提高BOD5考核样品成功率的方法

BOD5考核样品的测定过程受到诸多因素的影响，时常出现一些不理想的分析结果。通过确定考核样品的CODcr值与其BOD5值之间的关系，预测其BOD，值，以此预测值来确定恰当的稀释倍数，并对不在最佳状态的测定值进行合理的校正等，可以有效地提高BOD，考核样品的成功率，具有很高的应用价值。     

基于响应曲面法的环境因素对生活污水三维荧光光谱的影响

采用响应曲面法(RSM)研究温度(10~35℃)、pH(3~11)、稀释倍数(1~10)及交互作用对生活污水溶解性有机物(DOM)三维荧光光谱特性的影响规律。研究表明:生活污水DOM主要含有类色氨酸蛋白质、类酪氨酸蛋白质和类富里酸荧光峰;响应曲面分析表明,温度、pH、稀释倍数其交互作用对于类色氨酸蛋白质荧光强度的影响强弱顺序为:稀释倍数pH温度、pH-稀释倍数温度-pH温度-稀释倍数,其中温度-pH和温度-稀释倍数对其荧光强度的影响为拮抗作用,pH-稀释倍数为协同作用;对于类酪氨酸蛋白质,单因素影响顺序为:pH稀释倍数温度,其他情况与类色氨酸蛋白质相似;对于类富里酸,温度、pH、稀释倍数及其交互作用对其影响规律与对类色氨酸蛋白质的相似,但交互作用类型与类色氨酸蛋白质情况相反。     

测定BOD_5时计算水样稀释倍数的通式及其求证和运用

本文从理论上探讨出一个简便、可靠、适应性强的计算水样稀释倍数的通式:用该式计算稀释倍数,测定地面水1193份,工业废水400份,命中率在99%以上,证明了该式具有可靠性好、准确度高、适应性强等优点。     

青霉素菌渣厌氧发酵沼液对红三叶种子萌发及幼苗生长的影响

为解决青霉素菌渣厌氧发酵沼液的综合利用问题,采用浸种实验和盆栽实验探究了不同稀释倍数的沼液对红三叶种子萌发及植株生长的影响。结果表明,沼液原液对红三叶种子萌发及植株生长均有显著且不可逆的抑制作用,适当稀释后可以显著促进红三叶种子萌发及植株生长。综合考虑浸种实验与盆栽实验结果,沼液的最适稀释倍数应为10。该研究可为抗生素菌渣厌氧发酵沼液的合理利用提供技术支撑,也为进一步研制商品化沼渣沼液肥提供了基础数据。     

餐厨垃圾两相厌氧发酵产甲烷相恶臭排放规律

为了研究餐厨垃圾两相厌氧发酵产甲烷相恶臭排放规律,在中温(35℃)条件下,以餐厨垃圾为发酵底物进行中试规模的两相连续式厌氧发酵试验,并对一个周期内不同时间段产甲烷相产生的气体进行采样,分析其臭气浓度和物质浓度,结合各组分的阈稀释倍数,筛选出主要的恶臭污染物。结果表明,在发酵系统稳定运行阶段,产甲烷相产生的臭气浓度较大,都在23万以上;产甲烷相产生的恶臭物质主要包括硫化物、萜烯类、含氧类和芳烃类四类化合物,其中质量浓度最高的恶臭物质是硫化氢,超过了150 mg/m3;产甲烷相的主要致臭物质是硫化物,其中贡献最大的是硫化氢,其阈稀释倍数都在26万以上,其次为乙硫醇﹥甲硫醇﹥乙硫醚,这3种物质的阈稀释倍数都在4 000以上;除了这4种硫化物,丁醛对恶臭的贡献也比较大,其阈稀释倍数也在4 000以上。     

城市生活垃圾焚烧厂渗滤液产甲烷潜力

为研究城市生活垃圾焚烧厂渗滤液的产甲烷潜力及其影响因素,在常规水质分析的基础上,采用瑞典AMPTSⅡ系统进行中温((37±1)℃)厌氧消化实验,探究稀释倍数和污泥投加量对城市生活垃圾焚烧厂渗滤液的甲烷产率和可生物降解性的影响。结果表明:城市生活垃圾焚烧厂渗滤液的甲烷产率(以CH4/CODadd计)高于326.0 mL·g~(-1)(理论甲烷产率为350 mL·g~(-1)),可生物降解性高于93.1%;城市生活垃圾焚烧厂渗滤液是一种高COD、高NH3-N的有机废水,但可生化性较好;无论污泥投加量还是稀释倍数对城市生活垃圾焚烧厂渗滤液的甲烷产率和可生物降解性影响都很小,但稀释倍数的增加可明显降低污泥驯化时间和厌氧消化时间。在工程应用中,采用生化出水回流稀释城市生活垃圾焚烧厂渗滤液的方法,可降低厌氧反应器启动时间和厌氧消化时间,提高城市生活垃圾焚烧厂渗滤液处理效率。     

废椰壳制备活性炭负载CuO处理活性艳红X-3B废水的工艺优化

为了综合利用废椰壳,进行了废椰壳制备活性炭并负载氧化铜处理活性艳红X-3B废水的研究。采用正交实验法,以COD和色度去除率为目标函数确定了活性炭的最佳制备工艺条件为：磷酸浓度65%（质量百分数）,m（磷酸）/m（椰壳）比3∶1,活化时间2.5 h,活化温度500℃。在该活性炭上负载氧化铜处理活性艳红X-3B染料废水,其COD和色度去除率分别为83.70%和99.72%。用扫描电镜（SEM）和X衍射仪（XRD）对裸活性炭和载铜活性炭样品表面形貌和结构进行了表征和分析。通过单因素实验法确定了废水处理的最佳工艺条件为：pH值5,曝气时间4 h和催化剂用量0.55 g,在此条件下,COD和色度去除率分别为86.70%和99.75%,相应的出水指标为75 mg/L和32稀释倍数。     

正丁烯气体标准样品制备方法研究及不确定度评定

采用4级稀释的方法制备了压力为10MPa的1μmol/mol氮气中正丁烯气体标准样品,确定了充装容器,并进行了不确定度评定。结果表明,2～8L的高压铝合金普通气瓶可以作为充装容器代替高压铝合金涂层气瓶。1μmol/mol的正丁烯气体标样品相对扩展不确定度为1.64%,可用于环境空气和污染源监测分析过程中正丁烯气体的质量控制和质量保证、仪器校准、赋值等工作,为保证监测数据准确性、可靠性和溯源性提供支持。     

影响硫酸盐测定的因素

用铬酸钡间接原子吸收法测定水中的硫酸盐，发现稀释倍数、盐度、酸度等对其影响特别大，通过试验比较，总结出应对措施，解决了测定结果的稳定度和可靠性。     

南京地区简易生活垃圾堆场的污染现状和稳定化评价

针对南京市废弃简易生活垃圾堆场,通过采集和分析渗滤液以及堆体不同深度固体样品,研究其污染现状和稳定化程度。结果表明,渗滤液COD、NH3-N、TN超标倍数分别为4～6倍、7～10倍和4～10倍;固体样品TOC含量在10%左右,含水率在25%左右,均处于基本稳定的水平;固体样品浸出液COD 39～249 mg/L、NH3-N 0.9～14.88 mg/L、TN 8.82～28.14 mg/L。为了评价稳定化程度,确定了3因子:渗滤液、固体样品、浸出液及6个参数:COD,NH3-N,含水率,TOC,COD,TN作为评价指标,评价结果表明堆场处于基本稳定到中度稳定阶段。     

Calcul du nombre le plus probable et de son intervalle de confiance dans le cas ou le nombre d'inoculums par dilution est important: Calcul of the most probable number and its confidence limit when the number of inoculum per dilution is considerable

The technique of the M.P.N. involving with a large number n of inoculum per dilution (e.g.96) gives a precise estimation of the microbial density. As no table can be used when n is greater than 10, the authors are proposing a computer program to calculate the M.P.N. with its confidence limits. They consider the most common case where number of dilution is greater than 3, dilution factor is 10 or other, and number of inoculated tubes (or wells) per dilution is different from one dilution to another.     

Temperature dependence of the infinite dilution activity coefficient and Henry's law constant of polycyclic aromatic hydrocarbons in water

The water solubility of 9,10-dihydroanthracene was experimentally determined between 278.12 and 313.17 K. Determinations were carried out by an experimental procedure developed in our laboratory, which is a modification of the dynamic coupled column liquid chromatographic technique. The uncertainty of the experimental determinations ranged from +/- 0.50% to +/- 3.10%. These data, as well as the water solubility data of other five polycyclic aromatic hydrocarbons (PAHs) previously studied, were used to calculate the temperature dependence of the infinite dilution activity coefficient of 9,10-dihydroanthracene, anthracene, pyrene, 9,10-dihydrophenanthrene, m-terphenyl, and guaiazulene in water. Molar excess enthalpies and entropies at infinite dilution, at 298.15 K, were also derived. The temperature dependence of the infinite dilution activity coefficients was used, together with literature values of the vapor pressures of supercooled liquid PAHs (p(B)(sc)), to estimate their Henry's law constants (HLC). Only HLC for anthracene, pyrene, and 9,10-dihydrophenanthrene were calculated, since no p(B)(sc) data were available in the literature for 9,10-dihydroanthracene, m-terphenyl, and guaiazulene. From the observed temperature dependence of the Henry's law constants the enthalpy and entropy of the phase change from the dissolved phase to the gas phase were also derived for anthracene, pyrene, and 9,10-dihydrophenanthrene.     

淀粉微球对苯酚的吸附性能研究

以可溶性淀粉为原料,N,N’-亚甲基双丙烯酰胺(MBAA)为交联剂,通过反相悬浮聚合得到淀粉微球作为吸附载体,研究了pH、吸附时间、温度对其苯酚吸附性能的影响,以及淀粉微球吸附苯酚的热力学和动力学特性,并利用扫描电镜仪、红外光谱仪对淀粉微球的结构进行了表征。结果表明,淀粉微球粒度分布均匀,表面粗糙多孔,具有相当大的孔容积和比表面积,具有较好的吸附性能;在20℃、pH为5.3时,吸附30 min后,淀粉微球对苯酚的吸附容量达到饱和,最大吸附量为18.71 mg/g;采用准二级吸附动力学方程能更好地描述淀粉微球对苯酚的吸附行为,淀粉微球对苯酚的吸附是以化学吸附为主控步骤的作用过程,淀粉微球对苯酚的吸附主要是通过氢键作用来完成的。     

Assessment of manure-application effects upon the runoff water quality by algal assays and chemical analyses

The effects of manure-application mode, rate to soil, and rainfall characteristics on the quality of agricultural runoff water have been assessed by means of the algal-growth-potential test (AGPT) and chemical analyses. This study used two modes of manure application (i.e. surface mode and incorporation mode), three manure-application rates (0, 150, 300 kg N ha(-1)), and two rainfall intensities and times (i.e. 11 mm h(-1) for 142 min and 22 mm h(-1) for 71 min). The effects of the dilution of runoff water on algal growth were also examined. The algal yields obtained with runoff from soil with the incorporated manure mode are similar to those from soil without manure application and are lower than those with the surface mode of manure application. A higher manure-application rate increases the load of nutrients in the runoff and subsequently the algal yield. The dilution of runoff water can stimulate or limit the algal growth, depending on the concentration of toxicants, N (nitrogen) and P (phosphorus) from runoff and in the aquatic diluting medium. A lower rainfall intensity plus a longer rainfall time increases algal productivity. This study showed that N is the limiting factor to algal growth at low dilution but that, at high dilution or with the incorporation mode of manure application, P becomes the limiting factor to algal growth.     

Can real-world diesel exhaust particle size distribution be reproduced in the laboratory? A critical review

Real-world particulate emission measurements usually include a fresh nanoparticle mode called the nucleation mode. The formation of the nucleation mode during mixing, dilution, and cooling of diesel exhaust is discussed based on existing experimental and modeling data. The further evolution of the nucleation mode and the local dilution ratio within the vehicle exhaust is reviewed. The nucleation mode forms at low dilution ratios (< or = 10) and is fully formed at the dilution ratio of approximately 100. The findings of the studies comparing real-world and dynamometer measurements are reviewed. A qualitative agreement of nucleation mode formation is generally observed. The geometric mean diameter of the nucleation mode, measured on-road, is well reproduced in the laboratory. However, the number concentration of the nucleation mode is too low in the laboratory (by a factor of 2-10). Nevertheless, the trends are reproduced, including those caused by differences in vehicle speed and engine load, engine and aftertreatment technology, as well as fuel and lubricant composition.     

Development of particle number size distribution near a major road in Helsinki during an episodic inversion situation

The influence of traffic on urban air quality is highest at low wind speeds and the presence of a temperature inversion. By relying on detailed aerosol measurements conducted simultaneously at two distances close to a major road, we studied one such episode encountered in Helsinki, Finland, during the wintertime. The observed episode was characterized by exceptionally weak dilution of traffic emissions, with particle number concentration decreasing by no more than 10–30% between 9 and 65 m distances from the road. During the nighttime with relatively minor traffic flow, dilution and particle growth by vapor condensation were found to be the dominant processes in this road-to-ambient evolution stage. The latter process shifted a significant fraction of nucleation mode particles to sizes >30 nm diameter, modifying thereby the shape of the particle number size distribution. During the rush hours in the morning, particle number concentrations were elevated by approximately an order of magnitude compared with nighttime, such that also the self-coagulation of nucleation mode particles became important. Our study demonstrates that under suitable meteorological conditions (low wind speeds coupled with temperature inversions), traffic emissions are able to affect submicron particle number concentrations over large areas around major roads and may be a dominant source of ultrafine particles in the urban atmosphere. Under conditions characterized by exceptionally slow mixing, simultaneous processing of ultrafine (nucleation and Aitken mode) particles by dilution, self- and inter-modal coagulation, as well as by condensation and evaporation seriously questions the applicability of particle number emission factors, derived from the measurements at few tens of meters from the roadside.     

SBR法短程硝化-反硝化生物脱氮工艺的研究

针对目前传统生物脱氮工艺存在的问题 ,结合国内外在该方向的研究现状 ,以实际豆制品废水为研究对象 ,控制反应器内混合液温度在 31± 0 .5℃的条件下 ,实现了短程硝化 反硝化生物脱氮工艺 ,NO-2 N NOx N的比率始终维持在90 %以上。并在此试验基础上 ,考察了曝气时间对反应器内氮形态变化的影响及系统对进水COD和NH3 N浓度的抗冲击负荷能力。结果显示 ,曝气时间对硝化效果影响较大 ,同时 ,本工艺具有较强的抗冲击负荷能力。     

Theoretical versus observed gas-particle partitioning of carbonyl emissions from motor vehicles

A state-of-the-science thermodynamic model describing gas-particle absorption processes was used to predict the gas-particle partitioning of mixtures of approximately 60 carbonyl compounds emitted from low-emission gasoline-powered vehicles, three-way catalyst gasoline-powered vehicles, heavy-duty diesel vehicles under the idle-creep condition (HDDV idle), and heavy-duty diesel vehicles under the five-mode test (HDDV 5-mode). Exhaust was diluted by a factor of 120-580 with a residence time of approximately 43 sec. The predicted equilibrium absorption partitioning coefficients differed from the measured partitioning coefficients by several orders of magnitude. Time scales to reach equilibrium in the dilution sampling system were close to the actual residence time during the HDDV 5-mode test and much longer than the actual residence time during the other vehicle tests. It appears that insufficient residence time in the sampling system cannot uniformly explain the failure of the absorption mechanism to explain the measured partitioning. Other gas-particle partitioning mechanisms (e.g., heterogeneous reactions, capillary adsorption) beyond the simple absorption theory are needed to explain the discrepancy between calculated carbonyl partitioning coefficients and observed partitioning. Both of these alternative partitioning mechanisms imply great challenges for the measurement and modeling of semi-volatile primary organic aerosol (POA) species from motor vehicles. Furthermore, as emitted particle concentrations from newer vehicles approach atmospheric background levels, dilution sampling systems must fundamentally change their approach so that they use realistic particle concentrations in the dilution air to approximately represent real-world conditions. Samples collected with particle-free dilution air yielding total particulate matter concentrations below typical ambient concentrations will not provide a realistic picture of partitioning for semi-volatile compounds.     

Theoretical versus Observed Gas-Particle Partitioning of Carbonyl Emissions from Motor Vehicles

Abstract

A state-of-the-science thermodynamic model describing gas-particle absorption processes was used to predict the gas-particle partitioning of mixtures of approximately 60 carbonyl compounds emitted from low-emission gasoline-powered vehicles, three-way catalyst gasoline-powered vehicles, heavy-duty diesel vehicles under the idle-creep condition (HDDV idle), and heavy-duty diesel vehicles under the five-mode test (HDDV 5-mode). Exhaust was diluted by a factor of 120–580 with a residence time of approximately 43 sec. The predicted equilibrium absorption partitioning coefficients differed from the measured partitioning coefficients by several orders of magnitude. Time scales to reach equilibrium in the dilution sampling system were close to the actual residence time during the HDDV 5-mode test and much longer than the actual residence time during the other vehicle tests. It appears that insufficient residence time in the sampling system cannot uniformly explain the failure of the absorption mechanism to explain the measured partitioning. Other gas-particle partitioning mechanisms (e.g., heterogeneous reactions, capillary adsorption) beyond the simple absorption theory are needed to explain the discrepancy between calculated carbonyl partitioning coefficients and observed partitioning. Both of these alternative partitioning mechanisms imply great challenges for the measurement and modeling of semi-volatile primary organic aerosol (POA) species from motor vehicles. Furthermore, as emitted particle concentrations from newer vehicles approach atmospheric background levels, dilution sampling systems must fundamentally change their approach so that they use realistic particle concentrations in the dilution air to approximately represent real-world conditions. Samples collected with particle-free dilution air yielding total particulate matter concentrations below typical ambient concentrations will not provide a realistic picture of partitioning for semi-volatile compounds.