多级A/OVTBR组合工艺处理焦化废水

采用水解酸化、多级A/O垂直折流生物膜反应器(vertical tubulant biological reactor,VTBR)、混凝和Fenton氧化组合技术对实际焦化废水进行处理。其中水解酸化预处理阶段提高了废水可生化性,混凝降低了生化处理的有机负荷,一级A/O VTBR以脱碳为主,二级A/O VTBR主要脱碳和脱氮,三级好氧VTBR强化对氨氮的去除,Fenton氧化则对生化出水进行深度处理。试验结果表明:在进水ρ(COD)为3 000～3 500 mg/L,ρ(BOD5)为1 212 mg/L,ρ(NH3-N)为109 mg/L条件下,保持好氧段ρ(DO)为3～7 mg/L,缺氧段ρ(DO)<1 mg/L,总停留时间HRT 56 h,该工艺对COD、BOD5、NH3-N的去除率分别为98%、99%、95%,出水达GB8978-1996《污水综合排放标准》中的一级排放标准。     

钢铁企业含锌尘泥资源化利用途径分析评价

通过分析锌元素进入钢铁制造流程的渠道,明确了钢铁企业含锌尘泥的来源与循环路径。根据含锌尘泥的循环途径,综合分析比较国内外含锌尘泥的不同利用方式和工艺——改变循环路径、物理选矿法、火法工艺以及湿法工艺。本着钢铁工业与锌冶炼之间形成工业化生态链的思路,提出了钢铁企业含锌尘泥的处理原则和资源化利用模式。     

石化企业玻璃钢设施静电特性及安全使用

通过测试玻璃钢设施的静电参数,研究分析玻璃钢设施的静电特性,表明玻璃钢设施有较大的静电危险性,提出了一般防静电措施,预防玻璃钢设施的燃爆风险。     

环氧化PVA载体固定漆酶的最佳工艺条件研究

在T=35℃,HAc-NaAc缓冲溶液pH为4的条件下,用环氧化PVA载体对漆酶进行固定化,固定后酶活为游离酶活的95%。用该固定化漆酶处理制浆造纸废水,反复使用6次后,酶活仍保持为初始酶活的45%,且每次COD去除率在40%以上,处理后的废水BOD增大了50%,废水可生化性得到很大提高。     

基于传声器阵列的声源定位技术的应用

基于传声器阵列的声源定位技术中的两个主要方法,STSF和Beamforming声源定位技术两者的实现方法不同。通过对STSF和Beamforming声源定位技术的推导,给出了两种测量技术适用的频率范围和空间范围,从理论上对其应用范围的差异进行了说明,并提出在实际测量中如何选择合适的声源定位方法。结合两种测量技术的特点,提出声源定位技术下一阶段研究的重点。     

道路交通噪声不同预测模型之比较

目前,我国在进行道路交通噪声环境影响评价工作中主要使用的预测模型有2009声导则模型、2006规范模型,此外,也有部分噪声评价工作采用了德国的CadnaA软件。因各种模型在使用条件和参数选取等方面存在不同,导致预测结果存在差异。如何选取合适的预测模型,一直是国内学者不断研究想解决的问题。本文对已有道路交通噪声进行现场实测,通过设计不同的预测模式进行模型验证,将预测结果与实测值进行比较,结果表明这五种噪声预测模式中,模式一、模式四、CadnaA软件的噪声预测值与实际情况最相符,模式一绝对预测误差昼间在3.3-6.0 dB(A)之间,夜间在-3.4-0.2 dB(A)之间。使用2009声导则模型、2006规范模型相结合的预测模式更为准确。     

空塔钠碱法烟气脱硫实验研究

在内径200mm,高度1100mm的喷淋塔内,采用Na2CO3作为吸收剂进行SO2吸收实验,重点研究了液气比(L/G)、空塔气速、进口SO2质量浓度、吸收液pH及初始浓度对脱硫效率的影响。通过实验得到该系统适宜操作条件:吸收液pH值在6.5～7.5之间,液气比在1～1.5之间,吸收液初始浓度5%,空塔气速1.6m/s,在此条件下,进口SO2质量浓度在3000mg/m3以内,脱硫效率可以达到80%以上。     

北京市门头沟区生态安全评估及预测

为研究和预测北京市门头沟地区生态安全形势,并在实践中为生态安全评价提供理论依据,在生态环境管理的方法论基础上,根据统计年鉴,采用压力状态响应模型建立生态安全指标体系,以不安全指数法对指标实际值归一化,运用层次分析法确定指标权重,采用加权指数法计算生态安全综合值,评价了门头沟区3年的生态安全状况。结果表明:门头沟地区2006-2008年3年期间,生态安全综合指数分别为:0.6192、0.639 3、0.6395。显示生态安全综合值缓慢上升,生态安全越来越好,但是仍然处于较不安全状态。指出其主要原因有经济欠发达、自然资源缺乏、人口众多等。建议该地区加快产业结构调整、改变增长方式、控制人口、提高土地利用率,保护环境并治理污染。     

Aerosol structure and vertical distribution in a multi-source dust region

The vertical distribution of aerosols was directly observed under various atmospheric conditions in the free troposphere using surface micro-pulse lidar (MPL4) at the Zhangye Station (39.08°N, 100.27°E) in western China in the spring of 2008. The study shows that the aerosol distribution over Zhangye can be vertically classified into upper, middle and lower layers with altitudes of 4.5 to 9 km, 2.5 to 4.5 km, and less than 2.5 km, respectively. The aerosol in the upper layer originated from the external sources at higher altitude regions, from far desert regions upwind of Zhangye or transported from higher atmospheric layers by free convection, and the altitude of this aerosol layer decreased with time; the aerosols in the middle and lower layers originated from both external and local sources. The aerosol extinction coefficients in the upper and lower layers decreased with altitude, whereas the coefficient in the middle layer changed only slightly, which suggests that aerosol mixing occurs in the middle layer. The distribution of aerosols with altitude has three features: a single peak that forms under stable atmospheric conditions, an exponential decrease with altitude that occurs under unstable atmospheric conditions, and slight change in the mixed layer. Due to the impact of the top of the atmospheric boundary layer, the diurnal variation in the aerosol extinction coefficient has a single peak, which is higher in the afternoon and lower in the morning.     

Soil warming effect on net ecosystem exchange of carbon dioxide during the transition from winter carbon source to spring carbon sink in a temperate urban lawn

The significant warming in urban environment caused by the combined effects of global warming and heat island has stimulated widely development of urban vegetations. However, it is less known of the climate feedback of urban lawn in warmed environment. Soil warming effect on net ecosystem exchange (NEE) of carbon dioxide during the transition period from winter to spring was investigated in a temperate urban lawn in Beijing, China. The NEE (negative for uptake) under soil warming treatment (temperature was about 5℃ higher than the ambient treatment as a control) was -0.71 μmol/(m².sec), the ecosytem was a CO₂ sink under soil warming treatment, the lawn ecosystem under the control was a CO₂ source (0.13 μmol/(m².sec)), indicating that the lawn ecosystem would provide a negative feedback to global warming. There was no significant effect of soil warming on nocturnal NEE (i.e., ecosystem respiration), although the soil temperature sensitivity (Q₁₀) of ecosystem respiration under soil warming treatment was 3.86, much lower than that in the control (7.03). The CO₂ uptake was significantly increased by soil warming treatment that was attributed to about 100% increase of α (apparent quantum yield) and A_max (maximum rate of photosynthesis). Our results indicated that the response of photosynthesis in urban lawn is much more sensitive to global warming than respiration in the transition period.