沸石填料电化学反应器处理低浓度氨氮的影响因素和机理

采用沸石填料电化学反应器处理低浓度氨氮废水,研究了阳极材料、粒子电极、阴极材料、电流密度、初始pH、曝气对氨氮去除效果的影响。结果表明,在钌铱锡阳极板(DSA)为阳极、活性碳纤维(ACF)为阴极、载铁斜发沸石为填料、电流密度为6 mA/cm2、pH为5、曝气量为5 L/min条件下,质量浓度为20 mg/L的模拟氨氮废水经处理后出水氨氮质量浓度为3 mg/L左右,且出水水质清澈。NH+4在直流电场作用下向阴极定向移动,曝气对阳极处理氨氮没有影响,·OH氧化氨氮可使氨氮质量浓度降低一半左右,氨氮降低至一定质量浓度时,·OH无法继续对其氧化,阴极附近氨氮质量浓度在20 min后基本保持不变。     

沸石三维电极电解体系协同对氨氮深度处理的试验探究

沸石的单独吸附作用并不能达到对高浓度氨氮废水深度处理的目的,利用沸石填充的三维电解反应器来提升对氨氮进一步处理的效果。在填充Na-P1型沸石的三维电解池内,当氨氮初始浓度为100 mg/L、电流密度控制在7.9 mA/cm~2、沸石填充密度为2.8 g/L、溶液氯离子浓度在200 mg/L时,对氨氮的电解效率最高。在0.5 h时,利用Na-P1型沸石作为三维电极材料,在加电协同作用下相比于Na-P1型沸石单一的吸附作用,氨氮去除率提升了约30%,其电解吸附能力为:46.4 mg/(g·h)。     

硅藻土处理低浓度氨氮废水效果研究

采用天然硅藻土处理低浓度氨氮废水,运用单因素试验法考察了硅藻土投加量、废水pH值和搅拌时间对氨氮去除率的影响,研究结果显示:在其对地表水氨氮(0.277 mg/L)的处理中,当硅藻土投加量为40 mg/L、pH值为7、搅拌时间为25 min时,处理效果最佳,氨氮去除率可达64.5%;在其对咸阳印染废水氨氮(13.4 mg/L)的处理中,当硅藻土投加量为800 mg/L、 pH值为8、搅拌时间为25 min时,处理效果最佳,氨氮去除率可达45.3%;在其对福建印染废水氨氮(26.76 mg/L)的处理中,当硅藻土投加量为2 500 mg/L、 pH值为7、搅拌时间为35 min时,处理效果最佳,氨氮去除率达到51.6%。硅藻土适用于低浓度氨氮废水的处理。     

硅藻土对废水中氨氮的吸附影响因素研究

利用硅藻土对氨氮废水的吸附进行实验研究,分别考察了硅藻土投加量、搅拌反应时间、静置时间、pH和沸石投加量对氨氮去除率的影响.试验结果表明,采用硅藻土处理氨氮废水的最佳运行条件为:硅藻土的投加量为0.8 g/L,pH为7.0左右,搅拌反应时间为15 0 min,静置时间为15 0 min,以及沸石的投加量为3.0 g/L...     

硅藻土-沸石复合吸附剂去除水体中氮磷的试验研究

本文主要通过静态吸附试验研究了硅藻土-沸石作为复合吸附剂对氮磷废水的处理效率,试验结果表明:与硅藻土或沸石相比,复合吸附剂对氮磷具有较强的吸附能力.吸附试验的最佳条件为:对于该吸附剂去除氨氮,pH=8,初始浓度为40 mg/L,吸附时间为350 min,吸附剂用量20 g/L;对于该吸附剂去除磷,初始浓度为5 mg/L,吸附时间为120 min,吸附剂用量20 g/L.     

超声与改性沸石强化处理高浓度氨氮废水

在对人造沸石进行NaCl溶液浸泡改性处理的基础上,采用超声强化吸附氨氮的传质过程。通过氨氮吸附试验、表征分析和吸附等温线拟合,进一步考察了改性沸石在超声和非超声条件下对氨氮的吸附特性,叠加超声作用后,溶液中氨氮去除效果更显著。试验结果表明,浓度为0.8 mol/L的NaCl溶液对人造沸石改性效果最佳;当改性沸石投加量为50g/L、吸附时间为40 min、常温为25℃、pH呈中性、超声功率为240 W时,氨氮去除效果最好。Langmuir和Freundlich吸附等温曲线皆可较好描述改性沸石对氨氮的吸附过程。     

次氯酸钠对污水处理厂二级出水消毒效果的影响因素探讨

采用次氯酸钠对城市污水厂二级生物处理出水进行消毒试验,从氨氮浓度、pH、消毒时间、水温这4个方面,分析其对次氯酸钠消毒效果的影响。当氨氮浓度≤0.2 mg/L时,次氯酸钠最佳投加量为15 mg/L;氨氮浓度为0.2～0.4 mg/L时,次氯酸钠最佳投加量为8 mg/L;氨氮浓度约0.6 mg/L时,次氯酸钠最佳投加量为6 mg/L;氨氮浓度为0.8～1.2 mg/L时,次氯酸钠最佳投加量为5 mg/L。当pH值为5. 0～6.0时,10 mg/L的次氯酸钠投加量即可使出水达标,若pH值为8.0～9.0时,必须加大次氯酸钠的投加量至15 mg/L。冬季气温较低时,尾水消毒要考虑延长消毒接触时间。夏季水温较高,可以相应减少加氯量。一般消毒接触时间为15～30 min时消毒效果最佳。     

改性沸石处理低浓度氨氮水的实验研究

在对NaCl改性沸石吸附处理模拟氨氮水单因素研究基础上,对该吸附过程的吸附等温线及动力学模型进行了分析。实验结果表明:在最佳改性条件下得到的NaCl改性沸石在室温(27℃),初始氨氮浓度30 mg/L,溶液pH值6,投加量5 g/L以及反应时间90 min时,氨氮去除率高达90.7%,吸附剂的吸附容量为8.97 mg/g。且吸附过程更符合Langmuir等温吸附模型,其相关系数为0.9973。吸附动力学分析表明,NaCl改性沸石吸附模拟氨氮水更符合准二级动力学模型,其相关系数为0.9988。     

沸石-炭复相材料对氨氮吸附性能研究

研究以沸石粉为主要原料,添加木屑、淀粉等有机物为碳化结合剂,通过造粒、氮气气氛低温热处理制备得到了粒度为0.5~1 cm的沸石-炭复相材料水处理剂颗粒,研究了不同碳化结合剂含量和不同热处理温度等氨氮超标污水的吸附性能影响。采用场发射扫描电镜对沸石-炭复相材料进行了显微形貌观察。通过氨氮吸附实验得出,相同质量条件下沸石-炭复相材料水处理剂颗粒在吸附速率上弱与沸石粉体,在足够吸附时间下对氨氮的吸附量同沸石粉体吸附量接近。5%碳化结合剂添加量样品有最优氨氮吸附性能,起始浓度为15 mg/L氨氮溶液被吸附24 h后氨氮溶液浓度降为4.69 mg/L,氨氮吸附量为1.03 mg/g;吸附100 h后氨氮溶液浓度降为1.35 mg/L,氨氮吸附量为1.36 mg/g。     

水源水突发性氨氮污染应急处理技术

针对水源水突发性氨氨污染,对沸石去除氨氮系统进行研究。先通过静态摇床试验筛选出最优的沸石种类和粒径,再通过动态固定床吸附柱试验确定最佳水力负荷,考察了进水氨氮浓度对吸附柱去除效果的影响。结果表明:1~2 mm的浙江缙云天然沸石对氨氮的去除效果最好;吸附柱水力停留甜(HRT)时间为10min时,水处理的总体效益最大;进水氨氮浓度为5mg/L,出水氨氮浓度达穿透点(0.5 mg/L时,沸石的吸附容量最大。     

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.     

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.     

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。     

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.     

Inorganic/organic nanocomposite coatings: The next step in coating performance

Inorganic/organic hybrid materials have considerable promise and are beginning to become a major area of research for many coating usages, including abrasion and corrosion resistance. Our primary approach is to prepare the inorganic phase in situ within the film formation process of the organic phase. The inorganic phase is introduced via sol-gel chemistry into a thermosetting organic phase. By this method, the size, periodicity, spatial positioning, and density of the inorganic phase can be controlled. An important aspect of the inorganic/organic hybrid materials is the coupling agent. The initial task of the coupling agent is to provide uniform mixing of the oligomeric organic phase with the sol-gel precursors, which are otherwise immiscible. UV-curable inorganic/organic hybrid systems have the advantages of a rapid cure and the ability to be used on heat sensitive substrates such as molded plastics. Also, it is possible to have better control of the growth of the inorganic phase using UV curing. It is our ultimate goal to completely separate the curing of inorganic and organic phases to gain complete control over the morphology, and hence optimization of “all” the coating properties. Thus far, it has been found that concomitant UV curing of the inorganic and organic phases using titanium sol-gel precursors afforded nanocomposite coatings which completely block the substrate from UV light while maintaining a transparent to visible light. Also, it has been found that the morphology of the inorganic phase is highly dependent on the concentration and reactivity of the coupling agent. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago, IL.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Some Large Wood-Boring Beetles in Southeastern USA

Ethanol and α-pinene were tested as attractants for large wood-boring pine beetles in Alabama, Florida, Georgia, North Carolina, and South Carolina in 2002–2004. Multiple-funnel traps baited with (−)-α-pinene (released at about 2 g/d at 25–28°C) were attractive to the following Cerambycidae: Acanthocinus nodosus, A. obsoletus, Arhopalus rusticus nubilus, Asemum striatum, Monochamus titillator, Prionus pocularis, Xylotrechus integer, and X. sagittatus sagittatus. Buprestis lineata (Buprestidae), Alaus myops (Elateridae), and Hylobius pales and Pachylobius picivorus (Curculionidae) were also attracted to traps baited with (−)-α-pinene. In many locations, ethanol synergized attraction of the cerambycids Acanthocinus nodosus, A. obsoletus, Arhopalus r. nubilus, Monochamus titillator, and Xylotrechus s. sagittatus (but not Asemum striatum, Prionus pocularis, or Xylotrechus integer) to traps baited with (−)-α-pinene. Similarly, attraction of Alaus myops, Hylobius pales, and Pachylobius picivorus (but not Buprestis lineata) to traps baited with (−)-α-pinene was synergized by ethanol. These results provide support for the use of traps baited with ethanol and (−)-α-pinene to detect and monitor common large wood-boring beetles from the southeastern region of the USA at ports-of-entry in other countries, as well as forested areas in the USA.