氧化-混凝工艺处理碱性含砷废水的试验研究

研究了用氧化与混凝组合工艺处理某锑冶炼厂排放的碱性含砷废水。研究结果表明,聚合硫酸铁较三氯化铁、硫酸亚铁对原水中砷的去除效果好;用氧化与混凝组合工艺较单纯用混凝工艺对砷的去除率高：双氧水、次氯酸钠这两种氧化剂中采用次氯酸钠氧化对原水中砷的去除效果及处理成本最佳。     

预氧化强化混凝工艺处理含锰水实验研究

分别研究了次氯酸钠、高锰酸钾、双氧水预氧化强化混凝工艺的除锰效果,优选次氯酸钠为预氧化剂,考察pH、氧化剂投加量、混凝剂投加量、预氧化时间对除锰效果的影响.结果表明,各因素对除锰效果影响程度从大到小依次为:pH>氧化剂投加量>混凝剂投加量>预氧化时间;在9.12的pH,次氯酸钠1.3 mg/L,混凝剂70 mg/L条件...     

氨-硫酸铵法生产饲料级氧化锌中除砷工艺研究

以锌焙砂和氨-硫酸铵溶液为原料生产饲料级高纯氧化锌,对除砷进行了重点研究.采用沉淀混凝吸附法,先用氧化剂氧化砷(Ⅲ)成砷(Ⅴ),再用沉淀吸附剂沉淀砷(Ⅴ).结果表明,温度为60℃,砷与氧化剂及沉淀吸附剂的物质的量比为1,0:1.2:1.2,搅拌浸出2 h,静置1 h,除砷效果最好.通过除砷所得氧化锌产品各项指标都符合HG 2792-1996标准.革新了氨法生产氧化锌的除砷工艺.     

冰点水的强化混凝剂及混凝方式优化选择

通过烧杯试验 ,比较了聚合氯化铝、三氯化铁、二次强化混凝的除浊和除有机物性能。结果表明 ,对于零度附近的冰点水而言 ,三氯化铁配合投加聚丙烯酰胺的混凝效果优于聚合氯化铝 ;二次混凝的效果优于一次投加 ,其中第一次混凝的搅拌时间在 90～ 12 0s为最佳。就助凝剂而言 ,聚丙烯酰胺的助凝效果明显比活化硅酸较好。另外发现 ,兼顾除浊和除有机物的效果评价和优选混凝剂的方法 ,是提高混凝沉淀工艺除污染效率的有效途径之一。     

低温藻暴发不同应急工艺消毒副产物及嗅味的影响

为实现某水库冰封期低温高藻水嗅味去除,同时降低消毒副产物生成势,比较了高锰酸钾、过氧化氢、次氯酸钠和臭氧四种预氧化剂在单独预氧化和预氧化混凝两个过程的处理效果。研究表明,预氧化混凝过程优于单独预氧化处理;综合考量浊度、UV254、嗅味感官评价、三卤甲烷生成势和卤乙酸生成势五项指标,臭氧有更好的控制效果,最佳投加量为1.0 mg/L;过氧化氢最佳投加量为2.0 mg/L,高锰酸钾最佳投加量在0.5 mg/L,次氯酸钠最佳投加量在1.0 mg/L。     

低温低浊受污染水处理中混凝剂的优化选择

通过烧杯试验，比较了硫酸铝、三氯化铁，聚合氯化铝的除浊和除有机物性能，同时探讨了混凝的最佳pH值，结果表明，对于低温低浊的松花江水而言，硫酸铝配合投加活化硅酸的混凝效果优于三氯化铁和聚合铝；混凝的最佳pH值介于6．0－7．0；在最佳的混凝条件下，三氯化铁的混凝效果最优，另外发现，兼顾除浊和除有机物的效果评价和优选混凝剂，是提高混凝沉淀工艺除污染效率的有效途径之一。     

臭氧预氧化/混凝处理活性藏青废水的试验研究

文章采用臭氧预氧化与三氯化铁混凝联用工艺处理活性藏青印染废水,考察了臭氧流量、三氯化铁投加量、pH、废水温度等参数对活性藏青废水色度去除率和CODCr去除率的影响。结果表明在臭氧流量为40 L/h,通气时间为3 min,三氯化铁投加量为200 mg/L,pH为7,混凝温度为30℃的条件下,臭氧预氧化与三氯化铁混凝联用工艺对活性藏青废水有比较理想的降解效果,印染废水的色度去除率达到95.3%,CODCr去除率达到71.5%。     

地下水除铁除锰水厂反冲洗废水混凝试验研究

通过试验,研究了地下水除铁除锰水厂反冲洗废水混凝处理的效果、影响因素以及混凝机理。结果表明,CPF和PAM的混凝效果最好,氯化铁次之,PAC较差,硫酸铝最差;含铁量为100mgL左右的冲洗废水自然沉淀效果较差,而投加少量混凝剂后,这种冲洗废水可在较短的时间内获得很好的沉淀效果;在混凝后的最初的10．30min内,废水上清液的含铁量急剧下降,此后随着沉淀时间的增加,上清液含铁量缓慢降低;当pH值为7．5左右时,硫酸铝、氯化铁和PAC的混凝机理可能以电性中和作用与吸附架桥作用为主,PAM可能主要是吸附架桥作用,而CPF的混凝机理除了吸附架桥作用以外,还可能存在一定的电性中和作用。     

三氯化铁除砷(Ⅲ)机理

采用XPS、SEM、TEM和红外分析的方法研究了三氯化铁除砷(Ⅲ)的机理。结果表明,三氯化铁是通过吸附共沉淀的方式去除水中的砷(Ⅲ)。XPS的数据表明在氯化铁处理含砷(Ⅲ)废水时有氧化还原反应发生;从SEM和TEM图可以看出随着溶液pH的升高,沉淀物从颗粒状态逐渐变为不规则的絮凝状态,颗粒粒径逐渐增大,表面有吸附物质存在;而从沉淀物的红外光谱图可以推断无砷酸铁生成。     

70米水深加压对螺旋藻细胞结构与絮凝沉淀性能的影响

为了研讨70 m水深加压对蓝藻颗粒的细胞结构影响以及混凝沉淀处理效果,选取螺旋藻为研究对象,利用70 m水深对含螺旋藻水进行加压处理,并进行混凝沉淀;另将加压后的螺旋藻制成细胞切片进行电镜扫描。试验结果表明:在PAC投加量为11 mg/L时,70 m水深加压混凝沉淀后,螺旋藻叶绿素a去除率达到93.12%,浊度小于1.66 NTU,其混凝沉淀处理效果较之原水直接混凝沉淀、传统预氧化混凝沉淀的处理效果明显提升。70 m水深加压混凝沉淀处理含螺旋藻水后,水中的藻毒素、DOC均未增加,阐明该工艺处理含螺旋藻水是安全的。     

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.     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、环氧树脂、不饱和聚酯树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍。     

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。     

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.     

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.     

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.