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1.
董雁如 《河南化工》2020,37(8):28-30
为了有效地处理含甲醛废水,提高其生化性、降低COD和甲醛,对季戊四醇含甲醛废水进行研究,实验采用"预处理+厌氧+好氧+混凝沉淀"的工艺。结果表明,当进水COD为6 000 mg/L左右,BOD5约1 500 mg/L,甲醛浓度1 200~1 500 mg/L时,预处理停留时间在36 h,曝气强度13 L/(m2·min),p H值6.5~7.0;厌氧反应器停留时间6天,COD容积负荷为0.88 kg/(m3·d)。好氧反应器停留时间为4天,曝气强度86 L/(m2·min),COD容积负荷为0.5 kg/(m3·d);混凝沉淀加PAC和PAM后,废水经过各个工艺段处理后出水COD可达130 mg/L,BOD5约20 mg/L,甲醛浓度0.88 mg/L;去除率分别可达97%、98%和99%;最终污水达到《污水综合排放标准》(GB8978-1996)的二级标准。  相似文献   

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采用ASBR-SBR-ASBR三级联合工艺处理高浓度含氮有机废水。结果表明,对于ASBRⅠ反应器,当有机容积负荷为2 kg/(m~3·d),HRT为12 h时,有机物降解率达到95%。对于SBR反应器,当NH_4~+-N容积负荷为0.30kg/(m~3·d),HRT为12 h时,出水NH_4~+-N与NO_2~--N的物质的量比接近1∶1.32。ASBRⅡ反应器内则发生厌氧氨氧化反应,NH_4~+-N与NO_2~--N同步去除;当总氮容积负荷为0.44 kg/(m~3·d),HRT为12 h时,NH_4~+-N去除率可达95%,NO_2~--N去除率达98%。经过75 d的连续培养,反应器启动成功。  相似文献   

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厌氧-好氧组合工艺处理制药废水的试验研究   总被引:12,自引:4,他引:8  
采用上流式厌氧污泥床反应器-移动床生物膜反应器串联装置,处理含有大量氨基酸和皂素的制药废水。系统的总COD去除率平均在86%左右。当厌氧反应器的COD容积负荷为10~21kg/(m3·d),COD去除率平均为70%左右;好氧反应器的COD容积负荷率为2.48~2.87kg/(m3·d),COD去除率为59%。  相似文献   

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缺氧/好氧SBR工艺去除亚铵法造纸废水中有机物的研究   总被引:1,自引:0,他引:1  
采用反应期缺氧/好氧SBR工艺处理亚铵法草浆造纸废水,结果表明:该工艺同单一好氧工艺相比有机物的去除率可提高15%,节能20%,当缺氧,好氧时间比为1:1.5,反应时间为5h,进水浓度COD为1200~1800mg/L,COD负荷小于0.9kg/kgMLSS·d时,COD和BOD5去除率分别为76%~80%和93%~95%,出水COD和BOD5浓度分别为250~420mg/L和25~40mg/L,符合GB3544~92国家二级排放标准.  相似文献   

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提出了催化转化-生物降解法处理高浓度甲醛废水的新方法。研究发现,在温度为70℃,催化转化剂与甲醛摩尔比为1∶5,反应30 min,废水中甲醛去除率可达99.96%。预处理后的甲醛废水BOD5/CODcr值由0.12升至0.50,甲醛浓度<3 mg/L,大大提高了废水的可生化性。实验结果还表明,在采用生物降解法处理预处理后的甲醛废水过程中,当温度为35~40℃,pH值为7.0~7.5,水力停留时间(HRT)为9~12 h时,厌氧反应器有机负荷(OLR)为8.0~10.0 kg/(m3.d),好氧反应器OLR为1.0~2.0 kg/(m3.d),CODcr总去除率达到98.81%,出水COD<100 mg/L。该方法具有工艺简单、处理效率高和成本低等特点,有极高的实际应用价值。  相似文献   

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通过对内循环(IC)厌氧反应器进行改进,使其成为垂直式厌氧好氧一体化组合工艺,实现对高浓度DHA废水的耦合处理。试验采用高负荷、高进水浓度的方式对反应器的启动进行了分段研究,并分别对厌氧及好氧段有机物降解进行了效能分析。研究表明,启动初期采用DHA废水与生活污水混合进水的方式并控制反应器在中温条件下运行,可完成对反应器的快速启动。经60 d的调试运行,一体化反应器中厌氧段容积负荷达到10 kg COD/(m~3·d),COD去除率稳定在60%左右,好氧段容积负荷达到4 kg COD/(m~3·d),出水COD小于500 mg/L,满足《污水排入城镇下水道水质标准》(CJ 343-2010)。60 d后厌氧段颗粒污泥形状规则、密实,经扫描电镜观察发现,污泥表面具有较大孔隙且杆状菌占优势,好氧污泥在电子显微镜下可观察到钟虫。  相似文献   

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针对苏南某化工企业油漆、涂料、树脂和高沸点溶剂等产品生产过程中排放的高浓度化工废水处理,中试结果表明:当两相厌氧COD负荷为5.6 kg/(m3·d),一级好氧COD负荷1.47 kg/(m3.d),二级好氧负荷COD 0.035kg/(m3·d),且废水温度高于20℃时,两相厌氧—二级好氧生化系统的COD平均去除率高于95%;工程化应用表明:该工艺具有处理效果好、耐冲击、运行稳定、处理成本低的优点,当废水温度维持在20℃以上时,两相厌氧—二级好氧生化系统COD平均去除率达98%以上.  相似文献   

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水解酸化-厌氧-好氧工艺处理抗生素废水   总被引:2,自引:0,他引:2  
试验采用生化工艺处理高浓度抗生素废水。结果表明 ,水解酸化反应器最大COD容积负荷达到 1 6.84kg/(m3·d)。厌氧复合床处理水解酸化后的抗生素废水 ,当容积负荷为 6.0kg/(m3·d)时 ,反应器对SS、COD、BOD5 的去除率分别为 75.6%、91 .7%、96.1 % ;厌氧出水采用周期循环活性污泥系统进行处理 ,当容积负荷为 1 .6kg/(m3·d)时 ,反应器对SS、COD、BOD5 的去除率分别为 91 .6%、88.7%、95.4%。  相似文献   

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多段内循环厌氧反应器设计三段反应室,分别进行废水厌氧反应的三个过程。为探索该反应器处理中、高浓度有机废水的实际运行效果,以屠宰废水为处理对象,考察反应器对COD的去除效果。结果表明,当温度为36~38℃,COD容积负荷为0.5 kgCOD/(m3·d)时,反应器运行16天实现反应器的快速启动。进水COD浓度为1000mg/L,通过缩短水力停留时间(HRT)提高有机负荷,确定最佳的HRT为20h,对应的COD容积负荷为1.21 kgCOD/(m3·d),COD总去除率稳定达到93%。固定HRT=20 h,在COD容积负荷由低至高的提升阶段,分别为1.68,2.40,3.12,3.60和4.00 kg COD/(m3·d),反应器去除COD的总能力由94%降至80%,单位容积反应器产气率分别为0.9,1.4,1.0,1.9和2.1m3/(m3·d),去除单位COD产生的气体体积分布在0.29~0.33 m3/kg COD之间。  相似文献   

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针对维生素C生产废水COD高、盐度高、色度高、可生化性差等特点,经过MVR预处理后,采用中温UASB厌氧反应器和HTO好氧工艺处理该废水。结果表明,UASB反应器在温度为(35±2)℃,pH为6~9,COD容积负荷为4.5~6 kg/(m~3·d)时,COD去除率达84%以上;HTO好氧反应器在COD容积负荷为0.68 kg/(m~3·d),氨氮容积负荷为0.12 kg/(m~3·d)时,COD、NH_3-N去除率分别在85%、90%以上。最终处理出水可达CJ 343—2010的C级排放标准。  相似文献   

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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   

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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   

14.
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   

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A highly moisture-proof polysilsesquioxane coating was obtained from a new bis-silylated precursor, which was synthesized from 3-aminopropyltriethoxysilane (APTES) and m-xylylene diisocyanate (m-XDI) in tetrahydrofuran (THF) and verified by 1H MAS NMR. For direct comparison purposes, an SiO2 coating was also prepared by the Stöber method using tetraethoxysilane (TEOS) as the reactant. Interestingly, the coating obtained from the polysilsesquioxane sol exhibited a much higher moisture resistance capability than its counterpart, which was attributed to its more compact feature between nanoparticles as characterized by N2 absorption experiment and transmission electron microscopy (TEM). Furthermore, its high transparency of about 92% showed potential for application in the protection of optical crystals.  相似文献   

16.
Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.  相似文献   

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