自然水体生物膜上铁、锰氧化物生长速率的研究

通过对南湖水体培养的生物膜上铁、锰氧化物生长速率的研究发现，生物膜上铁、锰氧化物的生长过程均属于一级动力学反应，可以用双常数速率方程、Elovich方程、抛物线扩散方程及指数函数方程进行描述，生物膜上铁氧化物的生长速率远远大于锰氧化物的生长速率，锰氧化物的生长速率随水深的增加而降低，并呈显著的线性关系。     

Characteristics of the natural organic matter sorption affects of organic contaminants

ＩｎｔｒｏｄｕｃｔｉｏｎＲｅｃｅｎｔｒｅｓｅａｒｃｈｈａｓｄｅｍｏｎｓｔｒａｔｅｄｔｈａｔｓｏｒｐｔｉｏｎｏｆｈｙｄｒｏｐｈｏｂｉｃｏｒｇａｎｉｃｃｏｍｐｏｕｎｄｓ(ＨＯＣ)ｉｎｓｏｉｌｓａｎｄｓｅｄｉｍｅｎｔｓｉｓｃｏｎｔｒｏｌｌｅｄｂｙｏｒｇａｎｉｃｍａｔｔｅｒｕｎｌｅｓｓｉｔｓｃｏｎｔｅｎｔｉｓｖｅｒｙｌｏｗ(Ｃｈｉｏｕ ,1 989) .Ｔｈｉｓｉｓｐａｒｔｉｃｕｌａｒｌｙｔｒｕｅｉｎｗａｔｅｒ ｓｏｉｌｓｙｓｔｅｍｓｂｅｃａｕｓｅｗａｔｅｒｍｏｌｅｃｕｌｅｓａｒｅｐｒｅｆｅｒａｂｌｙａｄｓｏｒｂｅｄ…     

塔里木天然气氮同位素组成与分布

利用制备气相色谱仪分离塔里木天然气中N2 并测定同位素比值 ,结果显示不同区域天然气氮的含量及其同位素比值不同 ,塔中、塔北与和田河地区天然气含氮量高 ,δ15N低 ,库车天然气则相反。结果还显示塔里木原油与天然气氮同位素比值具有可比性 ,表明同源油 气成因上的内在联系     

天然气中N_2来源及其地球化学特征分析

天然气中N2的来源很多，其地球化学特征也不相同：①大气源N2：N2／Ar≤84，且δ15NN2≈0‰（ATM）；②地壳越深部和上地幔来源的原生N2∶δ15NN2≈-2‰～＋1‰．且伴生Ar的40Ar／36Ar＞2000和He的3He／4He＞10－6；③微生物反硝化作用生成的N2∶δ15NN2＜－10‰和地下水中NO3-及NO2-浓度异常高；④未成熟沉积有机质经微生物氨化作用形成的N2∶δ15NN2＜－10‰，伴生CK4的δ13C＜－55‰（PDB）；⑤成熟（包括高成熟）沉积有机质经热氨化作用形成的N2∶δ15NN2值≈-10‰～－1‰，且伴生CH4的δ13C≈－55‰～－30‰；⑥过成熟沉积有机质裂解产生的N2∶δ15NN2≈＋5‰～＋20‰；⑦沉积岩中无机及在高温变质作用下释放出的N2∶δ15NN2≈＋1‰～＋3．5‰，N2／Ar》84。     

城市生态公园及其评估

综述了城市生态公园的研究进展,分析了城市生态公园对解决城市生态问题及满足市民渴望回归自然的重要性.在总结目前城市生态公园理论与实践的基础上,对城市生态公园的定义及内涵进行了分析.首次提出了以生物多样性、生物量、乡土物种和景观为核心指标组成的城市生态公园评估指标体系,对中国正在兴起的城市生态公园建设具有指导意义.     

Dendroremediation of trinitrotoluene (TNT) part 1: Literature overview and research concept

BACKGROUND, AIM AND SCOPE: For decades, very large areas of former military sites have been contaminated diffusely with the persistent nitroaromatic explosive 2,4,6-trinitrotoluene (TNT). The recalcitrance of the environmental hazard TNT is to a great extent due to its particulate soil existence, which leads to slow but continuous leaching processes. Although improper handling during the manufacture of TNT seems to be a problem of the past in developed countries, environmental deposition of TNT and other explosives is still going on unfortunately, resulting from thousands of unexploded ordnance or low order explosions at munitions test areas and at current battlefields. OBJECTIVE: Sustainable phytoremediation strategies for explosives in Germany, which intend to use trees to decontaminate soil and groundwater ('dendroremediation'), have to consider that most of the former German military sites are already covered with woodlands, mainly with conifer stands. Therefore, parallel investigation of the remediation potential is necessary for both of the selected hybrids of fast growing broadleaf trees, which are waiting for planting and forest conifers, which have already proven for decades that they are able to grow on explosive contaminated sites. MAIN FEATURES: A short literature review is given regarding phytoremediation of TNT with herbaceous plants and some general aspects of dendroremediation are discussed. Furthermore, an overview of our TNT-dendroremediation research network is introduced, which has the strategic goal to make dendroremediation more calculable for a series of potent trees for site-adapted in situ application and for the assessment of tree remediation potentials in natural attenuation processes. RESULTS AND DISCUSSION: Some of our methods, results and conclusions yet unpublished are presented. For a preliminary calculation of area-related annual TNT dendroremediation potential of five-year-old trees, the following values were assessed: Salix EW-13 6.0, Salix EW-20 8.5, Populus ZP-007 4.2, Betula pendula 5.2, Picea abies 1.9 and Pinus sylvestris 0.8 g m(-2) a(-1). For a 45-year-old spruce forest, an annual natural attenuation potential of 4.2 g TNT m(-2) a(-1) was found. CONCLUSION, RECOMMENDATIONS AND PERSPECTIVE: Our main results deliver quantitative proposals for dendroremediation strategies in situ and provide decision aids. Also aspects of growth of raw materials for energy production are considered. Our dendroremediation research concept for TNT and its congeners can be easily completed for other trees of interest and it can also be applied to herbaceous plants. Knowing the current bottlenecks of phytoremediation and considering the known environmental behaviour of other contaminants, elements of our methodological approach may be easily adapted to those pollutant groups, e.g. for pesticides, pharmaceuticals, PAHs, chlorinated recalcitrants and, with some restrictions, to inorganics and to multiple contaminations. Our dynamical dendrotolerance test systems will help to predict tree growth on polluted areas. To provide some light into the black box of TNT dendroremediation, experimental data regarding the uptake, distribution and degradation of [14C]-TNT in mature tree tissues will be reported in the second part of this publication.     

Geochemical techniques on contaminated sediments-river basin view

The big flood in the upper Elbe River catchment area has revealed a wide spectrum of problems with contaminated sediments. So far, an effective strategy for managing contaminated sediments on a river basin scale is still missing and it seems that not much has been learned from the lessons received during the last decade. In the following overview, special emphasis is given to the utilization of geochemically-based techniques for sediment remediation, which can be applied in different parts of a river basin. The examples presented here are mostly from the Elbe River catchment area. In general, new technical problem solutions need a set of practical process knowledge that uses a wide range of simulation techniques, as well as models in different spatial and temporal scales. The evaluation of recent flood events clearly demonstrates the importance of chemical expertise in the decision-making process for the sustainable development in river basins.     

Natural formation and degradation of chloroacetic acids and volatile organochlorines in forest soil--challenges to understanding

- DOI: http:/dx.doi.org/10.1065/espr2005.06.262 Goal, Scope and Background The anthropogenic environmental emissions of chloroacetic acids and volatile organochlorines have been under scrutiny in recent years because the two compound groups are suspected to contribute to forest dieback and stratospheric ozone destruction, respectively. The two organochlorine groups are linked because the atmospheric photochemical oxidation of some volatile organochlorine compounds is one source of phytotoxic chloroacetic acids in the environment. Moreover, both groups are produced in higher amounts by natural chlorination of organic matter, e.g. by soil microorganisms, marine macroalgae and salt lake bacteria, and show similar metabolism pathways. Elucidating the origin and fate of these organohalogens is necessary to implement actions to counteract environmental problems caused by these compounds. Main Features While the anthropogenic sources of chloroacetic acids and volatile organochlorines are relatively well-known and within human control, knowledge of relevant natural processes is scarce and fragmented. This article reviews current knowledge on natural formation and degradation processes of chloroacetic acids and volatile organochlorines in forest soils, with particular emphasis on processes in the rhizosphere, and discusses future studies necessary to understand the role of forest soils in the formation and degradation of these compounds. Results and Discussion Reviewing the present knowledge of the natural formation and degradation processes of chloroacetic acids and volatile organochlorines in forest soil has revealed gaps in knowledge regarding the actual mechanisms behind these processes. In particular, there remains insufficient quantification of reliable budgets and rates of formation and degradation of chloroacetic acids and volatile organochlorines in forest soil (both biotic and abiotic processes) to evaluate the strength of forest ecosystems regarding the emission and uptake of chloroacetic acids and volatile organochlorines, both on a regional scale and on a global scale. Conclusion It is concluded that the overall role of forest soil as a source and/or sink for chloroacetic acids and volatile organochlorines is still unclear; the available laboratory and field data reveal only bits of the puzzle. Detailed knowledge of the natural degradation and formation processes in forest soil is important to evaluate the strength of forest ecosystems for the emission and uptake of chloroacetic acids and volatile organochlorines, both on a regional scale and on a global scale. Recommendation and Perspective As the natural formation and degradation processes of chloroacetic acids and volatile organochlorines in forest soil can be influenced by human activities, evaluation of the extent of this influence will help to identify what future actions are needed to reduce human influences and thus prevent further damage to the environment and to human health caused by these compounds.     

Natural attenuation/phytoremediation in the vadose zone of a former industrial sludge basin

The natural attenuation of polyaromatic hydrocarbons (PAHs) in the vadose zone of a naturally revegetated former industrial sludge basin (0.45 ha) was examined. This was accomplished by comparing the concentration of 16 PAH contaminants present in sludge collected below the root zone of plants with contaminants present at 3 shallower depths within the root zone. Chemical analysis of 240 samples from 60 cores showed the average concentration of total and individual PAHs in the 0-30 cm, 30-60 cm, and bottom of the root zone strata were approximately 10, 20, and 50%, respectively, of the 16, 800 ppm average total PAH concentration in deep non-rooted sludge. Statistically significant differences in average PAH concentrations were observed between each strata studied and the non-rooted sludge except for the concentrations of acenaphthene and chrysene present at the bottom of the root zone in comparison to sludge values. The rooting depth of the vegetation growing in the basin was dependent on both vegetation type and plant age. Average rooting depths for trees, forbs (herbaceous non-grasses), and grasses were 90, 60, and 50 cm, respectively. The deepest root systems observed (100-120 cm) were associated with the oldest (12-14 year-old) mulberry trees. Examination of root systems and PAH concentrations at numerous locations and depths within the basin indicated that plant roots and their microbially active rhizospheres fostered PAH disappearance; including water insoluble, low volatility compounds, i.e. benzo(a)pyrene and benzo(ghi)perylene. The reduced concentration of PAHs in the upper strata of this revegetated former sludge basin indicated that natural attenuation had occurred. This observation supports the concept that through appropriate planting and management practices (phytoremediation) it will be possible to accelerate, maximize, and sustain natural processes, whereby even the most recalcitrant PAH contaminants (i.e. benzo(a)pyrene) can be remediated over time.     

天然气引射调峰系统的噪声形成及其治理研究

采用天然气引射调峰技术，能使上海某储配站10台天然气高压球罐的储气调峰能率提高68％，大大有助于解决天然气用气高峰时的供需平衡问题，并能节约初投资人民币1亿元。但使用超音速引射器后，当球罐压力下降到某一值时会产生高频噪声，影响管束区操作环境。本文分析了噪声产生的原因．提出了合理的噪声治理方案，并进行了方案的实施。实践证明：噪声治理效果良好，降低了管束区噪声污染，达到了国家“工业企业噪声卫生标准”。