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排序方式: 共有502条查询结果,搜索用时 15 毫秒
281.
Akira Watanabe Benito H. Purwanto Ho Ando Ken-ichi Kakuda Foh-Shoon Jong 《Agriculture, ecosystems & environment》2009,134(1-2):14-18
Tropical peatland is a vast potential land source for biological production, but peatland is a major natural source of greenhouse gases, especially methane (CH4). It is important to evaluate the changes in greenhouse gas emissions induced by cultivation practices for sustainable agricultural use of tropical peatland. We investigated the effects of fertilizer application and the groundwater level on CH4 and carbon dioxide (CO2) fluxes in an Indonesian peat soil. The crop cultivated was sago palm (Metroxylon sagu Rottb.), which can grow on tropical peat soil without drainage and yield great amounts of starch. CH4 emission through sago palm plants was first estimated by collecting gas samples immediately after cutting sago suckers using the closed chamber method. The CH4 fluxes ranged from negative values to 1.0 mg C m−2 h−1. The mean CH4 flux from treatment with macroelements (N, P, and K) and microelements (B, Cu, Fe, and Zn) applied at normal rates did not differ significantly from that of the No fertilizer treatment, although increasing the application rates of macroelements or microelements by 10-fold increased the CH4 flux by a factor of two or three. The relationship between CH4 flux and the groundwater table was regressed to a logarithmic equation, which indicated that to maintain a small CH4 flux, the groundwater table should be maintained at <−45 cm. The CO2 fluxes ranged between 24 and 150 mg C m−2 h−1, and were not significantly affected by either fertilizer treatments or the groundwater level. The inclusion of sago palm suckers in a chamber increased CH4 emission from the peat soil significantly. Thus, gas emissions mediated by certain kinds of palm plants should not be disregarded. 相似文献
282.
落地油泥污染及油土分离处理的工艺研究 总被引:1,自引:0,他引:1
对落地油泥的组成、性质及其对环境的污染进行了调查和分析;根据落地油泥油土分离小型试验的结果,进行了0.5t/h油土分离的放大试验。 相似文献
283.
化学破乳絮凝与SBR二段法处理采油污水的试验研究 总被引:1,自引:0,他引:1
采用化学絮凝与 SBR生化联合的二段法工艺对采油污水进行处理 ,采油污水经第一段化学破乳絮凝后 ,CODCr去除率可达 85 %以上 ,油去除率可达 95 %以上 ;第一段处理出水再经第二段 SBR生化处理后可使出水中 CODCr≤ 60 mg/L、BOD≤ 3 0 mg/L、SS<3 0 mg/L、油 <10 mg/L,达到了油田回注水标准和含油污水的国家二级排放标准 ,可实现废水的资源化 相似文献
284.
Syncrude Canada Ltd. is currently developing environmentally acceptable oil sands process-affected water management methods as part of their land reclamation strategy. Surface waters of the “wet landscape” reclamation option characteristically have elevated concentrations of sodium sulphate and naphthenic acids (NAs), with low levels of PAHs. The following experiment compared early-life stage responses of yellow perch (Perca flavescens) to those of Japanese medaka (Oryzias latipes) when exposed to Mildred Lake settling basin (MLSB) surface water and a commercial sodium naphthenate (Na-NA) standard. Perch eggs were fertilized and incubated in: 100%, 50%, 20%, 4%, 0.8%, and 0.16% dilutions of MLSB water, as well as 20, 10, 5, 2.5, and 1.25 mg/l solutions of the commercial standard. Medaka embryos were exposed to the same treatments, post-fertilization. Both species demonstrated an increase in the incidence of deformity, and a decrease in length at hatch as NA concentrations increased. MLSB surface water contained higher levels of NAs than the commercial standard, however, showed consistently higher NA threshold effect concentrations for both species. Significant differences between the MLSB water and the Na-NA standard suggest that they contain NA congeners with different toxicity, or other compounds such as PAHs. Species differences in thresholds could be explained by the difference in developmental stage in which the exposures were initiated. 相似文献
285.
1株好氧菌对不同油脂的降解 总被引:8,自引:0,他引:8
从某餐馆排污渠污泥分离到10株油脂降解菌,以植物油脂花生油为唯一碳源,通过适应性培养驯化并检测细菌生长的OD值筛选出1株优势菌。在确定其最佳生长环境条件的基础上,分别以花生油、餐厅污水和一种含有油脂的膜为对象污染物,进行了优势菌的降解试验。结果表明,该菌对花生油溶液中油脂和CODcr的去除率在24h以内分别达到98.91%和97.27%;对餐厅污染中油脂和CODcr的降解率在30h内分别达到88.66%和85.42%。另外,该优势菌对油脂膜也有良好降解效果,在固体和液体培养基中30d内油脂膜量分别减少了3.31%和11.29%以上。试验证实了该菌对植物油脂、含油脂污水和固体油脂废弃物有良好的净化效果。 相似文献
286.
D. Jones A.G. Scarlett C.E. West R.A. Frank R. Gieleciak D. Hager J. Pureveen E. Tegelaar S.J. Rowland 《Chemosphere》2013
‘Naphthenic acids’ (NAs) in petroleum produced water and oil sands process water (OSPW), have been implicated in toxicological effects. However, many are not well characterized. A method for fractionation of NAs of an OSPW was used herein and a multi-method characterization of the fractions conducted. 相似文献
287.
Al-Khashman OA Al-Muhtaseb AH Ibrahim KA 《Environmental pollution (Barking, Essex : 1987)》2011,159(6):1635-1640
The leaves of date palms were evaluated as a possible biomonitor of heavy metal contamination in Ma’an city, Jordan. Concentrations of (Fe), (Pb), (Zn), (Cu), (Ni), and (Cr) were determined in washed and unwashed leaves and soil samples collected from different sites with different degrees of metal contamination (urban, suburban, industrial, highway and rural sites); separate leaves were taken from outside the city to be used as a control sample. Samples collected from industrial sites were found to have high concentrations of all metals except those of Cu, Ni and Pb, which were found at high levels in the highway site samples which is associated with the road traffic. The difference between unwashed and washed samples showed that metal pollutants exist as contaminants, particularly Pb, Zn and Ni, which varied in concentration, depending on the source of the metal. 相似文献
288.
Broz J Grabic R Kilián J Lojkásek M Marklund S Ocelka T Pekárek V Pribyl J Tydlitát V Výska J 《Chemosphere》2000,41(12):1948-1911
The effect of synthetic and mineral oils on the formation of polyaromatic hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) in emissions from a spark ignition engine was studied on a Skoda Favorit engine fueled with leaded gasoline. The test cycle simulated urban traffic conditions on a chassis dynamometer, in accordance with the ECC 83.00 test. The data for selected PAHs as well as PCDDs, PCDFs, and PCBs congener profiles are presented. PCDD/Fs emissions for an unused oil and the oil after 10000-km operation varied from 300 to 2000 fmol/m3, PCBs emissions from 75 to 178 pmol/m3, and PAHs emissions from 150 to 420 microg/m3. The content of PCBs in oils varied from 2 to 920 mg/kg. 相似文献
289.
The effects of acute and subchronic aqueous hydrocarbon exposures in the ppb range (0.2-127microg/L total PAH) on the immune system in Pacific herring (Clupea pallasi) were examined through specific immunocompetency assays and a host resistance model using Listonella anguillarum. Short-term hydrocarbon exposure at the highest concentration significantly enhanced respiratory burst activity (RBA) in macrophages and decreased plasma lysozyme concentrations, however, subchronic exposure (4-57d) reduced RBA. Fish in the high exposure group were also less susceptible to the pathogen L. anguillarum following acute hydrocarbon exposure; however, this group was the most susceptible following subchronic exposures. These results are explained by a measured transient physiological stress response and long-term effects on ionoregulation. This study illustrates that hydrocarbon-elicited effects are dynamic and that toxic outcomes with respect to the teleost immune system depend on chemical concentrations and composition, exposure durations and the specific pathogen challenge. 相似文献
290.
小型油水分离器的设计及试验 总被引:2,自引:0,他引:2
简要介绍了CYF-0.1/CYF-0.05型油水分离器的基本原理、主要参数、设计计算及台架试验情况。 相似文献