缺氧/好氧SBR工艺去除亚铵法造纸废水中有机物的研究

采用反应期缺氧/好氧SBR工艺处理亚铵法草浆造纸废水,结果表明:该工艺同单一好氧工艺相比有机物的去除率可提高15%,节能20%,当缺氧,好氧时间比为1:1.5,反应时间为5h,进水浓度COD为1200～1800mg/L,COD负荷小于0.9kg/kgMLSS·d时,COD和BOD5去除率分别为76%～80%和93%～95%,出水COD和BOD5浓度分别为250～420mg/L和25～40mg/L,符合GB3544～92国家二级排放标准.     

分格式SBR法处理冬季校园生活污水试验研究

;建立分格式序批式活性污泥(SBR)中试装置处理冬季低水温(8～10℃)校园生活污水,考察了空间推流和空间交替运行模式对COD、氮及磷的去除率影响.结果表明,曝气1.5 h各区增设好氧.缺氧空间交替运行效果最好,出水COD为35～60mg·L-1,去除率达75%～90%,出水磷质量浓度接近0mg·L-1,去除率高达95%,较仅有空间推流运行省电2/5.3种模式下出水氨氮质量浓度均为20～30 mg·L-1,去除率为20%～45%.温度(15℃和25℃)对氨氮去除率影响试验表明,低温抑制了硝化菌,与延长曝气时间和交替的电子受体环境无关.     

曝气生物法深度处理制药废水

设计利用曝气生物法处理经过两级接触氧化的制药废水,研究了曝气生物滤池的启动和水力停留时间、水力负荷及进水COD对废水中COD、NH4+-N去除率的影响。结果表明,在气水体积比为10:1,水力停留时间为12 h时,COD去除率最大;进水COD在320～780 mg/L,COD去除率随进COD的增加而增加;在进水COD为320～780 mg/L,水力停留时间12 h,水力负荷0.23 L/h,气水体积比10:1的条件下,NH4+-N的去除率稳定在45%～56%。出水达到国家生活杂用水标准。     

吸附法固定化白腐真菌的研究

研究了不同的固定化方式、吸附载体及载体体积对吸附法固定化白腐真菌去除苯酚和COD的影响.结果表明,直接吸附效果较佳,16 h时苯酚去除率达到100%、COD去除率约为97%;稻草粉末、棉花秆粉末、麸皮、花生壳粉末、木屑、玉米芯、丝瓜囊、活性炭等载体中丝瓜囊效果最佳,15 h时苯酚去除率为100%、COD去除率约为96%;载体体积对COD和苯酚的去除率影响不同,粉末状花生壳在提高苯酚去除率的同时会降低COD去除率.     

纤维素乙醇废水处理研究

采用微电解+厌氧折流板反应器(ABR)+上流式厌氧污泥床(UASB)+膜生物反应器(MBR)组合工艺对纤维乙醇滤液进行处理.结果表明,当滤液COD在12 000 mg·L-1左右,该组合工艺中厌氧停留时间(HRT)为48 h时,厌氧COD去除率达到72%,MBR停留时间(HRT)20 h时,COD的去除率在80.8%～87.5%之间,出水COD浓度稳定在301～537mg·L-1,且MBR抗冲击负荷能力较强.     

浮选与生物吸附联合处理含油污水研究

采用浮选与AB法联合工艺处理含油污水。试验表明:调节pH为6.5～7.8,按20～40 mg/L比例投加PAC,浮选对油和COD的平均去除率分别为70.3%、42.6%;AB法的A段在HRT=48 min、DO为0.8～1.2 mg/L时,COD平均去除率为35.9%,COD负荷达到3.68 kg/(m3.d);B段在HRT为8.0 h、DO为2.5～3.0 mg/L时,COD的平均去除率为58.0%,COD负荷为0.36 kg/(m3.d)。处理后的出水达到《污水综合排放标准》(GB 8978—1996)的一级标准。     

TiO2光催化剂处理再生造纸废水的研究

以TiO2为催化剂,用光催化氧化法处理再生造纸废水.讨论了不同实验条件如焙烧温度、焙烧时间、催化剂用量、H2O2用量、光照时间及废水pH值等对废水COD去除率的影响.结果表明:在焙烧温度为500 ℃,焙烧时间2 h,pH=8.0,TiO2用量为2.0 g/L,H2O2量(体积分数)0.6 %,光照时间4 h的条件下,废水COD的去除率可达90 %.     

焦粉吸附深度处理焦化废水研究

为解决焦化废水经常规生化处理后污染指标不符合排放标准的问题,将焦化厂生产过程中自身产生的焦粉用于焦化厂废水处理工艺中生化出水的深度处理环节,考察了焦粉投加量、焦粉粒径、溶液pH值、吸附时间对焦化废水COD和色度去除率的影响,通过正交试验设计优化了工艺条件得到最优工艺方案,最后采用SEM-EDX对比分析了焦粉使用前后的形貌变化及表面元素分布。结果表明:焦粉投加量从40 g/L增至120 g/L时,COD和色度去除率显著提高;焦粉投加量大于120 g/L时,两者去除率增速减缓,投加量超过200 g/L后,两者去除率基本稳定。焦粉粒径超过5～6 mm后,COD和色度去除率基本稳定不变。焦化废水p H值调节至8附近时,两者去除率达到最大值。吸附时间从0. 5 h逐渐增加到2. 5 h时,COD和色度去除率显著提高;超过2. 5 h后,两者去除率基本稳定。通过L18(37)正交设计试验设计优化的最佳方案为焦粉投加量200 g/L,焦粉粒径5～6 mm,溶液p H值8,吸附时间3 h;在优化条件下的多次平行试验表明,COD平均去除率达到66. 8%,色度平均去除率达到71. 2%。SEM-EDX表征显示,吸附前,焦粉孔径大,表面有较大缝隙,吸附后孔径和缝隙明显减小,分析原因可能是有较多物质附着在焦粉表面及孔道内造成。吸附后焦粉表面碳、氧、硫、氮元素相对含量大幅增加,这说明焦粉对焦化废水中的有机物和部分含硫、含氮物质具有较好的吸附性能。     

HRT对悬挂链曝气式接触氧化处理污染河水的影响

考察了不同水力停留时间(HRT)下,厌氧-缺氧-悬挂链曝气式接触氧化对重,轻度污染河水的净化效果.结果表明,HRT为2、4、8,12h时,在重、轻度污水水质COD为58.67～85.33mg·L-1、26.67～42.67mg·L-1;NH4+-N为5.20～11.30 mg·L-1、2.79～3.47 mg·L-1,TN为8.10～14.18 mg·L-1,3.15～3.38mg·L-1;TP为0.62～O.82 mg·L-1,0.135～0.39mg·L-1两种典型进水水质情况下,COD、NH+-N和TN的平均去除率都随HRT的增加而升高,但在HRT为8 h后,平均去除率的增幅都变小.TP在重、轻度污水时随HRT变化去除率差异不大.考虑节能与效率,该工艺适宜的HRT为8 h,此时重、轻度污染河水的主要污染指标平均去除率COD为61.87%、25.39%;NH4+-N为61.25%、51.04%;TN为37.66%、26.51%;TP为10.19%、8.77%.     

复合膜/SBR组合的SMBR系统脱氮除磷效果及膜性能变化试验研究

采用自主研发的复合膜与SBR反应器组合的SMBR系统,考察了在不同充水比及缺氧搅拌和曝气时间的条件下,系统对COD、氨氮、总氮、总磷的去除效果以及膜性能的变化。结果表明:在不同工况条件下,COD、氨氮的去除率均分别大于90%、95%,总氮平均去除率均大于70%,但在充水比为33%时,系统对总氮的平均去除率达到79%;总磷的去除效果受充水比和搅拌段时间的影响较大,当充水比为43%、搅拌时间为2 h时,总磷平均去除率达96%;在整个试验过程中,膜出水平均浊度为0.02 NTU;在反应器运行的两个月里,未对膜进行任何清洗,跨膜压差保持在6.0 kPa以下,透水率为3.5～4.5 L/(m2.h.kPa),没有出现膜丝断裂及严重的膜污染现象。     

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.     

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.     

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.