Biological Activity in a Heavily Organohalogen-Contaminated River Sediment (8 pp)

Background, Aims and Scope Sediments of the Spittelwasser creek are highly polluted with organic compounds and heavy metals due to the discharge of untreated waste waters from the industrial region of Bitterfeld-Wolfen, Germany over the course of more than one century. However, relatively few data have been published about the chloroorganic contamination of the sediment. This paper reports on the content of different (chloro)organic compounds with special emphasis on polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F), and chlorobenzenes. Existing concepts for the remediation of Spittelwasser sediment include the investigation of natural attenuation processes, which largely depend on the presence of an intact microbial food web. In order to gain more insight in terms of biological activity, we analyzed the capacity of sediment microflora to degrade organic matter by measuring the activities of extracellular hydrolytic enzymes involved in the biogeochemical cycling of carbon, nitrogen, phosphorus and sulfur. Furthermore, the detection of physiologically active bacteria in the sediment, particularly of those known for their capability to reductively dehalogenate organochlorine compounds, illustrates the potential for intrinsic bioremediation processes. Methods PCDD/F and chlorobenzenes were analyzed by gas chromatography(GC)/mass spectrometry and GC/flame ionization detection, respectively. The activities of hydrolytic enzymes were determined from freshly sampled sediment layers using 4-methylumbelliferyl (MUF) or 7-amino-4-methylcoumarin-conjugated model compounds and kinetic fluorescence measurements. Physiologically active bacteria from different sediment layers were microscopically visualized by fluorescence in situ hybridization (FISH). Specific bacteria were identified by 16S rRNA gene amplification and sequencing. Results and Discussion The PCDD/F congener profile was dominated by dibenzofurans. In addition, the presence of specific tetra and pentachlorinated dibenzofurans supported the assumption that extensive magnesium production was one possible source for the high contamination. A range of other chloroorganic compounds, including several isomers of chlorobenzenes, hexachlorocyclohexane and 1,1,1-trichloro-2,2-bis (p-chloro-phenyl)ethane (DDT), was present in the sediment. Activities of extracellular hydrolytic enzymes showed a strong decrease in those sediment layers that were characterized by high contents of absorbable organic halogen (AOX), indicating disturbed organic matter decay. Interestingly, an abnormal increase of cellulolytic enzyme activities below the organochlorine-rich layers was observed, possibly caused by residual cellulose from discharges of sulfite pulping wastes. FISH revealed physiologically active bacteria in most sediment layers from the surface down to the depth of about 60 cm, including members of Desulfitobacterium (D.) and Sulfurospirillum. The presence of D. dehalogenans was confirmed by its partial 16S rRNA gene sequence. Conclusions Results of chemical sediment analyses demonstrated high loads of organochlorine compounds, particularly of PCDD/F. Several years after stopping the waste water discharge to Spittelwasser creek, this sediment remains a main source for pollution of the downstream river system by way of the ongoing mobilization of sediment during high floods. As indicated by our enzyme activity measurements, the decomposition potential for organic matter is low in organochlorine-rich sediment layers. In contrast, the comparably higher enzyme activities in less organochlorine-polluted sediment layers as well as the presence of physiologically active bacteria suggest a considerable potential for natural attenuation. Recommendations and Perspectives From our data we strongly recommend to explore the degradative capacity of sediment microorganisms and the limits for in situ activity towards specific sediment pollutants in more detail. This will give a sound basis for the integration of bioremediation approaches into general concepts to reduce the risk that permanently radiates from this highly contaminated sediment. Submission Editor: Dr. Henner Hollert (Henner.Hollert@urz.uniheidelberg.de)     

湛江市土地资源的可持续利用

湛江市位于祖国大陆的最南端，地形以平原、台地为主，土地资源利用受台风、干早等自然因素的影响。作者对湛江市土地资源可持续利用的限制因子进行了分析，提出了滋江市土地资源可持续利用的对策和措施。     

黄土滑坡的滑前地貌重建

以渭河中游陕西省宝鸡市李家窑滑坡为实例,在搜集大量资料的基础上,运用先进的软件给出了重建滑前地貌所必需的3个要素,即现今实际地貌形态、滑床面形态和滑动后的地貌形态,并进行了滑前地貌重建.依据重建的结果,得到了滑坡发生前的许多重要参数,如滑坡的稳定性、重量、体积、初滑角以及质心的滑动角度和释放的势能等.最后对该滑坡从滑前到现今各阶段的滑坡稳定性演化进行了分析.     

经济欠发达山区矿泉水资源的开发利用--以梅州市为例

基于矿泉水与人体健康的关系、在社会经济发展中的作用,以及对梅州市矿泉水资源条件及其开发利用现状的调研,探讨了经济欠发达山区矿泉水资源的开发利用对策和前景.认为应统一资源管理,加强质量监督力度,打造优质品牌,提高市场竞争能力,争取与食品、旅游等部门联营,使矿泉水产品多样化、系列化;结合地方工业建设和梅州旅游市场需求,培育矿泉水消费市场.     

夏季富营养化滆湖中沉水植物群落重建及水质净化效果

通过滆湖原位围隔试验分析了不同单种及混种沉水植物群落随环境变化的生长状况及对水质的净化效果.结果表明:(1)夏季,沉水植物生物量的平均值与透明度/水位存在显著线性相关性,进一步表明沉水植物的生长在很大程度上依赖于光强和水深.(2)各植物区(除马来眼子菜区外)的高锰酸盐指数、TN高于空白对照区.(3)对比空白对照区,苦草...     

Characterization of polychlorinated biphenyls and brominated flame retardants in surface soils from Surabaya, Indonesia

In this study, soil contamination by PCBs, PBDEs, HBCDs and two novel BFRs such as 1,2-bis-(2,4,6-tribromopenoxy) ethane (BTBPE) and decabromodiphenyl ethane (DBDPE) in various locations such as industrial, urban, rural, dumping site and agricultural areas of Surabaya, Indonesia has been characterized in order to evaluate their contamination status, profiles, potential sources, fate and behavior. Range and median concentrations of PCBs, PBDEs, HBCDs, BTBPE and DBDPE were ND - 9.6 (1.2), 0.069 - 24 (7.4), ND - 1.8 (0.48), ND - 1.7 (0.14) and ND - 7.6 (2.2) ng g⁻¹ dw, respectively. Industrial, urban and dumping areas were inventoried as the main sources of these pollutants. Decreasing gradient levels were observed for these contaminants from industrial district, urban, dumping site, rural and agricultural areas, in that order. Furthermore, organic carbon contents and proximity to the point sources were found as the major controlling factors. Contaminant profiles were characterized by the predominance of hexa-, hepta- and penta-homologues for PCBs; deca-, nona- and octa- for PBDEs and α-isomer for HBCDs. Product mixtures such as Ar1260/KC600 and Ar1254/KC500 for PCBs, deca- and octa-BDEs for PBDEs were the possible common formulations used in study area. To our knowledge, this is a first comprehensive study on characterization of soil contamination by PCBs, PBDEs and HBCDs together with two novel BFRs in a highly industrialized city located in tropical region. This study provides baseline information for establishing national monitoring programs in Indonesia.     

玛纳斯河流域生态问题的潜在风险性评估

玛纳斯河流域是中国干旱区最具代表性的山地-绿洲-荒漠生态系统,三大生态系统表现出的区域生态、经济要素的空间状况有所分异,所存在的生态安全问题的表现形式也各不相同。根据流域土地利用和水资源数据库,在生态经济功能分区的基础上,针对流域不同分区存在的生态安全问题,选取相应的17个生态风险评估指标,建立了生态-经济风险性评价模型,对流域各个生态经济功能亚区的生态问题潜在的风险性进行了生态风险评估。结果表明:Ⅰ1,Ⅱ1,Ⅱ2,Ⅱ3,Ⅲ1,Ⅲ2和Ⅲ3亚区的生态问题潜在的风险性在增大,说明生态问题日益突出,而Ⅰ1和Ⅱ4亚区生态问题潜在的风险性指数存在波动;Ⅰ,Ⅱ和Ⅲ三个大区中生态问题潜在的风险性指数最高的分别是Ⅰ1,Ⅱ1和Ⅲ1亚区。评价结果能够较为客观地反映了当地的实际情况,因而对流域可能出现的灾害性的环境问题及由此引起的巨大的经济损失提出了警示。     

Strategic planning for post-disaster temporary housing

Temporary housing programmes suffer from excessively high cost, late delivery, poor location, improper unit designs and other inherent issues. These issues can be attributed in part to a prevalence of ad hoc tactical planning, rather than pre-disaster strategic planning, for reconstruction undertaken by governments and non-governmental organisations (NGOs) in the chaotic post-disaster environment. An analysis of the process and outcomes from six case studies of temporary housing programmes after disasters in Turkey and Colombia in 1999, Japan in 1995, Greece in 1986, Mexico in 1985, and Italy in 1976 yields information about the extent to which strategic planning is employed in temporary housing programmes, as well as common issues in temporary housing. Based on an understanding of these common issues, this paper proposes a framework for strategic planning for temporary housing that identifies organisational designs and available resources for temporary housing before the disaster, but allows modifications to fit the specific post-disaster situation.     

RETRACTED ARTICLE: Environmental Impact Assessment of Industrial Structure Change in a Rural Region of China

As the embodiment of human activities, the change of regional industrial structure is an essential driving factor of global environmental change. Consequently, the research on the change of regional industrial structure and associated effects on the environment is one of the key issues of researches on sustainable development, human–environment relationship, and regional response to global environment change. However, compared to the flourish of researches on environmental impact assessment of industrial departments, few studies have been conducted to assess the environmental impact of regional industrial structure. In this study, based on a synthetic analysis of environmental disturbances of different industrial departments, the environmental impact coefficient of industrial department associated with the index of environmental impact of industrial structure was constructed, so as to make a quantitative assessment of environmental impact of the change of regional industrial structure. And the results of the case study in Lijiang City, a rural region of China, have showed that there are two obvious changes of industrial structure in the study area from 1992 to 2003, associated with a continuous decreasing of the index of environmental impact of industrial structure, which indicated a positive environmental effects of the change of regional industrial structure.     

安徽明光市凹凸棒石粘土资源的开发利用

安徽明光市凹凸棒石粘土资源丰富，在我国稀有非金属矿产资源中占有重要地位。通过调查明光市凹凸棒石粘土资源、的基本状况和开发利用现状特征，分析了资源开发利用中存在的问题，提出了可持续发展的对策建议。