混凝沉淀-Fenton氧化法在垃圾渗滤液生化处理出水中的研究

采用混凝沉淀-Fenton氧化处理垃圾渗滤液生化处理出水,通过单因素试验研究了混凝沉淀和Fenton氧化中各因素对去除CODCr的影响,试验结果表明,最佳混凝试验工艺条件为:复合混凝剂比例n(无机组分)∶n(有机组分)为4.0∶1、p H值为8.5、混凝剂投加量0.6 g/L,CODCr的去除率可达到88.6%。Fenton氧化阶段,当体系p H值为4.0、H2O2投加量为16 mg/L、Fe SO4·7H2O投加量为6 g/L、反应时间为110 min时,CODCr去除率高达95.9%。     

混凝-Fenton法对中晚期垃圾渗滤液预处理研究

利用混凝-Fenton法对中晚期垃圾渗滤液进行预处理研究。首先以PAC为混凝剂,PAM为助凝剂对垃圾渗滤液进行混凝处理,然后对混凝后渗滤液进行Fenton氧化。考察混凝剂用量,起始pH值,H2O2/FeSO4·7H2O投加比,Fenton试剂投药量和搅拌速度对垃圾渗滤液COD去除的影响,并进行正交试验分析。结果表明:混凝法的最佳投药量为1 L渗滤液投加1.5 g PAC和5 mg PAM;Fenton法的最佳条件为:起始pH值为3,H2O2/FeSO4·7H2O投加比为8∶1,Fenton试剂投药量为135 g/L,搅拌速度为150 r/min;各因素对Fenton试验影响大小为:起始pH值Fenton试剂投药量搅拌速度。在最佳条件下,混凝-Fenton法对垃圾渗滤液COD去除率可达91.41%。     

气浮-混凝-Fenton氧化处理垃圾渗滤液动态模拟研究

采用气浮-混凝-Fenton氧化组合工艺对垃圾渗滤液进行处理。试验研究结果表明,最佳气浮条件:气水比为45～60mL/L、氧化石蜡皂用量为300mg/L、气浮时间为15min;最佳混凝条件:PAM投加量为9mg/L、PAC投加量为1100mg/L、pH值为5、搅拌强度为200r/min;最佳Fenton氧化条件:pH值为3,Fe2+投加量为0.04mol/L,n(H2O2)/n(Fe2+)为15,反应时间为90min。垃圾渗滤液经过气浮-混凝-Fenton氧化处理后COD、NH3-N得到了较好的去除,最终出水COD、NH3-N、TP可达《生活垃圾填埋场污染控制标准》(GB16889—2008)中的排放浓度限值。     

混凝-芬顿法在垃圾渗滤液预处理中的比较研究

垃圾渗滤液是一种较难处理的废水,本文采用混凝法、Fenton氧化法对垃圾渗滤液进行预处理研究,通过单因素试验结果分析可知：当10%PFS投药量为1.2 g/L,搅拌转速为350 r/min,pH值为7,沉淀时间为120 min时,COD的去除率达到最佳,最高可以达到47.1%,色度去除率达到52.7%。采用芬顿法时当pH值为3,H2O2投加量为6 mL/L,反应时间为90 min,n（H2O2）/n（Fe2＋）为8∶1,COD的去除率达到最佳,COD和色度去除率分别可达45.6%和93.8%。综合比较在预处理中运用混凝法无论在工艺还是经济方面都是比较可行的。     

微电解-Fenton氧化法去除垃圾渗滤液中有机物

采用Fe/C微电解和Fe/C微电解-Fenton氧化联合工艺对垃圾渗滤液进行处理,研究了废水初始pH、药剂投加量、药剂投加比例和反应时间等对处理效果的影响,获得Fe/C微电解处理垃圾渗滤液的最佳工艺条件:初始pH=3、m(Fe)/m(C)为4、ρ(Fe/C)为0.6 g/L、反应时间为60 min,处理后COD降至5 960 mg/L,COD去除率达51.8%。Fe/C微电解-Fenton氧化处理垃圾渗滤液的最佳工艺条件:在Fe/C微电解最佳条件下,H2 O2投加量为11 mL/L,反应时间为100 min,出水COD为4 480 mg/L,COD总去除率为63.8%。垃圾渗滤液中的腐殖酸类有机质经过Fe/C微电解或微电解-Fenton氧化处理后变成小分子产物,与Fe/C微电解相比,Fenton氧化对腐殖酸等大分子有机质有更强的氧化降解效果。     

Fenton处理较长填埋龄垃圾渗滤液的作用机制研究

采用Fenton工艺对较长填埋龄垃圾渗滤液进行处理。试验结果表明,Fenton工艺对经过吹脱后的填埋场渗滤液处理的最佳条件为pH=4、n(H2O2)∶n(Fe2+)=10以及Fe2+投加量为0.08 mol/L。同时,在整个试验过程中发现,氧化与絮凝去除有机物作用的相对大小比值a平均为4.6。     

催化湿式氧化法处理垃圾渗滤液膜浓缩液的应用研究

以垃圾渗滤液膜浓缩液为研究对象,采取催化湿式氧化工艺进行深度处理;以COD去除率为主要指标,开展实验室研究及中试实验验证。结果表明,在初始pH=4、H2O2投加量=40 mL/L、n(H_2O_2)∶n(Fe~(2+))=6、反应时间=8 h、反应温度=60℃时,COD去除率90%;且在该条件下,中试实验能够稳定高效运行,具有一定的工程可行性及应用价值。     

混凝+铁炭微电解/H2O2+活性炭处理化学清洗废水

利用混凝+铁炭微电解/H2O2+活性炭吸附法对高浓度的化学清洗废水进行联合处理,同时简单分析了反应机理及影响因素。通过实验确定了混凝最佳条件(pH=8、PAC投加量为50 mg/L、PAM投加量2 mg/L、沉淀时间40 min),铁炭微电解/H2O2最佳条件〔pH=2、(Fe+C)总投加量60 g/L、m(Fe)∶m(C)为1∶1、H2O2投加量4 mL/L、反应时间60 min〕,活性炭吸附最佳条件(吸附时间120 min、pH=6、活性炭投加量20 g/L)。结果表明,在上述最佳工艺条件下对化学清洗废水进行处理,COD去除率可达98%以上,达到国家一级排放标准(GB 8978—1996)要求。     

MAP法处理垃圾渗滤液中高浓度氨氮的研究

MAP法处理垃圾渗滤液,以Na2HPO4·12H2O和MgSO4·7H2O为试验药剂对垃圾渗滤液中高氨氮进行处理,以氨氮作为考察指标,根据单因素试验确定其最佳的工艺条件.试验研究表明:在室温条件下,pH=8.5、M矿∶NH4+∶PO43-的最佳物质摩尔投配比为1.3∶1∶1.2、反应时间20 min、对垃圾渗滤液中的氨氮去除率达到94％,为后续处理奠定了良好的基础.     

Fenton-eMBR工艺处理垃圾渗滤液的试验研究

采用Fenton-eMBR组合工艺处理垃圾渗滤液,先通过正交试验确定Fenton法的优化条件,再使预处理后的尾水进入eMBR系统。结果表明,Fenton过程影响因素的主次关系为pH>Fe2+>n(H2O2):n(Fe2+)>反应时间,优化反应条件为:pH=5、反应时间2 h、n(H2O2):n(Fe2+)为3:1、FeSO.47H2O的投加量为0.03 mol/L;以陶粒为填料的eMBR系统稳定运行后COD、BOD5去除率为71.21%、73.72%,实现了同步硝化与反硝化,NH3-N的去除率达到88.61%;经Fenton-eMBR工艺处理后的渗滤液出水中COD、BOD5、NH3-N、TN、TP的去除率分别达到91.6%、90.2%、92.0%、89.9%、96.8%。     

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.     

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.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。