大气颗粒物和降水化学特征的相互关系

分别于2007年在泰安市郊区和深圳市郊区采集了大气颗粒物并同时对降水进行了分级采样,通过降水过程中降水化学特征的变化和降水前后颗粒物浓度和化学组成的改变,讨论了云下冲刷过程中大气颗粒物对降水化学组分的贡献和降水对颗粒物的去除作用.泰安降水雨量加权pH为5.97,总可溶解离子浓度为1 187.96μeq.L-1,PM10的质量浓度为131.76μg/m3,PM2.5为103.84μg/m3.深圳降水雨量加权pH为4.72,总可溶解成分离子浓度为175.89μeq.L-1,PM10的质量浓度为56.66μg/m3,PM2.5为41.52μg/m3.泰安和深圳降水过程中pH和离子浓度都逐渐降低,冲刷过程主要是中和作用.泰安和深圳降水中Na+和Ca2+的去除效率较高,NH4+和NO3-去除效率较低.两地降水化学性质的差别取决于云水酸度、大气颗粒物性质和大气中酸碱性气体差别的共同作用.降水对大气颗粒物质量浓度、离子组分和元素组分都有显著清除作用.     

Use of coupling agents to stabilize asphalt–rubber–gravel composite to improve its mechanical properties

The mechanical performance of rubber-modified asphalt roads depends, besides the intrinsic properties of the constituents (asphalt, rubber and gravel), on their interfaces. To improve the adhesion between constituents, two different coupling agents were required: one to link asphalt with the rubber particles to stabilize the composite creating an elastic network in the interior of the material to improve its elastic recovery, and other to increase the adhesion between the hydrophobic asphalt and the hydrophilic gravel. A phenolic resin was used to link the rubber particles with the asphalt, while a switterionic molecule (phosphatidyl-choline) was used to change the OH groups on the gravel surface by hydrocarbon chains to make it compatible with the asphalt.     

多分散颗粒悬浊液声传播衰减模型研究

利用Bouguer-Lambert-Beer-Law理论,推导出了多分散颗粒悬浊液声传播衰减模型,并在实验室利用配制的玻璃微珠和二氧化钛悬浊液进行了5个频率下的声衰减测量.结果与衰减模型进行的数值模拟吻合.通过对渤海某淤积港口的声衰减测量验证,该模型同样适用于浑浊海域的声传播衰减计算.这对于浑浊海域的声纳探测和设计具有重要的工程价值.     

秸秆焚烧期的碳黑气溶胶观测及研究

2007年5～6月在合肥市郊3个站点连续实时监测碳黑气溶胶,研究其在秸秆焚烧期的变化特征和来源.正常时期碳黑气溶胶平均质量浓度约为4.85　μg/m³,而秸秆焚烧期其平均浓度约为 8.38　μg/m³,这说明秸秆焚烧是碳黑气溶胶的重要来源.同步监测的PM₁₀与BC一致性较好,相关系数为0.74,一般情况下BC约占PM₁₀的4.7%,而秸秆焚烧期BC/PM₁₀的统计平均值较高,约为7.9%.比对2004年秸秆焚烧期BC浓度数据,证实了合肥市在实行农作物秸秆禁烧后,碳黑气溶胶的污染情况有较大好转.     

采暖期开始前后北京大气颗粒物中化学元素特征及来源

为比较研究采暖期与非采暖期大气颗粒物的特征,2006年11月,在北京城区采用Andersen分级撞击式采样器进行了大气气溶胶分级采样,并利用ICP-MS对其中22种化学元素浓度进行了分析.结果表明,采暖期As、Se、Mo、Cd浓度较采暖前上升2倍以上,Zn、Pb、Tl、K、Se、As、Cu、Cd、Ag在细粒径段的分布出现大幅度的增长,Zn、Na出现向细粒径段移动的趋势.因子分析表明,在采暖期燃烧源的贡献增强,地壳源的贡献减弱.     

Extraction of 17p-estradiol in water using non-imprinted polymer submicron particles in membrane filters

17β-Estradiol (E2) is an endocrine disrupting chemical of harm to both animals and human beings at a low concentration level (ng/L).It cannot be completely removed by wastewater treatments,and is often detected in both environment and drinking waters.The purpose of this feasibility study,towards environmental engineering in the field of water analysis and treatment,was to remove E2 by extraction using non-imprinted polymer (NIP) submicron particles.Experimental results showed that 0.5 mg/L of E2 could be completely extracted by adding 10 mg of NIP particles directly into 10 mL of water.However,the extraction efficiency decreased to 64% for 100 mL of water.prefilling the NIP particles inside a membrane filter showed a potential for water treatment of a large volume,requiring no effort to distribute the particles uniformly in the water.High extraction efficiency (80±10)% for E2 was achieved for 100 mL of water.A total mass of 0.29 mg E2 was extracted from 1000 mL of water containing 0.8 mg/L E2 (by using only 10 mg of NIP particles).Both efficiency and mass capacity can be increased,by scaling up the amount of NIP particles,towards environmental engineering applications.     

应用化学提取法评价大气颗粒物中重金属的生物有效性

以广州市楼顶降尘为研究对象,在分析其粒度分布和重金属总量的基础上,采用单一化学提取法（DWLP、TCLP）和多级化学提取法（SEP）研究了大气颗粒物中4种重金属元素的生物有效性。结果表明：样品中96％以上颗粒小于100μm,其中10μm和2．5μm以下颗粒分别占33％和11％。大气颗粒物中重金属含量很高,Cu、Pb、Zn和Cd的平均含量分别为362．43、1033．81、830．32和5．80mg／kg,是广东省环境土壤背景值的17～64倍。单一提取法中,TCLP的提取效率明显高于DWLP,表明pH值是影响大气颗粒物中重金属释放的主要因素。SEP法结果显示,Zn和Cd的生物可利用态比例远高于Cu和Pb。经DWLP和TCLP法提取后,颗粒物中重金属的总含量有不同程度的降低,生物可利用态所占比例明显增加。通过综合分析,发现SEP此其他两种方法更适用于评价大气颗粒物中重金属的生物有效性。     

Sludge granulation and e ciency of phase separator in UASB reactor treating combined industrial e uent

Sludge granulation and the effect of gas-liquid-solid separator （GLSS） design on the efficiency of upflow anaerobic sludge blanket （UASB） and upflow anaerobic sludge filter （UASF） reactors, operating at HRTs ranging from 3 to 12 h was investigated. VSS/TS ratio gradually increased in both the reactors with increasing sludge age （from 0.5 to more than 0.7 for UASB reactor and 0.012 to 0.043 for UASF reactor）. X-Ray diffraction analysis of the UASF sludge showed the presence of expanding clays revealing its additional absorption capability. Fuoraphyllite and albite precipitation related to excellular polymers of the microbial shell structure, showed the extended growth of microorganisms during sludge granulation. A gradual decrease （82%-69%） in COD removal with decreasing HRT was apparent in UASF reactor. In case of UASB reactor, this decrease was marginal because addition of GLSS device significantly improved （14%-20%） the overall efficiency of the UASB reactor. GLSS enhanced the efficiency of the UASB reactor by increasing the settleability of suspended particles and accelerating the coagulation of colloidal particles due to the velocity gradient.     

南水北调中线源头区降雨径流中多环芳烃分布特征

研究了南水北调中线源头区降雨径流中多环芳烃的分布特征及来源.根据不同土地利用类型修建了5组径流场收集径流,采用GC/MS对径流中美国EPA优先控制的16种PAHs进行了检测分析.结果表明,3种土地利用类型降雨径流水相中PAHs含量平均值为：耕地（26.53 ng·L^-1）〉栎林（20.91 ng·L^-1）〉果园（1...     

油粒子体积对扩散的影响及油膜粒子化改进

在应用油粒子法模拟溢油运动时,特征油粒子在体积和油膜粒子化方法上可以有多种选择,文章就不同特征体积的油粒子对溢油面积的影响进行了分析和比较,结果显示,溢油量相同时,特征油粒子的体积每减小一倍,溢油扩散面积增加14%-25%,减小10倍时,达到31%-43%.针对溢油扩散面积计算不足的情况,已有学者提出用"两阶段"法进行...