硫酸盐还原—甲烷发酵两步厌氧法处理含高浓度硫酸盐有机废水可行性研究

本文以合成废水为基质,采用软性纤维填料反应器和UASB反应器,研究了硫酸盐还原作用与甲烷发酵相结合的两阶段厌氧消化工艺处理含高浓度硫酸盐有机废水的可行性,并探讨了处理系统的最佳工艺条件。研究表明,反应器通过18天的启动,硫酸盐的去除率可达到95％;硫酸盐还原的同时有机物被酸化,酸化产物以乙酸为主;废水pH在6.48-7.14时,反应器可获得最高的硫酸盐去除率并使出水中硫酸盐浓度在国家规定标准以下。     

硫酸盐化工废水生物处理的研究进展

介绍了硫化物抑制微生物活性的机理、硫酸盐还原菌(SRB)的特性以及硫酸盐还原菌和其他微生物的协同作用,综述了国内外处理含硫酸盐化工废水的生物处理工艺概况和最新进展.简要介绍了单相吹脱工艺、两相厌氧工艺、生物膜法、硫酸盐还原和化学沉淀联合等较为成熟的工艺,进一步阐述了近年来新开发的折流挡板反应器、厌氧序批式污泥法(ASBR)以及限量曝气工艺,同时提出了含硫酸盐化工废水处理方法的发展趋势.     

含硫酸盐有机废水厌氧处理影响因素分析

讨论了在厌氧消化中硫酸盐还原菌与产甲烷菌之间的关系以及硫酸盐有机废水厌氧处理中的各种影响因素，分析了进水COD／SO4^2-值、体系pH值以及工艺类型对消化过程的影响。     

射流循环厌氧流化床两相厌氧处理高浓度硫酸盐有机废水

设计了射流循环新型厌氧生物流化床反应器(JLAFB),以该反应器为酸化相(或称硫酸盐还原相),厌氧颗粒污泥流化床(AGSFB)为产甲烷相组成两相厌氧工艺处理高浓度硫酸盐有机废水。在培养出耐酸性硫酸盐还原厌氧颗粒污泥基础上,成功实现了硫酸盐还原菌（SRB）和产甲烷菌（MPB）的相分离,消除了SRB对MPB的基质竞争性抑制。在进水SO2-4负荷达12.0 kg·m-3·d-1条件下,JLAFB和AGSFB反应器内硫化物浓度分别为78.3 mg·L-1和92.4 mg·L-1,远小于200 mg·L-1的抑制浓度,消除了硫化物在反应器内的积累和对微生物的毒性作用。在稳态运行条件下,当进水COD和SO2-4负荷分别为26.0和8.5 kg·m-3·d-1时,工艺总的COD和SO2-4去除率分别达到86.9％和97.6％。试验确定工艺的最优运行条件为：进水COD/SO2-4>3.0;碱度为400～500 mg·L-1;JLAFB反应器吹脱气体流量为0.04 L·min-1,水力回流比为5∶1。     

两级两相厌氧工艺处理高浓度化工废水的技术研究

（1）原创理论：针对高浓度化工废水的水质特点，依据两相厌氧工艺、分级厌氧工艺原理，及厌氧微生物的生理生态学特征，以外循环（EC）厌氧反应器作为两级产甲烷段的处理单体，提出高浓度化工废水的两级两相厌氧处理技术；构建高浓度化工废水两级两相厌氧处理理论，并对其中有机物转化、降解机理进行探讨；     

硫酸盐还原—甲烷化两相厌氧工艺中的相分离

硫酸盐还原－甲烷化两相厌氧工艺中的相分离与一般意义上的相分离不同。废水中有硫酸盐存在时，由于硫酸盐还原作用的协助，顺利建立了两相。在第一相中进行经和硫酸盐还原，产甲烷菌不表现活怀；第二相中进行大部分的ＣＯＤ去除和产生与一般厌氧消化中质量相当的生物气。     

两级两相厌氧工艺处理高浓度化工废水的技术研究

一、主要内容 （1）原创理论：针对高浓度化工废水的水质特点，依据两相厌氧工艺、分级厌氧工艺原理，及厌氧微生物的生理生态学特征，以外循环（EC）厌氧反应器作为两级产甲烷段的处理单体，提出高浓度化工废水的两级两相厌氧处理技术；构建高浓度化工废水两级两相厌氧处理理论，并对其中有机物转化、降解机理进行探讨；对两级厌氧工艺各单体中的高效微生物的种群结构、生态位、生长限制因子等进行探讨，揭示其生理生态规律，并通过控制主要生态因子来实现反应器运行的优化；     

硫酸盐还原─甲烷化两相厌氧工艺中的相分离

硫酸盐还原─甲烷化两相厌氧工艺中的相分离与一般意义上的相分离不同。废水中有硫酸盐存在时，由于硫酸盐还原作用的协助（包括解除酸化反应产物抑制和液相中游离硫化氢对产甲烷作用的抑制），顺利建立了两相。在第一相中进行酸化和硫酸盐还原，产甲烷菌不表现活性；在第二相中进行大部分的ＣＯＤ去除和产生与一般厌氧消化中质量相当的生物气。     

SRB法处理高浓度硫酸盐废水的试验研究

研究了在厌氧序批式反应器(ASBR)中,利用硫酸盐还原菌(SRB)处理含高浓度SO42-的酸性钛白粉废水的技术可行性及ASBR处理工艺的最佳运行参数。试验结果表明:SRB法处理含高浓度SO42-的酸性钛白粉废水是可行的,在选定试验条件下,模拟废水和钛白粉废水的SO42-去除率分别为92.7%和88.3%,且出水硫酸盐浓度在250mg·L-1以下,达到了国家地面水环境质量标准(GB3838-83)。     

SRB法处理高浓度硫酸盐废水的试验研究

研究了在厌氧序批式反应器(ASBR)中,利用硫酸盐还原菌(SRB)处理含高浓度SO42-的酸性钛白粉废水的技术可行性及ASBR处理工艺的最佳运行参数.试验结果表明:SRB法处理含高浓度SO42-的酸性钛白粉废水是可行的,在选定试验条件下,模拟废水和钛白粉废水的SO42-去除率分别为92.7%和88.3%,且出水硫酸盐质量浓度＜250 mg/L,达到了国家地面水环境质量标准(GB 3838-1983)的要求.     

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.     

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.     

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.     

Highly moisture-proof polysilsesquioxane coating prepared via facile sol-gel process

A highly moisture-proof polysilsesquioxane coating was obtained from a new bis-silylated precursor, which was synthesized from 3-aminopropyltriethoxysilane (APTES) and m-xylylene diisocyanate (m-XDI) in tetrahydrofuran (THF) and verified by ¹H MAS NMR. For direct comparison purposes, an SiO₂ coating was also prepared by the Stöber method using tetraethoxysilane (TEOS) as the reactant. Interestingly, the coating obtained from the polysilsesquioxane sol exhibited a much higher moisture resistance capability than its counterpart, which was attributed to its more compact feature between nanoparticles as characterized by N₂ absorption experiment and transmission electron microscopy (TEM). Furthermore, its high transparency of about 92% showed potential for application in the protection of optical crystals.