Decolorization of oxygen-delignified bleaching effluent and biobleaching of oxygen-delignified kraft pulp by non-white-rot fungus Geotrichum candidum Dec 1

Decolorization of oxygen-delignified bleaching effluent (abbreviated as OBE) and biobleaching of oxygen-delignified kraft pulp (OKP) were conducted using a non-white rot fungus Geotrichum candidum Dec 1 (abbreviated as Dec 1) which has ability to decolorize various synthetic dyes and molasses. Dec 1 decolorized up to 77% of OBE for 6 days. In addition, Dec 1 increased the brightness of OKP from 47.8% to 51.2% and decreased the kappa value of OKP from 12.4 to 10.4 points during a 6-day incubation period at a 25% of pulp-concentration. At 2% pulp-concentration, the brightness of OKP increased by 13% and the kappa value of OKP decreased by 4 points only for a 3-day incubation period. When the decolorized OBE was used for bleaching of OKP, the brightness of OKP increased to 62.7% under the shaking culture to a 2% pulp-concentration using culture fluid of decolorized OBE. It was revealed that Dec 1 is a potential to apply for decolorization of wastewater and biobleaching of pulp in paper-mills.     

Homogeneous and heterogeneous reactions of anthracene with selected atmospheric oxidants

The reactions of gas-phase anthracene and suspended anthracene particles with O3 and O3-NO were conducted in a 200-L reaction chamber, respectively. The secondary organic aerosol (SOA) formations from gas-phase reactions of anthracene with O3 and O3-NO were observed. Meanwhile, the size distributions and mass concentrations of SOA were monitored with a scanning mobility particle sizer (SMPS) during the formation processes. The rapid exponential growths of SOA reveal that the atmospheric lifetimes of gas-phase anthracene towards O3 and O3-NO are less than 20.5 and 4.34 hr, respectively. The particulate oxidation products from homogeneous and heterogeneous reactions were analyzed with a vacuum ultraviolet photoionization aerosol time-of-flight mass spectrometer (VUV-ATOFMS). Gas chromatograph/mass spectrometer (GC/MS) analyses of oxidation products of anthracene were carried out for assigning the time-of-flight (TOF) mass spectra of products from homogeneous and heterogeneous reactions. Anthrone, anthraquinone, 9,10- dihydroxyanthracene, and 1,9,10-trihydroxyanthracene were the ozonation products of anthracene, while anthrone, anthraquinone, 9-nitroanthracene, and 1,8-dihydroxyanthraquinone were the main products of anthracene with O3-NO.     

鼎湖山秋季大气细粒子及其二次无机组分的污染特征及来源

利用大气颗粒物质量浓度分析仪（TEOM）及大气细粒子快速捕集及其化学成分自动在线分析系统（RCFP-IC）于2008年10～11月在中国科学院华南植物园鼎湖山定位站进行了大气细粒子（PM2.5）及其二次无机组分（SO42-、NH 4＋和NO 3-）与相关污染气体组分的同步观测与分析,同时结合主成分分析和HYSPLIT轨...     

人工湿地净化海水养殖外排水影响因素与效果实验研究

以海水养殖外排水为处理对象,构建芦苇复合垂直流人工湿地模拟系统进行处理效果的影响因素(盐度,水力负荷,污染负荷)实验。植物选择芦苇,种植密度为48株/m2,基质填料选择细纱、蛭石、高炉矿渣、沸石和砾石。实验结果显示,随着盐度的升高,人工湿地对CODMn和NH4-N的去除率差异不显著(P>0.05),对PO4-P的去除率在逐渐降低,变化显著(P<0.05),但芦苇表现出较强的耐盐性,在盐度20时生长良好。随着水力负荷的增加,人工湿地对CODMn、NH4-N和PO4-P的去除率呈现出降低的趋势,变化显著(P<0.05);而当污染负荷增加时,去除率呈现出先增加后降低的趋势。综合考虑运行合理性及运行效果,得出合理工况为盐度20,水力负荷0.4 m3/(m2.d),污染负荷CODMn 10 mg/L,NH4-N 2 mg/L,PO4-P 0.5 mg/L。在此工况下,系统稳定运行2个月,显示人工湿地对海水养殖外排水中的污染物具有较好的去除效果。     

区域空气质量模拟中查表法的应用研究

在自行开发完善的区域空气质量模式系统RegSRRMS中应用查表法,模拟中国典型城市群对流层大气主要污染物的浓度变化,评估该方法在大气复合污染事件预测和控制中的有效性.首先,利用具有国际先进水平的空气质量模式WRF-CHEM中的化学模块建立了包含完善气相化学、气溶胶过程的箱模式WRFBOX.其次,利用WRFBOX进行化学反应敏感性分析,基于影响污染物的重要因子分别建立了臭氧(O3)及其前体物、无机盐气溶胶和二次有机气溶胶(SOA)查算表数据库,并检验其有效性.最后,将此查算表数据库引入RegSRRMS,建立简化的查表算法.利用直接耦合机制法和查表法对2000年3月珠三角地区污染个例中主要大气污染物浓度进行模拟.通过比较2种方法的模拟结果,显示查表法计算效率提高了57%,能够反映大气光化学反应的非线性特征、气溶胶及其前体物的平衡关系,具有高分辨率、高时效性,能够方便快捷地给出源和受体之间的响应关系,结果可靠.在区域空气质量模式中应用查表法有利于大气污染事件的快速预测以及大气污染控制的快速决策.     

利用嗜酸性硫杆菌的生物产酸作用处理洗毛废水

利用洗毛废水在低pH条件下,有机物絮凝沉降的特点,通过嗜酸性硫杆菌(Acidophilic thiobacillus)的产酸作用降低体系pH,破坏废水固有的稳定性,改变有机物的亲水性能,实现固液分离,达到去除COD的目的.试验结果表明,生物产酸作用能有效地去除废水COD,改善其脱水性能.当体系pH降至3.00, COD去除率达到最大值91.4%,处理后的废水有很好的机械脱水和沉降性能,比阻从大于9.81×10¹³　m·kg^-1降至5.60×10¹¹ m·kg^-1.而对照处理在整个培养期内,未发生明显的改变,仅有20%的COD被去除.本研究为油脂含量高、难被生物利用的有机废水提供了一条新的处理方法.     

Denitrification potential enhancement by addition of external carbon sources in a pre-denitrification process

The aim of this study is to investigate the denitrification potential enhancement by addition of external carbon sources and to estimate the denitrification potential for the predenitrification system using nitrate utilization rate （NUR） batch tests. It is shown that the denitrification potential can be substantially increased with the addition of three external carbon sources, i.e. methanol, ethanol, and acetate, and the denitrification rates of ethanol, acetate, and methanol reached up to 9.6, 12, and 3.2 mgN/（g VSS.h）, respectively, while that of starch wastewater was only 0.74 mgN/（g VSS,h）. By comparison, ethanol was found to be the best external carbon source. NUR batch tests with starch wastewater and waste ethanol were carried out. The denitfification potential increased from 5.6 to 16.5 mg NO3-N/L owing to waste ethanol addition. By means of NUR tests, the wastewater characteristics and kinetic parameters can be estimated, which are used to determine the denitrification potential of wastewater, to calculate the denitrification potential of the plant and to predict the nitrate effluent quality, as well as provide information for developing carbon dosage control strategy.     

Modeling of air quality with a modified two-dimensional Eulerian model： A case study in the Pearl River Delta （PRD） region of China

A modified two-dimensional Eulerian air quality model was used to simulate both the gaseous and particulate pollutant concentrations during October 21-24, 2004 in the Pearl River Delta （PRD） region, China. The most significant improvement to the model is the added capability to predict the secondary organic aerosols （SOA） concentrations because of the inclusion of the SOA formation chemistry. The meteorological input data were prepared using the CALMET meteorological model. The concentrations of aerosol-bound species such as NO3^-, NH4^＋, SO4^2-, and SOA were calculated in the fine particle size range （〈2.5 μm）. The results of the two-dimensional model were compared to the measurements at the ground level during the PRD Intensive Monitoring Campaign （IMC）. Overall, there were good agreements between the measured and modeled concentrations of inorganic aerosol components and O3. Both the measured and the modeled results indicated that the maximum hourly O3 concentrations exceeded the China National Air Quality Standard. The predicted 24-h average SOA concentrations were in reasonable agreement with those predicted by the method of minimum OC/EC ratio.     

Effects of seed aerosols on the growth of secondary organic aerosols from the photooxidation of toluene

Hydroxyl radical （.OH）-initiated photooxidation reaction of toluene was carried out in a self-made smog chamber. Four individual seed aerosols such as ammonium sulfate, ammonium nitrate, sodium silicate and calcium chloride, were introduced into the chamber to assess their influence on the growth of secondary organic aerosols （SOA）. It was found that the low concentration of seed aerosols might lead to high concentration of SOA particles. Seed aerosols would promote rates of SOA formation at the start of the reaction and inhibit its formation rate with prolonging the reaction time. In the case of ca. 9000 pt/cm^3 seed aerosol load, the addition of sodium silicate induced a same effect on the SOA formation as ammonium nitrate. The influence of the four individual seed aerosols on the generation of SOA decreased in the order of calcium chloride〉sodium silicate and ammonium nitrate〉ammonium sulfate.