超声波-复合絮凝剂对石化厂剩余污泥脱水的研究

以污泥含水率为考察指标,研究了超声波-复合絮凝剂对石化厂剩余污泥脱水效果的影响.实验结果表明,复合絮凝剂的脱水效果优于单一絮凝剂;污泥采用复合絮凝剂PAM-PAFC进行絮凝脱水,在投加质量浓度190 mg/L、m(PAM)∶m(PAFC)=1∶1条件下,再经20 kHz、400 W/m2超声处理2.5 min后,污泥含水率从97%降至79%,污泥体积缩小86%左右,比仅投加PAM处理时污泥含水率降低5%左右.可见,超声波-复合絮凝剂可以强化污泥脱水,在提高污泥脱水效果的同时,减少了有机絮凝剂PAM的用量,降低了污泥处理成本.     

超声与阳离子型聚丙烯酰胺联合作用对剩余活性污泥脱水的影响

对石化污水处理厂的剩余活性污泥采用超声与阳离子型聚丙烯酰胺(CPAM)联合作用促进脱水的情况进行了研究。实验结果表明,单独添加CPAM虽然改善了污泥的脱水性质,加快了过滤速率,但要达到较好的脱水效果,CPAM添加量比较大。用超声对污泥进行预处理后,污泥脱水能力得到了强化,不但可以减少CPAM用量,还可以使污泥滤饼含水率降低约2个百分点(质量分数)。采用28.7 kHz超声处理时,最佳处理时间为2 min左右,声强约为470 W/m2,CPAM添加量约为0.5%(污泥干基质量分数)。     

超声波结合复合絮凝剂强化生物污泥脱水研究及其作用机理

研究了超声波结合复合絮凝剂促进剩余生物污泥脱水及其作用机理。实验结果表明，复合絮凝剂PAM—PAFC的投加比（质量比）为1：1、投加量为污泥干基7％。时，其絮凝效果优于单一絮凝剂，再经20kHz、400W/m^2超声处理2．5min后，污泥体积缩小86％左右，含水率可降至79％，比无超声作用时污泥干基含水率减少7％左右。通过电镜观察发现，小功率超声可促进污泥中小团块的碰撞，增加污泥的絮凝性；投加PAFC后，污泥絮体呈现较为平坦的均匀絮状形态，存在孔洞；再投加PAM后，絮体具有起伏不平的链网状结构，形成比表面较大的复杂形体的絮体，脱水效果优于单独投加PAFC；再经超声处理后，污泥絮体比未加超声时团聚性增强，孔洞增大，脱水性能更佳，脱水效果优于单独投加PAFC—PAM。     

类芬顿试剂对污泥减量化处理研究

含水率是影响污泥的处理效果和处理成本的重要因素,本文通过污泥的含水率、离心脱水性能、污泥的总固体数(TS)、污泥的总悬浮固体量(TSS)等指标,研究了类芬顿试剂对污泥污泥减量化处理的影响。投加三价铁离子60 mg/g、过氧化氢0.025 m L/g,污泥含水率大幅降低,再经过投加絮凝剂、机械脱水等联用技术对污泥的脱水效果的改善作用,含水率就能降到74%左右。     

双氧水生产工艺混合污泥脱水处理技术

随着环保节能政策不断推进,我国污泥处理处置形式紧迫,采用传统方法脱水干化混合污泥,含水率高,后期处理效率低,弊端明显。以生化污泥与氧化污泥组成的混合污泥作为研究对象,采用氯化铁水溶液和聚丙烯酰胺(Polyacrylamide, PAM)水溶液以体积比为1∶3复配成复合絮凝剂,絮凝剂用量为污泥处理量的1.5%,搅拌器转速200 r/m时,污泥的含水量可由原来的92%下降为73%,污泥产生的总质量较使用单一氯化铁作为絮凝剂时可降低40%。     

改性壳聚糖对处理污泥脱水性能影响的研究

研究了聚合氯化铝、壳聚糖和3种羧甲基壳聚糖(N-羧甲基壳聚糖、N,O-羧甲基壳聚糖和O-羧甲基壳聚糖)絮凝剂对污泥的脱水性能作用。实验结果表明,羧甲基壳聚糖作为絮凝剂对污泥进行脱水时,形成的絮体强度大,不易破碎,对污泥脱水的效果明显好于普通絮凝剂。在3种所研究的羧甲基壳聚糖中,N-羧甲基壳聚糖对污泥的脱水效果最好,污泥比阻抗最低,与未加絮凝剂时相比,含水率从99.1%下降到73%,污泥的体积减少为原来的1/30,热值提高为原来的40倍。     

某污水厂污泥脱水絮凝剂上机试验研究

某污水厂污泥处理采用转鼓浓缩机浓缩预处理,浓缩后进入带式压滤机压滤脱水,带式压滤机进泥浓度在1.08%~1.16%范围内。为了使得带机脱泥含水率达到要求,对小试试验筛选出的絮凝剂进行上机试验,试验结果显示:絮凝剂药耗维持在4.4~5.8 kg/tds范围内即可获得较好的污泥脱水效果,泥饼干度在17.2%~18.8%的范围内,滤液清澈,污泥固体回收率可达95%以上。     

炼油废水生化污泥絮凝处理试验

针对炼油废水生化污泥含水率高、脱水困难等问题,进行了污泥絮凝处理试验研究。试验结果表明阳离子聚丙烯酰胺(CPAM)是炼油废水生化污泥处理的理想絮凝剂。生化污泥经絮凝处理后,污泥具有良好的沉降性能和脱水性能,过滤脱水后,污泥的含水率可从94%~99.8%降低到70%~85%,降低了污泥的含水率和体积,便于运输和最终处置。     

Fenton联合氧化钙调理强化船舶含油生化污泥的脱水性能

油船洗舱和压载含油废水生化处理污泥采用Fenton氧化联合氧化钙的工艺处理,以提高脱水性能,实现深度减量。实验考察了初始pH值、Fe²⁺和H₂O₂投加量对污泥脱水性能的影响,并探讨污泥深度脱水的作用机制。结果表明,初始pH为4.0,Fe²⁺、H₂O₂、CaO投加量分别为20,30,60 mg/g干基(DS)时,污泥脱水性能提升最大,处理后污泥的比阻(SRF)降低了95%。高压压滤结果表明,Fenton氧化联合氧化钙工艺处理后泥饼的含水率降低至(42.65±0.25)%,实现船舶含油生化污泥深度脱水,处理成本为391.05元/t DS。机理研究结果表明,酸处理和Fenton反应都有助于中和污泥颗粒表面电荷,提高污泥颗粒的絮凝能力,进而降低结合水含量。酸处理能有效去除溶解型胞外聚合物(S-EPS),然而Fenton反应可有效氧化S-EPS和松散结合型胞外聚合物(LB-EPS),并实现紧密结合型胞外聚合物(TB-EPS)的部分去除。     

聚丙烯酸絮凝剂在印染污泥低温热处理中的应用

污泥脱水是实现污泥减量化和资源化利用的关键步骤。研究了自制聚丙烯酸絮凝剂PR在低温热处理条件下对印染污泥脱水性能的影响,探究其脱水机理。结果表明,PR能显著改善污泥的脱水性能。最佳工艺条件:PR用量15 mg/g,硫酸用量0.002 mL/g,75℃下热处理30 min。处理后污泥比阻降至2.80×10~(12) m/kg,降低了98.80%,泥饼含水率降至84.59%,结合水含量降至28.27%。     

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。