深型地下土壤渗滤系统中氮的去除途径

为了系统研究氮在深型地下土壤渗滤系统中的去除途径，本次实验采用直径30cm，高200cm的有机玻璃柱模拟地下土壤渗滤系统；柱内分层装填取自北京顺义的土壤。在水力负荷为8cm／d的条件下，取得了较好的脱氮效果；氨氮去除率为99．80％；TN去除率为83．68％。通过观察氮沿土柱深度的变化规律发现，在1．30m以上的区域随着氨氮浓度的降低硝氮浓度逐渐增大，同时总氮浓度也在不断降低，约有30．55％在此区域被去除；通过氮元素质量平衡证明这部分氮是通过厌氧氨氧化反应去除的。在1．30m以下反硝化反应是脱氮的主要途径，在此过程中难降解有机物被利用。     

Investigations of nitrogen fluxes and pools on a limestone site in the Alps

In the North Tyrolean Limestone Alps a site was investigated over a four-year period (1998–2001) in order to assess the nitrogen saturation status, the nitrogen budget (quantification of the net uptake of nitrogen by the canopy and of the nitrogen mineralization, nitrogen uptake from roots and N₂O emission rates, proof of the origin of nitrate in the soil water with stable isotope analyses), and the effects of the actual nitrogen input on ground water quality. The main goals were to quantify the nitrogen input rate, the nitrogen pools in above-ground and below-ground compartments, nitrogen turnover processes in the soil as well as the output into the groundwater and into the atmosphere. The findings are based on continuous and discontinuous field measurements as well as on model results.While nitrogen input exceeded the Critical Loads of the WHO (1995), nitrogen deficiency and nutrient imbalances were verified by needle analyses. The atmospheric input of inorganic nitrogen was higher than the nitrogen output in 50 cm soil depth. A tracer experiment with¹⁵N helped to prove that not more than half of the applied nitrate could be discharged. This allows the conclusion that nitrogen is stored in the system and that the site cannot yet be said to be saturated with nitrogen. The same result was also obtained by modelling. In addition, it was proved that the nitrogen discharge did not stem from deposition but from processes within the system.     

上海大气氮湿沉降的污染特征

为探讨上海大气氮湿沉降的污染特征,采集了2007年11月至2008年10月上海雨水样品,分析了大气氮湿沉降浓度,探讨了上海大气湿沉降氮通量及上海市区,市郊和远郊大气氮湿沉降的时空污染特征.结果表明:(1)上海市区、市郊和远郊大气氮湿沉降质量浓度平均值分别为2.96、2.31、2.21 mg/L.从上海大气湿沉降总体来看,大气氮湿沉降劣V类、V类的超标率分别达到51.09%和13.87%.推断大气氮湿沉降的主要来源是机动车辆所排放的大量氮氧化物.(2)除冬季外,其余季节上海市区大气氮湿沉降浓度均大于市郊和远郊;市区和远郊大气氮湿沉降浓度均在秋季最大,市郊大气氮湿沉降浓度在春季最大.(3)上海大气年氮湿沉降通量为78.42 kg/hm~2,同其他区域相比较,属于世界上高氮沉降区域.(4)上海大气月氮沉降通量与月平均降雨量呈显著的线性正相关(p<0.05),说明上海大气氮湿沉降通量主要受降雨量的影响.     

Can the foliar nitrogen concentration of upland vegetation be used for predicting atmospheric nitrogen deposition? Evidence from field surveys

The deposition of atmospheric nitrogen can be enhanced at high altitude sites as a consequence of cloud droplet deposition and orographic enhancement of wet deposition on hills. The degree to which the increased deposition of nitrogen influences foliar nitrogen concentration in a range of upland plant species was studied in a series of field surveys in northern Britain. A range of upland plant species sampled along altitudinal transects at sites of known atmospheric nitrogen deposition showed marked increases in foliar nitrogen concentration with increasing nitrogen deposition and altitude (and hence with decreasing temperature). For Nardus stricta L., Deschampsia flexuosa (L.) Trin., Calluna vulgaris (L.) Hull, Erica cinerea L. and Hylocomium splendens (Hedw.) Br. Eur. on an unpolluted hill, foliar nitrogen increased by 0.07, 0.12, 0.15, 0.08 and 0.04% dry weight respectively for each 1 kg ha(-1) year(-1) increase in nitrogen deposition. Most species showed an approximately linear relationship between foliar nitrogen concentration and altitude but no trend with altitude for foliar phosphorus concentration. This provided evidence that the tissue nutrient status of upland plants reflects nutrient availability rather than the direct effects of climate on growth. However, differences in the relationship between foliar nitrogen concentration and atmospheric nitrogen deposition for N. stricta sampled on hills in contrasting pollution climates show that the possibility of temperature-mediated growth effects on foliar nitrogen concentration should not be ignored. Thus, there is potential to use upland plant species as biomonitors of nitrogen deposition, but the response of different species to nitrogen addition, in combination with climatic effects on growth, must be well characterised.     

Socioeconomic Driving Factors of Nitrogen Load from Food Consumption and Preventive Measures

To diagnose environmental nitrogen (N) load from food consumption and to suggest preventive measures, this study identified relationships between nitrogen load from food consumption and driving factors by examining six representative countries and regions for the period 1970–2009 as an example. The logarithmic mean Divisia index technique was used to disassemble nitrogen load growth into four driving factors: population, economic activity, food intensity of the economy, and nitrogen content of food. In all study areas, increased economic activity was the main factor driving nitrogen load increase. The positive effect of population growth was relatively small but not negligible and changes in food intensity had a decreasing effect on nitrogen load. Changes in nitrogen content of food varied between areas. Broad strategies to reduce and mitigate nitrogen loading and decouple nitrogen load from economic growth in both developed and developing countries are suggested.     

中国主要湖泊营养氮沉降临界负荷的研究

水体营养氮沉降临界负荷是不致使水体产生富营养化的最高氮沉降量。文中探讨了一种依据湖泊氮质量平衡原理计算营养氮沉降临界负荷的方法。用该方法计算表明 ,我国主要湖泊的营养氮沉降临界负荷比较低 ,大部分小于 1keq· hm- 1 · a- 1 ,部分已为目前的氮沉降量或者两者相当接近 ,意味着只接受氮沉降也能导致这些湖泊产生富营养化。但实际统计结果表明 ,氮沉降在导致受工农业生产和生活影响很大的城市和郊区湖泊的水质富营养化的所有氮污染源中所占比例较低 ,而其它来源的氮输入如河道入湖、工业生活废水和农田径流等才是导致富营养化的最主要因素 ,它们的量已远远超过了这些水体可随最高允许氮负荷。因此 ,对控制这些湖泊的水质富营养化而言 ,控制氮沉降并不是目前最紧迫的任务 ,而其它人为污染源的控制才是最急需的。但氮沉降临界负荷在湖泊富营养化的中长远控制中仍具有十分重要的意义。     

Genotypic variation of nitrogen use efficiency in Indian mustard

This experiment was conducted to investigate the variation of nitrogen efficiency (NE), nitrogen uptake efficiency (UE), physiological nitrogen use efficiency (PUE) among Indian mustard genotypes, grown under N-insufficient and N-sufficient conditions. Nitrogen efficiency varied from 52.7 to 92.8. Seed yield varied from 1.14 t ha(-1) to 3.21 t ha(-1) under N-insufficient condition, while 2.14 t ha(-1)-3.33 t ha(-1) under N-sufficient condition. Physiological basis of this difference was explained in terms of nitrogen uptake efficiency and physiological nitrogen use efficiency, and their relationship with the growth and yield characteristics. While nitrogen uptake efficiency was positively correlated with plant biomass (0.793**), leaf area index (0.664*), and leaf nitrogen content (0.783**), physiological nitrogen use efficiency is positively correlated with photosynthetic rate (0.689**) and yield (0.814**). This study suggests that genotype having high nitrogen uptake efficiency and high physiological nitrogen use efficiency might help in reducing the nitrogen load on soil without any penalty on the yield.     

固定源氮氧化物排放及控制技术应用

固定源是氮氧化物排放的一个主要来源.通过对主要固定源氮氧化物生成机理及现有的排放控制技术进行论述,分析我国固定源氮氧化物排放的实际情况,提出我国固定源氮氧化物排放控制还处于起步阶段,氮氧化物排放标准相对宽松,氮氧化物排放控制技术有待进一步普及,并提出固定源氮氧化物排放治理的一些建议.     

骆马湖水体氮污染特征分析

2005年通过对骆马湖水质监测，并结合近几年的监测资料进行了分析，结果表明，氮是骆马湖水体的主要污染物，包括总氮、氨氮和硝酸盐氮，其主要特征是入湖河流、降水、围网养殖和点源带来的污染。     

固定源氮氧化物排放及控制技术应用

固定源是氮氧化物排放的一个主要来源。通过对主要固定源氮氧化物生成机理及现有的排放控制技术进行论述，分析我国固定源氮氧化物排放的实际情况，提出我国固定源氮氧化物排放控制还处于起步阶段，氮氧化物排放标准相对宽松，氮氧化物排放控制技术有待进一步普及，并提出固定源氮氧化物排放治理的一些建议。     

Deposition of fixed atmospheric nitrogen and foliar nitrogen content of bryophytes and Calluna vulgaris (L.) Hull

Atmospheric deposition of fixed nitrogen as nitrate and ammonium in rain and by dry deposition of nitrogen dioxide, nitric acid and ammonia has increased throughout Europe during the last two decades, from 2-6 kg N ha(-1) year(-1) to 15-60 kg N ha(-1) year(-1). The nitrogen contents of bryophytes and the ericaceous shrub Calluna vulgaris have been measured at a range of sites, with the objective of showing the degree to which nitrogen deposition is reflected in foliar plant nitrogen. Tissue nitrogen concentrations of herbarium bryophyte samples and current samples of the same species collected from the same sites were compared. No significant change in tissue nitrogen was recorded at a remote site in north-west Scotland where nitrogen inputs are small (< 6 kg N ha(-1) year(-1)). Significant increases in tissue N occurred at four sites ranging from 38% in central Scotland to 63% in Cumbria where nitrogen inputs range from 15 to 30 kg N ha(-1) year(-1). The relationships found between the estimated input of atmospheric nitrogen and the tissue nitrogen content of the selected bryophytes and Calluna at the sites investigated were found to be generally linear and fitted the form N(tissue) = 0.62 + 0.022 N(dep) for bryophytes and N(tissue) = 0.83 + 0.045 N(dep) for Calluna. There was thus an increase in total tissue nitrogen of 0.02 mg g(-1) dry weight for bryophytes and 0.045 mg g(-1) dry weight for Calluna for an increase in atmospheric nitrogen deposition of 1 kg ha(-1) year(-1). The lowest concentrations were found in north-west Scotland and the highest in Cumbria and the Breckland heaths of East Anglia, both areas of high atmospheric nitrogen deposition (30-40 kg N ha(-1) year(-1)). The implications of increased tissue nitrogen content in terms of vegetation change are discussed. Changes in atmospheric nitrogen deposition with time were also examined using measured values and values inferred from tissue nitrogen content of mosses. The rate of increase in nitrogen deposition is not linear over the 90-year period, and the increases were negligible over the period 1880-1915. However, during the period 1950 to 1990 the data suggest an increase in nitrogen deposition of 2 kg N ha(-1) every 10 years.     

Hydraulic response and nitrogen retention in bioretention mesocosms with regulated outlets: part II--nitrogen retention

We observed dissolved nitrogen retention in vegetated bioretention mesocosms using different media with varying hydraulic conductivities. Elevated outlets were installed to regulate hydraulic response, with one treatment left free draining. The treatments (three replicates each) were loaded weekly with 50 cm of effluent averaging 2.47 mg/L nitrogen oxides (NOx) and 4.67 mg/L total nitrogen for 1 year. The NOx and total nitrogen retention by the outlet regulated treatments was significantly greater than the unregulated treatment. The systems then were dosed 6 times with 53 cm of synthetic stormwater averaging 0.77 mg/ L NOx and 1.46 mg/L total nitrogen, applied over 90 minutes. The outlet regulated treatment retained 68% NOx and 60% total nitrogen, while the corresponding free draining treatment retained 25% NOx and 27% total nitrogen. Over the following winter, the outlet regulated treatment retained 50% NOx and 73% total nitrogen, while the corresponding free draining treatment exported 17% more NOx, while retaining 50% total nitrogen.     

Nitrogen saturation of terrestrial ecosystems

Nitrogen saturation, in the sense that nitrogen additions to an ecosystem lead to losses of the same order of magnitude, is analyzed as an interplay between a plant subsystem and a soil subsystem. The plant system is defined by its nitrogen productivity, which allows calculations of the maximum amount of nitrogen that can be held in, and the maximum nitrogen flux density that can be utilized by, the plant subsystem. The most important response of the soil subsystem is a change in the microbial nitrogen concentration, from which the nitrogen absorption capacity can be derived. It is shown that of the two subsystems the soil must always saturate first. The time to reach saturation depends strongly on site history in terms of the sources of litter forming the soil organic matter and on the ratio between the external nitrogen inflows and the litter nitrogen flow.     

不同基质在人工湿地脱氮中的应用及其研究进展

在比较了不同基质脱氮效率的基础上,认为基质作为人工湿地的重要组成部分,在为植物和微生物提供生长介质的同时,也能通过沉淀、过滤和吸附等作用直接去除污染物质,其中基质的类型、级配等因素会影响基质作用的发挥;不同基质对脱氮性能存在较大差异,沸石和蛭石是目前研究中脱氮效率较高的两种基质。在归纳了脱氮机制和影响因素的基础上,认为不同基质由于脱氮机制不同,脱氮性能和脱氮效率也存在较大差异;人工湿地基质所有理化性状都可能影响到它对污水的脱氮效率。最后,对今后的相关研究方向进行了展望。     

Seasonal nitrogen fluxes of the Lena River Delta

The Arctic is nutrient limited, particularly by nitrogen, and is impacted by anthropogenic global warming which occurs approximately twice as fast compared to the global average. Arctic warming intensifies thawing of permafrost-affected soils releasing their large organic nitrogen reservoir. This organic nitrogen reaches hydrological systems, is remineralized to reactive inorganic nitrogen, and is transported to the Arctic Ocean via large rivers. We estimate the load of nitrogen supplied from terrestrial sources into the Arctic Ocean by sampling in the Lena River and its Delta. We took water samples along one of the major deltaic channels in winter and summer in 2019 and sampling station in the central delta over a one-year cycle. Additionally, we investigate the potential release of reactive nitrogen, including nitrous oxide from soils in the Delta. We found that the Lena transported nitrogen as dissolved organic nitrogen to the coastal Arctic Ocean and that eroded soils are sources of reactive inorganic nitrogen such as ammonium and nitrate. The Lena and the Deltaic region apparently are considerable sources of nitrogen to nearshore coastal zone. The potential higher availability of inorganic nitrogen might be a source to enhance nitrous oxide emissions from terrestrial and aquatic sources to the atmosphere.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01665-0.     

曝气生物滤池中碳和氮代谢特性

用充填陶瓷滤料的曝气生物滤池研究碳和氮代谢特性.曝气生物滤池进水氨氮为52 mg/L左右、COD为100 mg/L左右和回流比为200%时,经过20多d的运行,出水氨氮小于0.05 mg/L、COD小于25 mg/L、亚硝态氮为4.7 mg/L和硝态氮为7.1 mg/L,COD去除率达75%,氨氮去除率达99.9%,总氮去除率达78%;过大和过小的回流比对曝气生物滤池的运行性能都是不利的.研究成果可以应用于一般城市污水以及含低COD、高氨氮工业废水的处理.     

Nitrogen fluxes on an intensive investigation plot in the North Tyrolean limestone Alps

In the framework of this study, nitrogen fluxes on a limestone site are investigated. The major goals are the assessment of the nitrogen status, the estimation of the nitrogen budget and the evaluation of the nitrogen saturation. The investigation area, the intensive investigation plot and the research equipment are described.     

Basic processes in phytoremediation and some applications to air pollution control

In this short review, basic processes for phytoremediation and plant enzymes that are potentially useful in phytoremediation are briefly summarized. The remaining part describes the applications of the basic processes to decontaminate pollutants in the environments that have been done in our laboratory. Our work includes (1) analysis of the capability of various naturally occurring plants to decontaminate atmospheric nitrogen dioxide and selection of nitrogen-dioxide-philic plants that grow with nitrogen dioxide as the sole nitrogen source, (2) production of transgenic plants to improve plants' capability to decontaminate atmospheric nitrogen dioxide, and (3) analysis of the denitrification process in plants to innovate a gas--gas-converting plants that convert nitrogen dioxide to nitrogen gas.     

Aerosol species concentrations and source apportionment of ammonia at Rocky Mountain National Park

Changes in ecosystem function at Rocky Mountain National Park (RMNP) are occurring because of emissions of nitrogen and sulfate species along the Front Range of the Colorado Rocky Mountains, as well as sources farther east and west. The nitrogen compounds include both oxidized and reduced nitrogen. A year-long monitoring program of various oxidized and reduced nitrogen species was initiated to better understand their origins as well as the complex chemistry occurring during transport from source to receptor. Specifically, the goals of the study were to characterize the atmospheric concentrations of nitrogen species in gaseous, particulate, and aqueous phases (precipitation and clouds) along the east and west sides of the Continental Divide; identify the relative contributions to atmospheric nitrogen species in RMNP from within and outside of the state of Colorado; identify the relative contributions to atmospheric nitrogen species in RMNP from emission sources along the Colorado Front Range versus other areas within Colorado; and identify the relative contributions to atmospheric nitrogen species from mobile sources, agricultural activities, and large and small point sources within the state of Colorado. Measured ammonia concentrations are combined with modeled releases of conservative tracers from ammonia source regions around the United States to apportion ammonia to its respective sources, using receptor modeling tools.

Implications: Increased deposition of nitrogen in RMNP has been demonstrated to contribute to a number of important ecosystem changes. The rate of deposition of nitrogen compounds in RMNP has crossed a crucial threshold called the “critical load.” This means that changes are occurring to park ecosystems and that these changes may soon reach a point where they are difficult or impossible to reverse. Several key issues need attention to develop an effective strategy for protecting park resources from adverse impacts of elevated nitrogen deposition. These include determining the importance of previously unquantified nitrogen inputs within the park and identification of important nitrogen sources and transport pathways.     

斜发沸石对城市污水处理厂二级出水中氨氮的处理效果研究

通过静态实验,研究天然斜发沸石去除城市污水处理二级出水中氨氮的性能。研究结果表明,投加量越大,沸石对废水中氨氮的去除率越高,但是吸附容量越低;沸石对氨氮的去除具有短时间内快速吸附,然后缓慢平衡的特点;粉末状沸石对氨氮的去除效果明显好于颗粒状沸石;pH对氨氮去除率有显著影响,pH值为6时,沸石对氨氮的去除率最高。NaCl和NaOH溶液对沸石的改性具有明显的效果,HCl溶液对沸石的改性作用不明显。