γ辐射及壳聚糖对污泥脱水的性能研究

通过对污泥比阻和浊度的测定,分析了壳聚糖及γ辐射对污泥脱水性能的影响.研究了单独使用壳聚糖和γ辐射时,污泥比阻和含水率的变化,并将二者结合起来,分析得出,当辐射剂量为4KGy,投加浓度为6g/L的壳聚糖6mL时将达到污泥脱水最佳效果.     

电化学预处理对后续厌氧消化工艺的作用研究

研究了经过电化学预处理后污泥性质的变化以及对后续厌氧消化工艺的改善,从产气效果、消化性能、脱水性能、污泥性质4个方面来体现电化学预处理的改善作用。结果表明,经过电化学预处理的厌氧消化工艺其污泥日产气量最大达到12.19 m L/g,远大于未经预处理的全程厌氧工艺。经过电化学预处理与厌氧消化耦合工艺后,污泥上清液中挥发性有机酸(VFA)含量、SCOD、碱度、p H都大于全程厌氧工艺,其中SCOD最大达到2 951 mg/L、VFA的质量浓度最大达到485.3 mg/L;25 d厌氧消化后,污泥经过耦合工艺处理后VSS去除率为42.13%,而全程厌氧工艺处理后VSS去除率只达到33.23%。因此,可以说明电化学预处理可以改善后续厌氧消化工艺。     

无机调理剂与表面活性剂联合调理对污泥脱水性能的影响

研究了CaO、PAFC联合表面活性剂预处理对污泥脱水性能的影响。以污泥滤饼含水率和比阻（SRF）作为评价污泥脱水性能的指标,通过测定污泥调理过程中胞外聚合物（EPS）含量、Zeta电位的变化来阐明污泥脱水性能的变化。实验结果表明,十二烷基二甲基苄基氯化铵（1227）的加入导致上清液中EPS含量发生变化,有效降低了SRF和滤饼含水率,提高污泥脱水性能。CaO、PAFC和表面活性剂的联合调理污泥比单独使用表面活性剂的效果更好,CaO、PAFC的投加不仅改善污泥脱水性能,并有助于减少表面活性剂的用量。污泥上清液中EPS及其各组分含量与污泥滤饼含水率、SRF均有较高的相关性,对污泥的脱水性能有重要贡献。实验中确定的最佳污泥调理条件是CaO投加量为66.67 mg·（g DS）^-1、PAFC投加量为33.33 mg·（g DS）^-1和表面活性剂投加量为56.25 mg·（g DS）^-1,污泥滤饼含水率和SRF分别降至69.41%、0.294×10¹³ m·kg^-1。     

沸石强化生物A/O工艺污泥脱水性能研究

沸石在强化A／O生物脱氮效果的同时改善了污泥的脱水性能。含沸石污泥的比阻随沸石含量的增加而降低,当沸石质量浓度在4g／L时,污泥脱水后体积变化梯度大。综合比较表明,含沸石污泥不投加混凝剂而直接脱水是适宜的。     

无机调理剂与表面活性剂联合调理对污泥脱水性能的影响

研究了CaO,PAFC联合表面活性剂预处理对污泥脱水性能的影响。以污泥滤饼含水率和比阻(SRF)作为评价污泥脱水性能的指标,通过测定污泥调理过程中胞外聚合物(EPS)含量、Zeta电位的变化来阐明污泥脱水性能的变化。实验结果表明,十二烷基二甲基苄基氯化铵(1227)的加入导致上清液中EPS含量发生变化,有效降低了SRF和滤饼含水率,提高污泥脱水性能。CaO,PAFC和表面活性剂的联合调理污泥比单独使用表面活性剂的效果更好,CaO,PAFC的投加不仅改善污泥脱水性能,并有助于减少表面活性剂的用量。污泥上清液中EPS及其各组分含量与污泥滤饼含水率、SRF均有较高的相关性,对污泥的脱水性能有重要贡献。实验中确定的最佳污泥调理条件是CaO投加量为66.67 mg·(g DS)-1,PAFC投加量为33.33 mg·(g DS)-1和表面活性剂投加量为56.25 mg·(g DS)-1,污泥滤饼含水率和SRF分别降至69.41%和2.94×1012m·kg-1。     

无机调理剂与表面活性剂联合调理对污泥脱水性能的影响

研究了CaO、PAFC联合表面活性剂预处理对污泥脱水性能的影响。以污泥滤饼含水率和比阻(SRF)作为评价污泥脱水性能的指标,通过测定污泥调理过程中胞外聚合物(EPS)含量、Zeta电位的变化来阐明污泥脱水性能的变化。实验结果表明,十二烷基二甲基苄基氯化铵(1227)的加入导致上清液中EPS含量发生变化,有效降低了SRF和滤饼含水率,提高污泥脱水性能。CaO、PAFC和表面活性剂的联合调理污泥比单独使用表面活性剂的效果更好,CaO、PAFC的投加不仅改善污泥脱水性能,并有助于减少表面活性剂的用量。污泥上清液中EPS及其各组分含量与污泥滤饼含水率、SRF均有较高的相关性,对污泥的脱水性能有重要贡献。实验中确定的最佳污泥调理条件是CaO投加量为66.67 mg·(g DS)?1、PAFC投加量为33.33 mg·(g DS)?1和表面活性剂投加量为56.25 mg·(g DS)?1,污泥滤饼含水率和SRF分别降至69.41%、0.294×1013 m·kg?1。     

微波能对化学污泥脱水性能的影响

研究大豆蛋白污水化学污泥的脱水性能，考察微波辐射的功率及时间对污泥脱水性能的影响，确定功率和时间的最佳条件。研究120s内污泥沉降、过滤脱水及比阻的变化，并探讨污泥胞外聚合物含量和污泥颗粒粒径的变化相关机理。结果表明：适宜的微波辐射可明显改善污泥的脱水性，800W、100W和60W微波改善污泥脱水性能的最适宜时间分别为60s、120s和120s，上清液中多糖的含量介于460～470mg／L时污泥脱水性能最佳。适宜的微波辐射能够改善污泥的脱水性能，过量的微波辐射则使污泥脱水性恶化。     

污泥深度脱水技术研究进展

随着经济的发展和国民生活水平的提高,污水污泥的排放量逐年增加,环境问题愈发严重,污泥的处理处置成为焦点问题,污泥脱水是制约污泥处置处理进一步发展的关键。本文针对目前污泥深度脱水技术开展,首先简述了不同来源污泥的分类及其基本特性,然后重点阐述了不同污泥预处理技术,分析了各污泥深度脱水技术作用机理,并对各自脱水效果及优缺点进行比较分析。结果表明,物理法中水热预处理对污泥的可脱水程度提升最大。较低声强、短时间的超声波处理对污泥脱水性能有着明显的改善。化学法在污泥过滤性能以及脱水速率方面有很大优势,酸碱处理后污泥zeta电位上升,污泥过滤性能及脱水速率得到改善。高级氧化法处理后污泥脱水效果高于酸碱处理,微生物细胞被溶解释放出有机物,可脱水程度改善。生物法处理污泥除改善污泥脱水性能外,还有对环境污染小等特点,但耗时较长。最后对污泥的后续脱水工艺进行综述,介绍了现存的主流脱水工艺,包括机械脱水、热干化技术、水热脱水工艺等;并针对不同的污泥后续利用方法,选取合适的预处理技术,提出相应优化的污泥处理工艺流程。     

Fenton试剂对剩余污泥脱水性能的改善

研究了利用Fenton试剂调理城市污水处理厂剩余污泥,通过测定污泥毛细吸水时间(CST)、污泥比阻(SRF)和泥饼含水率来表征污泥脱水性能的变化,分别考察了污泥初始pH、H2O2投加量、H2O2/Fe2+、反应温度和反应时间对污泥调理效果的影响。综合考虑,确定Fenton调理污泥的最佳条件为:pH=3、抽滤脱水和离心脱水H2O2最佳投加量分别为3 g/L和9 g/L、H2O2/Fe2(+质量比)最佳范围为8～12、反应温度50℃、反应时间60 min。对污泥离心上清液中胞外聚合物(EPS)含量的研究表明,Fenton调理后污泥上清液中蛋白质和多糖含量有大幅升高,说明Fenton试剂能有效氧化破解EPS,从而提高污泥的絮凝性,改善污泥的脱水性能。Fenton氧化后污泥颗粒粒径变小,比表面积增大。     

污水厂浓缩池污泥絮凝材料复配优化实验研究及评价

为提升浓缩池污泥沉降性能,利用聚丙烯酰胺(PAM)、氯化铁、阳离子微生物试剂、H1碱性试剂对污水厂浓缩池污泥进行絮凝实验。结果表明,这4种絮凝剂能显著改善淤泥的脱水性能,其中阳离子生物试剂的效果最优,选作为后续复配絮凝的基准絮凝剂。100 m L浓缩池污泥中,加入0.05 g阳离子微生物试剂,分别加入0.06 g的H1碱性试剂、0.045 g聚丙烯酰胺、0.03 g氯化铁进行复配,污泥比阻分别降低了76%,73%和72%,泥饼含水率由原泥泥饼的89.17%降低至77.74%,79.28%和81.78%,阳离子微生物絮凝剂与H1碱性试剂的复配效果最佳,污泥脱水性能改善明显。     

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。