UV/O_3工艺深度降解印染废水的研究

采用UV/O3工艺对印染废水进行了深度降解实验研究。结果表明,UV/O3对印染废水COD的去除效果明显大于O3及UV单独作用的简单加和,UV和O3之间存在协同效应。在pH值为5、O3流量为13 L.h-1、紫外光强度为80 W、辐射时间为120 min的条件下,UV/O3工艺处理印染废水效果较好,对色度及COD的去除率分别达到97%和90%。     

焦化废水二级生化出水中有机污染物的氯化特性

考察了O3氧化法与UV/O3氧化法对焦化废水二级生化出水中溶解性有机物的去除效果,以及二级出水中有机污染物的氧化特性。结果表明,O3氧化法对于二级出水的UV2H值具有较高的去除效率,30min内即可达75．7％,但对COD和DOC的去除效果很差,150min的去除率仅为37．1％和33.7％。而UV／O3氧化法对二级生化出水UV254．COD和DOC均具有良好的去除效果,150min时的去除率分别为95．3％。90．2％和77．8％。经过O3氧化法处理后,疏水性物质的浓度明显下降,而弱疏水有机物与亲水性有机物浓度有所上升;UV／O3氧化法处理对疏水性有机物和弱疏水有机物均具有良好的去除效果,而亲水性有机物浓度仅得到部分降低。     

UV/Fenton氧化法对苯酚氧化效果的实验研究

研究UV/Fenton氧化法中各个因素对降解水中苯酚的影响,确定UV/Fenton法处理苯酚废水的工艺条件。保持UV/Fenton体系的基准条件不变,通过改变H2O2浓度、n(Fe2+)∶n(H2O2)、废水初始pH值等实验条件,考察这些因素对UV/Fenton法处理苯酚废水效果的影响。结果表明:UV/Fen-ton氧化法对苯酚废水有较好的去除效果和较高的反应速率。当废水初始pH值为3.0时,经30 min的反应,苯酚去除率达到99%,COD去除率达到86%。但是苯酚废水COD去除率滞后于苯酚去除率。UV/Fenton法能够在较短的时间内去除苯酚和COD,H2O2浓度、n(Fe2+)∶n(H2O2)对处理效果影响较大,H2O2浓度决定苯酚去除率和COD去除率,而n(Fe2+)∶n(H2O2)是影响降解速率的主导因素。     

UV／Fenton处理苯酚废水的研究

采用UV／Fenton联合体系降解苯酚模拟废水,苯酚的初始质量浓度为300mg／L,COD。的初始质量浓度为760mg／L。探讨了pH值、H202（30％）和FeSO4·7H2O投加量、反应时间等因素对苯酚和CODcr去除率的影响。结果表明,UV／Fenton联合体系降解苯酚废水的最佳工艺条件是：溶液pH值为3、H2O2投加量为2．5mL／L、FeS04·7H20投加量为0．020g／L、反应时间为90min。此时,苯酚的去除率为95％,CODcr的去除率为90％。UV／Fenton联合体系能较好地处理苯酚废水。     

TiO2/UV与O3联用工艺对溴胺酸废水的预处理

采用TiO2/UV与O3联用工艺对中低浓度溴胺酸废水进行预处理。实验结果表明,TiO2／UV与O3联用对溴胺酸的降解具有一定协同效应,本质原因是TiO2／UV与O3协同产生了更多羟基自由基。初始pH值对溴胺酸的降解效果影响不大,COD去除率基本稳定在90％-95％之间。溴胺酸废水经过2h催化降解,脱色率能达到70％以上,COD也能得到一定的去除,同时废水的B／C值能从0．030—0．043上升至0．320—0．368,可生化性得到大幅度提高,为后续生物处理创造了有利条件。     

Fe2O3/γ-Al2O3催化剂用于降解苯酚的非均相Fenton反应研究

采用浸渍法制备Fe2O3/γ-Al2O3催化剂,利用扫描电镜(SEM)、X射线衍射仪(XRD)、X射线光电子能谱仪(XPS)对催化剂进行了表观形貌、晶体结构、表面元素组成的分析,并将其用于降解苯酚的非均相Fenton反应体系。在有UV与无UV条件下,通过对质量浓度为250 mg/L的苯酚废水降解效果的考察优化催化剂制备条件及反应条件。实验结果表明,UV条件下的降解速率明显高于无UV条件,2种条件下苯酚降解2 h后降解率分别最高能达到89.4%、94.7%。     

O3/UV法对炼油含碱废水降解的试验研究

炼油含碱废水中COD、Oil、Ar-OH、S^2 浓度较高，可生化性极差，选用O3/UV的方法对其进行降解研究，结果表明，通过控制O3浓度、反应时间，可使各污染物的降解达到预处理的目的。与单独用03法相比，UV使COD、0H、Ar-OH的平均降解率分别提高了24％、31％、28％。同时此反应具有不产污泥、没有二次污染等优点。     

UV/O3氧化工艺处理水中六氯苯的研究

采用UV、O3及UV/O3，高级氧化法对水中六氯苯（HCB）的降解效果及机理进行了研究，并对结果进行了比较。结果表明，UV本身对HCB的去除贡献不大，HCB可被O3、UV/O3快速降解，即UV〈03〈UV/O3；在pH=3，HCB=0．2mg／L，反应40rain时，UV/O3对HCB的去除可达50％左右，酸性条件下有利于降解反应的进行；无论是O3单独作用还是UV/O3，联令作用，HCB的降解基本上满足准一级反应动力学规律，如果体系的pH值基本保持恒定，这种规律就更为明显。根据离子色谱（IC）、GC对六氯苯降解中间产物进行了测定，探讨了O3、UV/O3，降解六氯苯的途径和机理。     

UV/O3处理丁基黄药废水

采用UV/O3氧化法处理丁基黄药溶液,考察了丁基黄药质量浓度、溶液pH对丁基黄药降解率的影响.研究结果表明,初始pH增大有利于丁基黄药的降解,在25℃,pH=1 1.36,光照强度为36W,臭氧浓度为7.32 mg·L-1,丁基黄药初始质量浓度为100 mg· L-1时,经10 min后丁基黄药去除率达到99％以上.在UV/O3联合作用下,丁基黄药的降解基本上满足准1级反应动力学规律,反应20 min后,COD与TOC去除率仅为33.9％与14.5％左右,这表明UV/O3不能使丁基黄药完全矿化,只能生成一系列中间产物.     

UV/H_2O_2/草酸铁络合物法光降解偶氮染料金橙G的研究

采用UV/H2O2/草酸铁络合物法处理偶氮染料金橙G(OG)废水。结果表明,降解浓度为5×10-5mol.L-1的OG模拟废水的最佳条件为:光照12 min,H2O2、FeSO4和C2H2O4浓度分别为8×10-2mol.L-1、6×10-5mol.L-1和4.2×10-4mol.L-1,此时,OG去除率可达95.1%。UV/H2O2/草酸铁络合物法降解OG的效果优于Fenton法和H2O2/草酸铁络合物法。紫外可见光谱分析表明,.OH破坏了OG的-N=N-和苯环结构。     

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.     

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.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.