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1.
Bunge Michael Khknen Mika A. Rmisch Winfried Opel Matthias Vogler Susanne Walkow Fred Salkinoja-Salonen Mirja Lechner Ute 《Environmental science and pollution research international》2007,14(1):3-10
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) 相似文献
2.
Stin OC Carnahan A Singh R Powell J Furuno JP Dorsey A Silbergeld E Williams HN Morris JG 《Environmental monitoring and assessment》2003,81(1-3):327-336
Molecular methods, including DNA probes, were used to identify and enumerate pathogenic Vibrio species in the Chesapeake Bay; our data indicated that Vibrio vulnificus exhibits seasonal fluctuations in number. Our work included a characterization of total microbial communities from the Bay; development of microarrays that identify and quantify the diversity of those communities; and observation of temporal changes in those communities. To identify members of the microbial community, we amplified the 16S rDNA gene from community DNA isolated from a biofilm sample collected from the Chesapeake Bay in February, 2000. The resultant 75 sequences were 95% or more similar to 7 species including two recently described Shewanella species, baltica and frigidimarina, that have not been previously isolated from the Chesapeake. When the genera of bacteria from biofilm after culturing are compared to those detected by subcloning amplified 16S fragments from community DNA, the cultured sample exhibited a strong bias. In oysters collected in February, the most common bacteria were previously unknown. Based on our 16S findings, we are developing microarrays to detect these and other microbial species in these estuarine communities. The microarrays will detect each species using four distinct loci, with the multiple loci serving as an internal control. The accuracy of the microarray will be measured using sentinel species such as Aeromonas species, Escherichia coli, and Vibrio vulnificus. Using microarrays, it should be possible to determine the annual fluctuations of bacterial species (culturable and non-culturable, pathogenic and non-pathogenic). The data may be applied to understanding patterns of environmental change; assessing the health of the Bay; and evaluating the risk of human illness associated with exposure to and ingestion of water and shellfish. 相似文献
3.
国际海事组织目前正在对《MARPOL73/78公约》附则Ⅱ-控制散装液体有毒物质污染规则作重大修改,内容包手胡毒液体物质和化学品,这很可能对主管机关、船公司和化工界造成严重的冲击。 相似文献
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7.
全球环境变化给发展中国家和南北关系带来深刻影响,理解环境问题的全球不平等需要以发展中国家80年代开始的经济结构调整和沉重债务为背景。南方的环境政策优先在很大程度上与其生活的可持续性相连,而不是通常与全球环境变化的长期性风险相关,然而,全球环境变化又与发展中国家贫困人口的日常生活紧密相关。从南方的立场看,当“问题”对他们不十分迫切时,就很难同意采取措施,仅此原因,北方对全球环境变化的关切要得到成功回应,真正的全球契约就需要解决基本“发展”问题,主要是贫困。 相似文献
8.
针对鱼油工业废水排放特点及处理技术难点,结合实例,采用混凝、破乳进行物化预处理;采用A/O生化处理技术,提出合适的工艺流程。 相似文献
9.
IntroductionChlorinatedorganiccompoundshavebeenusedonalargescaleinthechemical,petrochemical,andelectronicindustries.Inrecentyears ,worldwideattentionhasbeengiventotheenvironmentalandhealthimpactofthemasaclassofcontaminants .Severalareknowntocauseozonedepletion ,whileothersproduceadverseeffectsonthehumancentralnervoussystemandhavebeenlinkedtodiseasessuchascancer.Almostallofthechlorinatedaromaticcompoundsaretoxicandthermallystable .Oncereleasedintoenvironment,theywillaccumulateinthesurroundings… 相似文献
10.
从二(?)(?)类化合物的结构、来源、毒性等简要说明对其监测的必要性,且从仪器监测(包括气相色谱、气质联用、串联质谱等)和生物监测(包括利用指示生物、生物标志物等)概述了80年代以来国内外对二(?)(?)类物质尤其是几种极毒性化合物如多氯代二苯二(?)(?)(PCDDs)和多氯代二苯呋喃(PCDFs)等化合物的检测技术成果。 相似文献