Effect of amendments on growth and metal uptake of giant reed(Arundo donax L.) grown on soil contaminated by arsenic,cadmium and lead

The effects of five amendments such as acetic acid（AA）, citric acid （CA）, ethylenediamine tetraacetic acid （EDTA）, sepiolite and phosphogypsum on growth and metal uptake of giant reed （Arundo donax L.） grown on soil contaminated by arsenic （As）, cadmium （Cd） and lead （Pb） were studied. The results showed that the shoot biomass of giant reed was enhanced by 24.8% and 15.0%, while superoxide mutase and catalase activities slightly varied when adding 5.0 mmol/kg CA and 2.5 mol/kg EDTA to soil as compared to the control, respectively. The concentrations of As, Cd and Pb in shoots were remarkably increased by the addition of 2.5 mmol/kg AA and CA, 5.0 mmol/kg EDTA, and 4.0 g/kg sepiolite as compared to the control. The accumulations of As and Cd were also significantly enhanced in the above condition, while the shoot Pb accumulation was noticeably enhanced by amending with 4.0 g/kg sepiolite and 8.0 g/kg phosphogysum, respectively. The results suggested that AA, CA and sepiolite could be used as optimum soil amendments for giant reed remediation system.

Relationships between plant colonization and soil characteristics in the natural recovery of an earthquaketriggered debris flow gully in the Wanglang National Nature Reserve,China

Fragmentation and loss of habitats due to natural disasters, like earthquakes and earthquaketriggered debris flows are existing threats to the long- term survival of the giant panda （Ailuropoda melanoleuca）. To better understand natural recovery processes of the damaged habitat, field investigation and laboratory analysis were used to analyze relationships between plant colonization and soil characteristics in an over 3o-year natural recovery of a damaged giant panda habitat in a debris flow gully after the 1976 Songpan-Pingwu earthquake in Sichuan Province, China. Four different damaged sites were selected that located at the center of the gully （center）, on a flat alluvial fan （fan）, in a side slope of the gully （slope）, and at the ecotone between the gully and native forest （ecotone）. Vegetation characteristics, soil physicochemical properties, and microbial biomass in the different sites and soil depths were measured. After the natural recovery, the soil fertility, water retention, and microbial biomass were highest at ecotone, followed by fan, slope, and center. Only a few perennial herbs colonized at center; shrubs started to invade at fan and slope, and the native trees dominated the community of ecotone. Furthermore, Fargesia spathacea （food for the giant panda） started to be re-established at ecotone, and the community characteristic of ecotone recovered similarly to the native habitat. These results suggested that improving the soil fertility, water retaining capacity and microbial biomass is fundamental to the plant colonization, particular for F. spathacea＇s re- establishment in a damaged giant panda habitat.

Spatial distribution of chromium in soils contaminated by chromium-containing slag

To evaluate the metal chromium (Cr) contamination of soil at a chromium-containing slag site by ferrochromium production, the contaminated sites, under slag heap, in the vicinity of slag heap and arable soils near the outlet of sewer channel, and unpolluted site 5 km away from one ferroalloy plant in Hunan Province, China, were selected. The concentrations of total Cr and water soluble Cr in bulk soil samples and profile depth samples were determined. The results show that the soils in the vicinity of slag heap have the highest total Cr content followed by the soils under the slag heap and near the outlet of sewer channel of the factory. The mean concentrations of total Cr in the top soils at above three contaminated locations exceed the critical level of Secondary Environmental Quality Standard for Soil in China by 3.5, 5.4 and 1.8 times. In most Cr polluted soils, total Cr has a relative accumulation in soil depth of 40-60 cm, but this trend is not found in unpolluted soils. The average concentrations of water soluble Cr (Ⅵ) in top soils under slag heap and in the vicinity of slag heap are 176.9 times and 52.7 times higher than that in the uncontaminated soils, respectively. However, water soluble Cr (Ⅵ) contents in soils near sewer channel are all low and the values are close to that in the uncontaminated soils. Although water soluble Cr (Ⅵ) content in soil profiles decreases with soil depths, it in soils under slag heap maintains a high level even at a depth of 100-150 cm. The results imply that the transportation of Cr (Ⅵ) can result in a potential risk of groundwater system in this area.

中原文旅城欢乐世界一期雪世界高区基础设计

中原文旅城欢乐世界一期雪世界高区采用了巨型钢框架结构体系,基础形式为群桩基础,满足了基础内力大、沉降控制要求高的要求。介绍了巨型框架结构以及基础设计内力大、沉降控制要求高等特点。以中原文旅城欢乐世界一期雪世界项目滑道高区的基础设计为例,详细介绍了该工程地质概况、桩型选择、基础设计原则;进行了基桩承载力计算和验算,并分别采用YJK和ABAQUS对基础的沉降进行分析。其中ABAQUS模型考虑了桩、土、承台的相互作用,克服了传统计算方法不能细致分析桩身弹性压缩、实体深基础侧阻力和应力扩散等的不足。

巨粒土填筑技术在高速公路路基施工中的应用

依托实际工程,详细阐述了巨粒土填料路基施工技术要点,即基底处理、施工准备、摊铺、整平、碾压等,施工完毕后分别对巨粒土填料路基平整度、压实度、经济性进行评价分析。研究结果表明,巨粒土填料路基碾压完毕后平整度和压实度良好,巨粒土填料中大粒径颗粒可形成骨稳定骨架结构,小粒径颗粒将骨架内部孔隙填充,最终构成完整的路基结构。

含氨基酸水溶肥料研究现状及其在农业生产中的应用

旨在为含氨基酸水溶肥料在农业生产中的高效应用拓宽思路,推动农业绿色、高质量发展。本文综述了氨基酸原料的来源和生产工艺,含氨基酸水溶肥料的功能特点、发展现状、在农业生产中的应用和未来发展趋势。结果表明:含氨基酸水溶肥料在粮食作物、蔬菜作物、水果作物、经济作物中均有广泛应用,对作物生长、果实品质提升和土壤改良等有积极作用,然而在不同作物上的应用需根据其生长发育规律和营养需求进行进一步探索。单一营养型的含氨基酸水溶肥料已不能满足市场需求,需开发功能与营养相结合的新型含氨基酸水溶肥料。

Validation of Growth and Nutrient Uptake Models for Tomato on a Gravelly South Florida Soil Under Greenhouse Conditions

The Soil and Water Assessment Tool(SWAT) has been widely used throughout the world to model crop growth and nutrient uptake in various types of soils.A greenhouse experiment was performed to validate the process equations embedded in SWAT for describing the growth and nutrient uptake of tomatoes in south Florida.The scaled growth curve of greenhouse-grown tomatoes was in close agreement with the theoretical model for field conditions,with the scaling factors being the maximum canopy height and the potential heat units.Similarly,the scaled leaf area index(LAI) growth curve and the scaled root depth curve for greenhousegrown tomatoes agreed with the SWAT functions,with the scaling factors being the maximum LAI and maximum root depth.The greenhouse experiment confirmed that the growth of biomass is a linear function of the intercepted photosynthetically active radiation.The fractions of nutrients in the plant biomass under greenhouse conditions were found to be on the order of 60% of those fractions observed in the field.Values of the initial P distribution(0.2 mg kg -1),initial ratio of mineral stable P to mineral active P(50:1),and initial ratio of humic N to humic P(2.4:1) were determined from soil measurements and can be used for field simulations.The conventional saturation-excess model for soil-water percolation was used to predict the movement of water in the top 10 cm of the greenhouse containers and the results agreed well with measurements.

含腐植酸褐煤施用下苏打盐碱土持水特性研究

以苏打盐碱土为研究对象,通过室内培养方法,研究含腐植酸褐煤对苏打盐碱土持水特性的影响,并对土壤持水特性指标进行相关和回归分析。结果显示:施用褐煤处理土壤饱和持水量、毛管持水量、田间持水量、毛管孔隙度、非毛管孔隙度和总孔隙度均显著高于CK处理(P<0.05),且均随着褐煤用量的增加呈升高趋势,但在褐煤用量较低时(<25%)非毛管孔隙度变化不显著。持水量与孔隙度呈极显著正相关,与容重、紧实度均呈极显著负相关(P<0.01)。饱和持水量、毛管持水量、田间持水量与毛管孔隙度相关系数分别为0.972、0.972、0.965,与非毛管孔隙度相关系数分别为0.697、0.691、0.672,与容重相关系数分别为-0.948、-0.948、-0.943,与紧实度相关系数分别为-0.693、-0.694、-0.677。饱和持水量、毛管持水量、田间持水量与容重、紧实度的回归趋势线均符合y=axb(a、b为常数)的幂函数线性关系,拟合优度均较好。综上所述,施用含腐植酸褐煤能够有效改善苏打盐碱土孔隙度,提高土壤持水量。利用持水量与容重、紧实度拟合方程可以间接估算相应持水量。

长期定位施氯对3种质地土壤理化性质及作物产量的影响

为了解含氯肥料对不同质地土壤理化性质及作物产量的影响,以不含氯肥料为对照(CK),连续5 a定位研究含氯15%肥料(T1)、含氯30%肥料(T2)对3种质地(砂土、壤土、黏土)土壤理化性质及小麦、玉米产量的影响。结果表明,壤土0~20 cm土层T1、T2处理和40~60 cm土层T2处理,黏土20~40 cm土层T1、T2处理,其pH值均较CK显著降低。砂土、黏土0~20、20~40、40~60 cm土层的T2处理氯离子含量均较CK显著升高。砂土40~60 cm土层T2处理水溶性盐含量较CK显著降低,壤土0~20、40~60 cm土层和黏土0~20、20~40 cm土层水溶性盐含量随含氯肥料施用量的增加有升高趋势。与CK相比,砂土0~20 cm土层及壤土40~60 cm土层T1、T2处理水溶性钙含量显著降低;壤土20~40 cm土层和黏土0~20、40~60 cm土层T1、T2处理水溶性钙含量显著升高。>0.05 mm土粒占比方面,与CK相比,砂土0~20、40~60 cm土层T1处理和壤土20~40 cm土层T2处理均显著升高,而壤土0~20 cm土层T1、T2处理均显著下降;0.05~0.001 mm土粒占比方面,砂土0~20、40~60 cm土层T1处理和壤土20~40 cm土层T2处理及黏土40~60 cm土层T1、T2处理均比同土层CK下降显著;≤0.001 mm土粒占比方面,与CK相比,壤土0~20 cm土层T1处理和黏土40~60 cm土层T2处理显著升高,而壤土20~40 cm土层T2处理,40~60 cm土层T1、T2处理及黏土0~20 cm土层T2处理显著降低。3种质地土壤连续3 a施用含氯肥料对小麦产量无显著影响,但第4年时,砂土T2处理降低了5.32%,壤土T1、T2处理分别降低了7.61%、7.13%,黏土T2降低了1.77%。含氯肥料处理对玉米产量影响方面,砂土T2处理在第4年、第5年时分别减产了5.20%、7.08%。建议含氯肥料连续施用不超过3 a。

土壤硒干预与5种作物集硒特性研究

[目的]探究不同施硒浓度对5种作物的影响,了解不同作物的硒吸收及积累特性,为筛选适宜大规模种植的硒蛋白原料提供理论依据。[方法]选用油菜、玉米、洋葱、番茄、绿豆分别代表不同科作物进行盆栽试验,以亚硒酸钠为硒源调控土壤基质中的施硒浓度分别达20、40、60、80 mg/kg,同时以不施硒的基质为对照组(CK),培育作物直至开花期,采收其地上部分并测定其硒含量、蛋白含量及蛋白中的硒含量,结合作物生物学产量计算硒积累量与蛋白中硒积累量,从而分析5种作物对硒的吸收与积累情况,并筛选出适合硒蛋白生产的最佳原料。[结果]玉米、洋葱、绿豆、番茄和油菜最佳施硒浓度分别为60、20、60、40、60 mg/kg。在最佳施硒浓度下玉米、洋葱、绿豆、番茄和油菜的蛋白中硒积累量表现为油菜>玉米>番茄>绿豆>洋葱。[结论]与玉米、洋葱、番茄和绿豆相比,油菜的蛋白含量与蛋白硒含量最高,是潜在优良的硒蛋白来源作物,且在施硒浓度为60 mg/kg时表现出最佳的集硒特性。

含腐殖酸复合肥对番茄植株生长及产量的影响

为考察含腐殖酸复合肥对农作物生长和产量的影响,以番茄为试验对象,开展了田间小区试验。试验共设3个处理,分别为常规施肥、常规施肥+普通复合肥、常规施肥+含腐殖酸复合肥。结果表明:与常规施肥处理相比,含腐殖酸复合肥处理的土壤全氮、有效磷、速效钾、有机质质量分数分别增加0.23 g/kg、6.18 mg/kg、20.51 mg/kg、2.03 g/kg,pH降低0.39,孔隙度增加1.58%,容重降低0.13 g/cm^(3);番茄坐果率提高4.34%,产量提高38.05%。在常规施肥的基础上施用含腐殖酸复合肥,可以改善土壤理化性状,提高农作物产量。

疏伐抚育对大熊猫栖息地八月竹纯林土壤细菌群落多样性的影响

疏伐抚育可改善大熊猫栖息地土壤质量和森林生态系统功能、提升生物多样性。然而,现有研究主要以提升人工用材林木材产量为主,对以提升自然保护地栖息地功能属性为目的的森林疏伐抚育如何影响地下生态过程,特别是土壤微生物群落变化研究相对较少。本文以大熊猫国家公园大相岭片区八月竹(Chimonobambusa szechuanensis)纯林为研究对象开展疏伐抚育,分析两种处理对纯林土壤理化性质和细菌微生物组的影响,重点研究疏伐抚育一年后土壤细菌群落多样性变化。结果表明:(1)不同疏伐抚育模式对土壤细菌群落影响差异较大。以促进主食竹更新复壮为目的的疏伐抚育模式(处理A)显著提高了土壤细菌群落Sobs指数(P=0.024)和Chao指数(P=0.027),表现出更高的群落丰富度。而以促进纯竹林向大熊猫更为喜爱的竹阔混交林转变的疏伐抚育模式(处理B)对纯林保留带中地下生态系统的影响并不显著。(2)LEfSe分析(LDA score>3,P<0.05)发现,八月竹林土壤细菌群落核心菌门为酸杆菌门(Acidobacteria)、放线菌门(Actinobacteria)和变形菌门(Proteobacteria)。与八月竹纯林相比,处理A显著提高了土壤pH值(pH=5.05,P<0.001),但有机碳(50.2 g/kg,P<0.001)、全氮(5.04 g/kg,P<0.05)和微生物生物量碳(700.54 mg/kg,P<0.01)含量均显著降低。(3)RDA分析表明土壤细菌群落门丰度变化主要与pH值(r^(2)=0.45,P<0.05)和全氮含量(r^(2)=0.39,P<0.05)变化有关。上述研究结果可以为进一步研究与纯竹林疏伐抚育相关的土壤微生物功能菌群提供参考。

放牧对大熊猫栖息地竹林及林下土壤性质影响

人类活动的影响,导致了物种栖息地的急剧丧失和破碎化。大熊猫是生物多样性保护的旗舰种,受到人类干扰的严重威胁。全国第四次大熊猫调查结果显示,放牧成为大熊猫栖息地最严重的的人类干扰因子。探究放牧对栖息地影响的内在机制和科学管控措施也成为了近年来大熊猫生态学研究的热点。本项目于2022年4–6月在美姑自然保护区放牧最严重的区域,采用野外实地调查并结合微观分析相结合的方法,精确评估放牧家畜对大熊猫主食竹及林下栖息地土壤质量的影响。研究发现,牲畜利用的样方中竹子株高和基径都比大熊猫利用样方中低,并且枯死竹数量更高;放牧会增加林下土壤的容重和酸碱度,降低土壤水分含量,可能是造成竹子的枯死原因之一。研究结果有助于制定合理的保护管理策略,为解决大熊猫栖息地内严重的放牧问题提供科学依据。

高速公路路基施工中巨粒土填筑技术的应用

为研究高速公路路基施工中巨粒土填筑技术的应用,结合实际工程,阐述了巨粒土填料路基工程特性,并重点对巨粒土填料路基施工工艺进行研究,如基底处理、基底处理、摊铺、整平、碾压等,并对路基施工质量检测进行阐述。

大型液化天然气储罐桩基抗震设计中桩-土动力交互作用的影响

大型液化天然气储罐通常采用群桩基础。国内群桩基础抗震设计中,桩体水平及抗弯承载力计算采用的m法仅考虑了上部结构在地震作用下产生的惯性力与桩体及桩侧土的交互作用。而群桩基础抗震设计相关国际标准针对软土地基,还将桩-土动力交互作用的影响纳入了设计考虑。以某220000 m^(3)预应力混凝土全容罐的桩基设计为例,对比分析了m法设计与考虑桩-土动力交互作用设计的桩身内力计算结果,认为在埋深较大的软土地基或存在深层软弱土夹层的地基中,考虑桩-土动力交互作用设计时,桩体下段确实存在较大弯矩和剪力,不应予以忽略。

水汽平衡法测定水稳定同位素的影响因素

水汽平衡法是近年来发展的测定土壤/植物水稳定同位素(^(2)H,^(18)O)的新方法,但由于以往研究存在容器气密性差、样品量不足等问题,降低了该方法测定水稳定同位素的适用范围。本研究以两种不同封口的玻璃顶空瓶、两种塑料袋和两种铝袋为容器,对纯水样在8种储存时间(0.5 d, 1 d,…,30 d),2种背景水汽浓度(0 ppmv, 28 000 ppmv)下进行水稳定同位素测定,探究容器气密性、背景水汽浓度和样品量对测定结果的影响,并在最优条件下与真空蒸馏法对比,验证该方法测定土壤水稳定同位素的适用性。研究结果可对水汽平衡法测定土壤水同位素时容器与样品量的选择提供参考。

含氟易去污整理剂SG-8011的亲水改性及应用

采用亲水整理剂AX-209对含氟易去污整理剂SG-8011进行亲水改性。研究了SG-8011与AX-209不同质量比的复配物在不同用量下对纯棉织物的亲水、防油和易去污整理效果。探讨了不同种类的交联剂对SG-8011和AX-209复配物亲水性的影响,以及不同用量的交联剂对整理效果耐洗性的影响。结果发现,当SG-8011和AX-209质量比为6∶4、用量为70 g/L时,整理后的纯棉织物具有较好的亲水性、防油性和易去污性;交联剂AX-101C对SG-8011和AX-209复配物亲水性的影响较小,且对亲水、防油和易去污整理效果的耐洗性有较好的提升。

A review on the chemical speciation and influencing factors of heavy metals in Municipal Solid Waste landfill humus

Heavy metal pollution in landfill humus can cause serious environmental problems and may endanger soil ecosystems and human health.The biological toxicity of heavy metals is not only related to their total amount but also influenced to a greater extent by the distribution of their chemical speciation.Exploring the different chemical speciation and proportions of heavy metals can provide a more comprehensive and accurate understanding of the pollution characteristics and biological toxic-ity of heavy metals in landfill soil.Based on a review of the relevant literature,this paper systematically summarizes the recent research status of typical heavy metal chemical speciation in landfill humus.This chemical speciation is diverse and complex.For instance,heavy metals in residual states and organically bound states have little impact on organisms,while heavy metals in exchangeable states and Fe-Mn oxide states can easily migrate and transform.The chemical speciation of heavy metals is affected by many factors,among which the soil pH and organic matter content are some of the most important factors.Finally,the existing gaps in the current research on the chemical speciation of heavy metals in landfills are described and future research directions are proposed.This work provides a theoretical reference for researching the restoration of heavy metal-contaminated humus soil and the resource utilization of humus soil.

功能型多效态含镁矿源肥料的制备及性能研究

针对低品位含镁矿物利用率偏低的现状及传统镁肥在农业生产中存在养分易淋失或释放速率过慢等问题,以低品位菱镁矿为主要原料,通过化学合成、集成矿质材料包覆与崩解技术,制备了功能型多效态含镁矿源肥料。通过肥料表征以及淋溶、崩解试验,对功能型多效态含镁矿源肥料的结构、组分含量以及缓释性能、崩解性能进行了分析。柑橘田间试验结果表明:功能型多效态含镁矿源肥料可显著提高柑橘产量、改善果实品质,同时可提高土壤的pH和交换性镁的含量。功能型多效态含镁矿源肥料含有水溶态镁、枸溶态镁和难溶态镁等,兼具缓释、崩解促释及土壤调理功能,提质增产效果明显。

沿海软基条件下桩基空箱结构的海塘安澜设计新思路——以温州某海塘安澜工程为例

为解决海塘安澜建设背景及多重限制条件下软土筑堤设计难题,以温州某海塘安澜工程为例,从结构优化、融合提升、堤身生态化、信息化等方面阐述浙江省海塘安澜建设背景及多重限制条件下桩基空箱结构堤防的设计新思路,破解占地受限、石料匮乏、深厚软基筑堤难题,在满足海塘防潮标准和结构安全的基本前提下进行生态海堤建设,并通过信息化建设实现智慧管护。