Ti/BDD/PbO_2复合电极在化学需氧量测定中的应用

以钛基掺硼金刚石为基体,采用电沉积的方法制备了Ti/BDD/PbO2复合电极,并将其用于化学需氧量（COD）的测定。采用扫描电子显微镜（SEM）和X射线衍射谱图（XRD）表征了电极的微观形貌及结构,采用电化学工作站考察了电极对有机物响应特性。实验结果表明,在1.45 V的低电位条件下,线性范围为0.5～175 mg/L,检测限为0.3 mg/L（S/N=3）。采用Ti/BDD/PbO2复合电极测定法和重铬酸钾标准方法对市政污水、食品废水及印染废水的对比结果表明,2种方法的相对误差小于10%,具有良好的一致性。     

Adsorption characteristics and mechanism of Cr （Ⅵ） on chitoan-yttrium porous microsphere

以壳聚糖和Y2（OH）5NO3为原料通过乳液交联法制备了壳聚糖-钇（Ch—Y）复合微球,通过扫描电镜、透射电镜、X射线衍射、红外光谱等方法对其表面形貌、结构进行了表征.探讨了溶液的pH值、反应时间、投加量、离子初始浓度对其吸附性能的影响.研究结果表明,壳聚糖-钇（Ch—Y）复合微球在pH值为3的酸性环境中对Cr（Ⅵ）保持了较高的吸附能力,吸附容量为52.39mg·g-1,其吸附行为符合Langmuir吸附等温模型;通过吸附机理的研究,发现壳聚糖-钇（Ch—Y）对Cr（Ⅵ）吸附是化学吸附静电吸附协同氧化Cr（Ⅵ）离子作用来实现的.     

CF8611/AC531复合材料的实验室加速老化行为研究

目的获得CFRP的老化行为规律,研究紫外辐照、温度和湿度等环境因素的影响,方法以湿热效应和光氧老化的等量、等效损伤为原则,确定实验室加速老化环境谱编制方法。以CF8611/AC531复合材料为对象,依据确定的加速老化试验方案,开展加速老化试验,观察其微观形貌,并测量开路电位和动电位极化曲线。结果老化前,CFRP表面完整无裂纹,碳纤维/树脂界面结合良好;老化后,树脂基体出现裂纹和孔洞,同时界面遭到破坏。极化曲线随着老化时间的增长会向右下方移动,自腐蚀电位微降,幅度为0.0326 V,自腐蚀电流密度增长了近1621倍。结论加速老化导致表面碳纤维裸露面积不断增大,时间越长,破坏作用越明显,实际使用中应防止其与金属直接接触。     

低浓度CO2在聚苯胺/Y分子筛复合材料上的吸附

根据原位聚合方法将不同量的苯胺分别聚合在Y分子筛上,得到3种聚苯胺(PANI)/Y分子筛复合材料PANI-Y~(-1)、PANI-Y-2及PANI-Y-3,用傅立叶红外及氮气吸附实验表征了材料的结构特征,探讨了复合材料对常压下低浓度CO_2的吸附及再生性能.结果表明,苯胺在Y分子筛上成功聚合,复合材料的比表面积分别为52、54和35 m2·g~(-1),孔道由大孔和少量中孔组成,微孔极少.PANI负载量越大,材料的孔容越低.20℃下,初始体积分数为10%的CO_2在复合材料与Y分子筛上的吸附符合Logistic模型,吸附量的顺序为PANI-Y-2(2.09 mmol·g~(-1))PANI-Y-3(1.79 mmol·g~(-1))PANI-Y~(-1)(1.07 mmol·g~(-1))Y分子筛(0.80 mmol·g~(-1)),复合材料对CO_2的吸附受PANI负载量和比表面积的共同影响.在2%~10%的范围内,CO_2在复合材料上的吸附量随初始体积分数增加而增加;在25~65℃下,吸附量随温度升高而降低.80℃下,PANI-Y-2的4次热再生效率较差,仅68%;采用氨水/热再生相结合的方式脱附CO_2,再生率提高到94%.     

原水性质对新型含Ca2+复合混凝剂混凝过程的影响

为了提高水处理效率,保证出水水质,需要开发新型高效混凝剂.本实验采用经过Ca2+改性的混凝剂针对不同水样进行混凝实验,考察了浊度、有机物去除、余铝和形成絮体性质.结果表明在纯颗粒物体系中,PACl(聚合氯化铝)和Al Cl3中加入的Ca2+对于浊度去除率无明显影响,在低投加量下能够有效降低沉后水中余铝浓度,Al Cl3做混凝剂,投加量0.10mmol·L~(-1)时,沉后水余铝浓度从0.15 mg·L~(-1)降低到0.10 mg·L~(-1).在腐殖酸体系中,混凝剂中的钙离子可明显降低腐殖酸分子的负电荷,降低沉后水余铝浓度以及增大絮体粒径.对于腐殖酸与蛋白质体系,当投加量为0.16 mmol·L~(-1)时,使用含有Ca2+的PACl做混凝剂时,钙离子的存在使得平衡时絮体粒径增加了大约50μm,可明显改善絮体的沉降性.碱性条件(pH=8.5)下改性混凝剂沉后水中DOC浓度降低0.2~0.6 mg·L~(-1),余铝降低0.4~0.7 mg·L~(-1).酸性条件(pH=5.5)下改性混凝剂沉后水DOC、余铝浓度无明显变化.     

Recent advances in thin film composites membranes for brackish groundwater treatment with critical focus on Saskatchewan water sources

Drinking water scarcity is an ever-increasing global concern. This issue appears as a greater threat to the countries with no access to sea water resources or rivers, since their potential water resources are only limited to ground waters only. There are serious concerns with the treatment of ground water resources, including landfill leachates, agricultural contaminations (pesticides, herbicides, and fertilizers), and rural contaminations. Membrane separation has been proved to be the governing technology in water and wastewater treatment plants, as these methods are responsible for more than half of the market share of the world's desalination capacity. This study intends to offer a holistic view of the groundwater contamination with specific focus on Saskatchewan province in Canada, and the recent efforts in the groundwater treatment using thin film composite membrane technology. This study begins with an introduction of the general aspects of ground water and membrane separation, polluting agents, and their sources. It is followed by a discussion of Saskatchewan's groundwater status and various issues. Furthermore, the recent research that became available since 2010 is reviewed in details and the results are summarized with respect to purification efficiency. Different affecting parameters in a groundwater-thin film composite system are synthesized and an in-depth overview is presented.     

“Measuring Sustainability”: A Multi-Criterion Framework

So far, the elementary question of whether one country’s or region’s economy is moving towards sustainability or away from it cannot be answered with unanimous consensus on the ‘measuring rod(s)’ to be employed. The main assumption of this article is that sustainability assessment needs a set of multi-dimensional indicators. From this assumption a question arises: how could such indicators be aggregated? Often, some indicators improve while others deteriorate. For instance, when incomes grow, SO₂ might go down while CO₂ increases. It has to be noted that this is the classical conflictual situation studied in multi-criteria decision theory. The use of a multi-criterion framework for making operational the ‘measuring of sustainability’ is discussed here by means of illustrative examples and more formal arguments.     

土壤和沉积物中重金属积累及其Pb、S同位素示踪

对榨子厂附近一个废弃多年的古老土法炼锌点土壤和沉积物中重金属的积累及污染程度进行了研究。研究区土壤、沉积物样品中Pb、Zn、Cd含量已大大高于该地区的背景值,zn的积累明显大于Pb的积累程度。相关分析表明,土壤和沉积物中Fe2O3对重金属有强烈的固定作用。沉积物和土壤中有很高的综合污染指数,显示出重金属的污染程度很高。化学形态分析表明重金属以碳酸盐结合态、残渣态和铁锰氧化物结合态为主,有效态所占的比例很低,但其含量并不很低,在酸性条件下,有释放导致污染的可能性。同位素示踪结果显示,研究区土壤和沉积物中积累的Pb、S为矿山物质来源。     

考虑过渡区影响的粉喷桩复合地基承载特性的有限元数值分析

粉喷桩成桩过程中不可避免地会带动桩间土产生强烈的挤压和振动,在固化剂与桩体发生物理化学反应的同时,桩周一定范围内的土体也进行了固化和挤密,使得在桩土交界处形成环向变化的过渡区,过渡区的材料由桩逐渐过渡到桩间土,因此有必要考虑该过渡区对粉喷桩复合地基承载特性的影响。本文从粉喷桩复合地基桩土交界处的特点出发,考虑了桩土材料性质变化的过渡区单元,利用上的摩尔—库仑本构模型,和Plaxis专业岩土软件对粉喷桩复合地基进行了有限元数值分析,就粉喷桩复合地基中桩和土的承载特性得出了一些有益的结论。     

CS/PEG/PFT膜制备及对含铜废水的处理

实验将溶胶凝胶法和高分子辅助倒相法结合,制备出一种新型的壳聚糖/聚乙二醇/亚铁氰化钾钛(CS/PEG/PFT)复合膜,通过FT-IR和SEM对膜进行表征后,将其用于模拟铜废水的吸附和脱附实验,并探究出膜吸附的最佳工艺条件为:p H 5.50、实验温度55℃、实验时间2 h,该条件下,膜对铜离子最大吸附量为9.85 mg/g,去除率达到95%以上。CS/PEG/PFT膜的除铜过程符合Langmuir等温吸附方程(y=0.0597x+0.0168),线性相关度达到0.9917。