负载纳米水合氧化铁活性炭去除水中铅的实验研究

通过共沉淀法制备一种负载纳米水合氧化铁活性炭,研究其对铅的吸附性能、负载前后活性炭的结构的影响,并进行TEM和XRD表征分析。利用动态小柱实验探究不同p H值、进水浓度和空床接触时间对铅吸附能力的影响,同时比较负载前后活性炭处理实际河道水中铅的吸附穿透曲线。结果表明:无定型的纳米水合氧化铁成功负载于活性炭上,负载后的活性炭显著提高了铅的吸附性能,其对铅的吸附容量随p H值、空床接触时间的增大而增加,进水浓度的变化基本不影响铅的吸附容量。以实际河道水为处理对象,得出负载前后的活性炭穿透点运行的床体积分别为1233和11004,显著提高了9倍,表明负载纳米水合氧化铁活性炭可以有效去除实际水体中的铅,具有良好的应用前景。     

MBR-CANON工艺处理生活污水的快速启动及群落变化

为研究全程自养脱氮工艺(CANON)处理生活污水的可行性,在常温膜生物反应器（MBR）中,保持进水氨氮不变,采用逐渐缩短水力停留时间(HRT)的策略在限氧条件下快速富集氨氧化菌(AOB),之后减小曝气量并进一步缩短HRT富集厌氧氨氧化菌(anammox),并通过DGGE技术分析不同阶段的种群变化．结果表明：CANON工艺在78 d内成功启动,总氮去除率达80％,总氮去除负荷RNR达0.95 kg·m-3·d-1;将该工艺应用于生活污水的处理,实现了COD和氨氮的同时高效去除;微生物群落发生了较大变化,稳定运行的反应器中氨氧化细菌为亚硝化单胞菌属(Nitrosomonas),厌氧氨氧化菌为Candidatus Kuenenia stuttgariensis．MBR-CANON工艺可以有效应用于常温生活污水的脱氮．     

Selective removal of heavy metal ions from aqueous solutions with surface functionalized silica nanoparticles by different functional groups

The industrial silica fume pretreated by nitric acid at 80 °C was re-used in this work. Then, the obtained silica nanoparticles were surface functionalized by silane coupling agents, such as（3-Mercaptopropyl） triethoxysilane（MPTES） and（3-Amincpropyl） trithoxysilane（APTES）. Some further modifications were studied by chloroaceetyl choride and 1,8-Diaminoaphalene for amino modified silica. The surface functionalized silica nanoparticles were characterized by Fourier transform infrared（FI-IR） and X-ray photoelectron spectroscopy（XPS）. The prepared adsorbent of surface functionalized silica nanoparticles with differential function groups were investigated in the selective adsorption about Pb2＋, Cu2＋, Hg2＋, Cd2＋ and Zn2＋ions in aqueous solutions. The results show that the（3-Mercaptopropyl） triethoxysilane functionalized silica nanoparticles（SiO2-MPTES） play an important role in the selective adsorption of Cu2＋ and Hg2＋, the（3-Amincpropyl） trithoxysilane（APTES） functionalized silica nanoparticles（SiO2-APTES） exhibited maximum removal efficiency towards Pb2＋ and Hg2＋, the 1,8-Diaminoaphalene functionalized silica nanoparticles was excellent for removal of Hg2＋ at room temperature, respectively.     

Electrolyte composition and removal mechanism of Cu electrochemical mechanical polishing

The optimization of electrolytes and the material removal mechanisms for Cu electrochemical mechanical planarization （ECMP） at different pH values including 5-methyl-1H-benzotriazole （TTA）, hydroxyethylidenediphosphoric acid （HEDP）, and tribasic ammonium citrate （TAC） were investigated by electrochemical techniques, X-ray photoelectron spectrometer （XPS） analysis, nano-scratch tests, AFM measurements, and polishing of Cu-coated blanket wafers. The experimental results show that the planarization efficiency and the surface quality after ECMP obtained in alkali-based solutions are superior to that in acidic-based solutions, especially at pH=8. The optimal electrolyte compositions （mass fraction） are 6% HEDP, 0.3% TTA and 3% TAC at pH=8. The main factor affecting the thickness of the oxide layer formed during ECMP process is the applied potential. The soft layer formation is a major mechanism for electrochemical enhanced mechanical abrasion. The surface topography evolution before and after electrochemical polishing （ECP） illustrates the mechanism of mechanical abrasion accelerating electrochemical dissolution, that is, the residual stress caused by the mechanical wear enhances the electrochemical dissolution rate. This understanding is beneficial for optimization of ECMP processes.     

介质阻挡放电反应器降解邻二甲苯的特性研究

采用介质阻挡放电(DBD)降解常压下流动态的邻二甲苯模拟废气,系统地考察了放电极值电压,气体的初始质量浓度、停留时间以及相对湿度等工艺参数对邻二甲苯降解的影响,并初步探讨了邻二甲苯的降解产物.实验研究结果表明:在7.0kV的放电极间电压下,邻二甲苯的初始质量浓度为1 500mg/m3,停留时间为9s,其去除率可达到80%以上.降解产物主要为CO2、H2O以及苯甲酸、苯乙酸、苯乙醛等有机物,并且经降解后产物的生物可生化性得到提高,因而为后续的等离子-生物法联合处理VOCs提供了依据.     

提高湿法烟气脱硫喷淋塔脱硫和除尘效率的探讨

分析了现代大型喷淋塔为提高脱硫与除尘效率在设计上所作的改进及存在的问题。通过一个曾经设计过的喷淋塔实例,结合烟气和吸收液两相逆向流动和两相间的化工传质过程,剖析了喷淋层覆盖率的实质,提出弱效喷淋覆盖和多重喷淋覆盖对喷淋塔脱硫和除尘效率的影响,给出喷淋覆盖率的选择、喷淋层和喷嘴布置的设计方法,对改善烟气脱硫和除尘效率均有明显效果。     

紫苏叶促进大鼠肠胃消化吸收作用的研究

研究紫苏叶促进肠蠕动与健胃消食的作用。实验分成两大组（A组,B组）。A组SD大鼠68只,随机分8组：阴性对照组、阳性对照组（1．4g／kg）、紫苏叶石油醚提取物低剂量组（15g／kg）、中剂量组（30g／kg）、高剂量组（60g／kg）,乙醇提取物低剂量组（10g／kg）、中剂量组（20g／kg）、高剂量组（30g／kg）。连续给药10d,测大鼠小肠碳末推进百分率。B组SD大鼠56只,随机分7组：阴性对照组、紫苏叶石油醚提取物及乙醇提取物大、中、小剂量组。连续给药8d,测大鼠胃部总酸度和总酸排出量。结果表明：与阴性对照组相比,各剂量组大鼠小肠碳末推进百分率与总酸排出量均增高（P〈0．05,P〈0．01）。紫苏叶的石油醚提取物及乙醇提取物具有促进肠胃消化吸收的作用。     

改性钢渣除藻效果研究

对改性钢渣在机械搅拌条件下的除藻效果进行了研究,并分析了改性钢渣预处理与混凝联用工艺对藻类的去除效果和协同作用.实验表明,钢渣经改性后,既能有效地去除水中的藻类,又能降低藻的光合活性,抑制藻的生长;高温活化改性钢渣预处理与混凝联用工艺对藻类有很好的去除效果,其对叶绿素a的平均去除率达91.4％,远高于单纯的钢渣预处理和混凝工艺.这暗示了两者之间在除藻方面存在协同作用.     

Bioelectrochemical sulfate reduction enhanced nitrogen removal from industrial wastewater containing ammonia and sulfate

Low organic carbon-to-nitrogen ratio and existing sulfate (SO₄²⁻) in industrial wastewater limited nitrogen removal. Coupling SO₄²⁻ reduction with sulfide autotrophic denitrification provides a novel strategy. Herein, bioelectrochemical sulfate reduction was coupled with heterotrophic sulfate reduction to drive sulfide autotrophic denitrification. In this coupled system, total nitrogen (TN) removal efficiency was increased from ~25% to ~85% by inputting −45 mA electricity. With the help of supplying electrons to denitrification through SO₄²⁻ reduction, coulomb efficiency was improved to 61.5%. Also, bioelectrochemical sulfate reduction could improve sulfur recovery and thus increase TN removal efficiency. Furthermore, through tuning turnover numbers of SO₄²⁻, high TN removal efficiency can be obtained at various concentrations of SO₄²⁻. Moreover, main functional bacteria in this system were identified. Finally, ~75% TN removal efficiency was achieved with real wastewater in this system. Overall, this work offered a new approach for efficient nitrogen removal from industrial wastewater containing SO₄²⁻.     

Feasibility study of the ultrasonic vibration assisted drilling of Inconel superalloy

The ultrasonic vibration assisted drilling of Inconel 718 superalloy is studied in this paper. The tool holder of a machining center is retrofitted so that axial resonant vibration can be provided. Experimental results show that the chip size is reduced, and the variation of torque in drilling becomes smaller. These phenomena are particularly apparent at the final stage of a drill's usable life. It is also found that there is little improvement in drilling performance when the frequency of the ultrasonic vibration is varied. On the contrary, a drill's life is greatly increased when the vibration with a smaller amplitude is applied. But too large a vibration amplitude, such as over 12 μm in this study, could lead to negative effects. For the testing conditions, the frequency of 31.8 kHz and the amplitude of 4 μm result in the best drill life and quality of the drilled hole in this study. Under this condition a drill's life is prolonged by as much as 2.7 times of that without vibration assisted drilling process. Concerning drilling efficiency, it is found that by applying ultrasonic vibration assisted drilling, lifting of the drill for chip removal as commonly employed in conventional drilling of a high aspect ratio hole is not necessary, and saving of the working time is obtained.