饮用水中二级胺的气相色谱快速检测方法研究

以二甲胺、二乙胺、甲乙胺、吗啉和N-甲基苄胺5种二级胺代表物质为例,分别使用气相色谱-氢火焰(GC-FID)技术和气相色谱-质谱(GC-MS)技术检测饮用水中二级胺质量浓度。结果表明,使用优化的预处理方法处理后进样分析,5种代表物质的线性范围在20~2 000μg/L,相对标准偏差(RSD)≤0.46%,最低检出限在3.18~24.19μg/L。FID比MSD具有较强优势。该方法对于直链脂肪类和杂环类的二级胺都有良好的检测效果,可用于对饮用水二级胺类物质的检测。     

我国硫化氢职业中毒现状、原因与对策

分析了硫化氢的主要存在场所,对近年来硫化氢职业中毒行业事故进行汇总并分析了易发事故行业中毒原因,介绍了当前硫化氢中毒的预防措施及我国管理政策。指出硫化氢职业中毒事故的发生与国家的监管力度、企业的重视程度以及工人的自我保护意识密切相关,相关部门加大监管力度是防治硫化氢职业中毒的一个不可忽视的环节,同时应加大力度开发防治硫化氢中毒及应急处理的技术与装备。     

毒气泄漏事故应急用个体呼吸防护用品防护效果研究

本文对毒气泄漏事故应急过程中公众常用的个体呼吸防护用品的防护效果进行了研究.针对硫化氢气体,利用无机气体防护时间检测系统,测试研究了滤毒盒、简易防护口罩、毛巾等个体防护用品在不同工况下的防护性能,试验结果表明,有毒气体浓度及温湿度两种工况条件均对个体防护用品的防护时间有较大影响,滤毒盒的防护效果远好于简易防护口罩,毛巾的防护效果较差,在此基础上进一步分析了毒气泄漏事故应急过程中个体呼吸防护用品的选择策略.本研究可为建立个体防护对策的选择方法提供基础数据和参考.     

上海市滨岸带沉积物中酸挥发性硫化物垂直分布及空间变化特征

对上海市滨岸带(北起浏河口,南至杭州湾的金丝娘桥)18个柱状沉积物中酸挥发性硫化物(AVS)质量分数及其垂直分布特征进行了研究. 结果表明:沉积物中w(AVS)为0.38～317.60 mg/kg,底层沉积物中w(AVS)平均值最高,是表层和中层的2倍左右. 各采样点沉积物中底层w(AVS)空间变化差异最大,表层w(AVS)变化较小. 人类活动干扰(滨岸带围垦、工业排污和生活排污和畜禽养殖等)显著改变了潮滩原有的自然环境特征〔w(有机碳)、含水率、粒度组成以及氧化还原电位等〕,可能成为控制上海市滨岸带沉积物中w(AVS)空间变化差异的决定性因素.      

Variation along the shy–bold continuum in extremophile fishes (<Emphasis Type="BoldItalic">Poecilia mexicana</Emphasis>, <Emphasis Type="BoldItalic">Poecilia sulphuraria</Emphasis>)

One potential trade-off that bold individuals face is between increased predation risks and gains in resources. Individuals experiencing high predation and hungry individuals (or individuals with low body condition) are predicted to show increased boldness. We examined one behavioral trait previously reported to be associated with boldness (the time individual fish needed to emerge from shelter) in various populations of mollies (Poecilia spp.). Our study system included several southern Mexican surface streams with high piscine predation and high food availability, sulfidic surface streams with high avian predation, in which the inhabiting fish show reduced body condition, and a sulfidic cave, where predation and body condition are low. Our comparison revealed very short times to emerge from the start box in populations from non-sulfidic streams. In sulfidic habitats (whether surface or cave), it took individual Poecilia mexicana considerably longer to emerge from the start box, and the same difference was also found in an independent comparison between P. mexicana and the closely related, highly sulfide-adapted Poecilia sulphuraria. Fish reared under common garden conditions (in the absence of predators and hydrogen sulfide) showed intermediate boldness scores to the extremes observed in the field. Our data thus indicate that (a) boldness is shaped by environmental conditions/experiential effects, but is not heritable, (b) predation affects boldness in the predicted direction, but (c) low body condition leads to reduced boldness. Extremophile Poecilia spp. spend most of their time surfacing to survive under sulfidic and hypoxic conditions, which exposes them to increased levels of predations, but the fish forage on the bottom. Hence, in this system, increased boldness does not increase foraging success. We argue that energy limitation favors reducing energetically costly behaviors, and exploring novel environments may be just one of them.     

城市生活垃圾有机组分厌氧发酵产氢和甲烷

为了提高能源回收效率,采用大米、土豆、生菜、瘦肉、花生油和榕树叶作为实验原料,模拟有机垃圾中普遍存在的淀粉、膳食纤维、蛋白质、脂肪和木质纤维类成分,进行厌氧发酵产氢以及对其剩余物厌氧发酵产甲烷.结果表明.在厌氧发酵产氢阶段,整个过程没有甲烷生成,大米、土豆、生菜、瘦肉、花生油和榕树叶的氢气产率分别为125、103、35、0、5和0 mL g-1(VS),能源回收效率分别为7.9%、6.8%、1.9%、0、0.1%和0.大米、土豆和生菜的氢气浓度分别为34%～59%、41%～56%和37%～70%,整个产氢阶段没有甲烷生成.在厌氧发酵产甲烷阶段,上述原料的甲烷产率分别为232、237、148、278、866和50 mL g-1(VS),生物气中甲烷含量分别为42%～70%、57%～71%、73%～77%、59%～73%、68%～80%和54%～74%.厌氧发酵联产氢气和甲烷整个过程上述原料的能源回收效率分别为56.3%、58.4%、28.8%、39.2%、81.2%和8.8%,总COD去除率分别为72.30%、81.70%、32.63%、47.59%、97.46%和11.29%.图4表5参35     

磁赤铁矿/多羧基有机酸体系中五氯酚的异相光化学降解

自然界广泛存在的铁氧化物与多羧基有机酸在光照条件下能够由内源自身生成活性物过氧化氢,构成异相类Fenton体系降解污染物.在实验室构建了由磁赤铁矿和多羧基有机酸组成的光化学体系,研究了五氯酚在此体系中的降解和脱氯.结果表明,五氯酚在此异相光化学体系中的降解效率受波长范围、有机酸种类和氧气的显著影响.在UV-A波长范围,五氯酚具有较高的光降解效率.草酸能够显著促进五氯酚在磁赤铁矿中的异相光降解,但柠檬酸不具有此作用.氧气是体系中生成各种含氧活性物的必要条件.五氯酚在此体系中的降解遵循一级反应动力学.最佳实验条件下,五氯酚1 h的降解率可达80%以上,脱氯率可达35%以上.对体系主要活性物过氧化氧的定量研究较好的解释了体系在各种条件下的活性差异.     

Effects of nitrate concentration on biological hydrogen production by mixed cultures

The effects of nitrate on fermentative hydrogen production and soluble metabolites from mixed cultures were investigated by varying nitrate concentrations from 0 to 10 g N/L at 35°C with an initial pH of 7.0. The results showed that the substrate degradation rate, hydrogen production potential, hydrogen yield, and average hydrogen production rate initially increased with increasing nitrate concentrations from 0 to 0.1 g N/L, while they decreased with increasing nitrate concentrations from 0.1 to 10 g N/L. The maximum hydrogen production potential of 305.0 mL, maximum hydrogen yield of 313.1 mL/g glucose, and maximum average hydrogen production rate of 13.3 mL/h were obtained at a nitrate concentration of 0.1 g N/L. The soluble metabolites produced by the mixed cultures contained only ethanol and acetic acid (HAc) without propionic acid (HPr) and butyric acid (HBu). This study used the Modified Logistic model to describe the progress of cumulative hydrogen production in batch tests. A concise model was proposed to describe the effects of nitrate concentration on average hydrogen production rate.     

过渡金属负载γ-Al2O3对HCN催化水解性能的影响

为高效催化水解净化废气中的HCN,采用等体积浸渍法改性γ-Al₂O₃制备HCN水解催化剂,考察不同金属组分及其负载量对HCN催化水解效率的影响. 结果表明:不同金属对HCN的催化水解活性依次为Cu>Cr>Fe>Zn>Ni>Co,Cu/γ-Al₂O₃系催化剂中Cu的最佳负载量为15.0%,添加1.0%的Ni有助于增加该催化剂对HCN的催化水解性能. 空速为18 000 h-1时,Cu/Ni/γ-Al₂O₃型催化剂在6 h内净化效率均能保持在91%以上,尾气中ρ(NH₃)为16.6 mg/m3. 采用X线衍射(XRD)、扫描电镜与能量色谱(SEM/EDS)、N₂物理吸附(N₂-BET)对Cu/Ni/γ-Al₂O₃系催化剂表征可知,CuO是Cu/Ni/γ-Al₂O₃系催化剂的主要活性成分,与未改性γ-Al₂O₃相比,Cu、Ni改性后催化剂微孔和中孔(孔宽为1.7~15.0 nm)的孔体积有所降低,其中直径较小的中孔对HCN的催化水解起主导作用.      

基于HPR在线监测控制SBR曝气历时实现短程脱氮

应用新型自动呼吸-滴定测量仪在线测量pH值、HPR等信号,进行了在SBR内实现短程脱氮的研究.采用SBR处理人工合成废水,COD和NH4+-N浓度分别为360,40mg/L,温度稳定在20℃,DO低于2mg/L,基于HPR在线监测控制SBR曝气历时.运行约60d后,亚硝酸盐积累率达到88%,COD和NH4+-N去除率均在90%以上,稳定实现了短程硝化反硝化.应用HPR估计硝化过程的NH4+-N浓度发现,NH4+-N实测值与基于HPR的计算值间存在良好的线性关系,相关系数为0.9722;计算值整体低于实测值,主要是由曝气初期的滴定启动滞后所致.