Ti-Cu-Mn复合物负载石墨烯催化剂制备及其降解二甲苯性能

采用水热法制备了4种不同摩尔比的Cu-Mn-Ti/GS复合物催化剂,利用固定式反应床评价了其对二甲苯的催化氧化性能,并对催化剂进行了BET、XRD、SEM、TEM、XPS等表征,探讨了其对二甲苯的降解动力学.结果表明,当催化剂的Cu、Mn含量增加时,其比表面积有所降低,总孔容也降低,降解活性减小.催化剂中Cu-Mn呈现Cu_(1.5)Mn_(1.5)O_4和CuMn_2O_4两种晶格,活性组分有Cu~+、CuMn O和TiO_2.石墨烯载体的稳定性较好,Ti-Cu-Mn/GS(1∶1∶1)催化剂的颗粒分布较均匀,粒径也较小,降解二甲苯的T50为97℃,表现出较好的低温催化降解性能.催化剂对二甲苯的催化氧化降解过程符合一级反应动力学方程.     

旁路水解酸化强化污泥过程减量运行性能与机理研究

旁路水解酸化技术既能实现污泥减量,又能为污水脱氮除磷补充碳源。采用水解酸化作为污泥旁路减量化技术,研究其污泥减量的运行性能和机理,同时考察了对污水处理工艺污染物去除的影响。采用污泥水解酸化旁路处理,得到污泥减量率为30%,其中水解酸化的贡献为0.7%,延长污泥龄贡献为17.1%,能量解偶联等贡献为12.2%。污泥水解酸化旁路处理对污水生物处理工艺的出水水质以及微生物活性影响不显著。水解酸化过程中会降低微生物脱氮活性,但对污水处理主反应器中微生物活性影响较小。污泥旁路水解酸化污泥减量工艺中,对污泥减量机理的解析,需要综合考虑水解酸化与污泥龄等对污泥减量效果的影响。     

SCR脱硝机组空气预热器堵塞治理建议

燃煤机组安装SCR脱硝装置后,空气预热器堵塞成为普遍现象,严重影响机组的安全性、经济性。通过对空气预热器堵塞物成分分析,提出治理空气预热器堵塞技术路线,结合实际运行中出现的问题,探寻SCR脱硝机组氨逃逸率高、SO_3浓度高、排烟温度低的原因,并且分析这些因素对空气预热器堵塞程度的影响,建议从保持催化剂活性,确保NO_x浓度,氨逃逸率均匀分布,防止氨过喷,降低入炉煤含硫量,提高锅炉排烟温度等方面,综合治理空气预热器堵塞,并提出详细的建议。     

微直流电场对大肠杆菌生长代谢活性的作用

对大肠杆菌（Escherichia coli,DH5α）培养液在连续培养时分别通入不同强度的直流电场,研究了其在持续直流电刺激下的生长曲线、pH曲线、ATP酶活性、胞内总蛋白含量、细胞膜通透性以及细菌微观形态变化.结果表明,适宜的直流电能够促进大肠杆菌增殖;大肠杆菌的ATP酶活在25 mA电流作用下在对数生长前期、对数...     

Satellite Observations of Lava Lake Activity at Nyiragongo Volvano, Ex-Zaire, during the Rwandan Refugee Crisis

In June 1994 the summit crater of Nyiragongo volcano, located in the Great Lakes region of central Africa, began to fill with new lava, ending nearly 12 years of quiescence. An earlier eruption of the volcano in 1977 had culminated in the catastrophic draining of a lava lake through fissures in the crater wall, feeding highly mobile lava flows which reached the outskirts of Goma and killed more than 70 people. By July 1994, as many as 20,000 Hutu refugees were arriving in Goma every hour, only 18km south from the summit of Nyiragongo. The exodus brought more than one million people to the camps near the town raising fears of a repeat of the 1977 eruption. This paper examines the role that satellite remote sensing could have played in surveillance of the volcano during this time, and demonstrates the potential for monitoring this and other volcanoes in the future. Images recorded by the spaceborne Advanced Very High Resolution Radiometer (AVHRR) – freely available over the Internet – provide semi-quantitative information on the activity of the volcano. The aim of this paper is to promote the wider use of readily available technologies.     

Chemical composition and antimicrobial activities of the essential oil from the seeds of Enterolobium contortisiliquum (leguminosae)

Seeds of Enterolobium contortisiliquum were subjected to steam distillation to obtain a light yellow essential oil in a yield of 3 ml/kg of seeds. The major components of the oil were identified using gas chromatography/mass spectrometry (GC-MS) and were furfural, limonene, linalool, estragole, carvone, and apiole with carvone representing more than 50% of the total composition. Antimicrobial activities of the essential oil were determined against four species of gram positive bacteria (Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, Micrococcus luteus) and two gram negative bacteria (Klebsiella pneumoniae, Serratia Marcescencs). The essential oil inhibited the growth of all tested bacteria but was most effective against the gram positive bacteria. Chemicals that are responsible for the antibacterial effect of the essential oil were determined using the bio-autography thin layer chromatography (TLC) technique. The active compounds responsible for the activity were found to be carvone and estragole.     

PCDFs的Ah受体结合能力的定量结构效应关系

应用单苯环氯取代方法取G₁～G₁₀10个分子结构描述符,通过正向逐步线性回归方法构建对于Ah受体结合能力的定量结构-性质相关(QSAR)模型.与有关文献相比,此模型能更好地预测多氯代二苯并呋喃(PCDFs)竞争结合Ah受体logEC₅₀值,各自变量间不存在共线性.模型可以较好地反映PCDFs分子Ah受体结合能力与其分子氯取代位点之间的关系.     

No difference in activity of Sod-1 genotypes of Poa annua to short-term treatment of ambient gaseous organic pollution

Our previous studies indicated that genotypes at locus Sod-1 of Poa annua changed clinally along a gradient of gaseous organic pollution. In the present study, we aimed to know whether there were differential responses of activities of different superoxide dismutase （SOD） genotypes to short-term treatment of ambient gaseous organic pollution. Significant bias from Hardy-Weinberg equibrium was observed on locus Sod-1, and no genotype Sod- l-BB was found. Significantly increased activities were observed in most treatments for genotype Sod-1-AA and in one treatment for genotype Sod-1-AB. However, no significant difference in SOD activities was found between the two genotypes. It was interpreted that fitness difference between the two genotypes was small and treatment duration was too short or extent of ambient organic pollution was too low to lead to differential responses. Other environmental factor effects on activities of superoxide dismutases can also explain the results.     

微生物絮凝剂产生菌的絮凝性能

从废水处理厂和土壤中分离产絮凝剂的菌株,其中一株产絮凝剂的细菌W7—1对高岭土的絮凝活性达94％,初步鉴定该菌为Klebiella sp．,W7—1对产絮凝剂的培养条件要求简单,产絮凝剂的最佳碳源和氮源为蔗糖和牛肉膏,pH在5～10的范围内都适应絮凝剂的产生,但pH为8．0时絮凝活性最高。絮凝剂的添加量为10mL／L、絮凝体系pH为7～10时絮凝活性好,提纯后的絮凝剂产量高于其它絮凝剂近10倍,分析表明,絮凝剂成分为多糖,且有很好的热稳定性,加热至100℃、30min后絮凝活性不变。     

渗滤液与城市污水合并处理过程的有机物去除特征

以上海老港垃圾填埋场调蓄池的渗滤液,及其经厌氧甲烷化垃圾填埋柱循环回灌处理后的出水和其再经过混凝处理后的出水等3种不同处理水平的渗滤液为研究对象,分别以不同的比例与城市污水混合,采用好氧活性污泥法合并进行处理,对进出水的COD、UV254吸光度和溶解性有机物的分子量分布及污泥的脱氢酶活性进行了测定分析．结果表明：当渗滤液混合比例小于10％时,出水的COD和UV254吸光度随混合比例线性升高,污泥的活性相应线性降低;而当混合比例大于20％时．污泥活性阶跃降低,出水COD和UV254吸光度的升高超出线性范围．渗滤液混合比例为20％与比例为5％的混合污水相比．分子量1k～4k的溶解性有机物去除率显降低．渗滤液与城市污水合并处理的混合比例大于10％时,微生物的有机物降解能力会受到严重损害,且常规的渗滤液生物和物化预处理不能减轻此种损害．