FTIR在环境毒理学研究中的应用

傅里叶变换红外光谱(FTIR)作为一种常用化学分析方法,与多元统计分析方法相结合,可以识别生物分子的变化情况.红外光谱具有操作简单、快速、灵敏、样品无损等特点,逐渐在环境监测和污染物毒性效应方面被广泛应用.通过研究生物体受到外界胁迫时生物大分子在结构上的变化情况,可从分子水平揭示污染物的毒性效应及其毒性机制.笔者从FT...     

无汞污染的水柱型大气压强计

提出一种小尺寸（１．２ｍ）的水柱型大气压强计,解决了生产和使用水银柱大气压强计时产生的汞污染环境问题,讨论水柱大气压强计的工作原理和使用方法,分析测量误差,简述应用中的若干问题,文中给出的压强计在海拔的０－３ｋｍ,环境温度为６－４０℃范围使,测量结果的标准误差小于±０．９ｍｍＨｇ,能分辨±０．１ｍｍＨｇ的大气压强变化,适用于环境温度变化不大的室内大气压强测定。由于水的饱和蒸气压随环境温度的较大变化     

城市污水处理厂的自动控制设计要点

通过一个城市污水处理厂自动控制系统的选取与设汁过程作为实例,说明了可编程逻辑控制器(PLC)自动控制方案是当今城市污水处理厂的最佳选择。论文对PLC自动控制方案的设计过程提出了详细的指导,将基于PLC的生产过程自动化与办公自动化进行了有机结合,为大型污水处理厂自动化控制设计提供了极重要的借鉴。     

燃煤锅炉烟气净化系统风机带水原因及对策研究

分析讨论了冲击水浴式和旋风水膜式燃煤烟气除尘脱硫系统产生风机带水的主要原因 ,研制开发了密闭式水位控制箱和锯齿形溢水槽 ,通过工程实践 ,能有效解决除尘系统引风机带水问题。     

某制药废水处理工艺运行分析

简要介绍了某化学合成制药废水处理工艺流程和主要运行参数,通过采集现场数据和SBR小试试验对其进行了分析。运行数据表明:现有工艺COD去除率68.9%,其中一级好氧去除62.6%,水解CASS组合去除6.3%;后续水解酸化对废水的可生化性没有改善,导致其和CASS的组合COD去除效果不佳,效费比低。温度对该工艺有重要影响,夏季水温可达43℃,严重影响出水水质。SBR小试结果表明:2%以下的盐度及其他可能基于浓度抑制的物质对好氧生化过程的COD去除没有影响,进一步对废水进行稀释没有意义。SBR小试以不到实际工艺一半的HRT,取得了明显优于后者的出水,意味着实际工艺有较大的改善潜力。     

硝酸铵与硝铵磷热稳定性对比研究

为了研究硝铵磷的热稳定性,用DSC－TG同步热分析仪测试了硝酸铵的热分解过程,根据升温速率分别为5,10,15 K／min的DSC和TG－DTG曲线,利用Ozawa法和Kissinger法求得的硝酸铵的活化能基本一致。用Rogers公式和Arrhenius公式求得指前因子和速率常数分别为1．62×1010 s－1,1．07×10－18 s－1（120℃）;硝酸铵在升温速率为5 K／min时,分解峰值温度的活化焓、活化熵、活化自由能分别为102．76 kJ／mol ,－62．35 J／（K·mol ）,134．98 kJ／mol;对比了硝酸铵和硝铵磷的DSC曲线,结果表明硝铵磷的吸热分解峰值温度低于硝酸铵,热稳定性更好。     

Foliar uptake and metal(loid) bioaccessibility in vegetables exposed to particulate matter

At the global scale, high concentrations of particulate matter (PM) enriched with metal(loid)s are currently observed in the atmosphere of urban areas. Foliar lead uptake was demonstrated for vegetables exposed to airborne PM. Our main objective here was to highlight the health risk associated with the consumption of vegetables exposed to foliar deposits of PM enriched with the various metal(loid)s frequently observed in the atmosphere of urban areas (Cd, Sb, Zn and Pb). Leaves of mature cabbage and spinach were exposed to manufactured mono-metallic oxide particles (CdO, Sb₂O₃ and ZnO) or to complex process PM mainly enriched with lead. Total and bioaccessible metal(loid) concentrations were then measured for polluted vegetables and the various PM used as sources. Finally, scanning electronic microscopy coupled with energy dispersive X-ray microanalysis was used to study PM–phyllosphere interactions. High quantities of Cd, Sb, Zn and Pb were taken up by the plant leaves. These levels depended on both the plant species and nature of the PM, highlighting the interest of acquiring data for different plants and sources of exposure in order to better identify and manage health risks. A maximum of 2 % of the leaf surfaces were covered with the PM. However, particles appeared to be enriched in stomatal openings, with up to 12 % of their area occupied. Metal(loid) bioaccessibility was significantly higher for vegetables compared to PM sources, certainly due to chemical speciation changes. Taken together, these results confirm the importance of taking atmospheric PM into account when assessing the health risks associated with ingestion of vegetables grown in urban vegetable crops or kitchen gardens.     

Sustainability of urban drainage management: a perspective on infrastructure resilience and thresholds

Urban wastewater infrastructures have been threatened by natural and socioeconomic disturbances. This study investigates infrastructure resilience against the risks of long-term changes rather than natural disasters. Urban expansion that leads to an increased urban runoff and massive population movements that cause fluctuations in domestic emissions are considered in this study. Pollution permits for water bodies are adopted as constraints on wastewater infrastructures. A land use-based accounting method, combined with a grid-based database, is developed to map domestic discharge and urban runoff to service areas of wastewater treatment plants. The results of a case study on downtown Sanya, the most famous seashore tourist attraction in China, show that the average resilient values of three sub-catchment areas in 2010 were -0.57, 0.10 and 0.27, respectively, a significant spatial variation. The infrastructure in the Sanya River sub-region is the least flexible, and is more likely to fail due to unstable inflows. The resiliencies will increase to 0.59, 1.01 and 0.54, respectively, in 2020, a considerable improvement in robustness. The study suggests that infrastructure resilience needs to be taken into further consideration for urban planning and the related realm of urban governance to foster more robust wastewater management under various risks.     

不同硬度条件下Cd~(2+)和Cu~(2+)对稀有鮈鲫的急性毒性

为研究水体硬度对稀有鮈鲫Cd~(2+)和Cu~(2+)毒性效应的影响,开展了96 h急性毒性试验。试验结果发现,当水体硬度(以CaCO_3计,下同)为50 mg·L~(-1)、250 mg·L~(-1)、450 mg·L~(-1)时,Cd~(2+)对稀有鮈鲫的96 h半数致死浓度(96 h-LC50)分别为4.30 mg·L-1、12.06 mg·L~(-1)、19.99 mg·L~(-1),对应的安全浓度(SC)依次为0.430 mg·L~(-1)、1.206 mg·L~(-1)、1.999 mg·L~(-1);Cu~(2+)对稀有鮈鲫的96h-LC50分别为0.046 mg·L-1、0.148 mg·L~(-1)、0.228 mg·L~(-1),对应的SC依次为0.0046 mg·L~(-1)、0.0148 mg·L~(-1)、0.0228 mg·L~(-1)。计算得到Cd~(2+)对稀有鮈鲫急性毒性与水体硬度的拟合方程为ln 96 h-LC50=0.687 ln H~(-1).243(r=0.998);Cu~(2+)对稀有鮈鲫急性毒性与水体硬度的拟合方程为ln 96 h-LC50=0.727 ln H-5.923(r=0.999),Cd~(2+)和Cu~(2+)对稀有鮈鲫的硬度斜率分别为0.687和0.727。这些结果表明,水体硬度可有效降低Cd~(2+)和Cu~(2+)对稀有鮈鲫的急性毒性,且稀有鮈鲫的硬度斜率与其他物种差异较大。在评估不同硬度水体下Cd~(2+)和Cu~(2+)的生物毒性及其生态风险时,应根据测试物种特异的硬度斜率而定。     

进水中碳水化合物分子大小对污泥沉降性能的影响

为弄清楚碳水化合物分子大小和污泥沉降性能之间的影响关系,在3个序批式系统中,分别以颗粒型淀粉、溶解型淀粉和葡萄糖为碳源,考察了长期运行中系统的污泥沉降性能和处理能力.结果证明:碳水化合物分子越小,活性污泥对环境的变化越敏感,当运行条件不利时越容易引发污泥膨胀问题;大分子碳源吸附于絮体内部能够提高污泥的沉降性能;糖类作碳源时,活性污泥的PHA贮存量约为0.6mmol C/L,但系统SVI仍然能够维持在150mL/g以下;胞外聚合物中多糖与蛋白质(C/P)的比值与污泥的SVI呈正相关性,SVI从100mL/g增长到600mL/g,C/P比从0.248增长到1.201;以颗粒型淀粉、溶解型淀粉和葡萄糖为碳源时,系统的优势丝状菌分别为Type 0041、M. parvicella和S. natans;进水以葡萄糖作单一碳源时,系统的除磷能力能达到80%以上.