WAO和CWAO工艺预处理制药废水的实验研究

采用湿式氧化（WAO）和催化湿式氧化（CWAO）工艺对制药废水进行预处理，考察温度，反应时间，初始氧分压，pH对COD去除率的影响。在反应温度260℃、初始氧分压2 MPa、反应时间2 h的条件下，采用WAO工艺的废水COD去除率达到74.1%,B/C由0.22提高到0.45，生化性显著改善。CWAO工艺通过添加5 g催化剂，COD去除率为91.3%，有效提高了湿式氧化法的处理效果。     

湿式过氯化氢氧化法处理吡虫啉农药废水研究

为优化反应条件,在2L压力反应器内,对吡虫啉农药废水进行湿式过氧化氢氧化（WPO）和催化湿式过氧化氢氧化（CWPO）降解处理,考察了过氧化氢加入量、反应温度、进水pH值和催化剂等对反应过程与污染物降解的影响规律。结果表明,WPO和CWPO能在温和的条件下降解难于生物降解的吡虫啉农药废水。温度为110℃,压力为0．6Mpa,过氧化氢用量为理论用量。进水pH值为3．5的条件下,WPO处理吡虫啉农药废水。COD去除率为47．7％：采用非均相Cu-Ni-Ce／SiO2催化剂,pH值为7．0。其他条件相同时,CWPO对相同吡虫啉农药废水的COD去除率可达89．1％。     

Fenton试剂对染料废水的降解脱色作用研究

为了进一步探讨Fenton法对某些难降解有机物的降解效果,研究影响降解的诸多因素,以甲基橙模拟染料废水为研究对象,以色度和COD去除率为检测指标,研究了Fenton反应中pH值、H2O2浓度、Fe2+离子浓度、反应时间、温度对甲基橙模拟染料废水脱色率及COD去除率的影响规律.结果表明:Fenten试剂可有效地去除甲基橙模拟染料废水中的色度和COD.染料浓度为200mg/L时,在pH=4、20℃、H2O2=(浓度为30%)投量为0.6mL/L、硫酸亚铁投量为200mg/L时,反应60min,甲基橙模拟染料废水的色度去除率可以达到99.66%,COD的去除率可达88%.     

催化湿式氧化法和厌氧发酵法联用处理异佛尔酮废水

分别以沉淀法、共沸蒸馏法和高温老化法制备ZrO₂载体,采用等体积浸渍法制备Ru/ZrO₂催化剂,用于催化湿式氧化法处理异佛尔酮废水。研究了反应温度、催化剂用量及反应时间对异佛尔酮废水乙酸浓度、COD去除率、TOC去除率及废水可生化性的影响。废水经催化湿式氧化处理的中间产物主要为乙酸,可由产甲烷菌转化为甲烷。结果表明,提高反应温度、增加催化剂用量及延长反应时间均可提高异佛尔酮废水COD去除率、TOC去除率及废水可生化性。在270 ℃、氧分压2.5 MPa和催化剂用量9 g·L^－1条件下,超过180 min异佛尔酮废水COD及TOC去除率分别可达90.4%和84.9%。在270 ℃、氧分压2.5 MPa和催化剂用量1 g·L^－1反应条件下,120 min时异佛尔酮废水乙酸浓度最大,为5 582.98 mg·L^－1。催化湿式氧化处理后出水利用产甲烷菌进行厌氧发酵,反应9天产甲烷体积达到最大值820 mL。     

催化湿式空气氧化处理磷霉素钠、黄连素制药废水试验研究

研究了用催化湿式空气氧化技术处理高含量、难降解的磷霉素钠和黄连素制药混合废水,考察了非贵金属Mn及稀土元素Ce协同Cu催化反应时CWAO处理效率。结果表明,以黄连素废水中的Cu2+作催化剂,反应温度为250℃、初始氧分压为1.3 MPa、反应停留时间0.5 h的条件下,COD平均去除率可达50%,此时废水中有机磷转化为PO43-;Mn、Ce的加入可使COD的去除率提高12%～18%,其中Mn与Cu协同作用效率最高,在初始氧分压为1.3 MPa下,COD去除率可提高至72%,99%以上的有机磷转化为PO43-,出水BOD5/COD提高至0.85,达到了CWAO预处理即提高2种制药废水可生化性的目的。     

高浓度有机废水的均相催化湿式氧化影响因素

乳化液废水的均相催化湿式氧化实验发现,单一金属盐催化活性:Cu(NO3)2＞MnSO4＞CoCl2.考察了不同反应条件(温度、氧分压、进水有机物浓度)对铜盐均相催化湿式氧化的影响,结果表明,该工艺在200℃活性最高,在进水COD 48 400 mg/L,反应2 h时,COD去除率为86.6%;供氧量以初始氧分压0.93～1.16 MPa(25℃)为宜;该工艺在较宽进水浓度范围内有较高的去除率.     

湿式氧化法处理高浓度染料废水的研究

研究了过氧化氢湿式氧化法处理某染料厂实际产生的染料废水原液,并与氧气作为氧化剂处理该废水的结果进行了比较。研究结果表明,采用过氧化氢湿式氧化法时,反应温度、过氧化氢投加量和反应时间是影响湿式氧化处理效果的三个主要因素;反应温度为200℃,双氧水投加量为10%,反应时间90 min时CODCr去除率达到82%,色度去除率达到99.99%。以氧气作为氧化剂湿式氧化法处理该废水时,氧气的初始压力为2.0 MPa时的处理效果可与过氧化氢湿式氧化法处理结果相近。本研究表明湿式氧化法适用于处理高浓度染料废水。     

催化湿式过氧化氢氧化预处理有机磷农药废水的研究

以自制Fe2O3-Ce O2/γ-Al2O3为催化剂,采用催化湿式过氧化氢氧化法(CWPO)预处理有机磷农药废水,通过单因素和正交试验研究了过氧化氢投加量、起始p H、反应温度和反应时间对COD的去除效果及影响规律。结果表明,反应最优条件为H2O2投加量2 m L、起始p H=5、反应温度80℃、反应时间40 min,在此条件下COD的去除率可达85.8%,可生化性提高到B/C=0.43。运用一级动力学模型和Arrhenius经验公式,建立了催化湿式过氧化氢氧化降解COD的动力学方程。     

催化湿式二氧化氯氧化法的研究

通过浸渍法制备了包含四类主活性组分的负载型催化剂,用于二氧化氯催化湿式氧化(CWCDO)处理印染废水、有机农药废水.由实验确定了催化湿式氧化的条件,结果表明,四元组合MnO2-CuO-CeO2-V2O5(质量比为2:4:1:1)催化剂性能较好,反应在常温常压下,维持pH为3.0～5.0,反应时间为30 min时,COD的去除率大于85%,色度去除率大于90%.     

白腐真菌生物接触氧化法处理染料废水试验研究

采用白腐真菌生物接触氧化法处理偶氮染料活性嫩黄K-6G模拟染料废水,考察其对染料废水的脱色效果和COD的降解情况。试验结果表明:该法对染料废水色度去除效果较好,在进水色度为2000倍左右时,去除率达98%;对经Fenton预处理后的染料废水,在进水COD的质量浓度为132~305mg/L时,其COD平均去除率为62%。由此可见,白腐真菌技术与生物膜反应器相结合,能有效地去除难降解偶氮染料废水的色度,并对COD有一定的降解效果。     

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.