双氰胺-甲醛聚合物阳离子印染废水脱色剂的合成及其应用

合成出一种以双氰胺、甲醛为原料的阳离子印染废水高效有机脱色剂,考察了双氰胺、甲醛、硫酸铝用量和反应温度、反应时间等合成条件对双氰胺-甲醛聚合物脱色性能的影响.结果表明,优化合成工艺条件为双氰胺:甲醛:硫酸铝=1:2.58:0.35(摩尔比)、80℃、反应3h.所制脱色剂对分散红167、BES蓝、分散蓝79三种典型染料废水的脱色率均达98%以上.脱色机理主要包括吸附电中和作用、压缩双电层、吸附架桥、网捕作用.将脱色剂应用于江苏省常州市马杭污水厂混合印染废水的处理,在pH8、投加量17.5mL/L的条件下,脱色率可达96%以上,出水色度从360倍降为10倍,达到GB8978-1996一级A排放要求.     

双氰胺甲醛改性脱色剂的合成及在模拟染料废水中的应用

以双氰胺、甲醛为主要原料,尿素、三聚氰胺为改性剂,合成双氰胺甲醛型改性脱色絮凝剂,并用于酸性红18模拟染料废水脱色絮凝沉降实验。实验采用单因素法研究了物料摩尔配比、反应温度、反应时间对改性脱色剂脱色性能的影响,探讨了与无机混凝剂聚合氯化铝(PAC)复配使用情况。通过红外光谱图发现产物为改性的脱色剂。研究结果表明:改性双氰胺甲醛脱色剂性能优于未改性产品,其最佳反应时间为3h,最佳反应温度为80℃,最佳的物料摩尔比为双氰胺:甲醛:氯化铵:尿素:三聚氰胺=1:3.5:0.75:0.13:0.03。改性脱色剂的最佳投加量为120mg/L,其脱色率达到94.6%;单独使用PAC时,最佳投加量为60mg/L,脱色率仅为57.6%;改性脱色剂与PAC复配之后,PAC用量不变时,改性脱色剂投加量为80mg/L时,脱色率就达到94.8%,脱色剂与PAC的复配,不仅提升了脱色性能,并可减少有机脱色剂使用量,降低处理成本。     

H2O2存在下壳聚糖处理印染废水的实验研究

壳聚糖作为絮凝剂单独用于印染废水的处理效果不明显。研究了在H2O2存在下壳聚糖对不同染料模拟废水的处理效果,发现对于所述的5种染料,其处理效果都较好。以孔雀石绿模拟废水为例,研究了壳聚糖和H2O2的投加量、pH、脱色时间、温度等对处理效果的影响。结果表明,当m(H2O2)∶m(壳聚糖)为1.91∶1,pH为7,脱色时间为1 h,温度为40℃时,处理效果最佳,脱色率达到99%以上。     

双氰胺-甲醛脱色剂的制备及性能研究

以双氰胺-甲醛等为原料,与聚合氯化铝和氯化铵混合使用,通过"二步法缩合"工艺,合成脱色絮凝剂。通过高锰酸钾法测定COD,模拟废水和染料来考察COD去除效果和脱色效果。结果表明,在COD去除中,p H对COD去除率无明显影响,脱色剂用量在0.062 5 m L/m L时效果最好,最佳条件下能将其去除至600 mg/L左右,去除率在40%⁴5%。在脱色率去除中,脱色最佳p H值为9,脱色剂用量在0.05 m L/m L时效果最好;脱色剂对于靛蓝甲基红染料脱色率能达到85%以上,对于模拟废水的脱色率达到了92%以上。本方法制得的脱色剂对COD及脱色率具有良好的效果。     

双氰胺-甲醛脱色剂的制备及性能研究

以双氰胺-甲醛等为原料,与聚合氯化铝和氯化铵混合使用,通过"二步法缩合"工艺,合成脱色絮凝剂。通过高锰酸钾法测定COD,模拟废水和染料来考察COD去除效果和脱色效果。结果表明,在COD去除中,p H对COD去除率无明显影响,脱色剂用量在0.062 5 m L/m L时效果最好,最佳条件下能将其去除至600 mg/L左右,去除率在40%~45%。在脱色率去除中,脱色最佳p H值为9,脱色剂用量在0.05 m L/m L时效果最好;脱色剂对于靛蓝甲基红染料脱色率能达到85%以上,对于模拟废水的脱色率达到了92%以上。本方法制得的脱色剂对COD及脱色率具有良好的效果。     

采用高效脱色剂处理染料废水的研究

以双氰胺-甲醛为主要原料并引入添加剂合成了水溶性阳离子有机絮凝剂,并与无机絮凝剂聚合氯化铝(PAC)配合使用,处理染料废水。考察了絮凝剂的投加量、投加顺序、投加配比以及pH值等对染料废水处理效果的影响,并通过正交试验确定影响脱色率的主要因素及处理废水的最佳条件。结果表明,染料废水的pH值为8～9,脱色剂用量为0.4～1.5mL/L,PAC用量为40～80mg/L时,所研究的8种染料(100mg/L)的脱色率均可达96%以上,CODCr的去除率因染料种类的不同而存在一定的差异。     

新型高效絮凝脱色剂DF的合成和印染废水的处理

以甲醛、氯化铵、双氰胺、尿素、硫脲等为原料合成了一种新型的絮凝脱色剂DF ,将该絮凝脱色剂与其它试剂复合使用对印染废水进行了处理。实验结果表明 ,DF对阴离子型印染废水具有很好的脱色效果 ,色度的一次去除率可达 6 0 %以上 ,对COD值的去除率也能达到 6 0 %。     

两种合成絮凝剂在处理染料废水中的比较

以羧甲基壳聚糖和羧甲基壳聚糖铁(Ⅲ)为絮凝剂处理染料废水,试验研究了其对染料废水的絮凝性能、脱色性能.初步考察了pH、投加量、搅拌时间与沉降时间等影响絮凝效果的因素,Fe3+的引入增加了合成絮凝剂处理染料废水的絮凝作用.在羧甲基壳聚糖处理染料红、黄、兰、黑废水的脱色实验中,脱色率达到76.3％～3.5％,COD去除率为...     

双元复合絮凝脱色剂的制备

以双氰胺、三聚氰胺、甲醛和氯化铵为主要原料合成双元复合絮凝脱色剂,通过添加甲醇进行醚化封端,尿素捕捉游离甲醛来降低ρ(游离甲醛)。首先研究了制备脱色剂的投料比、反应温度和反应时间等因素对絮凝脱色剂脱色效果的影响,然后分析了影响降低游离甲醛含量的因素。结果表明,n(三聚氰胺):n(双氰胺):n(氯化铵):n(甲醛):n(甲醇):n(尿素)=1:3:2:15:2.5:0.1,反应温度为65℃,反应时间为2.0h,pH=8,w(脱色剂)=0.28%时,脱色率达到99.91%,ρ(游离甲醛)降低到0.001 51g/L,最终合成低游离甲醛、高脱色率的絮凝脱色剂。     

羧甲基壳聚糖处理染料废水的正交试验研究

通过正交试验,用羧甲基壳聚糖(CMCTS)作为絮凝剂,对4种水溶性染料废水和实际废水进行脱色处理．确定了影响脱色效果的主次因素顺序为pH、絮凝剂用量、染料种类、搅拌时间、静置时间,绘制出CMCTS对4种水溶性染料的吸附等温线。结果表明,羧甲基壳聚糖在pH3、投加质量浓度为100mg／L时,对印染实际废水有较好的处理效果。处理10h后,脱色率达90％。     

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.     

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.     

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.     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。