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341.
以甲基丙烯酸和丙烯磺酸钠为单体、过硫酸铵溶液为引发剂合成聚合物分散剂(PMS)。最佳合成条件:单体总质量为60g,甲基丙烯酸和丙烯磺酸钠的摩尔比为3.0,过硫酸铵溶液加入量为12g,亚硫酸氢钠加入最为1g,反应温度为75℃。对最佳条件下制得的PMS进行应用实验,当100g陶瓷氧化铝粉末中PMS加入量为0.5g时,浆料的黏度较小,分散效果良好。PMS属于非品态聚合物,热稳定性良好,相对分子质量为2127。  相似文献   
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343.
Human activities are a key driver of air pollution, so it is hardly surprising that celebrations affect air quality. The use of fireworks contributes to high particulate concentrations in many parts of the world, with the Chinese Lunar New Year (spring festival) particularly noticeable, as firecrackers are traditionally used to drive off evil spirits. Fireworks lead to short-term peaks in the concentration of PM10, PM2.5 and SO2. Regulatory actions that restrict the use of fireworks have been evident in China since the 1990s. This paper investigates the particulate concentrations in nine Chinese cities (Beijing, Chengdu, Chongqing, Tianjin, Xi’an, Nanjing, Shanghai, Guangzhou and Shenzhen, along with Hong Kong (a Special Administrative Region) and Taipei and Kaohsiung (Taiwan) with a particular focus on the celebrations of 2015. Extremely high concentrations of particulate matter were observed, with some sites revealing peak PM10 concentrations in excess of 1000 μg m?3 in the early hours of the New Year. In Beijing, Tianjin and Chongqing, the activities caused high particulate matter concentrations at most sites throughout the city. These peaks in particulate load in the early hours of Chinese New Year do not appear to be closely related to meteorological parameters. However, in cities where fireworks appear to be better regulated, there are fewer sharp pollution peaks just after midnight, although lowered air quality can still be found in the outer parts of some cities, remote from regulatory pressures. A few cities seem to have been effective at reducing the impact of the celebrations on air quality, with Nanjing a recent example. An increasing focus on light displays and electric lanterns also seems to offer a sense of celebration with much reduced impacts on air quality.  相似文献   
344.
深部煤层对CO2地质处置机制及应用前景   总被引:1,自引:0,他引:1  
CO2是重要的温室气体之一,CO2的有效处置对减缓全球变暖具有重大意义。由于煤介质具有特殊的双重孔隙结构、吸附性强等物性特征,对CO2具有很强的吸附能力,且大于煤介质吸附CH4的能力,因此,可将CO2注入深部不可开采煤层储存,在长久处置CO2的同时亦可促进深部煤层气的开采。在我国,深部不可开采煤层处置CO2显示了巨大的潜力,可以处置26-46年的CO2排放量,尤其在华北煤炭能源基地具有良好的应用前景。  相似文献   
345.
The aim of this research was to reuse blast furnace slag (BFS) as a mud cake modifier (MCM) to improve the annular isolation quality in oil and gas wells. For the optimum formula of drilling fluid, the effects of MCM on the drilling fluid rheology were investigated. The relationship between the MCM addition and shear strength at cement–formation interface (SSCFI) was evaluated. The experimental results showed that the optimized formula of the drilling fluid has 1.0 wt% MCM and 0.5 wt% XY-27. The simulation results showed that SSCFI increased significantly with the addition of MCM. Based on the mechanism analysis of BFS as an MCM to improve SSCFI, it is found that the transformation of mud cake to agglomerated cake can be the main reason. The application results showed that the success rate of five wells reached 100%, and the rate of quality in cement was 100%. Especially, the average high quality rate of five wells reached 83.7%. Compared with conventional methods, the average high quality rate is increased by 32.6% points. This research provides a new way for sustainable utilization of BFS.  相似文献   
346.
Municipal solid waste incinerators (MSWIs) have long been the major contributors of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) to ambient air in Taiwan. After stringent MSWI emission standards were introduced in 2001, the long-term continuous monitoring of flue gas and ambient air quality became necessary to ensure the effectiveness of the related control strategies. Three MSWIs and the surrounding ambient air were investigated in the current study for PCDD/F characteristics during 2006 to 2011. The average concentrations in the flue gas ranged from 0.008?~?0.0488 ng I-TEQ/Nm3, which is much less than the emission standard in Taiwan (0.1 ng I-TEQ/Nm3) (I-TEQ is the abbreviation of International Toxic Equivalent). This led to extremely low levels in the ambient air, 0.0255 pg I-TEQ/Nm3, much less than the levels seen in most urban areas around the world. Additionally, the results obtained using the Industrial Source Complex Short-Term Dispersion Model (ISCST3) indicate that the PCDD/F contributions from the three MSWIs to the ambient air were only in the range from 0.164?~?0.723 %. Principal component analysis (PCA) showed that the PCDD/Fs in the air samples had very similar characteristics to those from mobile sources. The results thus show that stringent regulations have been an effective control strategy, especially for urban areas, such as Taipei City.  相似文献   
347.
随着生物除磷脱氮工艺的大量使用,初沉池的设置和取消一直在学术和工程界存在争议。以重庆市某污水厂为对象,从对无机悬浮固体(ISS)、COD和TN去除效果的角度探讨了初沉池在污水处理系统的重要性。研究结果表明,在合流制排水体制下,该污水厂进水污染物浓度非常高,COD、SS和ISS的平均浓度分别为560、1 100和780 mg/L;初沉池对COD、SS和ISS的去除率分别为61%、78%和85%,对ISS的去除率比COD高20%左右;污水经过初沉池沉淀之后,ISS/COD从1.7下降到0.7左右,COD/TN从8.0左右下降到4.3,粒径由40μm下降到30μm。初沉池对大粒径的ISS具有较好的去除效果,未能被去除的小粒径ISS容易悬浮在混合液中,降低MLVSS/MLSS。从ISS/COD的削减和保持混合液MLVSS/MLSS正常的角度来讲,初沉池不应取消。  相似文献   
348.
Concentrations of 22 polycyclic aromatic hydrocarbons (PAHs) were estimated for individual particle-size distributions at the airport apron of the Taipei International Airport, Taiwan, on 48 days in July, September, October, and December of 2011. In total, 672 integrated air samples were collected using a micro-orifice uniform deposition impactor (MOUDI) and a nano-MOUDI. Particle-bound PAHs (P-PAHs) were analyzed by gas chromatography with mass selective detector (GC/MSD). The five most abundant species of P-PAHs on all sampling days were naphthalene (NaP), phenanthrene (PA), fluoranthene (FL), acenaphthene (AcP), and pyrene (Pyr). Total P-PAHs concentrations were 152.21, 184.83, and 188.94 ng/m3 in summer, autumn, and winter, respectively. On average, the most abundant fractions of benzo[a]pyrene equivalent concentration (BaPeq) in different molecular weights were high-weight PAHs (79.29 %), followed by medium-weight PAHs (11.57 %) and low-weight PAHs (9.14 %). The mean BaPeq concentrations were 1.25 and 0.94 (ng/m3) in ultrafine particles (<0.1 μm) and nano-particles (<0.032 μm), respectively. The percentages of total BaPeq in nano- and ultrafine particulate size ranges were 52.4 % and 70.15 %, respectively.  相似文献   
349.
The present paper aims to assess the phytoremediation performance based on pollution removal efficiency of the highly polluted region of Alur Ilmu urban river for its applicability of on-site treatment. Thirteen stations along Alur Ilmu were selected to produce thematic maps through spatial distribution analysis based on six water quality parameters of Malaysia’s Water Quality Index (WQI) for dry and raining seasons. The maps generated were used to identify the highly polluted region for phytoremediation applicability assessment. Four free-floating plants were tested in treating water samples from the highly polluted region under three different conditions, namely controlled, aerated and normal treatments. The selected free-floating plants were water hyacinth (Eichhornia crassipes), water lettuce (Pistia stratiotes), rose water lettuce (Pistia sp.) and pennywort (Centella asiatica). The results showed that Alur Ilmu was more polluted during dry season compared to raining season based on the water quality analysis. During dry season, four parameters were marked as polluted along Alur Ilmu, namely dissolve oxygen (DO), 4.72 mg/L (class III); ammoniacal nitrogen (NH3–N), 0.85 mg/L (class IV); total suspended solid (TSS), 402 mg/L (class V) and biological oxygen demand (BOD), 3.89 mg/L (class III), whereas, two parameters were classed as polluted during raining season, namely total suspended solid (TSS), 571 mg/L (class V) and biological oxygen demand (BOD), 4.01 mg/L (class III). The thematic maps generated from spatial distribution analysis using Kriging gridding method showed that the highly polluted region was recorded at station AL 5. Hence, water samples were taken from this station for pollution removal analysis. All the free-floating plants were able to reduce TSS and COD in less than 14 days. However, water hyacinth showed the least detrimental effect from the phytoremediation process compared to other free-floating plants, thus made it a suitable free-floating plants to be used for on-site treatment.  相似文献   
350.
The discharge characteristics during the degradation of MNZ by DBD were investigated. Increasing the discharge frequency can promote the degradation of MNZ. MNZ removal reaches 99.1% at the initial concentration of 40 ppm within 120 min. Coexisting organic matter inhibits the degradation of MNZ. The energy efficiency of DBD for MNZ removal is higher than other technologies. Degradation of metronidazole (MNZ) which is a representative and stable antibiotic by dielectric barrier discharge (DBD) in an aqueous solution has been studied. Effects of initial MNZ concentration, solution pH and coexisting organics on the degradation were investigated. The results illustrated that increasing the input power and the discharge frequency can improve the removal of MNZ. At low initial concentration, the removal of MNZ can reach up to 99.1%. Acidic and neutral conditions are more favorable for MNZ removal than alkaline condition in the early stage of degradation. However, the difference in MNZ removal between those in acidic or neutral media and that in alkaline one could be neglected with prolonging of the treatment time. Therefore, this method can be applied to MNZ degradation with a wide pH range. Coexisting organic matter in water can attenuate the removal to some extent. This study could provide valuable references for the degradation of nitroimidazole antibiotics by DBD.  相似文献   
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