序批式生物反应器工艺脱氮除磷过程控制参数

为了实现序批式生物反应器(SBR)的自动控制,利用SBR工艺厌氧-好氧-缺氧(AOA)的运行方式处理模拟废水,考察溶解氧(DO)、p H值及氧化还原电位(ORP)作为各反应阶段终止(包括厌氧释磷、好氧硝化、曝气、好氧吸磷和缺氧反硝化)控制参数的可行性。结果表明:厌氧段,p H值与ORP曲线下降至平台的转折点对应厌氧释磷的终点;好氧段,p H值曲线的最低点对应硝化作用的终点,p H值、DO与ORP在硝化结束后均上升至一个稳定的平台,三者结合来判断曝气时间的结束以及好氧吸磷的终点;缺氧段,ORP曲线的最低点对应反硝化作用的终点。DO,p H值与ORP的特征点可以作为SBR工艺脱氮除磷的过程控制参数。     

无泡曝气供氢修复三氯乙烯污染地下水实验研究

以中空纤维膜作为无泡曝气供氢的载体,对三氯乙烯污染地下水进行生物厌氧还原修复,考察了曝气压力、水相流速、温度等因素条件对三氯乙烯降解速率以及去除率的影响。结果表明,随着曝气压力的升高,水相氧化还原电位降低,三氯乙烯的还原率提高;随着水循环流速的升高,水相氧化还原电位降低,三氯乙烯的还原率出现先增大后减小的趋势;随着水相温度的降低,三氯乙烯的还原率仅出现略微的下降。     

微孔曝气氧化沟生物脱氮除磷影响因素的研究

七里店污水净化厂采用微孔曝气Carrousel氧化沟工艺,单座氧化沟日处理量达到改造工程设计规模的2倍,氧化沟水力停留时间约为5 h。进水BOD5/TP平均为19.86,碳源基本满足聚磷菌释磷的要求;氧化沟分为缺氧区和好氧区,没有严格的厌氧区,但TP去除率高;温度对生物除磷无明显影响。系统BOD5/TN偏低、氧化沟水力停留时间短是影响系统脱氮效果的重要因素;温度对生物脱氮有显著的影响,生物脱氮效率随着温度的下降而降低。二沉池出水氨氮、TP浓度比进水高,二沉池明显的磷释放现象和氨化现象对系统脱氮除磷的效果影响大。     

氧化沟不同分区脱氮除磷研究

采用混合反应器模拟氧化沟运行方式,探讨氧化沟不同好氧缺氧分区对脱氮除磷效果的影响。结果表明,在分点曝气氧化沟系统中氧传质推动力大,溶氧效率高,在相同的供氧条件下,其一个循环的好氧区比分段曝气系统好氧区长,但是分点曝气系统有机物耗氧多,DO浪费大,而分段曝气溶氧效率低,但DO的有效利用率(用于脱氮除磷)高,二者硝化能力相当,NH4+-N去除率分别为96.68%和97.03%,硝化菌活性分别为4.65、4.66 mg.g-1.h-1。在好氧区和缺氧区比例相同的条件下,分区越多,有机物被好氧异养菌利用的越多,脱氮除磷效果越差。分区减少,可以有效地增加反硝化菌对碳源的利用,对提高脱氮效果更有利。在同样的供氧条件下,分段曝气单个A/O分区长,反硝化菌和聚磷菌对碳源利用多,脱氮除磷效果优于分点曝气,在满足硝化的前提下,缺氧区和好氧区比例越大,碳源被利用的越完全,对脱氮除磷越有利,DO的有效利用率也越高,此时越接近于前置缺氧-好氧(A/O)工艺。     

原位修复氯代烃污染场地地下水的现场中试研究

以典型氯代烃污染场地为试验基地,采用原位注入方法,研究了添加强化药剂对地下水氯代烃厌氧还原脱氯降解和化学环境变化的影响。结果表明,强化药剂能有效促进氯代烃污染地下水的原位还原修复,且对1,1,1-三氯乙烷、1,1-二氯乙烷的去除效果(平均去除率>99%)好于对1,1-二氯乙烯的效果(平均去除率78.9%);药剂最佳作用时间为注入后90d内,最佳作用半径为1.5m,主要作用途径为药剂中缓释有机碳介导的厌氧生物还原脱氯。     

气升式生物反应器用于废水脱氮的组合工艺研究

在内循环气升式反应器中,研究开发了一套半硝化(PN)和厌氧氨氧化(ANAMMOX)单级一体化同步处理高浓度含氮废水工艺。反应器的内筒为限氧区,借助于富集的好氧氨氧化菌(AOB)活性污泥实现废水的半硝化反应,内筒底部进行间歇式曝气,提供半硝化反应所需氧气和水力环流所需动力;反应器的外环筒为厌氧区,借助于富集的厌氧氨氧化菌(ANAMMOX)活性污泥实现厌氧氨氧化反应。反应温度为(35±2)℃,p H维持在7.5~8.0。反应器成功启动并稳定运行120 d,考察反应器内、外筒溶解氧浓度(DO)的变化和系统的脱氮性能。结果表明,反应器内、外筒有效地分隔了限氧区和厌氧区,内筒平均DO值为2.5 mg/L,外筒平均DO值为1.5 mg/L,可满足半硝化和厌氧氨氧化的反应条件。合成废水的氨氮浓度最高达200 mg/L,氮负荷为280 g/(d·m3),反应器运行120 d后,总氮去除率达到75%,表明反应器内AOB菌和ANAMMOX菌能够协同作用,从而实现了组合脱氮的工艺。     

2槽式间歇曝气法脱氮除磷的溶解氧·氧化还原电位折点控制

２槽式间歇曝气法脱氮除磷的溶解氧·氧化还原电位折点控制北京银燕环保设备工程公司范懋功２槽式间歇曝气法溶解氧·氧化还原电位（ＤＯ·ＯＲＰ）折点控制，是在串联连接的２个反应槽内各自周期性地反复进行曝气和搅拌，用嫌气·好气活性污泥法同时除去有机物、氮和磷时...     

悬浮填料单元在活性污泥改造中的应用

将悬浮填料装填入格网,制成体积一定的悬浮填料单元。分别投入曝气池的厌氧区和好氧区,形成悬浮填料和活性污泥复合工艺中试系统。然后,考察在复合系统在不同填料填充率、曝气量和水力停留时间的氨氮去除率。我们发现最优条件下,氨氮去除率较高,复合系统最稳定。最优条件为：填充率为35%;好氧段曝气量为5 m3/h,厌氧段曝气量为0.3 m3/h;水力停留时间为8 h。在此条件下,氨氮去除率比活性污泥工艺提高了18%。     

好氧曝气时间对纯氧曝气式SBR法除磷的影响

研究在氧气曝气的条件下,不同好氧曝气时间对序批式活性污泥法(SBR)的影响。实验采用合成废水,利用N_2、O_2交替曝气实现厌氧-好氧环境,在保持相同的厌氧时间(3 h)的情况下,通过调节好氧曝气时间(3.5、2.5、1.5 h),连续运行30 d,考察不同时间组合情况下的系统除磷效率及污水特性变化规律,并确定最佳的时间组成。通过实验对比发现,3组实验除磷效果差异明显,最终磷酸盐去除率分别为71%、94%和54%,反应过程中实验2(好氧曝气2.5 h)在厌氧-好氧阶段生成和消耗最多的聚羟基脂肪酸酯,在厌氧反应时释放出最多的游离磷且在好氧反应时摄取最高量的磷酸盐,最终实现了良好的脱磷效果,达到了节约曝气时间,缩短曝气能源消耗成本的目的,但当好氧曝气时间过长或过短,都难以取得良好的磷去除效率。     

新型AmOn反应器好氧区流场优化与实验研究

基于气升式环流反应器原理设计的新型AnOn反应器,是集传统氧化沟和二沉池工艺于一体,同时实现有机物去除、反硝化脱氮除磷、污泥回流以及泥水分离等功能的高效污水处理生化反应器。曝气装置是该反应器的核心部件,不但起到曝气充氧、紊动传质的作用,而且还是整个反应器内液相垂直流动的动力来源。本文借助CFD技术,对好氧区曝气方式改进前后流场特征进行模拟,分析不同流场情况对好氧区紊动传质及处理效果的影响。实验表明,双管曝气方式下,中间一道曝气管的曝气搅拌作用破坏了单管曝气方式下的循环涡流,使得液速和气含率分布更加均匀合理,好氧区流场更加有利于气液和液固传质,相同曝气量条件下污水处理效果得到很大加强。     

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。