Environmental and economic comparison of waste solvent treatment options

The sustainable development and consumption need more efficient use of natural resources. As a consequence, the use of industrial solvents demands their recovery instead of end-of-pipe treatment. It is not always clear, however, which treatment alternative should be applied. Based on an industrial case study, the environmental and economic evaluation and comparison of the treatment alternatives of a non-ideal solvent mixture containing azeotropes is investigated for determining the preferable option. For the recovery of the industrial solvent mixture, two different separation alternatives are evaluated: a less effective alternative and a novel design based on hybrid separation tools. An end-of-pipe treatment alternative, incineration, is also considered and the split of the solvent mixtures between recovery and incineration is investigated. The environmental evaluation of the alternatives is carried out using ‘Eco-indicator 99 life-cycle impact assessment methodology’. Economic investigation is also accomplished. The economic features clearly favour the total recovery, however, the environmental evaluation detects that if a recovery process of low efficiency is applied, its environmental burden can be similar or even higher than that of the incineration. This motivates engineers to design more effective recovery processes and reconsider the evaluation of process alternatives at environmental decision making.     

微量元素锌在治疗Bell麻痹中的作用

为探讨急性早期应用补锌和综合疗法治疗Bell麻痹 ,将 1 5 8例Bell麻痹患者 ,随机分成两组 :(1 )补锌组 (补锌 +综合疗法 ) ;(2 )对照组 (单纯综合疗法 )。对其进行了观察对比治疗 ,同时检测了所有患者治疗前后自身对照发锌值 ,还对所有患者进行了定位诊断、面神经电反应测试、并对面肌功能进行评分。结果表明 ,对定位诊断其病变在D段、面肌功能评分在 1 1分以下、面神经无电反应患者 ,即使给予早期综合治疗 ,效果仍较差 ,而早期给予补锌加综合治疗效果优于对照组 ,其它段内患者治疗次数和治愈天数也均优于对照组。可见微量元素锌在发挥免疫应答、免疫调控中的重要作用     

Surface characterization of cellulose fibres by XPS and inverse gas chromatography

Inverse gas chromatography (IGC) was used to determine the dispersive component of the free energy as well as the acid-base properties of cellulose fibre surfaces, before and after modification by corona treatment. It was found that the corona treatment increases both the dispersive contribution to surface energy and its acidic character, whereas only a slight increase in its basicity was observed. It was also found that some chemical degradation of the surface occurs at high corona currents. The extent of modification of the surface properties, as revealed by IGC, was correlated to the surface chemical composition deduced from XPS analysis as well as with the electrical conductance and the pH of the water suspensions of the cellulose fibres.     

Determination of heavy metal concentration in feed and permeate streams of polymer enhanced ultrafiltration process

Polymer enhanced ultrafiltration (PEUF) is a newly developed method for the removal of heavy metals from aqueous solutions. This method was applied for the removal of mercury and cadmium with the presence of polyethyleneimine (PEI) as a water soluble polymer. After ultrafiltration experiments for metal–polymer mixtures, two separate streams, namely, retentate and permeate, former of which contains mainly metal–polymer complex and free polymer molecules while latter of which mainly contains free metal ions, were obtained. At the end of PEUF experiments, performance of operation was determined by concentration analyses which was achieved by atomic absorption spectroscopy (AAS) applied in a different way for permeate and retentate streams considering the effect of presence of polymer. For mercury analysis, cold vapor AAS was applied. It was observed that the presence of PEI did not affect the atomic absorption signal when 10% HCl was added to the sample solutions. For calcium and cadmium, flame AAS was used. It was observed that change in PEI concentration results in change in measured concentration of calcium and cadmium. Therefore, two new approaches were developed for accurate measurement of concentrations of calcium and cadmium. It was also observed that presence of other metals did not affect the accuracy of the measurement of a particular metal in the concentration range studied.     

笼形聚偕胺肟树脂的研究—酚处理对树脂吸附贵金属性能的影响

研究了笼形聚偕胺肟树脂（CAO）和酸式（ACAO）及碱式（BCAO）树脂对于苯酚、对-氨基酚、对-硝基酚、对-甲氨基酚和对-苯二酚的吸附和吸留作用，测定了酚处理树脂的中和当量。它反映了笼形树脂吸留外来物的特性。酚处理树脂有效地吸附Ag 、AuCl4－、PtCl62-、PdCl42-和IrCl62-等贵金属离子，吸附方式似乎与溶液的pH值有关。SEM观察表明，Ag 、Au－Cl4-和IrCl62-离子在吸附过程中被还原为零价态，在树脂表面生成形态各异的结晶。     

检测易爆气体的催化发光传感器研究

报道了一种用于定量分析易爆气体混合物丙烷和异丁烷的基于碳酸锶纳米材料的催化发光传感器。基于该传感器在不同温度下对两种气体的灵敏度不同，在320℃和342℃两个工作温度下，两种气体的浓度范围均为1000mL／m^3～10000mL／m^3时，分别建立了混合组分浓度相对催化发光强度的两个线性回归方程。在342℃时，丙烷和异丁烷的检出限（3σ）分别为50mL／m^3和20mL/m^3。可通过解上述两个联立方程式求得未知混合物中两组分的浓度。外来物质甲烷、乙烷、CO、氨气通过传感器时，甲烷和乙烷分别引起5．6％和17．2％的干扰，其它气体不干扰测定。20000mL／m^3的水蒸气不干扰2000mL／m^3丙烷和异丁烷气体的测定。用该法分析了人工合成样品中两种气体的浓度。     

热处理对Co(Ni)-Mo/Al2O3催化剂加氢脱硫活性的影响

介绍了硫化Ｃｏ－Ｍｏ／Ａｌ２Ｏ３催化剂的热处理方法及其结果。实验表明，硫化催化剂经热处理后，加氢脱硫活性明显增加，以塞吩转化率表示的催化活性随处理温度升高而变化，在４５０℃时观察到催化活性的极大值。     

Interaction of long chain alkylammonium cations with reduced charge montmorillonite

Reduced charge montmorillonites (RCM) were prepared using lithium thermal treatment. The sorption of octylammonium (OA), dodecylammonium (DDA) and hexadecylammonium ions (HDA) on differently charged samples were studied. The amounts of DDA and HDA sorbed on each RCM exceed the cation exchange capacity (CEC) but that of OA exceeds only the CEC of samples with the lowest CEC. The sorption is affected not only by the layer charge but also by the formation of collapsed interlayer spaces in the lowest charged montmorillonites. X-ray measurements confirmed the decrease of the layer charge after lithium thermal treatment and the layer charge heterogeneity in RCMs.     

大孔吸附树脂处理含磺胺废水的研究

利用大孔吸附树脂处理含磺胺废水。实验表明，DRHⅢ树脂对磺胺具有良好的吸附－解吸效果。原废水中磺胺浓度约为17.2g/L,COD约为13750mg/L，经树脂吸附处理后，废水中COD去除率约86％，磺胺的吸附率88．2％，树脂的解吸率为97．5％，磺胺的回收率约86．0％，其纯度达99．8％。在废水有效处理的同时实现了废物资源化，具有良好的环境效益和较高的经济效益。     

笼形聚偕胺肟树脂的研究─—H_2PtCl_6在酸处理树脂上的吸附过程

H2PtCl6可被一系列的酸处理定形聚偕胺肟树脂所吸附，吸附容量的大小与处理树脂的质子酸的Pka值有关．认为是解高度低的酸所处理的树脂上的伯胺基成盐的机会较少，即树脂的吸附中心保留着较多的空穴，有利于H2PtCl6的接近而被吸附下来．吸附动力学的研究表明化学反应是吸附速度的控制因素。