臭氧催化氧化技术深度处理煤气废水的实验研究

经生化法处理后的煤气废水,COD、总氰化合物、色度没有达到排放标准。通过实验研究了臭氧催化氧化技术对煤气废水的处理效果,并考察了反应时间、pH、催化剂对臭氧氧化效果的影响。实验结果表明,当反应时间>30 min、pH在9~12,臭氧有较高的氧化效率;当反应时间为30 min、pH=9时,煤气废水COD的去除率达到65.3%。TS-2型催化剂的使用使煤气废水COD去除率提高到66.9%,增加了1.6%。达到最佳时的反应时间降低了5 min。     

O3/H2O2高级氧化技术对实验室有机废水处理研究

O_3/H_2O_2高级氧化技术具有氧化能力强和无选择性等优点,被广泛用于高浓度、难降解和有毒有害的有机废水处理。考察了O_3/H_2O_2高级氧化技术在不同的处理条件(臭氧投加量、H_2O_2投加量、p H值、反应时间)下对实验室高浓度有机废水中COD的去除率影响,并通过页岩气采出水验证,结果表明:当臭氧投加量为40 mg·L~(-1)、双氧水投加量为0. 7 mg·L~(-1)、p H值为5、反应时间为40 min时,其COD去除率达90. 41%,可排入城市管网;在相同条件下处理COD浓度为1426 mg·L~(-1)的页岩气采出水,COD去除率达88. 3%。     

处理废碱液中硫化物和有机物的方法研究

本文主要研究用化学催化氧化和光学氧化相结合的方法处理废碱液中所含的高浓度硫化物和有机物 ,并研究各影响因素的作用情况。实验结果表明 ,硫化物的转化率随反应温度升高、反应时间的延长而增大 ;而且当反应温度 6 0℃ ,曝气量 0 6m3 /h、Mn2 初始浓度 15mg/L、反应时间 90min时 ,硫化物的转化率为 95 3%。COD的去除率随反应时间的延长而增大 ;反应时间 15 0min时 ,COD的去除率即可达到6 5 2 %     

药厂包衣液废水的处理

药厂薄膜包衣液废水COD浓度高、可生化性差,属于难生物降解的有机废水。本研究将Fenton试剂氧化技术与AB法工艺(生物处理)相结合,处理该难降解有机废水,取得了一定效果。通过正交试验,确定Fenton试剂氧化最优条件:Fe SO4·7H2O浓度为1.5 g/L、H2O2浓度为30 m L/L、反应时间120 min;在此条件下,Fenton试剂氧化处理包衣液废水的COD去除率为83.7%;AB法工艺在容积负荷为1.5 kg COD/kg MLSS·d、运行时间50 min时,COD去除率为70.1%;COD的总去除效率达到95%。为药厂薄膜包衣液废水处理提供了一项可行的处理技术。     

铁炭微电解/Fenton氧化预处理高浓度煤化工废水的研究

采用铁炭微电解/Fenton氧化组合工艺预处理高浓度煤化工废水,研究了工艺条件对COD去除率的影响。结果表明,铁炭床微电解的最佳运行条件为:进水pH=2,反应时间为20 min;Fenton氧化的最佳条件为:进水pH=4,30%H2O2投加量为3 mL/L,反应时间为60 min。在此运行条件下,COD总去除率可以达到60%～70%,其中微电解反应床COD去除率为40%～47%。采用该工艺预处理高浓度煤化工废水,降低了后续生物处理的负荷,同时不会引起铁炭床的钝化和板结。     

微电解氧化技术预处理黄姜皂素废水的研究

皂素废水属于高浓度有机废水,具有色度大、有机物浓度高、酸度大等特点。将微电解氧化技术应用于皂素废水预处理研究中,发现进水pH=3,铁碳微电解填料加量为450 g/L,反应时间为120 min,曝气量为20~25 m L/min时,COD去除率为40.6%,色度去除率为46.0%。     

聚合硫酸铁-Fenton法预处理高浓度丙烯酸酯类乳液废水

采用聚合硫酸铁(PFS)-Fenton氧化法对高浓度丙烯酸酯类乳液废水进行预处理。通过混凝实验研究了不同的混凝剂(PAC、FeCl_3、PFS)及助凝剂PAM投量、pH、絮凝时间对废水COD去除率的影响;Fenton氧化实验探讨了H_2O_2和FeSO_4投加量、初始反应pH值、反应时间等因素对混凝处理水样处理效果的影响。结果表明,混凝处理最佳混凝剂为PFS,PFS用量90 mL/L,PAM投药量为5 mL/L,絮凝时间为80 min,pH为6,最大COD去除率达61.4%;Fenton氧化实验最适宜条件为:H_2O_2(浓度30%)投加量28.6 mL/L,FeSO_4(浓度15%)投加量500 mL/L,初始反应pH值为3,反应时间为60 min。处理水COD降低到5195 mg/L,COD去除率达84.4%,可以满足接下来的生物系统对进水有机污染物浓度的要求,对于解决高浓度丙烯酸酯类乳液废水预处理提供了一种参考方案。     

活性炭载体下二氧化氯催化氧化直接大红染料废水研究

研究了二氧化氯化学氧化体系和二氧化氯催化氧化体系。实验结果表明:单用二氧化氯化学氧化处理COD为3400mg/L的直接大红染料配制废水时,最佳反应pH值为1,氧化剂经济用量为400mgClO2/L废水,反应时间为10min,COD去除率可达85.9%左右,氧化指数(COD削减量∶ClO2投加量)=7。当二氧化氯与自制催化剂所组成的催化氧化体系用于对直接大红染料配制废水的处理时,最佳反应pH值为2左右,氧化剂经济用量为600mgClO2/L废水,反应时间为10min,COD去除率可达99.2%以上,氧化指数=17。结果表明,二氧化氯催化氧化法是一种新型高效的处理难降解废水的技术,有着广阔的应用前景。     

二氧化氯催化氧化处理染料废水技术的研究

本文研究了二氧化氯化学氧化和二氧化氯催化氧化处理染料废水。实验结果表明单用二氧化氯化学氧化处理酸性大红染料配制废水时,最佳反应pH值为6~8,氧化剂经济用量为1000mg ClO2/L废水,反应时间为60min,COD去除率可达50%左右,氧化指数(COD削减量ClO2投加量)=2.3。当二氧化氯催化氧化酸性大红染料配制废水时,最佳反应pH值为2左右,氧化剂经济用量为800mg ClO2/L废水,反应时间为45~60min,COD去除率可达80%以上,氧化指数=3.5,去除每公斤COD氧化剂费用为3.7元人民币,并且废水的可生化性有很大的提高,效果明显优于二氧化氯化学氧化。     

超临界水氧化法处理丙烯腈剧毒废水的实验研究

丙烯腈生产过程中排放的废水为高浓度剧毒有机废水,采用焚烧等方法处理均不能满足环保要求.使用2.0 L的超临界水氧化反应器对该废水进行处理实验研究.实验结果表明,当反应温度为650℃,压力为28 MPa,氧气过量为理论量的200%,反应时间为180 s时,COD最高去除率可达到99.998%.笔者考察了反应温度、压力、时间、氧气浓度以及催化剂等对COD去除率的影响.处理后出水水质中的COD、氢氰酸、色度、pH等指标均达到国家规定的《污水综合排放标准》.     

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.