L DTPA提取态表征的重金属反应活性库以及由0.01 mol/L CaCl_2提取态表征的直接有效库;分析铅锌冶炼区农田土壤Cd、Pb不同有效库的分布特征,建立土壤-溶液分配模型,并讨论土壤理化性质的影响。结果表明:历史污染土壤中Cd和Pb的直接有效库占全量比例分别比人工污染土壤低4倍和223倍,然而历史污染土壤Cd和Pb的反应活性库(0.43 mol/L HNO_3提取态)占全量比例要高于相应人工污染土壤中的比例。拓展Freundlich形式吸附方程能够准确描述各提取态表征的Cd和Pb活性库与土壤全量Cd和Pb的关系,尤其0.43 mol/L HNO_3提取方法能够克服土壤理化性质对土壤Cd和Pb提取的影响而与总量建立极显著的相关关系。pH依附性Freundlich吸附方程准确描述了Cd和Pb的总反应活性库分别与土壤溶液Cd和Pb的关系,对于Pb而言,还要考虑土壤有机质和有效磷的影响。本研究可为矿区农田土壤重金属污染评价、修复以及农田有效态标准的推导提供参考。  相似文献   

10.
高压脉冲电场对大肠杆菌噬菌体灭活效果初探   总被引:1,自引:0,他引:1  
为探讨高压脉冲电场(pulsed electric field,PEF)在噬菌体污染治理方面的工业应用,研究了高压脉冲电场对λ噬菌体、ΦX174噬菌体以及宿主菌E.coli MV1184的灭活效果。采用不同电场强度E,脉冲个数N和脉冲宽度г体系对λ噬菌体、ΦX174噬菌体以及λ噬菌体和E.coli MV1184混合悬液进行处理。结果表明在输出电压1~10kV,脉冲宽度1~10μs范围内,灭活效率随着脉冲数的增加而提高。PEF对噬菌体的灭活效率并不依赖于噬菌体的颗粒结构,但噬菌体颗粒结构对脉冲宽度г灭活效率有影响。在噬菌体与宿主菌E.coli MV1184的混合悬液中,λ噬菌体对PEF的灭活作用更加敏感,失活率显著高于E.coli MV1184。高压脉冲电场可以用于常温下溶液中噬菌体的灭活处理并达到消毒水平,是一种高效的噬菌体灭活方法。  相似文献   

11.
低氮和干旱胁迫对富士和秦冠生长及氮素利用的影响   总被引:2,自引:2,他引:0  
【目的】以富士(Fuji)、 秦冠(Qinguan)嫁接在平邑甜茶(Malus hupehensis Rehd.)上的当年生盆栽苗为试验材料,采用砂培方法,研究了缺氮胁迫和干旱对富士和秦冠生长情况、 光合参数、 植株各部位氮磷钾含量及氮素利用效率的影响,分析比较了低氮干旱条件下富士和秦冠生长及氮素利用的差异,以期为果树生产高效肥水利用提供理论指导。【方法】试验共设四个处理: 正常氮正常水(ZZ)、 低氮正常水(DZ)、 正常氮干旱(ZG)、 低氮干旱(DG)。氮素和水分均设置两个水平,分别为正常氮(6 mmol/L NO-3-N)、 低氮(0.3 mmol/LNO-3-N)、 正常供水(保持盆中砂子相对含水量为饱和含水量的80%~85%)、 干旱处理(保持盆中砂子相对含水量为饱和含水量的60%~65%)。【结果】富士和秦冠的生物量(茎和叶)、 株高茎粗等生长指标以及光合速率、 气孔导度、 蒸腾速率均为正常氮正常水(ZZ)>低氮正常水(DZ)>正常氮干旱(ZG)>低氮干旱(DG),并且相对应处理下秦冠的以上指标均高于富士;正常供水下,缺氮处理使富士、 秦冠的根冠比比正常氮处理均有所增加,富士提高了2.05%,秦冠提高了22.40%。富士和秦冠的氮、 磷、 钾含量均表现出正常氮正常水(ZZ)>低氮正常水(DZ)>正常氮干旱(ZG)>低氮干旱(DG); 氮、 钾元素含量在植株各部位的分布顺序依次是叶>根>茎,磷元素则是根>叶>茎;光合氮素利用效率(PNUE)和氮素利用效率表现为秦冠处理之间差异极显著,富士处理之间差异不显著;秦冠的PNUE和NUE明显高于富士,在低氮正常水(DZ)处理下,秦冠氮肥利用率比富士高42.07%,在低氮干旱(DG)处理下高64.14%;低氮胁迫下富士和秦冠的NUE显著提高,并且秦冠提高的幅度高于富士。【结论】施用氮肥能够显著提高富士与秦冠的干物质量,同等水肥条件下,秦冠生长优于富士;水分亏缺会减少叶片对氮的吸收,干旱条件下适度增施氮肥,可提高果树的抗旱能力;低氮干旱胁迫下秦冠的生长指标、 光合指标及氮素利用效率指标均优于富士,表现出较强的抗低氮干旱胁迫的能力。  相似文献   

12.
Staff members of the Department of Botany of Palacký University in Olomouc and Gene Bank Department – Workplace Olomouc, Research Institute of Crop Production in Prague, Czech Republic, conducted an expedition in seven European countries (Austria, Czech Republic, France, Germany, Italy, the Netherlands, Switzerland) in August/September 1999 to collect wild Lactuca spp. germplasm and study its geographic distribution, ecology and biodiversity. During the mission, more than 600 locations were visited resulting in the collection of 602 seed samples (accessions) of wild Lactuca species and 13 seed samples of related genera (Chondrilla and Mycelis). Lactuca serriola f. serriola, L. serriola f. integrifolia, L. saligna and L. viminea subsp. chondrilliflora were prevalent in southern Europe (Italy, France), however, only L. serriola was common in central and western Europe (Austria, Czech Republic, Germany, Netherlands, Switzerland). The greatest diversity of Lactuca species was found in France, where also the most seed samples (165) were collected. The most characteristic habitats with a high density of Lactuca spp. populations were observed along roads and highways, grassy ditches, ruderal communities, and dust-heaps. Natural infections by powdery mildew (Erysiphe cichoracearum) and downy mildew (Bremia lactucae) on some wild Lactuca spp. were observed. Recent observations concerning the geographic distribution, population structure, habitats, and natural occurrence of diseases of Lactuca spp. are discussed. This assemblage of genetic resources of Lactuca spp. can serve as the basis of future studies of species diversification, spatial population structure, plant microevolution, domestication processes, and genetic variability of host-parasite interactions.  相似文献   

13.
Laser-induced breakdown spectroscopy (LIBS) is a new technique for the analysis of plant material. This study investigates the application of LIBS to pasture-based plant samples. The LIBS measurements were obtained from pelletized pasture samples (100 samples) that had been also analyzed by inductively coupled plasma–optical emission spectroscopy (ICP-OES) following microwave digestion for calibration and comparison purposes. Comparisons for elements sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), boron (B), phosphorus (P), and sulfur (S) showed that LIBS could be used for almost all the standard profile total elements with concentrations down to low mg/kg levels (observed error of Na: 0.024 percent, K: 0.18 percent, Mg: 0.016 percent, Ca: 0.073 percent, P: 0.017 percent, Mn: 31 mg/kg, Fe: 150 mg/kg, Zn: 6.6 mg/kg, and B: 1.1 mg/kg). Elemental analysis at less than mg/kg levels was not possible using LIBS. The elements S and Cu were particularly difficult to analyze with reliability using LIBS at the concentration levels found in the plant samples. Replacing microwave digestion and subsequent ICP analysis with a direct analysis of dried plant samples using LIBS has the potential to improve the productivity and reduce the cost of testing.  相似文献   

14.
We have studied the effect of anaerobically digested (ADMSW) and composted municipal solid waste (CMSW) on mineralization and foodweb dynamics to verify the hypothesis that ADMSW would immobilize N right after addition to soil in contrast to addition with CMSW. Another hypothesis was that the mesofauna (enchytraeids and microarthropods) would stimulate N release from the decomposer community. We measured excretion of -N and urea-N from the mesofauna and hypothesized that enchytraeids would release urea. ADMSW and CMSW were amended to pots with sandy loam and barley. The pots were divided into treatments with or without mesofauna. Mesofauna, plant N and biomass, soil N and ergosterol (fungal biomass) were measured over a 113-day period of four equidistant samplings. Soil respiration, N mineralization and N release by the mesofauna were modelled from concurrent studies. ADMSW- and CMSW-treated soils initially (<20 days) immobilized N. The amendments did not increase plant growth substantially, and this was probably due to N-limitation in the early stages of plant growth. Enchytraeid abundance was about three times higher in ADMSW- than CMSW-treated soils, indicating that ADMSW contained more labile compounds, bacteria, and microfauna. The mesofauna did not affect N-content, but the cumulated -N excreted by the mesofauna was estimated to be substantial and about one-fifth of total plant N in ADMSW. An explanation for this discrepancy might be that in the absence of the mesofauna, other members of the detrivore and microbivore community performed the mesofauna’s function. Neither enchytraeids nor microarthropods excreted urea.  相似文献   

15.
正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,  相似文献   

16.
正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,  相似文献   

17.
正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,  相似文献   

18.
The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils.  相似文献   

19.
“Wicked” problems are those that are complex and that change when solutions are applied. Many conflicts in conservation fall into this category. The study approached the problem of how to constrain the apparent wickedness of a problem in the conservation management of a species by using simple empirical indicators to carry out iterative assessment of the risk to a population and to document how this risk evolves in relation to the addition of new data and the implementation of management actions. Effects of high levels of uncertainty within data and also concerning population structure were examined through stochastic simulation and by exploration of scenarios. Historical trends in the example used, the Steller sea lion, showed rapid declines in abundance in some regions during the 1980s. The current total population is 130,000-150,000 Steller sea lions through Alaska and British Columbia and this number has been stable since about 1990 in spite of regional differences in population dynamics. Regional differences in the sequence of changes in the number of pups and non-pups, suggested that an internal re-distribution of juveniles could have happened between 1980 and 1990. Current productivity also appears close to the long-term mean. Stochastic population projection using various scenarios showed that, based upon this history, the risk of extinction for the population has declined and is below reasonable thresholds for considering the population to be endangered. The trends in risk suggest that management actions taken since 1990 have probably been effective. Consequently, the conservation management objectives for the Steller sea lion are probably being met. The approach provides a mechanism, based upon experience and scenario analysis, for exploring future policy options and may help to constrain the debate amongst stakeholders about the cost-benefit trade-offs associated with different options.  相似文献   

20.
Nutrient distributions under no tillage (NT) compared with conventional disk-and-bed tillage (CT) management in the warm, humid region of the southeastern USA need to be assessed so that future placement, quantity, and type of fertilizers can be altered, if necessary, to efficiently match crop demands. We determined soil-profile distributions of pH, N, P, S, K, Ca, Mg, Na, Zn, Fe, Mn, and Cu to a depth of 0.9 m at the end of 8.5 years of continuous CT and NT management on a Weswood silty clay loam (fine, mixed, thermic Fluventic Ustochrept) in southcentral Texas. Most dramatic changes occurred within the 0–0.05 m depth, where soil under NT had lower pH, Fe, and Cu than under CT, but greater P, K, Zn, and Mn. Greater P and K under NT than under CT also occurred below the till-zone (0.15–0.3 m). At a depth of 0–0.3 m, soil under NT contained greater amounts of extractable P, K, Zn, Fe, Mn, and Cu than under CT. Nitrogen fertilization had little effect on nutrient distributions, except resulting in greater extractable K at 0–0.05 m and greater nitrate at 0–0.15 m. Few changes in soil-profile distributions were observed for extractable S, Ca, Mg, and Na. Long-term continuous use of NT on this fine-textured, high-fertility (except for N) soil had no apparent adverse effects on nutrient distributions relative to CT, but enhanced conservation and availability of P, K, Zn, Fe, Mn, and Cu near the soil surface where crop roots proliferate.  相似文献   

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