活性污泥1号模型含碳组分测定方法探讨

阐述了活性污泥 1号模型中含碳有机物的分析方法,并用这些方法测定了西安市北石桥、电子村 2个排放口的城市污水水质。实验结果表明快速可生物降解COD(SS)采用间歇实验法、慢速可生物降解COD(XS)采用测定BOD5间接计算法既操作简单又准确可靠,能为利用活性污泥数学模型进行城市污水处理厂的设计、模拟及管理提供含碳组分分析依据     

活性炭吸附紫外分光光度法测定油烟挥发组分

建立了用活性炭作吸附剂、脱芳烃石油醚萃取、紫外分光光度法测定油烟挥发组分的方法。取家用抽油烟杯内的油烟气冷凝液加热到200C的样品萃取液作标准油品,在225nm处测紫外吸光值,绘制校准曲线,相关系数在0．986～0．999之间。实验样品分析结果表明,脱芳烃石油醚对样品中油烟挥发组分萃取率可达90％以上,样品测定重现率达76．7％。红外光谱分析标准油品挥发组分初步认定为烃类、卤代烃类、醇酚醚类、醛酮类、羧酸及其衍生物类、稠环杂环类和胺类等。     

机载电子元器件环境应力筛选初探

讨论了某直升机机载电子元器件在环境应力筛选过程中存在的主要问题及其解决方法。包括环境应力筛选的实施原则,筛选项目的确定,失效元器件分析情况及失效元器件的处理等问题。     

Organic carbon and environmental quality of riverine and off-shore sediments from the Gulf of Cádiz,Spain

Here we show that heavy metal geoaccumulation is apparent in the Tinto and Odiel estuary and, at a lower magnitude, in off-shore sediments. Values above probable effects level (PEL) are recorded for As, Cu, Hg, Pb and Zn in the Tinto and Odiel estuary, for As and Hg in the associated off-shore sediments and for As in the Guadiana River. Significant correlations were found between total organic carbon (TOC) and Cr, Cu, Ni and Zn in the Tinto and Odiel estuary, and Cr, Cu, Ni, Pb, Hg and As in the Guadiana River. PCA analysis differentiated the three studied locations.     

基于故障树分析法的舰载武器装备电子元器件及PCB的失效研究

目的 对极端海洋环境下某型舰声呐装置中的多功能信号发生器进行失效研究。方法 使用故障树分析法作为失效分析基本方法。首先通过微焦点CT检测技术对样品进行准确的失效定位,并通过扫描电子显微镜和能谱分析样品的失效机理。然后结合应用背景,分析归纳样品失效的机理因子和影响因素。最后,针对每种失效形式提出具体的改善方案。结果 由电阻本身表面形貌、额定温度及外部环境（高温、高湿、高盐）等原因,导致含有盐雾的水汽进入电阻内部,致使电阻内部出现电化学迁移现象,电阻阻值因此明显降低,最终导致多功能信号发生器出现失效。结论 舰艇中的电子设备,如多功能信号发生器的失效往往是由设计制造及各种海洋环境因素综合作用所造成的。这就要求舰载电子设备的研制方、使用方都应重视海洋环境适应性问题,并采取一定的改善措施。     

扁豆中脂溶性毒物与农药增毒作用的探讨

针对食用扁豆中毒事故是否同扁豆中脂溶性毒物与残留农药的增毒作用有关,进行了探索性研究。经对扁豆脂溶性毒物的提取、纯化、筛选,以家绳和小鼠为试材进行了毒性与农药增毒作用测定。结果表明,除石油醚-乙醚萃取系统F2的c段与乐果和呋喃丹,乙醚萃取系统D的a段和F2的a段与拉硫磷对家蝇表现出微弱的增毒作用外,其他分寓物与乐果、呋喃丹、甲胺磷和溴氰菊酯均表现出拮抗作用.小鼠试验表明,无论是单用分离物或与乐果混用,都未观察到中毒症状。      

基于激光雷达和超级站监测的一次沙尘过程分析

利用南京市气溶胶激光雷达网和草场门超级站监测数据,对2022年3月2—3日南京地区一次沙尘污染过程的垂直特征和地面PM_2.5组分变化进行了分析。结果表明,草场门、八卦洲和土桥3处点位的气溶胶激光雷达均观测到消光系数和退偏振比在凌晨至清晨时段有垂直分层现象,说明高空输入的沙尘气团位于城市污染气团上空,而此时地面PM_2.5组分以二次无机盐(硝酸盐、硫酸盐和铵盐)为主。中午前后,各高度的退偏振比及消光系数发生突变,主要是由高空输入沙尘和城市污染气团的垂直混合引起的。随着日间大气垂直交换的加大,PM_2.5中地壳物质的浓度均值和占比显著上升,其中浓度从3 μg/m³升高至5 μg/m³,占比从3%上升至10%。     

Effect of activated sludge treatment on the formation of Nnitrosamines under different chloramination conditions

Municipal wastewater discharge is considered as one of the main sources of N-nitrosamine precursors which can impact the qualities of downstream source waters and reclaimed wastewaters for potable reuse. NNitrosamine precursors can be removed to various degrees during biological wastewater treatment (e.g., the activated sludge (AS) process). So far, little is known about the impact of the AS process on N-nitrosamine formation under practical disinfection condition (e.g., uniform formation condition (UFC)). In this study, N-nitrosamine UFC from selected model compounds, sewage components (i.e., blackwaters and greywaters) and sewage samples were comprehensively investigated during batch AS treatment tests. NNitrosodimethylamine (NDMA) formation from the tested precursor compounds (i.e., trimethylamine (TMA) and sumatriptan (SMTR)) under UFC chloramination decreased mostly after 6 or 24 hr treatment with different types of AS (i.e., domestic rural AS, domestic urban AS, and textile AS), and the reductions in NDMA UFC were comparable to their NDMA formation potential (FP) reductions. In urine and feces blackwaters, NDMA UFC increased after 6 or 24 hr treatment with the domestic (i.e., rural and urban) AS, while NDMA FP decreased substantially. The increases in NDMA UFC after AS treatment was presumably attributed to the removal of bulk organic matters (e.g., dissolved organic carbon (DOC)) which favored NDMA formation under UFC. On the other hand, in laundry greywaters having relatively abundant DOC, N-nitrosamine UFC was less affected by DOC removal before or after AS treatment, but decreased to similar degrees with N-nitrosamine FP. In sewage samples collected from wastewater treatment plants, N-nitrosamines UFC tended to increase or remain constant during AS treatment, despite the decreases in their FPs. These results suggest that biological wastewater treatment (e.g., the AS process) may not effectively reduce N-nitrosamine formation (e.g., measured under UFC) partially because the concurrent removal of bulk organic matters (e.g., DOC) favored N-nitrosamine formation in s econdary effluents.     

城市不同区域空气冷凝水的化学组成

采集了5个不同区域的空气冷凝水样品，检测了其化学成分。结果显示，空气冷凝水的化学成分在不同区域存在着明显差异，5个区域各类化学物质总量的关系是，阴阳离子：城区〉工业〉道路〉城郊〉景区；微量元素：工业〉城区〉道路〉景区〉城郊；总有机碳（TOC）：城区〉景区〉道路〉工业〉城郊；总无机碳（TIC）：景区〉城区〉道路〉工业〉城郊；物质总量：城区〉工业〉道路〉景区〉城郊；其质量浓度分布与区域内的空气污染状况密切相关，大部分物质的质量浓度日间低于夜间。     

成都碳质气溶胶变化特征及二次有机碳的估算

利用2020年6月~2021年5月在成都市观测的碳质气溶胶小时分辨率数据,分析了气溶胶中总碳(TC)、有机碳(OC)、元素碳(EC)和二次有机碳(SOC)的变化特征.结果表明:观测期间m(TC)、m(OC)、m(EC)和r(OC/EC)的年均值分别为(9.5±4.4)μg/m³,(6.4±3.2)μg/m³,(3.2±1.1)μg/m³,2.2±0.5.成都m(TC)、m (OC)、m (EC)均表现冬为季最高((15.8±8.2),(11.1±5.8),(4.6±2.5)μg/m³),春秋次之,夏季最低((6.1±0.9),(4.5±2.0),(2.7±1.4)μg/m³)的特征.r(OC/EC)季节均值(1.9~2.6)以及四个季节的m(TC)、m(OC)、m(EC)呈现早(07:00~09:00)晚(22:00~01:00)“双峰”的日变化特征,表明机动车排放源对成都碳质气溶胶的影响较大.春夏季OC与EC的相关性小于秋冬季,表明春夏季OC、EC来源差异较大.由EC示踪法和最小相关性法得到m(SOC),r(SOC/OC)在夏季最大(40.4%),冬季最小(27.3%).春、夏季SOC与O₃呈显著正相关,表明较强的光化学反应对SOC生成有重要贡献.选取各季节连续高m(TC)时段与季节平均作对比,发现碳质气溶胶有明显夜间积累过程,夏季高浓度时段二次生成使得m(OC)增长显著高于m(EC),r(OC/EC)也迅速上升.