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81.
峡山地不同垂直带土壤层的水文功能及其影响因子   总被引:2,自引:0,他引:2  
渗透性能和持水能力是土壤重要的水力学性质,是土壤调节径流、保持水土和涵养水源等水文功能的基础。以三峡库首的夷陵-大老岭山地为对象,采集亚高山棕壤针叶林地、中山黄棕壤针阔混交林与茶园地和低山黄壤针叶林地等4个样点剖面的土壤样品,在室内进行土壤饱和导水率、水分特征曲线和理化性质测定,量化了不同样地土壤渗透性能、持水能力和水分库容等水文功能参数,并明确了其主要影响因子。结果表明: 研究区山地土壤饱和导水率在0.06~14.78 mm/min之间,亚高山棕壤和中山黄棕壤林地土壤渗透性能较好,其平均饱和导水率在7.15~14.78 mm/ min之间,低山黄壤次之(1.3 9 mm/min),中山黄棕壤茶园土壤渗透能力最差(1.17 mm/min)。不同类型土壤的饱和含水量、毛管含水量、田间持水量存在较大差异,凋萎含水量差异较小。同一类型土壤的不同发生层内,土壤饱和含水量随土壤深度的增加而递减,毛管持水量和田间持水量随土层深度的增加波动上升。不同样地间土壤水分总库容差异较大,随着海拔的升高,土壤水分总库容增加。土壤水分特征参数与土壤性质的相关分析表明,饱和导水率与土壤总孔隙度呈显著正相关,与容重呈显著负相关;饱和含水量、毛管持水量、田间持水量均与土壤总孔隙度、粘粒含量呈显著性正相关,与容重呈显著负相关;饱和含水量与根系重量呈显著正相关;毛管持水量、田间持水量与砂粒含量呈显著负相关。与中山茶园地和低山黄壤林地相比,亚高山棕壤和中山黄棕壤林地渗透性能较好且持水性更强,具有更好的调蓄径流和涵养水源的水文功能。 关键词: 山地土壤;土壤孔隙度;饱和导水率;持水能力;三峡库区  相似文献   
82.
Gelatin-Zr(IV) phosphate composite (GT/ZPC) was synthesized by sol–gel method. Different techniques viz. Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray powdered diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used for the characterisation of GT/ZPC composite ion exchanger. The ion exchange capacity (IEC) of GT/ZPC was observed to be better (1.04 meq g?1) than its inorganic counterpart (0.64 meq g?1). The pH studies revealed the monofunctional nature of GT/ZPC with one inflection point. The distribution studies showed that the GT/ZPC was highly selective for Cd2+ as compare to other metal ions. The environmental applicability of ion exchanger has been analysed for binary separations of metal ions using column method. Cd2+ was effectively removed from synthetic mixture of metal ions (Zn2+, Pb2+, Ni2+, Co2+ and Cu2+).  相似文献   
83.
Interdisciplinarity is needed to gain knowledge of the ecology of invasive species and invaded ecosystems, and of the human dimensions of biological invasions. We combine a quantitative literature review with a qualitative historical narrative to document the progress of interdisciplinarity in invasion science since 1950. Our review shows that 92.4% of interdisciplinary publications (out of 9192) focus on ecological questions, 4.4% on social ones, and 3.2% on socialecological ones. The emergence of invasion science out of ecology might explain why interdisciplinarity has remained mostly within the natural sciences. Nevertheless, invasion science is attracting social–ecological collaborations to understand ecological challenges, and to develop novel approaches to address new ideas, concepts, and invasion-related questions between scholars and stakeholders. We discuss ways to reframe invasion science as a field centred on interlinked social–ecological dynamics to bring science, governance and society together in a common effort to deal with invasions.  相似文献   
84.
针对实际海水养殖废水低碳高氮的特点,采用间歇式活性污泥法(SBR)和好氧活性污泥添加硅藻土载体的方式,考察硅藻土载体和活性污泥共同作用下的好氧曝气系统对海水养殖废水中氨态氮(NH+4-N)、亚硝酸态氮(NO-2-N)和化学耗氧量(COD)的去除效果,以及对污泥沉降性能和硝化细菌特征的影响。实验结果表明,常温条件下,溶解氧(DO)≥4.5mg/L,p H控制在7.0~8.0,HRT为11 h,沉降时间10 min,反应器可以处理NH+4-N浓度在50 mg/L左右的海水养殖废水,NH+4-N和COD去除率分别达到98.93%左右和76.62%以上,NO-2-N出水浓度低于0.028 mg/L。载体污泥颗粒照片和扫描电镜结果表明,添加硅藻土载体内核后,颗粒污泥的成熟期缩短,颗粒的稳固度和沉降性能提高。在系统启动成功稳定运行后,通过FISH分析表明,在氨氧化菌(AOB)与亚硝酸盐氧化菌(NOB)成为优势菌群后,AOB大约占总菌群的33.5%,并且AOB与NOB菌群数量约为1∶1.33,AOB和NOB两大类菌群之和约占总菌群的77.2%,成为系统中优势菌群。  相似文献   
85.
兰坪铅锌矿区不同污染梯度下优势植物的重金属累积特征   总被引:5,自引:0,他引:5  
对兰坪铅锌矿区污染程度不同的3个样地(云南松林、魁蒿群落和马桑灌丛)进行植被调查,选择其中9种共有的自然生长的优势草本植物为研究对象,测定了土壤及植物体的重金属含量。结果显示,3个样地土壤Cu、Cd、Pb和Zn等4种重金属含量均表现为马桑灌丛>魁蒿群落>云南松林;植物体内重金属积累呈现出随着土壤污染程度增加而增加的趋势;所选择的9种植物均不符合超富集植物的标准,依据不同的耐性机制将9种植物分为3类,野棉花能较强吸收土壤中重金属,并转移到地上部分,属于富集型植物;西南金丝梅、倒提壶、长籽柳叶菜、魁蒿、翻白叶和四脉金茅吸收的重金属主要积累在根部,属于根部囤积型植物;尼泊尔蓼和中华山蓼体内重金属含量较低,属于规避型植物。讨论了利用这些植物进行矿山治理。  相似文献   
86.
通过采用铁碳微电解-Fenton法预处理苯胺基乙腈生产废水的实验研究,分析了处理过程的COD降解动力学;同时研究了单纯活性炭吸附和微电解过程中COD去除率的变化。结果表明,铁碳微电解的初期COD降解过程近似符合一级反应动力学,并且得到微电解与活性炭吸附对铁碳微电解降解COD的关系式;Fenton反应中通过研究有机物浓度和过氧化氢初始浓度与反应进程的关系,建立了反应动力学模型;单纯吸附实验COD去除率在24h内快速下降,而微电解在相应时间内COD去除率波动较小,为实际应用提供了数据经验和理论依据。  相似文献   
87.
Predicted no-effect concentration (PNEC) is often used in ecological risk assessment to determine low-risk concentrations for chemicals. In the present study, native marine species were selected for toxicity testing. The PNECs for three polycyclic aromatic hydrocarbons (PAHs), specifically phenanthrene (Phe), pyrene (Pyr), and benzo[a]pyrene (BaP), were derived from chronic and acute toxicity data with log-normal statistical methods. The achieved PNECs for Phe, Pyr, and BaP were 2.33, 1.09, and 0.011 μg/L, respectively. In Jinzhou Bay and the Shuangtaizi River Estuary of Liaodong Bay in the Bohai Sea, China, the surface water concentrations of the three PAHs were analyzed by gas chromatography–mass spectrometry. Based on two probabilistic ecological risk assessment (PERA) methods, namely probabilistic risk quotient and joint probability curve, the potential risk of Phe, Pyr, and BaP in Jinzhou Bay and Shuangtaizi River Estuary was assessed. The same order of ecological risk (BaP > Phe > Pyr) was found by both models. Our study considered regional characteristics of marine biota during the calculation of PNECs, and the PERA methods provided probabilities of potential ecological risks of chemicals. Within the study area, further research on BaP is required due to its high potential ecological risk.  相似文献   
88.
The halophytic shrub Halimione portulacoides is known to be capable of growth in soils containing extremely high concentrations of Zn. This study evaluated in detail the tolerance and accumulation potential of H. portulacoides under moderate and high external Zn levels. A greenhouse experiment was conducted in order to investigate the effects of a range of Zn concentrations (0-130 mmol L−1) on growth and photosynthetic performance by measuring relative growth rate, total leaf area, specific leaf area, gas exchange, chlorophyll fluorescence parameters and photosynthetic pigment concentrations. We also determined the total zinc, nitrogen, phosphorus, calcium, magnesium, sodium, potassium, iron and copper concentrations in the plant tissues. H. portulacoides demonstrated hypertolerance to Zn stress, since it survived with leaf concentrations of up to 2300 mg Zn kg−1 dry mass, when treated with 130 mmol Zn L−1. Zinc concentrations greater than 70 mmol L−1 in the nutrient solution negatively affected plant growth, in all probability due to the recorded decline in net photosynthesis rate. Our results indicate that the Zn-induced decline in the photosynthetic function of H. portulacoides may be attributed to the adverse effect of the high concentration of the metal on photosynthetic electron transport. Growth parameters were virtually unaffected by leaf tissue concentrations as high as 1500 mg Zn kg−1 dry mass, demonstrating the strong capability of H. portulacoides to protect itself against toxic Zn concentrations. The results of our study indicate that this salt-marsh shrub may represent a valuable tool in the restoration of Zn-polluted areas.  相似文献   
89.

Introduction

The Consolider-Ingenio 2010 project SCARCE, with the full title ??Assessing and predicting effects on water quantity and quality in Iberian Rivers caused by global change?? aims to examine and predict the relevance of global change on water availability, water quality, and ecosystem services in Mediterranean river basins of the Iberian Peninsula, as well as their socio-economic impacts. Starting in December 2009, it brought together a multidisciplinary team of 11 partner Spanish institutions, as well as the active involvement of water authorities, river basin managers, and other relevant agents as stakeholders.

Methods

The study areas are the Llobregat, Ebro, Jucar, and Guadalquivir river basins. These basins have been included in previous studies and projects, the majority of whom considered some of the aspects included in SCARCE but individually. Historical data will be used as a starting point of the project but also to obtain longer time series. The main added value of SCARCE project is the inclusion of scientific disciplines ranging from hydrology, geomorphology, ecology, chemistry, and ecotoxicology, to engineering, modeling, and economy, in an unprecedented effort in the Mediterranean area. The project performs data mining, field, and lab research as well as modeling and upscaling of the findings to apply them to the entire river basin.

Results

Scales ranging from the laboratory to river basins are addressed with the potential to help improve river basin management. The project emphasizes, thus, linking basic research and management practices in a single framework. In fact, one of the main objectives of SCARCE is to act as a bridge between the scientific and the management and to transform research results on management keys and tools for improving the River Basin Management Plans. Here, we outline the general structure of the project and the activities conducted within the ten Work Packages of SCARCE.  相似文献   
90.
以三氯化铁和硫酸铝为混凝剂,印染废水二级生化出水为研究对象,并利用XAD-8/XAD-4吸附树脂联用技术将印染废水生化出水中溶解性有机物分为疏水酸、非酸疏水物质、弱疏水物质及亲水物质4类有机物,通过小试实验探讨了2种混凝剂对生化出水中各类溶解性有机物的去除效果及特点。实验结果表明,对于该印染废水的生化出水,溶解性有机物的主要成分是疏水性物质,以DOC表征时占总DOC的75%,其中疏水酸约占41%,疏水性物质也是引起色度的主要物质,所占比例以ADMI7.6表征时为89%,其中以非酸疏水物质的贡献最大,达到52%,并且非酸疏水物质中不饱和双键或芳香环有机物的含量较高。在三氯化铁和硫酸铝各自最佳的混凝条件下,均能够有效去除由疏水性物质(疏水酸和非酸疏水物质)引起的色度,但三氯化铁对弱疏水性物质以及亲水物质的去除率高于硫酸铝,这使得三氯化铁对印染废水生化出水中的溶解性有机物的去除效果优于硫酸铝。并且三氯化铁和硫酸铝混凝工艺均能明显降低生化出水的毒性。  相似文献   
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