温度冲击引起的丝状菌污泥膨胀菌群特征

为探究温度冲击引起的污泥膨胀机理,以生活污水为处理对象,采用SBR工艺分别运行温度骤降系统和温度梯度降低系统,利用Illumina MiSeq高通量测序技术分析温度变化过程中微生物群落整体变化,并对膨胀阶段优势丝状菌类型进行解析.结果表明,温度骤降系统优势丝状菌为微丝菌(Microthrixparvicella),SVI值升高至291mL/g以上,温度梯度降低系统优势丝状菌为Eikelboom Type 0092型丝状菌,SVI值稳定维持在250mL/g,因此Eikelboom Type 0092型丝状菌适宜在温度冲击环境中生长繁殖.温度冲击方式不同导致菌群组成具有差异性,Proteobacteria相对丰度均值为39.3%,其占比在不同阶段变化较小.两个系统在污泥膨胀阶段Actinobacteria和Chloroflexi的相对丰度占比不同.各样本中与去除有机物相关微生物菌群丰度均值为13.6%,Nitrospira其相对丰度均值为2.48%,占NOB总含量80%以上.温度梯度降低系统发生的Eikelboom Type 0092型丝状菌型污泥微膨胀,其出水水质没有发生严重恶化,COD和NH₄⁺-N的去除效果均高于温度骤降系统.     

Highly selective catalytic reduction of NOxby MnOx–CeO2–Al2O3 catalysts prepared by self-propagating high-temperature synthesis

We first present preparation of MnOx–CeO_2–Al_2O_3 catalysts with varying Mn contents through a self-propagating high-temperature synthesis(SHS) method, and studied the application of these catalysts to the selective catalytic reduction of NOxwith NH3(NH_3-SCR).Using the catalyst with 18 wt.% Mn(18 MnCe1Al2), 100% NO conversion was achieved at 200°C and a gas hourly space velocity of 15384 hr-1, and the high-efficiency SCR temperature window, where NO conversion is greater than 90%, was widened to a temperature range of 150–300°C. 18 MnCe1Al2 showed great resistance to SO_2(100 ppm)and H_2O(5%) at 200°C. The catalysts were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller(BET) analysis, scanning electron microscopy, Fourier transform infrared spectroscopy, and H_2 temperature programmed reduction. The characterization results showed that the surface atomic concentration of Mn increased with increasing Mn content, which led to synergism between Mn and Ce and improved the activity in the SCR reaction. 18 MnCe1Al2 has an extensive pore structure,with a BET surface area of approximately 135.4 m~2/g, a pore volume of approximately 0.16 cm~3/g, and an average pore diameter of approximately 4.6 nm. The SCR reaction on 18 MnCe1Al2 mainly followed the Eley-Rideal mechanism. The performances of the MnOx–CeO_2–Al_2O_3 catalysts were good, and because of the simplicity of the preparation process,the SHS method is applicable to their industrial-scale manufacture.     

Reuse of Fenton sludge as an iron source for NiFe2O4 synthesis and its application in the Fenton-based process

The potentially hazardous iron-containing sludge from the Fenton process requires proper treatment and disposal, which often results in high treatment cost. In this study, a novel method for the reuse of Fenton sludge as an iron source for the synthesis of nickel ferrite particles(NiFe_2O_4) is proposed. Through a co-precipitation method followed by sintering at 800°C, magnetic NiFe_2O_4 particles were successfully synthesized, which was confirmed by powder X-ray diffraction(XRD), scanning electronic microscopy(SEM), energy dispersive spectroscopy(EDS), Fourier transform infrared spectroscopy(FT-IR) and Raman spectroscopy. The synthesized NiFe_2O_4 could be used as an efficient catalyst in the heterogeneous Fenton process. In phenol degradation with H_2O_2 or NiFe_2O_4 alone, the phenol removal efficiencies within the reaction time of 330 min were as low as 5.9% ± 0.1% and 13.5% ±0.4%, respectively. However, in the presence of both NiFe_2O_4 and H_2O_2, phenol removal efficiency as high as 95% ± 3.4% could be achieved, indicating the excellent catalytic performance of NiFe_2O_4 in the heterogeneous Fenton process. Notably, a rapid electron exchange between_Ni II and_Fe III ions in the NiFe_2O_4 structure could be beneficial for the Fenton reaction. In addition, the magnetic catalyst was relatively stable, highly active and recoverable, and has potential applications in the Fenton process for organic pollutant removal.     

苯水相光氧化反应形成二次有机气溶胶的实验研究

来源于机动车尾气的苯能溶于大气水滴、云雾等水相中并发生水相光氧化反应,在水分蒸发后,产物保留在颗粒相中形成二次有机气溶胶(SOA)粒子.本文采用雾化器将羟基启动苯水相光氧化反应溶液雾化产生气溶胶粒子,通过扩散干燥管除去水蒸气后产生SOA粒子,采用气溶胶激光飞行时间质谱仪进行在线检测,利用紫外可见吸收光谱仪、红外光谱仪和液相色谱串联质谱仪离线测量SOA的化学组分.实验结果表明,激光解吸附质谱中存在醛类(m/z=29(CHO~+)、57(CHOCO~+))、羧酸(m/z=44(COO~+))和苯环(m/z=39(C_3H~+_3)、65(C_5H~-_5))特征裂解碎片峰.SOA粒子的红外光谱图中存在苯环C—H和C=C双键,以及C=O双键、C—O、O—H和C—O—C键的伸缩振动吸收峰,电喷雾电离质谱中存在m/z高达915的离子峰.这表明醛类、羧酸、酚类、芳香醚类产物和酚类产物发生聚合形成的高分子量化合物是SOA粒子的主要化学组分.这为研究人为源挥发性有机化合物水相反应形成SOA的机理提供了实验依据.     

Zn-TiO2纳米管的光催化活性

采用水热合成-浸渍法制备锌掺杂TiO2纳米管(Zn-TiO2纳米管),透射电镜照片显示Zn-TiO2纳米管为两端开口形貌均一的中空管状结构,管径约6～8 nm,壁厚约1 nm,长度约50～200 nm。研究了Zn-TiO2纳米管对甲基橙的光催化性能,结果表明:掺杂适量锌提高了TiO2纳米管对甲基橙的光催化降解性能,0.4%Zn-TiO2纳米管的光催化性能最佳。同时还探讨了Zn-TiO2纳米管用量和初始pH值等因素对光催化降解甲基橙的影响,结果显示Zn-TiO2纳米管能有效地降解甲基橙。随着光催化反应进行,CODCr去除率和脱色率变化规律不完全相同,可能是由于芳基和烷基降解速率不同所致。     

国林大酒店CI形象策划研究--MI策划部分

一家酒店发展前景与这家酒店现状息息相关，酒店发展需在现实基础上扬长避短，也就需要对现状因素进行整合，使之形成推动酒店发展的合力．于是首先对国林大酒店现状进行即时调查，并进行SWOT分析，在此基础上进行了酒店MI设计．     

确定滤袋室内喇叭安装个数和位置的新方法

初步建立 了滤袋 室内声压 分布 的数 学 模型 ，并 利用 实 测结 果对 此 数学 模型 进 行了 检验 ，证明所建 立的模 型是合理 的。可以 利用此模 型计算 滤袋室内 的声 压分 布，并 确定 喇叭 的安 装个 数和安装位 置     

微弧氧化6061铝合金的腐蚀行为研究

采用室内海水浸泡试验、电偶试验等方法研究了6061铝合金微弧氧化层厚度和封孔处理对其耐海水腐蚀性能的影响。试验发现,微弧氧化后,铝合金在海水中的腐蚀形貌为点蚀,封孔处理可明显抑制点蚀的发生,厚度变化对耐蚀性影响不大。与铜合金偶合后,微弧氧化铝合金的腐蚀速率增加,因此在实际使用中应尽量避免这2种材料的电接触。     

蚯蚓生物滤池污水处理技术研究进展

蚯蚓生物滤池作为一项新的生态型污水处理技术,由于其具有工艺简单、建设费用低、处理效果好、剩余污泥少等优点,近年来越来越受到了国内外研究人员的重视。文章详细介绍了蚯蚓生物滤池的基本原理,发展过程以及在污水净化机理、工艺流程和应用方面的最新研究进展,以期为蚯蚓生物滤池及相关领域的研究提供参考。     

原生态环境下广西涠洲岛近50年气候变率的分析

广西涠洲岛气象站由于其特定的地理位置,使得该站成为广西为数不多、大气观测环境50年来持续保持原有生态环境的气象台站之一。应用该岛屿气象站及与之相邻的广西北海市合浦气象站1956~2005年的气温、雨量等气象资料,分析、比较近50年来北部湾海域气候自然变化和在城镇大规模发展影响下气候变化的差异及发展趋势:用Yamamoto法和Mann-Kendall法对5年滑动平均气温、雨量等要素季和年时间序列进行突变检验,对定量地论述在全球气候变暖情况下区域性气候自然变化的响应有非常重要的意义。