复配表面活性剂协同促进氨氮吹脱效能研究

在传统吹脱法处理高浓度氨氮废水的基础上,以表面活性剂为主、乙酸乙酯(ETAC)为溶剂复配有机复合脱氮剂,探究表面活性剂碳数、水温、复配有机溶剂及复配比对氨氮吹脱效能的影响。结果表明:投加表面活性剂对吹脱去除氨氮有促进作用,随着表面活性剂碳数的增加,氨氮吹脱效能逐渐升高,升高水温可提高氨氮吹脱效能;以表面活性剂复配乙酸乙酯作为脱氮剂时,ODTMS/ETAC复合脱氮剂对吹脱去除氨氮的促进作用最佳,氨氮去除率高达99.79%,剩余氨氮浓度为12 mg/L;以表面活性剂间复配及复合表面活性剂复配ETAC作为脱氮剂时,ODTMS/EGA/ETAC复合脱氮剂对吹脱去除氨氮的促进作用最佳,吹脱5 h后对氨氮的去除率接近100%,而使用ODTMS/EGA复合脱氮剂,吹脱6 h后对氨氮的去除率为98.72%,复配ETAC能够提高脱氮效率,缩短吹脱时间。     

吹脱联合MAP法处理高氨氮废水的研究

高氨氮高盐百草枯废水属于难处理的工业废水,对吹脱和MAP法联合处理该高氨氮废水进行了研究。当吹脱反应的p H值为10.5、气液比为4 000、温度为(45±2)℃、反应时间为6 h时,对氨氮的去除率达到97.4%。吹脱之后的废水继续通过MAP法处理,当p H值为10.2、n(Mg)∶n(N)∶n(P)为1.2∶1.0∶1.2、反应时间为40 min时,对氨氮的去除率为95.5%。氨氮浓度最终可由23 066 mg/L降至26.99 mg/L,且吹脱和MAP法对COD也有一定的去除作用。小试的运行参数在生产性工程中得到进一步的调整优化,既保证了去除效果又控制了运行成本。     

城镇高氨氮污水的吹脱除氮试验研究

针对高浓度氨氮废水进入城镇市政管网所造成的污水厂脱氮效果较差的情况,提出了采用吹脱除氮法作为污水厂的二级生物处理或一级强化处理的预处理,并进行了试验研究,考察了污水pH、吹脱气水比、进水氨氮浓度、水力负荷等因素对吹脱效果的影响。结果表明,污水最佳pH值为10.511,增加水力停留时间可提高对氨氮的去除率,水温为15℃时气水比应控制在3 360∶1以上,水力负荷可选择在2.04~3.57 m3/(m2.h)。试验表明吹脱法除氮处理工艺可作为脱氮除磷二级生物处理或一级强化处理的预处理。     

吹脱法去除ADU母液中氨氮的研究

对吹脱法处理除铀、除氟后的ADU母液进行了研究,考察了吹脱p H值、时间、气液比、温度对氨氮去除效率的影响。结果表明:在p H值为12,吹脱温度为30℃,气液比为6000,控制吹脱时间为210min,可将氨氮浓度从3325mg/L降至212mg/L。采用硫酸吸收尾气,避免了二次污染。     

吹脱法及其工程应用

本以综述的形式简单地介绍了吹脱的基本原理和吹脱法处理石油污染水、中低浓度氨氮废水、2－萘酚生产废水、高浓度氨氮废水、硫化氢废水、预处理垃圾渗滤液等的工程实践以及所得到的结论和存在的问题。     

SBBR处理老龄化垃圾渗滤液的自养脱氮效能

针对老龄化垃圾渗滤液高氨低碳的水质特征,在序批式生物膜反应器(SBBR)中构建能承受高浓度氨氮的自养脱氮系统,探讨负荷及温度对该自养脱氮系统效能的影响,并考察两级SBBR自养脱氮系统的处理效能。结果表明:负荷及温度对反应器自养脱氮效能的影响显著。在温度为28℃、DO为5.0 mg/L、挂膜密度为60%、氨氮负荷为0.83 kg/(m3.d),反应器运行周期为进水0.25 h、反应23 h、沉淀0.5 h、出水0.25 h,以及进水氨氮、总氮、BOD5分别为3 330、3 435、120 mg/L的条件下,两级SBBR系统的出水氨氮和TN分别为110、434 mg/L,对氨氮及总氮的去除率分别为96.7%和87.4%,实现了高效脱氮。     

分段进水A/O工艺强化脱氮除磷研究

为解决传统工艺同步脱氮除磷效率低的问题,采用分段进水A/O工艺处理高氨氮浓度生活污水,考察了在低COD/TN值(平均为3.8)条件下曝气量和协同化学除磷对系统去除COD、氨氮、TN和TP的影响.在0.7、0.5和0.3 m3/h三种曝气量条件下,系统对COD的去除效果稳定,平均去除率分别为87.97％、90.72％和91.27％;在曝气量为0.5 m3/h的条件下,通过对各好氧区DO浓度的优化分配,对氨氮的去除率达到了95％以上,并且由于发生了好氧反硝化,对TN的去除率明显高于其他两种工况;在碳源成为脱氮除磷限制因素的条件下,平均除磷率分别为31.76％、32.84％和44.49％,通过同步投加聚合氯化铝和硫酸铝的复配药剂,出水TP浓度基本达到了0.5 mg/L.     

碳源对缺氧/厌氧/好氧工艺脱氮除磷效果的影响

通过投加有机碳源改变进水的碳氮比,考察了不同碳氮比条件下缺氧/厌氧/好氧工艺的脱氮除磷效果.结果表明:在污泥回流比为120%的条件下,当C/N值为7、C/P值为75时,缺氧/厌氧/好氧工艺对污水的脱氮除磷效果最佳,对TP、NH4M+-N和TN的去除率分别可达95%以上、98%和67%.     

老龄化垃圾渗滤液的短程硝化效能研究

老龄化垃圾渗滤液具有高氨低碳的水质特征.以构建能承受高氨氮浓度的自养生物脱氮系统为目标,考察了DO、负荷、pH及挂膜密度对该系统短程硝化效能的影响.结果表明:在温度为30℃、DO为2.5 mg/L、氨氮负荷为1.0 kg/(m3·d)、pH值为8.0、挂膜密度为30%、反应器运行工况为进水0.25 h/反应23 h/沉淀0.5 h/出水0.25 h、进水氨氮为2 000 mg/L的条件下,系统能够获得87.7%的氨氮去除率及77.4%的亚硝态氮积累率.挂膜密度对系统自养脱氮效能的影响显著,在挂膜密度为60%时,系统对总氮的去除率为55.5%,其中自养脱氮的分担率约为76.6%.     

铁炭微电解工艺对高硝态氮制药废水的脱氮效能

以高硝态氮、难降解的有机制药废水为处理对象,探讨了铁炭微电解工艺对其脱氮效能及影响因素.结果表明:填料粒径、pH值、铁炭比、气水比、停留时间等因素均对铁炭微电解系统的脱氮效能有显著影响;在铁屑和活性炭粒径均为35目、pH值为3、Fe/C值为3:1(体积比)、气水比为5:1、停留时间为1.5 h的最佳条件下,当进水TN、NH4+-N和NO3--N的平均浓度分别为823、30和793 mg/L,BOD5/COD值为0.1时,铁炭微电解系统对TN、NH4+-N和NO3--N的平均去除率分别可达到51.5%、70%和50.94%.     

水渣填料曝气生物滤池去除氨氮特性研究

利用水渣为主要原料开发了一种新型曝气生物滤池填料,并以陶粒为参比填料,通过改变进水pH值和氨氮负荷等工艺参数,研究了水渣填料去除氨氮的特性.试验结果表明：水渣曝气生物滤池较陶粒曝气生物滤池具有更明显的去除氨氮的效果.在进水pH值为5.2～5.5,进水氨氮浓度分别为16、32、64 mg/L时,水渣曝气生物滤池对氨氮的平均去除率分别为90.63%、85.39%、63.46%,这是因为该填料能够溶出CaCO3,为硝化反应提供了碱度;而陶粒曝气生物滤池则因碱度不足而导致对氨氮的去除率较低.水渣曝气生物滤池内的pH值沿水流方向呈逐渐升高的趋势,而陶粒曝气生物滤池的则相反.当处理pH值较低而氨氮浓度较高的原水时,与传统的陶粒曝气生物滤池相比,水渣曝气生物滤池更能显示出在去除氨氮方面的优势.     

氧化镁改性沸石处理猪场废水的研究

在不同作用时间和pH下,采用动态吸附方法,考察了氧化镁改性沸石对猪场废水的处理效果.结果表明:在不同作用时间和pH下,改性沸石对猪场废水的处理效果均好于天然沸石的;最佳作用时间为4 h,此时改性沸石对氨氮、总磷的去除率分别为88.6%和76.2%;改性沸石去除氨氮的最佳pH值为7,此时去除率为88.7%;改性沸石去除总磷的最佳pH值为9,此时去除率为86.3%.     

组合生态系统氨氮去除最佳单元及其去除机制研究

通过考察稳定塘-湿地组合生态处理系统各单元对氨氮去除速率的差异，提出了去除氨氮的最佳单元类型，分析了该单元对氨氮的主导去除机制。结果表明，在该组合生态处理系统中，水深为1．0m左右、大量生长浮萍等水生植物及溶解氧浓度较高的水生植物塘是去除氨氮的最佳单元。在水生植物塘中，生物吸收（有机氮固定）作用是低温期去除氨氮的主导机制，同步硝化反硝化作用则是高温期去除氨氮的主导机制。     

Organic removal by denitritation and methanogenesis and nitrogen removal by nitritation from landfill leachate

A system consisting of a two-stage UASB and anoxic-oxic reactor was used to enhance COD and nitrogen removal from landfill leachate. To improve denitrification efficiency, the raw leachate with recycled final effluent was pumped into the first-stage UASB (UASB1) to carry out simultaneous denitrification and methanogenesis. The results over 180 d show that the maximum organic removal rate in UASB1 and UASB2 was 12.5 and 8.5 kgCODm(-3)d(-1) in the oxic zone of the A/O reactor, respectively. The COD and biochemical oxygen demand (BOD5) removal efficiency of the system was 80-92% and about 99%, respectively. Without controlling temperature (17-30 degrees C) and dissolved oxygen (0.5-4.0 mgL(-1)), the maximum NH4+-N removal rate was 0.68 kg NH4+-Nm(-3)d(-1), and about 99% of NH4+-N removal was obtained by nearly complete nitritation. The 81-93% total nitrogen removal was obtained by complete denitrification in the UASB1 and in the anoxic zone of the A/O reactor. Fluorescence in situ hybridization (FISH) analysis of the sludge samples from A/O reactor showed that ammonia oxidizing bacteria (AOB) consisted 4% of the eubacterium, while nitrite oxidizing bacteria (NOB) counted less than 0.2% of that. The study shows that the main factors achieving and maintaining nitritation are a proper range of free ammonia concentration obtained by dilution recycled final effluent that inhibits NOB but not AOB; effective control on aeration time by indication of "ammonia valley" on pH profile; and highly efficient denitrification and its reproducing alkalinity to result in pH above 8.5.     

以DO、ORP、pH控制SBR法的脱氮过程

为实现SBR法脱氮在线模糊控制,以啤酒废水为研究对象,通过不同进水混合液氨氮浓度的试验,详细地研究了SBR法在去除有机物和硝化、反砂化过程中DO、ORP、pH的变化规律。试验表明,DO、ORP、pH的特征点和平台的重现性很好,可以作为SBR法去除有机物、砂化、反硝化的过程控制参数。     

进水氨氮对厌氧同步脱氮除硫工艺的影响

通过比较含氨氮和不含氨氮两种进水水质条件下接种物不同的两个反应器的脱氮除硫特性,研究进水氨氮对厌氧同步脱氮除硫性能的影响。结果表明,进水未加氨氮的反应器对硫化物和硝态氮的去除率均高达95%,当加入氨氮后,仅有40%～50%的硝态氮被去除,消耗1 g硫化物所还原的硝态氮量减少,去除硝态氮的能力降低了近50%,然而对硫化物的去除率仍维持在90%左右,表明脱氮过程比脱硫过程受进水氨氮的影响大。扫描电镜观察结果证实,当进水中存在氨氮时硫化物的毒性增大,杀死了大量的脱氮硫杆菌,降低了硫化物转化为单质硫的能力,干扰了系统的反硝化脱氮过程,这是导致体系脱氮能力降低的主要原因。     

前置反硝化BAF工艺处理景观水体

为了提高曝气生物滤池(BAF)对景观水体的脱氮效果,开发了前置反硝化BAF工艺,考察了其对景观水体的处理效果及影响因素,并与传统BAF工艺作比较。结果表明,前置反硝化BAF工艺对TN和浊度的去除效果明显优于传统BAF工艺,前者对TN和浊度的平均去除率分别为45%和88%,而后者的分别为30%和47%;两种工艺对COD和氨氮的去除效果相近,但前置反硝化BAF工艺的出水水质更稳定;对于前置反硝化BAF工艺,当水力负荷为1.42~4.95 m/h时,对COD、氨氮和TN的去除率均随水力负荷的增加而降低;在水力负荷为2.12 m/h的条件下,回流比对COD和氨氮的去除效果影响不大,但对TN的去除率随回流比的增加呈先升高后降低的趋势,最佳回流比为1.5∶1;另外,对TN的去除率随进水C/N值的增加而升高,当C/N6时,系统的脱氮效果较好。     

新型生物反应器处理微污染原水的硝化效果

为探寻适宜的微污染原水处理工艺,将蜂窝陶瓷载体置于内循环管中而构成气升式内循环蜂窝陶瓷反应器(IAL-CHS)。采用该工艺处理上海漕河泾水,考察了HRT、水温、pH值、溶解氧对去除氨氮的影响。在反应器挂膜启动后,连续运行的去除效果比间歇运行的好。HRT是影响硝化效果的重要因素,通过连续运行试验确定了最佳的HRT为1.03 h,此时对氨氮的去除率稳定在84.8%～99.2%。对氨氮的去除率与水温近似呈直线关系,温度越高则去除效果越好;河水的pH值对硝化反应影响不大;DO达到3.16 mg/L就能获得较好的处理效果,此时的曝气量为0.15 m3/h。此外,该反应器还具有抗冲击负荷能力强、不易堵塞等优点。     

Productivity and nitrogen balance in large scale phytoplankton cultures

Biomass production and nitrogen balance was studied in 35,000 gal (133,000 1) phytoplankton cultures comprising the first stage in a tertiary sewage treatment-mariculture system. The diatom Phaeodactylum tricornutum persisted for most of the study. At secondary sewage effluent loadings sufficient to produce residual dissolved inorganic nitrogen concentrations above approximately 5 μg atoms l⁻¹, an N:C ratio (molar) of 0.17 was obtained and algal growth was not nutrient-limited. Biomass levels, and hence pond particulate carbon and nitrogen output, varied in response to solar irradiance and dilution rate, but not temperature. Mean winter and summer yields were approximately 1 and 5 g (83 and 417 mg atoms) C m⁻² d⁻¹ respectively. An inverse relationship existed between algal biomass concentration and dilution rate, such that in the late spring optimal pond yields occurred between 0.55 and 0.65 dilutions d⁻¹. Better than 95% dissolved total nitrogen removal was obtained. Net dissolved organic nitrogen production, that would offset dissolved inorganic nitrogen removal, did not occur. Pond particulate nitrogen output was usually less than dissolved total nitrogen removal. Probable explanations for this include (1) ammonia evolution to the atmosphere at high pond pH, (2) particulate nitrogen sedimentation, and (3) denitrification. Of these, the first is believed to be quantitatively the most significant.     

Degradation of acetonitrile through a sequence of microbial reactors

Degradation of nitrogen containing organic compounds often leads to formation of ammonium and some low molecular weight organic compounds. The study is focused on degradation of acetonitrile in a sequence of stirred biofilm reactors, where the degradation of acetonitrile into acetic acid and ammonia takes place in the first two reactors. A large fraction of the acetic acid is also degraded in these reactors. The subsequent two reactors were introduced in order to take care of the ammonia, while a fifth reactor was a polishing step before the water was released to the recipient. From earlier studies it is known that the rate of acetonitrile degradation is approximately 80 g acetonitrile/ (m3 reactor h). In the present study nitrification proceeded with 10 g NH4(+)-N/(m3 reactor h) and the denitrification by 35 g NOx(-)-N/ (m3 reactor h). This means that the reactors involved in removal of the nitrogen component needs to be far larger than those dealing with degradation of the more complex molecules.