Applicability and Limits of Bioremediation of Contaminated Groundwater by Organic Compounds

This paper gives in some ways a broad look at the Bioremediation Technology in the treatment of polluted groundwater. Environmentalists and Hydrologeologists around the world, especially in the developed countries welcomed this revolutionizing technique at a moment when other methods were becoming rather expensive and sources of secondary and more challenging pollution problems across sole fresh groundwater. Bioremediation of contaminated groundwater is based on the use of bacteria which breakdown organic matters to more stable forms, which will not create nuisance or give off foul odors. The Applicability of this technology at a specific site lies in the understanding of the site's hydrogeologic, physiochemical backgrounds and the knowledge of the properties of the designated bacteria colonies, which would likely stabilize the contaminants. These are key points, which determine the success of the all process. Only, by complying with all those measures, Bioremediation can meet all the expectations.     

有机污染物环境行为过程中的稳定同位素分馏效应研究进展

稳定同位素技术是近来发展起来用于识别和评价环境有机污染物来源和降解的新方法。介绍了近年来在实验室和现场对包括含氯有机试剂、石油烃类、多氯联苯等多种有机污染物在生物和非生物降解、挥发和吸附等物理过程中的稳定同位素分馏效应研究中所取得的成果和可能存在的问题,在此基础上,对稳定同位素分馏效应在污染物环境研究中面临的困难以及应用前景进行了论述,指出未来应拓展研究污染物种类,加强环境因素对稳定同位素分馏效应影响的研究。     

Applicability and Limits of Bioremediation of Contaminated Groundwater by Organic Compounds

IntroductionDuring the past two decades much of the em-phasis in groundwater investigation and managementin industrialized countries has sllifted from problemsof groundwater supply to consideration of groundwa-ter quality. This new step is a direct reacti…     

2D-Cell Experiment on Methyl Tert-Butyl Ether Transport in Saturated Zone of Groundwater

As an additive of gasoline,methyl tert-butyl ether(MTBE)has a higher solubility in water,which is about 20 times as high as that of benzene.This characteristic results in MTBE dissolving out of the gasoline into the soil and groundwater.Due to relative unique physicochemical behavior of MTBE it would be an ideal candidate for use in environmental forensic investigations.In order to study the transport and distribution of MTBE in saturated zone of ground water,a two-dimensional experimental cell was setup to simulate the real environment of the groundwater flow.The effects of soil and groundwater flow velocity on the MTBE transport were investigated.The results show that the mobile distance of MTBE in vertical direction was smaller than that in horizontal direction paralleling with the groundwater flow.Because the main dynamics of groundwater flow direction was convection and dispersion,the movement of MTBE is also diffusion in the vertical direction.In addition,the transport of MTBE was more quick in high permeability porous media,and the increase of groundwater flow velocity can accelerate the MTBE plume de-velopment,but the irregularity and randomness of the plume are enhanced synchronously.These research results can give some helps for the investigation of MTBE movement in the groundwater,also can make some references for other petroleum contamination behavior.     

QUANTITATIVE STUDY OF SOIL EROSION AND ELEMENT RUN-OFF IN THE SONGHUA LAKE VALLEY

Under the condition of different precipitation intensities, different gradients, different land-use types and different vegetation coverage, the soil erosion and transference of element (or pollutant) are studied by simulating and analyzing the surface run-off of experimental plots in the catchment area of Songhua Lake, with an area of about 43 370.8km^2. And the influencing factors that produce the spatial difference are analyzed and assessed. It is put for-ward that the irrational land utilization is the reason of soil erosion and pollutant run-off. The gradient of farmland,the growing season of vegetation and the vegetation coverage are chiefly restricting factors that lead to the soil ero-sion and pollutant run-off. This study can provide the fundamental data for comprehensive planning and harnessing of the non-noint source t3ollution in the valley.     

THE CHARACTERISTIC OF MARINE ENVIRONMENT IN LINGDINGYANG ESTUARY

1 HYDROLOGIC FEATURES Lingdingyang Estuary, located at the middle south of Guangdong Province, is a bell-shaped estuary with a north-south direction. Its area is about 2100km2. The north of Qi′ao Island and Inner-Lingding Island, and the south of Humen are grouped as Neilingdingyang Estuary, having an area of 1041km2. Affected by topography, runoff and tide, its dynamic condition is very complicated. Different water areas have different hydrologic features. The topography under …     

Water quality, nutrient budget, and pollutant loads in Chinese mitten crab (Eriocheir sinensis) farms around East Taihu Lake

To understand the factors causing frequent outbreaks of harmful algae blooms in the Taihu Lake, China, we studied water quality and nutrient budget in Chinese mitten crab (Eriocheir sinensis) farm ponds in the eastern part of the lake from November 2007 to December 2009. We estimated the nitrogen (N), phosphorus (P), and chemical oxygen demand (COD) loads. Materials input and output ponds, water exchange, and applied management practices of 838.5-hm2 crab ponds were surveyed using questionnaires. Water quality of 12 ponds, which were located no more than 2 km from East Taihu Lake, were monitored. The results show that water quality in the crab ponds was better than reference data. Feeds, including corn seed, commercial feed, trash fish, and gastropod, were the major sources of N and P input in the crab ponds, contributing 88.7% and 94.9%, respectively. In total, 60.5% of N and 37.3% of P were sequestered by macrophytes, and only 15.7% and 8.5% of them were discharged as effluent. The net loads of N and P in effluent were 16.43 kg/hm2/cycle and 2.16 kg/hm2/cycle, respectively, while the COD load was -17.88 kg/hm2/cycle. This indicated that crab farming caused minor negative impact on the trophic status of the lake area, which was attenuated by macrophytes. However, wastewater purification is still necessary in crab faming.     

顾及风向和风速的空气污染物浓度插值方法

随着经济的快速发展,中国大部分地区空气污染状况日趋严重。空气污染物浓度插值对于进一步分析污染物时空分布情况,估计不同地区人群的暴露风险,制定防范措施具有重要作用。然而,现有空间插值方法由于没有充分考虑风向和风速因素对于污染物扩散的影响,故直接应用于空气污染物浓度插值,会对插值结果造成不利的影响。因此,本文提出一种顾及风向和风速的空气污染物浓度插值方法（Direction-Velocity IDW,DVIDW）。该方法首先根据离散气象站点处的风向和风速数据建立风场表面,然后利用风场数据计算空气污染物的扩散距离,根据扩散距离计算风场中待求点与采样点间的最短路径距离,最后由最短路径距离替代欧式距离进行反距离加权插值。本文分别采用2组实际空气污染物浓度数据,对DVIDW方法和其他常用的空间插值方法进行实验对比分析,验证了本文方法的可行性和优越性。     

Impacts of Migration on Urban Environmental Pollutant Emissions in China: A Comparative Perspective

In recent years,researchers have devoted considerable attention to identifying the causes of urban environmental pollution.To determine whether migrant populations significantly affect urban environments,we examined the relationship between urban environmental pollutant emissions and migrant populations at the prefectural level using data obtained for 90 Chinese cities evidencing net in-migration.By dividing the permanent populations of these cities into natives and migrants in relation to the population structure,we constructed an improved Stochastic Impacts by Regression on Population,Affluence and Technology model(STIRPAT)that included not only environmental pollutant emission variables but also variables on the cities’attributes.We subsequently conducted detailed analyses of the results of the models to assess the impacts of natives and migrants on environmental pollutant emissions.The main findings of our study were as follows:1)Migrant populations have significant impacts on environmental emissions both in terms of their size and concentration.Specifically,migrant populations have negative impacts on Air Quality Index(AQI)as well as PM2.5 emissions and positive impacts on emissions of NO2 and CO2.2)The impacts of migrant populations on urban environmental pollutant emissions were 8 to 30 times weaker than that of local populations.3)Urban environmental pollutant emissions in different cities differ significantly according to variations in the industrial structures,public transportation facilities,and population densities.     

基于静风期污染物的PM2.5排放清单空间精细化方法

有利气象条件之后的静风期,极大降低了PM_2.5跨区域传输的影响,能够揭示本地源的排放状况。本文尝试性引入了静风期污染物分布揭示本地源排放特征的概念,提出了一种基于遥感数据的PM_2.5排放清单空间精细化方法：首先,利用 MODIS MCD19A2反演的ChinaHighPM_2.5数据,构建高时空分辨率PM_2.5数据融合方法;然后,构建唐山市有利气象条件之后的静风期污染物遴选方法（合理风向和风速：有利气象条件为东风,地面10 m高度风速大于3 m/s,其他风向,持续的较大风力5~10 m/s;静风期风速小于1.5~2.0 m/s）;其次,基于遴选的静风期PM_2.5数据分配MEIC清单中的PM_2.5总排放量,同时对比传统插值方法：基于GDP、人口密度、路网、土地利用类型数据,实现清单各污染源PM_2.5的1 km×1 km空间分配;最后,利用WRF-CMAQ模拟数据和地面台站实测数据进行真实性检验。研究结果表明：① PM_2.5数据填补融合方法能够有效提高PM_2.5监测数据的时空分辨率,且与地面监测值显著相关（R²=0.94,RMSE=4.64 µg/m³,NMB=2%,NME=7%）;② 引入有利气象条件后的静风期概念,提出了静风期污染物的遴选方法,有效降低了PM_2.5跨区域传输的影响,更好地反映了本地源排放的空间分布特征;③ WRF-CMAQ模拟方法的精度验证结果表明,该方法较传统面积插值法NME降低7%,NMB降低10%,RMSE降低1.54 µg/m³,R²提高11%。该方法为排放清单的空间精细化提供了新的研究思路。     

The impact of physical processes on pollutant transport in Hangzhou Bay

A Lagrangian tracer model is set up for Hangzhou Bay based on Coupled Hydrodynamical Ecological model for Regional Shelf Sea (COHERENS). The study area is divided into eight subdomains to identify the dominant physical processes, and the studied periods are March (the dry season) and July (the wet season). The model performance has been first verified by sea-surface elevation and tidal current observations at several stations. Eight tracer experiments are designed and Lagrangian particle tracking is simulated to examine the impact of physical processes (tide, wind and river runoff) on the transport of passive tracer released within the surface layer. Numerical simulations and analysis indicate that: (1) wind does not change the tracer distribution after 30 days except for those released from the south area of the bay during the wet season; (2) the tide and the Qiantang River runoff are important for particle transport in the head area of the bay; (3) the Changjiang River runoff affects the tracer transport at the mouth of the bay, and its impact is smaller in the dry season than in the wet season. Supported by the Natural Science Foundation of China (No.40576080); National High Technology Research and Development Program of China (863 Program, No. 2007AA12Z182)     

Thermohaline structure inhomogeneity associated with polynia at the northern margin of Emery Ice-shelf

Based on the hydrographic data in austral summer during the 22nd Antarctic Expedition of China(2005/2006),some features can be found about the northern margin of Emery ice shelf as follows.The heat content in the surface layer(0-50 m) at the eastern end and the western end of the ice-shelf margin is much higher than that at the middle.The upper mixing-layer depth and the seasonal thermocline depth at the middle of the ice-shelf northern margin are much shallower than those at the both ends.However there is much less difference between the middle and the ends in the bottom layer.The remote sensing photos show that the inhomogeneity in the surface-layer water is closely related to the spatial distribution of the floes and polynia in the area.     

Phylogenetic analysis of cultivable bacteria isolated from Arctic sea-ice

Phylogenetic analysis based on 16S rDNA of 8 strains of cultivable bacteria isolated from Arctic sea-ice was studied.The results showed that strain BJ1 belonged to genus Planococcus,which was a genus of low mole percent G C gram-positive bacteria;strain BJ6 belonged to genus Burkholderia of β-proteobacteria and the rest 6 strain all belonged to γ-proteobacteria,of which strain BJ8 was a species of Pseudoalteromonas,strain BJ2-BJ5 and BJ7 were members of genus Psychrobacter.Phylogenetic analysis also indicated that bacteria of genus Psychrobacter of the isolates formed a relatively independent phylogenetic cluster in comparison with other bacteria belonged to genus Psychrobacter.     

Information for authors

正1 Aims and Scope Advances in Polar Science(APS)is an international,peer-reviewed journal jointly sponsored by the Polar Research Institute of China and the Chinese Arctic and Antarctic Administration.APS is a comprchensive academic journal dedicated to presentation of multi-disciplinary achievements in Arctic and Antarctic expeditions and research.Its primary purpose is to publish achievements in fundamental research,applied     

Advances in Polar Science CONTENTS(Volume 25,2014)

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Guide to Authors： Journal of Mountain Science

<正>AIMS AND SCOPE(Editorial Policy)The Journal of Mountain Science(JMS)is devoted to mountains and their surrounding lowlands-ecoregions of particular global importance,with a particular emphasis on the important highlands/mountains in the world,such as the Tibetan Plateau,the Himalayas,the Alps,the Andes,the Rockies and many other mountain ranges of our planet.     

Journal of Mountain Science(JMS)

<正>The Journal of Mountain Science(JMS),founded in2004,is an international English-language journal on mountain sciences.JMS is supervised by the Chinese Academy of Sciences(CAS),sponsored by the Chengdu Institute of Mountain Hazards and Environment,CAS,published by Science Press China,and distributed by Springer exclusively throughout the world(excluding Mainland China).The JMS is published bimonthly,fulltexted in SpringerLink and CNKI,indexed/abstracted by     

Relationship of Arctic sea ice and Northern Hemispheric 500 hPa Polar vortices

Using the NCEP/NCAR reanalysis monthly 500 hPa height data on a 2.5 latitude-longitude grid and 1°×1° sea ice data,the polar vortex area,intensity index and arctic sea ice area index are calculated respectively,and the meridional distribution,period variation and the abrupts in the long range trend are analyzed to study their relationship.The results show that the meridional distribution of sea ice and polar vortex h-ave distinctive difference,the relative positions of them are different in the eastern and western hemispheres,and exept they have periods of 4 months,quasi half year,quasi year,4-5 years and 10 years commonly,and each of them has its own respective variation as well.The sea ice area is decreasing apparently since 1980's,so is the polar vortex area,but their abrupt changge time are different totally.The area of sea ice and polar vortex has prominent positive correlation,but the relationship of sea ice intensity,polar vortex intensity,polar vortex area is complicated.     

Preliminary study on plasma membrane fluidity of Psychrophilic Yeast Rhodotorula sp.NJ298 in low temperature

The ability of cell to modulate the fluidity of plasma membrane was crucial to the survival of microorganism at low temperature. Plasma membrane proteins, fatty acids and carotenoids profiles of Antarctic psychrophilc yeast Rhodotorula sp. NJ298 were investigated at -3 ℃, 0 ℃ and 8 ℃. The results showed that plasma membrane protein content was greater at -3 ℃ than that at 8 ℃, and a unique membrane polypeptide composition with an apparent molecular mass of 94.7 kDa was newly synthesized with SDS-PAGE analysis; GC analysis showed that the main changes of fatty acids were the percentage of unsaturated fatty acids (C18∶ 1 and C18∶ 2) and shorter chain saturated fatty acid (C10∶ 0) increased along with the decrease of the culture temperature from 8 ℃ to -3 ℃; HPLC analysis indicated that astaxanthin was the major functional carotenoids of the plasma membrane, percentage of which increased from 54.6±1.5% at 8 ℃ to 81.9±2.1% at -3 ℃. However the fluidity of plasma membrane which was determined by measuring fluorescence anisotropy was similar at -3 ℃, 0 ℃ and 8 ℃. Hence these changes in plasma membrane's characteristics were involved in the cellular cold-adaptation by which NJ298 could maintain normal plasma membrane fluidity at near-freezing temperature.