微波强化Fenton氧化法对老龄垃圾渗滤液的处理试验

对预处理过的老龄垃圾渗滤液,进行微波强化Fenton氧化法试验,考察了该处理方法对垃圾渗滤液的作用效果并分析微波作用机理。结果表明:对厌氧/好氧工艺处理过的老龄垃圾渗滤液进行微波强化Fenton氧化法处理时,在最优处理条件下COD去除率可达75.6%以上;以负载Fe2+的颗粒活性炭(GAC)为催化剂替代Fe2+,在最优条件下处理,COD去除率可达87.1%以上。当预处理后的垃圾渗滤液中含有大量SO42-时,微波辐射会导致Fenton氧化法的处理效果降低。微波强化Fenton氧化法处理垃圾渗滤液只起到缩短处理时间的作用,并不能提高COD去除率。对NH3-N去除率在微波辐射条件下有所提高,但是效果并不明显。     

长春市石碑岭填埋场垃圾渗滤液处理技术研究

以长春市石碑岭垃圾填埋场渗滤液为研究对象,采用混凝-生物接触氧化-电絮凝组合工艺处理垃圾渗滤液,PFS混凝预处理渗滤液最佳运行条件时投药量为0.375g/L;搅拌方式为250r/min;pH值为6;沉降时间为120min,COD去除率可达35.02%。生物接触氧化-电絮凝工艺适于处理COD<5000 mg/L的渗滤液,COD去除去除率可达89.91%,平均BOD5去除率可达91.25%,NH4+-N去除率最高可达86.13%,出水水质可达到国家污水二级排放标准。     

黄铜矿颗粒三维电极电化学氧化垃圾渗滤液

以黄铜矿作为颗粒电极和催化剂,系统考察了三维电极-电类Fenton氧化处理垃圾渗滤液的影响因素,初步分析了电化学氧化反应机制。在废水初始p H=10.0、黄铜矿投加质量浓度5 g/L、电流密度为40 m A/cm2、极板间距为2 cm时,反应4.0 h后,垃圾渗滤液COD去除率可高达98.75%,氨氮去除率可达到95.67%。研究结果表明,黄铜矿颗粒三维电极-电类Fenton氧化对垃圾渗滤液具有良好的处理效果。     

垃圾渗滤液的氧化降解处理

通过研究臭氧氧化法对垃圾渗滤液的降解处理,实验研究得出较优的通气速度为5 g/h,通气时长为20 min,在此条件下,垃圾渗滤液的COD由4400 mg/L下降到1341 mg/L,水样COD降解率达到了69.52%。使用三维电极氧化法对垃圾渗滤液的处理效果进行研究,实验结果显示当电流强度为10 m A时,选用1.5 mm活性炭作为填充电极,三维电极的处理能力达到最高,原液的COD由4400 mg/L降为1221 mg/L,COD的总去除率达到69.33%,以及臭氧氧化+三维电解复合处理垃圾渗滤液的COD的总去除率达到90.65%。     

Fenton/化学沉淀法处理垃圾渗滤液的研究

在分析和总结已有垃圾渗滤液处理技术的基础上,采用Fenton氧化和化学沉淀组合工艺开展了垃圾渗滤液的处理研究,并对工艺参数进行了优化。首先应用Fenton试剂对渗滤液进行氧化处理。实验表明,在p H为3、氧化时间为150min、Fe SO4·7H2O投加量为0.03 mol·L-1、H2O2/Fe2+投加比例为6∶1时,CODCr的去除率高达90.01%。再对经Fenton试剂处理过的垃圾渗滤液使用Mg Cl2·6H2O和H3PO4,在碱性条件下与渗滤液中的NH3-N发生化学反应,生成六水磷酸铵镁(Mg NH4PO4·6H2O)沉淀物。实验结果表明,在p H为9.5,试剂摩尔投加比n(NH4+)∶n(Mg2+)∶n(PO43-)=1∶1.3∶1.3的条件下,渗滤液中NH 3-N的去除率达到75.7%,CODCr最终去除率为93.1%。     

混凝加氧化预处理垃圾渗滤液的试验研究

采用Fe Cl3混凝联合H2O2氧化作用处理垃圾渗滤液,考察混凝-氧化法对垃圾渗滤液的处理效果。比较了先混凝后氧化(方法一)与先氧化后混凝(方法二)的处理效果,结果表明,方法一优于方法二,主要是因为方法二中的混凝效果低于方法一。无论是方法一还是方法二,加入氧化剂均不能提高对浊度的去除效果。在原水CODCr的质量浓度为4 100 mg/L、浊度为147 NTU、UV254为20、色度为2 125度的条件下,采用方法一,H2O2能大大提高垃圾渗滤液中有机物的去除率,在H2O2的投加量为5~80 m L/L范围内,CODCr、UV254、色度的去除率均呈增加趋势,最高去除率分别达60.84%、62.66%、73.79%。     

混凝-电催化氧化预处理垃圾渗滤液

研究了聚合磷硫酸铁絮凝剂(PFPS),混凝和电催化氧化方法相结合,预处理垃圾渗滤液。实验结果表明当絮凝剂用量为8‰、搅拌速度为450 r/min、搅拌时间为6 min、pH为7时,化学需氧量(COD)、固体悬浮物(SS)和浊度的去除率分别可达51.5%、86.7%和96.8%。其渗滤液出水经过随后的电催化氧化处理后,在pH为9、槽电压为16 V、曝气量为0.04 m3/h、极板间距为2 cm时,可以高效率去除氨氮(NH3-N),达到国家渗滤液排放标准(GB 16889-2008),并且对COD也有较高的去除效果,其去除率可达69.1%。混凝-电催化氧化作用预处理垃圾渗滤液可以有效降低其后续生化处理的运行负荷。     

臭氧降解垃圾渗滤液中难降解的腐殖质

腐殖质是垃圾渗滤液中的主要污染物,而O_3氧化是一种有效的处理方法。对垃圾渗滤液中腐殖质进行提取与分离,结果表明腐殖质是垃圾渗滤液中主要的有机污染物,约占COD总量的70%。O_3能快速降解腐殖酸(HA)和富里酸(FA),去除率分别达到了58%和70%,但是溶液的TOC去除率较低。设计实验测定了O_3分子与HA和FA的表观速率常数,结果表明FA比HA更容易降解,并计算出了O_3分子氧化和·OH自由基氧化对腐殖质降解的贡献。     

微气泡-电催化协同氧化降解高浓度垃圾渗滤液的研究

利用微气泡-电催化协同氧化技术对高浓度垃圾渗滤液进行降解研究,考察了电流密度、pH、微气泡通气量等工艺条件对处理高浓度垃圾渗滤液的影响,对比研究了单一使用微汽泡、双氧水、电催化及其双组合协同工艺方案去除COD和氨氮的效果,并采用Design Expert 8软件进行响应面优化协同氧化工艺。结果表明,响应面预测的最优工艺条件为：电流密度为33.3 mA/cm²、通气量为8.5 L/min、渗滤液初始pH 8.5,在该条件下COD和氨氮的去除率分别为75.3%和97.1%,与预测值(COD为75.0%,氨氮去除率为95.4%)基本相符。     

改性粉煤灰处理垃圾渗滤液中氨氮的研究

采用溶胶-凝胶法对粉煤灰进行改性,并在500℃条件下煅烧以去除残留的有机物质。研究改性粉煤灰处理淮南市垃圾渗滤液中氨氮去除效果,从而为垃圾渗滤液中氨氮的去除提供一个有效途径。通过垃圾渗滤液吸附实验,研究表明:在p H接近中性,粉煤灰投加量为3.0 g/L,垃圾渗滤液在低浓度下氨氮去除率接近100%;垃圾渗滤液初始氨氮浓度为16 mg/L时,垃圾渗滤液中氨氮去除率为80.24%。改性后的粉煤灰的吸附性能更好。     

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。