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201.
近年来我国各类典型固定源排放可过滤颗粒物(Filterable Particulate Matter,FPM)的水平已经明显降低,然而固定源可凝结颗粒物(Condensable Particulate Matter,CPM)的排放水平却逐渐引起人们的关注和重视.因此研究不同类型固定源CPM的排放特征对进一步了解和控制固定源颗粒物的排放具有重要意义.本研究根据美国EPA Method 202搭建了一套CPM的采样装置,对5个不同固定源排放的CPM进行了采样.实验结果表明在两个燃煤电厂、一个烧结厂和两个垃圾焚烧厂中,CPM的排放浓度分别为 7.65、26.00、28.89、6.82和5.53 mg·m-3,无机组分在CPM中的占比分别为69%、62%、43%、62%和71%.其中SO42-是燃煤电厂和烧结厂排放CPM中最主要的水溶性离子,占总离子的67%以上.Cl-是垃圾焚烧厂排放CPM中最主要的水溶性离子,占总离子的37%以上.K、Ca、Na、Fe、Mg和Al等元素在各类固定源CPM排放的总元素中占比较高,大约在80%以上.此外,在燃煤电厂和烧结厂排放CPM中的未知组分比例大约在20%以上,说明现阶段我们对CPM组成成分的研究还有限,未来应当继续探索研究. 相似文献
202.
Sustainable harvest of natural products that meets the needs of local people has been viewed by many as an important means for sustaining conservation projects. Although plants often respond to tissue damage through compensatory growth, it may not secure long-term sustainability of the populations because many plants enhance individual well-being at the expense of propagation. Sustainability may further be threatened by infrequent, large-scale events, especially ill-documented ones. We studied the impacts of sprout harvesting on sprout growth in a dwarf bamboo (Pseudosasa usawai) population that has seemingly recovered from an infrequent, large-scale masting event. Experimental results suggest that although a single sprout harvest did not significantly alter the subsequent abundance and structure of sprouts, culm damage that accompanied sprout harvesting resulted in shorter, thinner, and fewer sprouts. Weaker recovery was found in windward, continually harvested, and more severely damaged sites. These findings suggest that sprout growth of damaged dwarf bamboos is likely non-compensatory, but is instead supported through physiological integration whose strength is determined by the well-being of the supplying ramets. Healthy culms closer to the damage also provided more resources than those farther away. Sustainable harvesting of sprouts could benefit from organized community efforts to limit the magnitude of culm damage, provide adequate spacing between harvested sites, and ensure sufficient time interval between harvests. Vegetation boundaries relatively resilient to infrequent, large-scale events are likely maintained by climatic factors and may be sensitive to climate change. Continual monitoring is, therefore, integral to the sustainability of harvesting projects. 相似文献
203.
Kae-Long Lin Wen-Kai Chang Tien-Chin Chang Ching-Hwa Lee Chun-Hsu Lin 《Journal of Cleaner Production》2009,17(16):1499-1503
The waste electrical and electronic equipment (WEEE) directives are designed to deal with the rapidly increasing waste stream comprised of electrical and electronic equipment. Recycling electrical and electronic equipment reduces the quantity of waste going to final disposal. The demand for thin film transistor liquid crystal display (TFT-LCD) panels, commonly used in everyday electronic products, is increasing. Conventionally adopted treatments of TFT-LCD waste glass cannot meet WEEE directives. This study adopts the following operating conditions in fabricating glass–ceramics: sintering temperature of 800–950 °C; sintering time of 6 h; and, temperature increase rate of 5 °C/min. The glass–ceramic samples then underwent a series of tests, including the Vickers hardness, water absorption and porosity tests, to determine product quality. The Vickers hardness was 12.1 GPa when fired at 900 °C for 6 h, and density was 2.4 g/cm3 and water absorption was 0%. Thus, TFT-LCD waste glass can be regarded as a good glass–ceramic material. 相似文献
204.
Ming-Chin Chang Wen-Pin Hsieh Min-Chao Wang 《Journal of the Air & Waste Management Association (1995)》2013,63(2):221-227
Abstract The sites contaminated with recalcitrant polycyclic aromatic hydrocarbons (PAHs) are serious environmental problems ubiquitously. Some PAHs have proven to be carcinogenic and hazardous. Therefore, the innovative PAH in situ remediation technologies have to be developed instantaneously. Recently, the nanoscale zero-va-lent iron (ZVI) particles have been successfully applied for dechlorination of organic pollutants in water, yet little research has investigated for the soil remediation so far. The objective in this work was to take advantage of nanoscale ZVI particles to remove PAHs in soil. The experimental factors such as reaction time, particle diameter and iron dosage and surface area were considered and optimized. From the results, both microscale and nanoscale ZVI were capable to remove the target compound. The higher removal efficiencies of nanoscale ZVI particles were obtained because the specific surface areas were about several dozens larger than that of commercially microscale ZVI particles. The optimal parameters were observed as 0.2 g iron/2 mL water in 60 min and 150 rpm by nanoscale ZVI. Additionally, the results proved that nanoscale ZVI particles are a promising technology for soil remediation and are encouraged in the near future environmental applications. Additionally, the empirical equation developed for pyrene removal efficiency provided the good explanation of reaction behavior. Ultimately, the calculated values by this equation were in a good agreement with the experimental data. 相似文献
205.
火焰原子吸收光度法测定水中铝的方法改进 总被引:1,自引:0,他引:1
研究了在盐酸介质中,壬基酚聚氧乙烯-7醚(NP-7)活化下,火焰原子吸收光度法测定环境水体中铝的方法改进。在25mL容量瓶中,加入5.0mL体积分数为50%的盐酸、2.0mL质量浓度为0.01g/mL NP-7和4.0mL质量浓度为75.0μg/mL的铝标准溶液,在原子吸收分光光度计的最佳测定条件下测定吸光度。根据吸光度与铝质量浓度绘制了工作曲线,线性范围3.0~24.0μg/mL,检出限1.32μg/mL。该法用于环境水体中铝含量的测定,加标回收率为94.4%~101.4%,最大相对标准偏差5.8%,方法对比最大相对误差4.1%。 相似文献
206.
207.
本文在回顾1990年陕西省灾情及救灾工作基础上,提出了强化政府在减灾中的职能,搞好灾情预测预报、及早制定防灾预案及灾前准备工作的减灾对策。 相似文献
208.
Prenatal diagnosis of monosomy 4p14→pter and trisomy 11q25→qter: clinical presentations and outcomes
Hsiu-Huei Peng Tzu-Hao Wang An-Shine Chao Yao-Lung Chang Shuenn-Dyh Chang Yung-Kuei Soong 《黑龙江环境通报》2005,25(12):1133-1137
We present the case of a pregnant woman with low free β-HCG in maternal serum Down syndrome screening that led to prenatal diagnosis of a fetus with 46,XY,der(4)t(4;11)(p14; q25). This chromosomal aneuploidy resulted from unbalanced segregation of a paternal balanced translocation, t(4;11)(p14;q25). Prenatal ultrasound revealed intrauterine growth restriction, cleft lip and palate, a thick nuchal fold, a single umbilical artery, and pyelectasis. Array-based comparative genomic hybridization and short tandem repeat markers further located the exact breakpoint of translocation. The woman had her pregnancy terminated at 23 weeks of gestational age. The proband had general appearance of Wolf–Hirschhorn syndrome and some unique findings, including single umbilical artery, severe immunoglobulin deficiency, scalp defect, and underlying bony defect. Our case underscores the importance of fetal karyotyping when low maternal serum free β-HCG is found. It also adds information on the fetal presentations of monosomy 4p14→pter and trisomy 11q25→qter. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
209.
The effects of the aeration, seeding, and agitation on the composting of vegetable waste were studied in a laboratory-scale reactor. Experimental results showed that the final product at the end of a 4-day composting period met multiple maturity indices suggested by many researchers. The evolution of carbon dioxide during the composting process could be modelled with a modified Gompertz equation that described the bacteria growth successfully. Multivariate regression analysis was used to study the effects of operating parameters on the carbon conversion. The response surface contour plots were constructed using the regression equation for the examination of the dependence of carbon conversion on operating parameters. The maximum carbon conversion of 14.54% was obtained when the percentage of seeding was set at 14.5%, the air suction rate was set at 2.6 L kg(-1) dry-solid min(-1), and the agitator operated half of the time, alternating on and off for every 5 min. Future work will focus on the application of the data and the experience gained in this work to composters of pilot and semi-commercial scales. 相似文献
210.
“固化赤泥-人工膜”复合防渗材料研究 总被引:1,自引:0,他引:1
赤泥本身具有良好的防渗性能,加入石灰作为激发剂,更可提高其防渗性。根据《土工合成材料测试手册》和GB/T 50123—1999《土工试验方法标准》进行渗透试验,结果表明:室内试验在赤泥中加入8%石灰,并夹一层人工防渗膜形成的复合防渗材料,在固化28 d后,其渗透系数可达(7.3~7.4)×10-9 cm/s。在工业试验中,夹入不同厚度和质地的人工防渗膜的石灰(8%)固化赤泥,渗透系数可达到6.32×10-9~1.89×10-7 cm/s。研究成果在中原某铝厂赤泥堆场防渗工程中得到了应用。 相似文献