壳聚糖复合絮凝剂处理含油废水

壳聚糖复合絮凝剂处理含油废水,正交实验结果分析表明：pH值为7,PAM量为2mg／L,壳聚糖量为2mg／L时,对废水化学耗氧量（COD）去除率可达47．33％;pH值为7.PAM量为1mg／L,壳聚糖量为8mg/L时,对废水浊度处理得到较为满意的效果,浊度去除率可达91．73％。对浊度和COD去除率的影响因素主次顺序是：pH值〉PAM投加量〉搅拌时间〉壳聚糖投加量。     

阳离子型天然高分子改性絮凝剂的合成及其絮凝效果研究

本研究主要以丙烯酰胺和天然淀粉为原料，进行接枝共聚及阳离子化，合成阳离子型天然高分子改性絮凝剂。正交试验研究表明丙稀酰胺浓度为7．108g／100mL，引发剂浓度为0．30g／50mL，温度为30～40℃时，接枝物产率高于60％。以高岭土悬浊液为处理体系，结果为投加量14mL／L时即有理想的絮凝除浊效果。对城市污水絮凝实验表明，浊度去除率最高达90％左右，COD去除率在80．0％以上。     

强化絮凝一生物接触氧化处理电子酸洗废水

采用强化絮凝和生化试验,确定了废水处理最佳工艺流程,研究了药剂种类、加药量对COD去除率的影响。结果表明,氧化絮凝剂对该有机废水有较好的净化效果,对生化处理具有促进作用,当氧化絮凝剂投加量150mg／L,停留时间7h时,系统进水COD为1500mg／L,经强化絮凝、两级好氧处理后,出水COD〈100mg／L,总去除率〉94％,达到了工业废水排放标准。     

气动絮凝用于城镇污染河水处理的试验研究

在设定的絮凝条件下,以小城镇典型污染河水为研究对象,聚合氯化铁铝(PFAC)和聚丙烯酰胺(PAM)为试验药剂,COD、浊度、总磷和溶解氧为测定指标,进行了气动絮凝试验。结果表明,以微孔曝气头充气,当混合充气量、第1格絮凝充气量和第2格絮凝充气量分别达到160、130、56 L·h-1时,COD、浊度和总磷的去除率分别为68·9%、93.6%和72.4%;以孔径2 mm穿孔管充气,当混合充气量、第1格絮凝充气量和第2格絮凝充气量分别达到220、180、76 L·h-1时,COD、浊度和总磷的去处理率分别为67.6%、92.7%和68.0%。在保证处理效果的前提下,2种充气方式均能使沉淀池出水的溶解氧含量达到2 mg·L-1左右。     

一种新型景观水体絮凝剂的研究

文章研究了用无机絮凝剂硫酸铝、聚丙烯酰胺（PAM）和天然高分子絮凝剂壳聚糖（CTS）进行复配对景观水体的处理效果。实验结果表明：在硫酸铝、聚丙烯酰胺和壳聚糖投加量分别为99.5 mg/L、2.0 mg/L和2.0 mg/L时,絮凝效果最佳,CODCr和浊度的去除率可分别达67.4%与91.0%,与传统的Al2（SO4）3-PAM絮凝剂相比,CODCr和浊度的去除率分别提高了13.8%和4.7%,而且大大减轻了硫酸铝和聚丙烯酰胺对环境的二次污染,具有明显的环境效益。     

壳聚糖及其衍生物对生活污水的处理性能研究

生活污水用壳聚糖及其衍生物CTS、CMC、HACC、QCMC以及阳离子聚丙烯酰胺(CPAM)处理,考察絮凝剂的投加量、体系pH、温度对浊度和COD去除率的影响。结果表明,絮凝效果依次为:QCMC>HACC>CMC>CTS>CPAM,各絮凝剂使用的最佳条件为,CMC、HACC和QCMC投加量为8 mg/L,水体pH为6,水温在40℃时,浊度去除率为99.2%,COD去除率为76.5%。羧甲基壳聚糖季铵盐(QCMC)与聚合硫酸铁(PFS)复配比例m(QCMC)∶m(PFS)=1∶5,水温30℃,pH为6,投加量为6 mg/L时,COD去除率99.9%,浊度去除率95.8%,效果最佳。与单剂使用相比,絮凝剂投加量减少,COD去除率提高了0.7%,浊度去除率提高了25.2%。     

壳聚糖及其衍生物对生活污水的处理性能研究

生活污水用壳聚糖及其衍生物CTS、CMC、HACC、QCMC以及阳离子聚丙烯酰胺(CPAM)处理,考察絮凝剂的投加量、体系pH、温度对浊度和COD去除率的影响。结果表明,絮凝效果依次为:QCMC>HACC>CMC>CTS>CPAM,各絮凝剂使用的最佳条件为,CMC、HACC和QCMC投加量为8 mg/L,水体pH为6,水温在40℃时,浊度去除率为99.2%,COD去除率为76.5%。羧甲基壳聚糖季铵盐(QCMC)与聚合硫酸铁(PFS)复配比例m(QCMC)∶m(PFS)=1∶5,水温30℃,pH为6,投加量为6 mg/L时,COD去除率99.9%,浊度去除率95.8%,效果最佳。与单剂使用相比,絮凝剂投加量减少,COD去除率提高了0.7%,浊度去除率提高了25.2%。     

壳聚糖接枝三元共聚阳离子絮凝剂对高岭土悬浊液的絮凝特性

采用烧杯混凝实验研究了壳聚糖（CTS）、CTS与丙烯酰胺和丙烯酸乙酯季铵盐三元接枝共聚阳离子絮凝剂（CAS）对高岭土悬浊液的絮凝特性。结果表明,CAS具有比CTS絮凝效果好、用量少、pH适用范围广等优点。CAS絮凝效能受胶体颗粒性质影响小,对自来水和蒸馏水配置的高岭土悬浊液均具有较好的絮凝效能。中性条件下,CAS最佳投加量仅为CTS的1／10。在pH2．0-11．10范围内,CAA对浊度的去除率在95％。CAS投加量与原水浊度的关系为：投加量低于0．5mg／L时,絮凝效果随原水浊度的升高降低：     

PAFC-PAM复配对铅酸蓄电池废水的处理研究

采用高分子絮凝剂(PAFC和PAM)对佛山市某铅酸蓄电池废水厂的废水进行絮凝实验,以pH、投加量、沉淀时间为变量,Pb~(2+)浓度、COD、氨氮和总氮实验表征絮凝剂的效果,选出针对本厂水质的絮凝剂优化条件。研究结果表明:PAFC和PAM复配时,其最佳絮凝条件是:pH=10、PAFC投加量是5 mg/L、PAM投加量为10 mg/L和沉淀时间为30 min,Pb~(2+)的去除率和COD的去除率分别为98.38%和92.45%。     

丙烯酰胺-阳离子瓜尔胶接枝共聚物的絮凝性能研究

研究了低温合成的高相对分子质量的天然高分子改性絮凝剂--丙烯酰胺-阳离子瓜尔胶接枝共聚物(CGG-g-PAM)对高浊度烟草废水的絮凝效果,以及PAC投加量、CGG-g-PAM投加量、pH和不同相对分子质量CGG-g-PAM等对浊度(》4 500 NTU)、COD和色度去除率的影响.结果表明,在pH 5,PAC投加质量浓度为120 mg/L,CGG-g-PAM投加质量浓度为3.6 ms/L时,去浊率达98%,COD去除率达24%,色度去除率达20%,且絮凝性能优于阳离子瓜尔胶(CGG)和阳离子聚丙烯酰胺(CPAM).实验研究表明,产品具有良好的絮凝效果,在工业废水处理中具有一定的应用前景.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.