首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 968 毫秒
1.
生物强化技术对水源地有机污染物的降解   总被引:1,自引:0,他引:1  
利用两种新型PM和ACP材料进行生物强化技术降解水源地水体有机污染物的研究。通过对比不同的载体密度和水力停留时间来考察有机物降解效率的影响,中试结果表明:当载体密度为13.1%、停留时间为7d、原水C0DMn为4.69~6.93mg/L、UV254为0.057-0.121cm^-1,TOC为3.92-7.85mg/L的条件下,生物强化技术对CODMn、UV254、TOC的平均降解率分别达到21.35%、14.51%、34.63%,而对比空白池,对CODMn、UV254、TOC的平均降解率低至0.85%、0.94%、1.51%。可见利用生物强化技术能有效降解水源地水体的有机污染物,它对富营养化水源地水体的水质和生态系统有明显的改善作用。  相似文献   

2.
南方部分城市由于水质型缺水,水源呈现微污染的水质特点,给常规工艺带来较大的处理难度。为保障饮用水供水安全,该文采用了纳滤工艺进行中试研究。试验结果表明:纳滤能高效去除水中的有机物,出水CODMn、UV254、TOC含量低于0. 3 mg/L、0. 010 cm-1、0. 4 mg/L。纳滤膜可以选择性去除水中的无机离子,保留部分对人体有益的钙镁离子。同时,对多环芳烃、有机氯农药、有机卤化物的截留率在50%、90%和90%左右。  相似文献   

3.
镇江市饮用水有机物分子量分布特性的研究   总被引:1,自引:0,他引:1  
研究分析了镇江市原水、净水工艺和管网水中有机物分子量分布的变化特性.试验结果表明:原水水质较好,溶解性有机物含量维持在1.4~2.8mg/L之间,小分子有机物占溶解性有机物的主要部分;与常规处理相比,臭氧活性炭深度处理能有效提高DOC和UV254的去除效果;各个处理流程对大于1000分子量区间的有机物去除效果较好;氯和臭氧氧化能使有机物由高分子量区间向低分子量区间推移.  相似文献   

4.
本试验研究了JMS-逆流气浮-纳滤集成工艺去除水中腐殖酸的工艺特征和效果.试验结果表明:JMS-逆流气浮工艺去除水中腐殖酸时,在最佳投药点(PFC),出水水质符合纳滤系统预处理单元的要求.该预处理系统与纳滤系统组合的集成工艺可以使水中的腐殖酸有机物浓度大大降低,且设有TQ56-36FC型纳滤膜的流程比设有M-N1812A型纳滤膜的流程效果好.前者出水的TOC值可达0.17~0.25mg/L,CODMn值为0.32~0.44mg/L,UV254nm值为0,且有95%以上的脱盐率;后者出水的TOC值在0.47~0.94mg/L,CODMn值为0.62~0.96mg/L,UV254nm值为0~0.0064cm^-1,脱盐率很低.另外,尽管保安过滤-活性炭预处理有利于纳滤膜(尤其是M-N1812A型纳滤膜)出水水质的提高,但活性炭柱与纳滤膜能去除的有机物种类是有些重合.  相似文献   

5.
O3/BAC工艺对微污染水源水中有机物有较好的去除效果,工艺稳定运行后对CODMn UV254、TOC的去除率均在20%左右。综合考虑工艺中有机物的去除情况,对活性炭性能比选顺序为6^#破碎炭〉4^#破碎炭≈1^#破碎炭≈5^#破碎炭〉2^#柱状炭≥3^#破碎炭。工艺稳定运行后,柱状炭表现出的各种性能与破碎炭相差不大。  相似文献   

6.
王丽华  朱溪  王晓昌  王磊 《水处理技术》2007,33(3):62-64,92
本试验通过对比两种预氧化剂对夏季滦河水的藻类、CODMn、UV254、TOC等指标的去除效果,分析水中分子量的分布情况,研究了高锰酸钾和氯预氧化对有机物的去除效果。结果表明,KMnO4预氧化在去除有机污染物方面的效果要好于预氯化的处理效果;高锰酸钾预氧化的UV254去除率为23.4%,而TOC去除率为7.1%,说明一部分UV吸收性有机物在预氧化过程中转变为UV非吸收陛有机物,低高锰酸钾投量条件下水中有机物不能得到完全去除。  相似文献   

7.
考察了O3氧化法与UV/O3氧化法对焦化废水二级生化出水中溶解性有机物的去除效果,以及二级出水中有机污染物的氧化特性。结果表明,O3氧化法对于二级出水的UV2H值具有较高的去除效率,30min内即可达75.7%,但对COD和DOC的去除效果很差,150min的去除率仅为37.1%和33.7%。而UV/O3氧化法对二级生化出水UV254.COD和DOC均具有良好的去除效果,150min时的去除率分别为95.3%。90.2%和77.8%。经过O3氧化法处理后,疏水性物质的浓度明显下降,而弱疏水有机物与亲水性有机物浓度有所上升;UV/O3氧化法处理对疏水性有机物和弱疏水有机物均具有良好的去除效果,而亲水性有机物浓度仅得到部分降低。  相似文献   

8.
谢磊 《广东化工》2009,36(8):156-157,183
采用自制的复合铝絮凝剂CPAC处理微污染原水。实验结果表明,CPAC去浊性能及卫生性能均优于PAC。在同等混凝剂投量的情况下,CPAC出水中残余铝含量小于PAC,且O/A比值越高,出水残余铝含量越低。在B为2.0,混凝剂投量2.7mg/L条件下,PAC处理出水残余铝浓度为0.156mg/L,而O/A比值分别为0.05和0.1的CPAC出水残余铝含量则分别为0.13mg/L和0.125mg/L,均低于生活饮用水卫生标准;此外,在试验考察的pH范围内,CPAC出水中残余铝含量均优于PAC,最佳pH在7.2左右。  相似文献   

9.
UV/O3-BAC与O3-BAC处理二级出水中有机污染物的研究   总被引:4,自引:1,他引:3  
将光助臭氧氧化-生物活性炭(UV/O3-BAC)新型组合工艺用于处理城市污水厂二级出水中有机污染物.考察了臭氧剂量、氧化反应时间和生物活性炭停留时间对出水水质影响,TOC去除率随着臭氧剂量、氧化反应时间和生物活性炭停留时间增加而增加;其优化工艺参数为:臭氧剂量为3 mg/L,氧化反应和生物活性炭空塔停留时间均为15 min.在优化工艺参数下,UV/O3-BAC工艺对TOC和UV254平均去除率分别达到46%和71%,比O3-BAC工艺(同样工艺参数下)对TOC和UV254平均去除率分别提高35.3%和14.5%;两组合工艺对有机物去除具有协同效应,其中UV/O3-BAC工艺的协同效应比O3-BAC工艺大.UV/O3和O3过程将水中大分子有机物氧化成小分子,增加了出水的可生化性,从而有利于后续BAC对有机污染物的去除.二级出水中主要有机污染物是酚类和酞酸酯等,经氧化处理后,二级出水中芳香烃和含一C=C-有机物消失或浓度减少,同时也生成一些小分子氧化产物,但经BAC处理后,污染物种类和浓度均大为减少.  相似文献   

10.
采用中试装置研究了预臭氧生物活性炭工艺对长江南京段微污染原水有机物的去除特性,考察了臭氧投加量和臭氧接触时间对预臭氧氧化、砂滤及生物活性炭单元中DOC、BDOC、CODMn、UV254和微量有机污染物去除的影响。结果表明当臭氧投加量为3 mg/L、臭氧接触时间为10 min时,预臭氧氧化单元中DOC、CODMn和UV254的去除率分别达到19%、31%和78%,BDOC增长了33%;砂滤单元四种指标的去除率分别为25%、52%、42%和44%,而生物活性炭滤柱对四种污染物指标的去除率分别为46%、83%、52%和20%,高于常规处理工艺。整个工艺对三种微量有机物(1,2,4三氯苯、DMP和DEHP)的去除率也分别达到了60%、68.6%和68.8%。与未投加臭氧相比,臭氧的投加有效促进了砂滤和生物活性炭对有机污染物的去除。采用预臭氧生物活性炭工艺处理微污染长江原水,有效提高了有机污染物的去除效果,可保障出水水质安全。  相似文献   

11.
12.
It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.  相似文献   

13.
14.
Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.  相似文献   

15.
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.  相似文献   

16.
17.
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.  相似文献   

18.
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.  相似文献   

19.
2008~2009年世界塑料工业进展   总被引:4,自引:1,他引:3  
收集了2008年7月~2009年6月世界塑料工业的相关资料,介绍了2008~2009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、环氧树脂、不饱和聚酯树脂)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。  相似文献   

20.
建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号