车载储氢瓶泄漏及车库内通风方式研究

为研究车库内燃料电池汽车氢气意外泄漏后的浓度分布情况,采用ANSYS软件,通过分析可燃性气体体积、水平方向和垂直方向氢气的扩散分布、不同泄漏位置氢气的扩散情况,研究6种不同通风方式对氢气意外泄漏扩散分布的影响,针对车库内氢气泄漏的特性,在通风方式上引入侧墙底部送风和侧墙顶部送风方式。研究结果表明：底部送风能显著加快氢气的扩散和排出。垂直高度上氢气浓度分布不均,侧墙顶部送风能使顶部堆积的氢气向下扩散,降低最大气体浓度;在墙角泄漏会由于墙壁的影响导致氢气堆积,对墙角局部通风尤为重要。研究结果可为氢燃料电池汽车专用车库的通风设计提供重要参考。     

中药渣生物炭的制备及其对水中四环素的吸附特性研究

以中药废渣为原料,四环素为目标污染物,采用限氧热解法在热解温度分别为300℃、500℃和700℃的条件下制备了不同中药渣生物炭(Biochar, BC),并采用比表面积分析仪(BET)、扫描电子显微镜(SEM)、傅里叶红外光谱分析仪(FTIR)、X射线光电子能谱仪(XPS)、X射线衍射仪(XRD)等手段对不同中药渣生物炭的物理化学性质进行了表征;通过中药渣生物炭对水中四环素(Tetracycline, TC)的吸附试验,研究了不同中药渣生物炭对水中四环素的吸附特性,考察了溶液初始浓度、吸附时间对溶液中四环素去除效果的影响,并结合吸附动力学、吸附等温线拟合结果探究了中药渣生物炭对水中四环素的吸附机制。结果表明：随着热解温度的升高,中药渣生物炭中有机物分解,含氧官能团种类及其相对含量发生变化,其中含氧官能团C—C的相对含量升高、C—H的相对含量降低,中药渣生物炭的芳香化程度增加,且700℃制备的中药渣生物炭对水中四环素的吸附性能更优;中药渣生物炭对水中四环素的吸附量依次为BC700(93.46 mg/g)>BC500(76.32 mg/g)>BC300(32.92 mg/g),...     

Roles of membrane and organic fouling layers on the removal of endocrine disrupting chemicals in microfiltration

To understand the adsorption behavior of endocrine disrupting chemicals(EDCs) is important for enhancing the treatment performance and preventing potential secondary pollution caused by EDCs desorption in a microfiltration system. The dynamic adsorption of four representative EDCs, namely estriol(E3), 17β-estradiol(E2), 17α-ethynylestradiol(EE2), and 4-nonylphenol(4-NP) in a microfiltration system was investigated using the Thomas' model.The product of the equilibrium constant and the total adsorption capacity of the membrane,Ka, for E3, E2, EE2, and 4-NP were 4.91, 9.78, 15.6, and 826, respectively, strongly correlating with the compound octanol–water partition coefficient(KOW). Adsorption appeared to be enhanced when organic fouling formed on the surface of membrane, indicating the role of an additional adsorption column for EDCs acted by a fouling layer in microfiltration. Results of a comparison between the Ka values for clean membrane and fouled membrane illustrated that the significant contribution made by fouling layers may be attributed to the foulant layer's hydrophobicity(in the case of calcium humate layer) and thickness(in the case of calcium alginate layer). This study provided a novel perspective to quantitatively analyze the dynamic adsorption behavior of trace pollutants in membrane process.     

芜湖市大气挥发性有机物污染特征、大气反应活性及源解析

2018年9月至2019年8月对芜湖市城区大气中挥发性有机物（VOCs）进行观测,探讨其污染特征、光化学影响和来源.结果表明,芜湖市大气中VOCs全年平均体积分数为27.86×10^-9,季节变化规律为：秋季（31.16×10^-9） > 夏季（28.70×10^-9） > 冬季（24.75×10^-9） > 春季（24.04×10^-9）,日变化规律呈双峰型,峰值在08：00~09：00时与18：00~19：00时出现,与交通流量的变化有关.芜湖市大气VOCs的平均臭氧生成潜势（OFP）为255.29 μg ·m^-3,不同组分对平均OFP的贡献率排序为：芳香烃（48.83%） > 烷烃（21.04%） > 烯烃（18.32%） > OVOCs（11.47%） > 卤代烃（0.35%）.总气溶胶生成潜势（AFP）为1.84 μg ·m^-3,芳香烃贡献率最高（87.69%）,其次为烷烃（12.31%）.苯/甲苯/乙苯（B/T/E）比值表明,芜湖市大气中苯系物的主要贡献源为机动车排放源和工业排放及溶剂使用源.源解析显示：油气挥发源、机动车排放源、溶剂挥发源、LPG排放源、植物排放源和二次生成源对采样期内的VOCs贡献率分别为11.57%、34.53%、16.63%、20.76%、3.54%和12.97%.     

自养反硝化技术研究进展

介绍了近年来水体硝酸盐污染的原因及危害,阐述了反硝化技术的特点及主要原理,综述了以硫及氢为电子供体的自养反硝化技术的发展及运用,探讨了其今后的研究方向和前景。     

基于新型载体AMC/UASB-SCMBBR生物工艺处理印染废水的中试研究

针对泉州某印染厂实际废水(COD 800～1800 mg·L~(-1),NH~+_4-N 20～50 mg·L~(-1),pH=8～14),以两种新型载体分别作为厌氧与好氧单元中微生物固定化载体,考察了中试规模上流式厌氧污泥床反应器(UASB)与柔性悬浮载体移动床生物膜反应器(SCMBBR)组合工艺对该废水的处理效果.4个月的连续试验结果表明:①经过30 d前期调试运行该工艺系统成功启动,处理量为1.5～2.2 m~3·d~(-1)时,AMC/UASB和SCMBBR反应器对COD的去除率分别达到22%和50%,AMC/UASB反应器出现明显的产气现象,SCMBBR中载体挂膜状况良好;②启动完成后经过90 d的连续运行,当AMC/UASB和SCMBBR反应器水力停留时间分别为10.7 h和8.8 h,废水处理量为5 m~3·d~(-1)时,稳定运行阶段整个工艺废水COD去除率达到78%,出水氨氮平均浓度为3.4 mg·L~(-1);此外,整体工艺色度去除率达到65%,其中,厌氧段色度去除率达到50%左右;③通过分析计算,整个系统污泥减量达到67.7%～76.6%,该生物组合工艺具有明显的污泥减量效果.     

生物炭对土壤中硫的迁移转化及植物有效性的影响研究

土壤中的硫是作物生长发育不可缺少的营养元素,也是合成植物体内蛋白质、核酸等的重要组成成分.硫素是不可再生资源,充分合理的利用现有的硫素资源,对于保持硫素的循环平衡具有重要意义.生物炭一般指农林废弃物在厌氧或缺氧条件下高温热解生成的一种富碳颗粒,因其在土壤性质改良等方面的广泛应用而备受关注.生物炭施入土壤,将直接或间接影响土壤中硫的植物有效性.评述了生物炭对土壤中硫素有效性的重要研究进展,为生物炭的农业应用提供参考价值.     

Effect of Ni–V loading on the performance of hollow anatase TiO2 in the catalytic combustion of dichloromethane

A catalyst based on mixed V-Ni oxides supported on TiO_2(Ni-V/TiO_2)was obtained using the sol-gel method.Its catalytic performance relative to dichloromethane(DCM)degradation was investigated.Characterization and analysis were conducted using transmission electron microscopy,H2 temperature-programmed reduction,pyridine-Fourier transform infrared spectroscopy(FTIR)characterization,and X-ray diffraction.Results showed that the original hollow anatase structure of pure Ti02 was well-maintained after Ni-V loading.The loading of NiO-VOx not only significantly improved the stability of pure Ti02 but also inhibited the formation of the by-product monochloromethane(MCM).Among the series of Ni-V/TiO_2 catalysts,4%Ni-V/TiO_2 possessed the highest catalytic activity,with 90%DCM conversion at only 203℃.No by-products and no significant changes in the catalytic activity were observed during combustion of DCM after 100 hr of a continuous stability test.Furthermore,thermogravimetric analysis(O_2-TG)and energy dispersive spectrometer(EDS)characterization of the used 4%Ni-V/TiO_2 catalyst revealed that no coke deposition or chlorine species could be detected on the catalyst surface.     

苏州河生态恢复初期自净能力的综合评估方法

利用苏州河水的化学及生物学参数,以及水样对几种添加化学品的降解延滞期及降解率,综合评估了水体自净能力,并探讨了苏州河生态恢复初期自净能力的评估方法。对比2008年上、下游水样对醋酸钠、苯酚、苯胺、二甘醇、乙二醇、三聚乙醛等6种化学品的降解情况,比较分析了2006年及2008年两年度间苏州河自净能力的变化。相对2006年而言,2008年水体的氧化还原电位急剧下降,上、下游水体对化学品降解能力整体减弱,三聚乙醛降解能力的减弱尤为明显,降解率从2006年的77.82%和88.73%降至2008年的35.83%和65.86%。在外部有机物输入量无明显变化的情况下,上游的好氧异养菌数由2006年的4.7×104CFU/mL降为2008年的2.2×103CFU/mL。2008年苏州河上游水体对化学品(二甘醇除外)降解能力较下游水体更弱,且延滞期长。与2006年相比,2008年苏州河水体的自净能力整体减弱,上游水体自净能力的损失更为明显。     

Chemical characterization of size-resolved aerosols in four seasons and hazy days in the megacity Beijing of China

Size-resolved aerosol samples were collected by MOUDI in four seasons in 2007 in Beijing. The PM₁₀ and PM_1.8 mass concentrations were 166.0 ± 120.5 and 91.6 ± 69.7 μg/m³, respectively, throughout the measurement, with seasonal variation: nearly two times higher in autumn than in summer and spring. Serious fine particle pollution occurred in winter with the PM_1.8/PM₁₀ ratio of 0.63, which was higher than other seasons. The size distribution of PM showed obvious seasonal and diurnal variation, with a smaller fine mode peak in spring and in the daytime. OM (organic matter = 1.6 × OC (organic carbon)) and SIA (secondary inorganic aerosol) were major components of fine particles, while OM, SIA and Ca^2 + were major components in coarse particles. Moreover, secondary components, mainly SOA (secondary organic aerosol) and SIA, accounted for 46%–96% of each size bin in fine particles, which meant that secondary pollution existed all year. Sulfates and nitrates, primarily in the form of (NH₄)₂SO₄, NH₄NO₃, CaSO₄, Na₂SO₄ and K₂SO₄, calculated by the model ISORROPIA II, were major components of the solid phase in fine particles. The PM concentration and size distribution were similar in the four seasons on non-haze days, while large differences occurred on haze days, which indicated seasonal variation of PM concentration and size distribution were dominated by haze days. The SIA concentrations and fractions of nearly all size bins were higher on haze days than on non-haze days, which was attributed to heterogeneous aqueous reactions on haze days in the four seasons.