PAC-PAM复合混凝处理钻井液废水研究

以某地钻井液废水为研究对象,投加混凝剂聚合氯化铝(PAC)和助凝剂聚丙烯酰胺(PAM)对钻井液废水进行预处理。通过单因素实验和正交实验确定了最佳混凝条件为PAC投加量5 g/L,PAM投加量10 mg/L,pH值7左右,搅拌速率300 r/min。在上述最佳处理条件下,钻井液废水COD由14256 mg/L降至2578 mg/L,COD去除率达81.92%。浊度由147 NTU下降到23 NTU,浊度去除率为84.35%;预处理后废水中的各项污染指标均有较大降幅,可生化性大大提高,为后续的生化处理减轻负荷。     

高COD枣加工生产废水预处理实验

针对枣加工生产废水具有COD高、pH低等特点,以聚合氯化铝(PAC)为混凝剂,聚丙烯酰胺(PAM)为助凝剂,通过单因素和正交实验预处理枣加工生产废水,结果表明,优化混凝条件为:混凝剂PAC投加量120mg/L,助凝剂PAM投加量15mg/L,pH为7,混凝时间为20min。在此条件下,处理后废水的COD为46.22g/L,浊度28NTU,COD和浊度的去除率分别为54%和88%。可保证后续生物处理的顺利进行。     

污水处理中物化与兼性生化低温下的协同作用

针对兼性生化低温状态去除效果差、污泥易流失等问题,提出采取物化兼性生化联用法来提高其处理效果.并采用对比法研究物化、兼性生化及二者联用技术处理低温城市污水.研究结果表明在聚合氯化铝（PAC）投加量为20mg/L时,物化与兼性生化在COD、浊度及TP的去除方面表现出良好的协同作用,但脱氮效果一般;二者协同作用能以较小的投药量有效改善低温状态兼性生化处理效果及污泥流失现象,为后续生态单元的稳定运行提供了保障.     

不同混凝剂对马铃薯淀粉废水混凝效果的影响

用混凝剂Fe2(SO4)3、PAC、PFSS、PAFC处理马铃薯淀粉废水,研究了混凝剂的种类、投药量、废水pH值、助凝剂PAM的投加量以及沉降时间等对混凝效果的影响。结果表明,混凝沉淀法预处理马铃薯淀粉废水优选混凝条件为:pH为7,混凝剂PAFC为1 200 mg/L,助凝剂PAM为5 mg/L,沉降25 m in。在此条件下,废水的浊度、COD去除率分别达97.27%及40.55%。投药量明显减少,而沉积物产量较高,为后续生化处理提供了有利条件。     

混凝沉淀法处理马铃薯淀粉废水的应用研究

采用混凝沉淀法对马铃薯淀粉废水进行了试验及工程应用研究.结果表明,混凝剂种类、投加量、投加方式、pH及沉降时间对处理效果都起着重要作用.在pH为10左右,PAC投加量为5 000 mg·L-1,PAM投加量为3.2mg·L-1时,沉降30 min,废水COD去除率达58.14%;浊度去除率可达91.97%;SS去除率达91.11%.用混凝沉淀法处理马铃薯淀粉废水可减轻后续生化处理系统的负担,在蛋白回收生产工艺中应用,可提高蛋白的回收率.     

强化预处理乙醇废水协同除磷试验研究

酿造行业废水具有高有机物浓度、高浊、高磷等特点,对后续生物处理的十分不利。采用混凝沉淀强化处理,能够有效提高化学需氧量（COD）、悬浮物（SS）的去除率,同时降低磷浓度,对后续生物处理具有促进作用。探讨了不同混凝剂、混凝剂的投加量对混凝沉降速度和COD、浊度、磷去除效果的影响。研究表明,三氯化铁为预处理乙醇废水最佳混凝剂,在p H值为7-8时,投加量为80mg/L,沉降速度较快,COD的去除率可达59%,磷的去除率〉90%。继续投加助凝剂聚丙烯酰胺（PAM）可以提高废水的处理效果,但是不显著。     

PAC、PFS混凝剂去除微污染水体中PCBs效果研究

以聚合氯化铝(PAC)、聚合硫酸铁(PFS)为混凝剂,采用强化混凝的水处理方法,完成对低浊度微污染水体中多氯联苯(PCBs)的去除,考察了2种混凝剂的投加量、水样初始浊度、水样pH值以及水力条件等因素对PAC、 PFS混凝剂去除低浊度水体中PCBs的效果影响。研究得出,当PAC投加量为7 mL/L,水样初始浊度为62NTU,慢速搅拌时间为15 min, pH值为5.0时, PAC强化混凝效果最佳,其对水样中PCBs的去除率为68.42%～76.02%,剩余浊度为1.01 NTU;当PFS投加量为5.5 mL/L,水样初始浊度为62 NTU,慢速搅拌时间为15 min,p H值为6.5时, PFS强化混凝效果最佳,其对水样中PCBs的去除率为70.30%～77.52%,剩余浊度为4.14 NTU。研究得出, PAC、 PFS均能有效去除微污染水体中的PCBs,且与PAC相比, PFS的去除效果更佳。     

PAC混凝沉降法处理凉果废水的研究

凉果废水引起的污染已经成为严峻的问题.研究了潮安县康辉集团凉果厂综合排放废水的性质,采用混凝沉降工艺处理该废水.为了强化凉果废水的混凝预处理效果,试验研究了混凝剂聚合氯化铝(PAC)的最佳投加量.实验表明:采用PAC工艺处理凉果废水的效果较好,投药后经混凝沉降,废水的COD去除率可以达到46.73%,出水COD可以降至...     

强化混凝处理大伙房水库低温高浊水试验研究

对强化混凝处理大伙房水库汛后冬季低温高浊度原水进行了试验研究,分析低温高浊水的处理效果,选出最佳混凝方案。经过试验对比混凝效果得到最佳投药量,找出最适宜水力条件、PAM投药量及投加时间,完善混凝工艺参数。试验得到最佳方案为:PAC投加量28mg·L~(-1),pH值为7.6,PAM投加量0.10 mg·L~(-1),在混凝1.5 min后投加。采用最佳方案处理后,剩余浊度为1.39 NTU,CODMn为2.18 mg·L~(-1),去除率分别为97.16%、39.28%,残留铝质量浓度为0.058 mg·L~(-1)。     

青藏高原地区低温生活污水的深度处理

针对青藏铁路沿线列车站段生活污水在低温（≤4℃）、缺氧条件下的处理要求及特点,研究了强化混凝、催化电氧化技术深度处理高原地区低温生活污水的机理,提出了青藏高原地区低温生活污水处理的最佳工艺组合。深度处理的研究结果表明：采用强化混凝处理技术即在投加无机絮凝剂PAC 50 mg•L^-1后,再投加有机絮凝剂PAM 0.5 mg•L^-1,可对COD一次性去除50%以上,之后再施以催化电氧化技术,通过电场与催化活性填料协同作用,低温生活污水的COD一次性去除率可达95%,NH₃-N去除率80%左右;经此组合工艺处理,可使低温生活污水达到地面水源水质二级标准。     

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.     

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.