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601.
F. Boukhoubza A. Jail F. Korchi L. Loukili Idrissi H. Hannache J.C. Duarte L. Hassani A. Nejmeddine 《Journal of environmental management》2009,91(1):124-132
The application of hypochlorite for the removal of soluble COD, phenolic and polyphenolic like compounds, and other organic compounds responsible for the olive mill wastewater (OOWW) colour has been experimentally studied. After the OOWW filtration on a sand column, the effluent was subjected to a fast liming under optimal conditions. Lime application reduced polyphenols, COD and SS contents to half of their initial values but an important blackening of the treated OOWW was observed, especially when adding high concentrations of lime (10% (W/V) and 15% (W/V)).A second stage of treatment was applied using calcium hypochlorite. In this stage, removal of the studied compounds reached as much as 95% at higher concentrations, and particularly the colouring of OOWW which is generally difficult to eliminate was greatly reduced. The OOWW hypochloration acted through coagulation–flocculation and a rapid oxidation of the organic matter proceeded from the first 5 min. The kinetic study of the degradation of the waste polluting compounds from liming showed that Ca(ClO)2 reacts similarly in the elimination of organic compounds, polyphenols, SS and colouration. The analysis of the organochloride compounds generated by the reaction between hypochlorite and the organic compounds showed that DDD, DDT and the heptachlor contents exceeded the values recommended by the International and European drinking water standards. 相似文献
602.
Anaerobic ammonium oxidation by Nitrosomonas spp. and anammox bacteria in a sequencing batch reactor 总被引:2,自引:0,他引:2
Lek Noophan P Sripiboon S Damrongsri M Munakata-Marr J 《Journal of environmental management》2009,90(2):967-972
A sequencing batch reactor (SBR) was inoculated with mixed nitrifying bacteria from an anoxic tank at the conventional activated sludge wastewater treatment plant in Nongkhaem, Bangkok, Thailand. This enriched nitrifying culture was maintained under anaerobic conditions using ammonium (NH(4)(+)) as an electron donor and nitrite (NO(2)(-)) as an electron acceptor. Autotrophic ammonium oxidizing bacteria survived under these conditions. The enrichment period for anammox culture was over 100 days. Both ammonium and nitrite conversion rates were proportional to the biomass of ammonium oxidizing bacteria; rates were 0.08 g N/gV SS/d and 0.05 g N/g VSS/d for ammonium and nitrite, respectively, in a culture maintained for 3 months at 42 mg N/L ammonium. The nitrogen transformation rate at a ratio of NH(4)(+)-N to NO(2)(-)-N of 1:1.38 was faster, and effluent nitrogen levels were lower, than at ratios of 1:0.671, 1:2.18, and 1:3.05. Fluorescent in situ hybridization (FISH) was used to identify specific autotrophic ammonium oxidizing bacteria (Nitrosomonas spp., Candidatus Brocadia anammoxidans, and Candidatus Kuenenia stuttgartiensis). The ammonium oxidizing culture maintained at 42 mg N/L ammonium was enriched for Nitrosomonas spp. (30%) over Candidati B. anammoxidans and K. stuttgartiensis (2.1%) while the culture maintained at 210 mg N/L ammonium was dominated by Candidati B. anammoxidans and K. stuttgartiensis (85.6%). The specific nitrogen removal rate of anammox bacteria (0.6 g N/g anammox VSS/d) was significantly higher than that of ammonium oxidizing bacteria (0.4 g N/g Nitrosomonas VSS/d). Anammox bacteria removed up to 979 mg N/L/d of total nitrogen (ammonium:nitrite concentrations, 397:582 mg N/L). These results suggest significant promise of this approach for application to wastewater with high nitrogen but low carbon content, such as that found in Bangkok. 相似文献
603.
A number of studies on the oxidation of various organic/inorganic contaminants by ferrate(VI) were reported in the 1980s and 1990s. The exploration of the use of ferrate(VI) for water and wastewater treatment has been well addressed recently. However, challenges have existed for the implementation of ferrate(VI) technology in practice due to the instability of a ferrate solution or high production cost of solid ferrate products. The research has been carried out aiming at the generation and application of ferrate(VI) in situ. This paper thus reviews ferrate chemistry and its overall performance as a water treatment chemical, discusses the factors affecting the ferrate yield efficiency using the electrochemical method, and finally, summarises the work on the production and use of ferrate in situ which is currently under study. 相似文献
604.
Benjamin Erable Isabelle GoubetAmira Seltana Thierry Maugard 《Journal of environmental management》2009
Traditional biological removal processes are limited by the low solubility of halogenated compounds in aqueous media. A new technology appears very suitable for the remediation of these volatile organic compounds (VOCs). Solid/gas bio-catalysis applied in VOC remediation can transform halogenated compounds directly in the gas phase using dehydrated cells as a bio-catalyst. 相似文献
605.
An Assessment of Stakeholder Perceptions and Management of Noxious Alien Plants in Spain 总被引:1,自引:1,他引:0
Despite biological invasions being a worldwide phenomenon causing significant ecological, economic, and human welfare impacts,
there is limited understanding regarding how environmental managers perceive the problem and subsequently manage alien species.
Spanish environmental managers were surveyed using questionnaires to (1) analyze the extent to which they perceive plant invasions
as a problem; (2) identify the status, occurrence, and impacts of noxious alien plant species; (3) assess current effort and
expenditure targeting alien plant management; and, finally, (4) identify the criteria they use to set priorities for management.
In comparison to other environmental concerns, plant invasions are perceived as only moderately problematic and mechanical
control is the most valued and frequently used strategy to cope with plant invasions in Spain. Based on 70 questionnaires
received, 193 species are considered noxious, 109 of which have been the subject of management activities. More than 90% of
species are found in at least one protected area. According to respondents, the most frequently managed species are the most
widespread across administrative regions and the ones perceived as causing the highest impacts. The perception of impact seems
to be independent of their invasion status, since only half of the species identified as noxious are believed to be invasive
in Spain, while 43% of species thought to only be casual aliens are causing a high impact. Records of management costs are
poor and the few data indicate that the total actual expenditure amounted to 50,492,437 € in the last decade. The majority
of respondents stated that management measures are insufficient to control alien plants due to limited economic resources,
lack of public awareness and support, and an absence of coordination among different public administrations. Managers also
expressed their concern about the fact that much scientific research is concerned with the ecology of alien plants rather
than with specific cost-efficient strategies to manage alien species. 相似文献
606.
Allen CD 《Environmental management》2009,43(2):346-356
Characterized by expensive housing, high socioeconomic status, and topographic relief, Upper Sonoran Lifestyle communities
are found primarily along the Wildland-Urban Interface (WUI) in the Phoenix, Arizona metro area. Communities like these sprawl
into the wildlands in the United States Southwest, creating a distinct urban fringe. This article, through locational comparison,
introduces and evaluates a new field assessment tool for monitoring anthropogenic impact on soil–vegetation interactions along
the well-maintained multi-use recreational trails in Upper Sonoran Lifestyle region. Comparing data from randomly selected
transects along other multi-use trails with data from a control site revealed three key indicators of anthropogenic disturbances
on soil–vegetation interactions: soil disturbance, vegetation disturbance, and vegetation density. Soil and vegetation disturbance
displayed an average distance decay exponent factor of −0.60, while vegetation density displayed a reverse decay average of
0.60. Other important indicators of disturbance included vegetation type, biological soil crusts, and soil bulk density. The
predictive ability of this new field tool enhances its applicability, offering a powerful rapid ecological assessment method
for monitoring long-term anthropogenic impact in the Upper Sonoran Lifestyle, and other sprawling cities along the WUI. 相似文献
607.
生物入侵中入侵种与土著种的相互作用 总被引:3,自引:0,他引:3
在全球范围内,生物入侵已经成为一个非常严重的环境问题,并产生了生态问题和经济问题。本文阐述了生物入侵中入侵种自身的变化及对土著种的影响,并讨论了生物入侵过程中入侵种与土著种的快速进化问题。 相似文献
608.
609.
610.
CASS处理技术的原理和应用 总被引:1,自引:0,他引:1
介绍了CASS工艺的原理、特点、核心构筑物和设计、运行中应注意的主要问题以及常见故障的排除方法。 相似文献