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51.
三阶段温度控制堆肥接种法对有机氮变化规律的影响 总被引:1,自引:0,他引:1
利用原生生活垃圾,通过三阶段温度控制技术进行堆肥试验,探讨在堆肥过程中有机态氮组分的动态变化规律.结果表明,全氮、酸水解有机态氮、氨基酸态氮均在堆肥的前期呈明显的下降趋势,呈较好的相关性.与CK(对照组)处理相比,在堆肥的后期,三阶段温度控制堆肥酸水解有机态氮、氨基酸态氮、氨基糖态氮及酸解未知态氮含量呈不同程度的上升趋势,增加幅度依次为:10.67%、16.17%、7.17%、22.44%.表明三阶段温度控制技术能减少堆肥中氮素的损失,堆肥产品施入土壤后,可提高土壤的供氮潜力. 相似文献
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Potential particulate pollution derived from UV-induced degradation of
odorous dimethyl sulfide 总被引:1,自引:0,他引:1
UV-induced degradation of odorous dimethyl sulfide (DMS) was carried out in a static White cell chamber with UV irradiation. The
combination of in situ Fourier transform infrared (FT-IR) spectrometer, gas chromatograph-mass spectrometer (GC-MS), wide-range
particle spectrometer (WPS) technique, filter sampling and ion chromatographic (IC) analysis was used to monitor the gaseous and
potential particulate products. During 240 min of UV irradiation, the degradation e ciency of DMS attained 20.9%, and partially
oxidized sulfur-containing gaseous products, such as sulfur dioxide (SO2), carbonyl sulfide (OCS), dimethyl sulfoxide (DMSO),
dimethyl sulfone (DMSO2) and dimethyl disulfide (DMDS) were identified by in situ FT-IR and GC-MS analysis, respectively.
Accompanying with the oxidation of DMS, suspended particles were directly detected to be formed by WPS techniques. These
particles were measured mainly in the size range of accumulation mode, and increased their count median diameter throughout
the whole removal process. IC analysis of the filter samples revealed that methanesulfonic acid (MSA), sulfuric acid (H2SO4) and
other unidentified chemicals accounted for the major non-refractory compositions of these particles. Based on products analysis and
possible intermediates formed, the degradation pathways of DMS were proposed as the combination of the O(1D)- and the OH- initiated
oxidation mechanisms. A plausible formation mechanism of the suspended particles was also analyzed. It is concluded that UV-induced
degradation of odorous DMS is potentially a source of particulate pollutants in the atmosphere. 相似文献
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The activities of CeO2 nanocubes calcined at different temperatures were tested for catalytic oxidation of o-xylene. Using CeO2 nanocubes as catalysts, complete catalytic oxidation of o-xylene was achieved below 210℃. The CeO2 nanomaterials were characterized by means of BET, X-ray diffraction (XRD), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM). From the TEM images, all Ce02 nanocubes displayed cubic morphology irrespective of calcination temperature. The HRTEM images revealed that these nanocubes were enclosed by reactive {001}planes, which may contribute to the intrinsically catalytic property of o-xylene oxidation. The higher activity of Ce02 nanocubes calcined at 550℃ than those calcined at above 550℃ was attributed to their smaller crystallite size and larger surface area. The influences of reaction conditions were also studied, which found that a higher reaction temperature was necessary for complete catalytic oxidation of o-xylene at higher weight hourly space velocity (WHSV) and o-xylene concentration. 相似文献
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The brominated products, formed in chlorination treatment of benzophenone-4 in the presence of bromide ions, were identified, and the formation pathways were proposed.Under disinfection conditions, benzophenone-4 would undertake electrophilic substitution generating mono- or di-halogenated products, which would be oxidized to esters and further hydrolyzed to phenol derivatives. The generated catechol intermediate would be transformed into furan-like heterocyclic product. The product species were p H-dependent,while benzophenone-4 elimination was chlorine dose-dependent. When the chlorination treatment was performed on ambient water spiked with benzophenone-4 and bromide ions, most of brominated byproducts could be detected, and the acute toxicity significantly increased as well. 相似文献