游离氨对城市生活垃圾渗滤液短程硝化的影响

为了考察游离氨(free ammonia,FA)对高氮城市生活垃圾渗滤液短程硝化的影响,采用“两级UASB-缺氧-好氧系统”处理实际城市生活垃圾渗滤液.首先在UASB1中实现同时反硝化与产甲烷反应,COD在UASB2中进一步去除,在A/O反应器中利用残余COD进行反硝化以及将NH⁺₄-N彻底硝化.试验共进行79 d,经历3个阶段,即稳定短程硝化(40 d)、短程硝化破坏(19 d)、短程硝化恢复(20 d).结果表明,适当的游离氨浓度（40～70 mg·L^-1）可实现稳定的短程硝化,如在阶段1中亚硝态氮积累率为97%,氨氮的去除率为99%.但游离氨浓度在160 mg·L^-1左右会抑制全部的硝化反应.在阶段3中,通过稀释原水降低了游离氨浓度,在短时间内就恢复了短程硝化.可见,游离氨是实现和维持城市生活垃圾渗滤液短程硝化的重要影响因素.     

Advanced landfill leachate treatment using a two-stage UASB-SBR system at low temperature

A two-stage upflow anaerobic sludge blanket(UASB) and sequencing batch reactor(SBR) system was introduced to treat landfill leachate for advanced removal of COD and nitrogen at low temperature.In order to improve the total nitrogen(TN) removal efficiency and to reduce the COD requirement for denitrification,the raw leachate with recycled SBR nitrification supernatant was pumped into the first-stage UASB(UASB1) to achieve simultaneous denitrification and methanogenesis.The results showed that UASB1 played an important role in COD removal and UASB2 and SBR further enhanced the nutrient removal efficiency.When the organic loading rates of UASB1,UASB2 and SBR were 11.95,1.63 and 1.29 kg COD/(m3·day),respectively,the total COD removal efficiency of the whole system reached 96.7%.The SBR acted as the real undertaker for NH4+-N removal due to aerobic nitrification.The system obtained about 99.7% of NH4+-N removal efficiency at relatively low temperature(14.9-10.9°C).More than 98.3% TN was removed through complete denitrification in UASB1 and SBR.In addition,temperature had a significant effiect on the rates of nitrification and denitrification rather than the removal of TN and NH4+-N once the complete nitrification and denitrification were achieved.     

高氮渗滤液缺氧/厌氧UASB-SBR工艺低温深度脱氮

在低温条件下,采用缺氧/厌氧UASB-SBR组合工艺处理实际垃圾填埋场渗滤液.结果表明,该工艺可实现有机物和氮的同步、深度去除.在进水COD平均为11950.2mg/L,NH4+-N为982.7mg/L的条件下,出水分别为390.1mg/L和2.9mg/L,去除率分别为96.7%和99.7%.同时,缺氧UASB1反应器的最大COD负荷达到13kg/(m3×d),最大COD去除速率为12.39 kg/(m3×d),具有高效缺氧反硝化和高效厌氧降解有机物反应的双重功效, 在SBR反应器的缺氧段和缺氧UASB,反应器内获得了99%以上的反硝化率.对于冬季水温分别为14.9,14.1,13.5,11.05℃的低温条件下,SBR反应器实现了完全硝化和反硝化,出水TN分别为4.1,5.7,14.1,16.5mg/L,达到了深度脱氮的目的.此外,在上述温度范围内,温度对反硝化速率(rN)的影响大于对硝化速率 (rDN)的影响, rN/rDN比值相对恒定.     

Three-stage aged refuse biofilter for the treatment of landfill leachate

A field-scale aged refuse(AR) biofilter constructed in Shanghai Refuse Landfill,containing about 7000 m3 aged refuse inside,was evaluated for its performance in the treatment of landfill leachate. This AR biofilter can be divided into three stages and can manage 50 m3 landfill leachate per day. The physical,chemical,and biological characteristics of AR were analyzed for evaluating the AR biofilter as leachate treatment host. The results revealed that over 87.8%-96.2% of COD and 96.9%-99.4% of ammonia nitrog...     

An autotrophic nitrogen removal process：Short-cut nitrification combined with ANAMMOX for treating diluted effluent from an UASB reactor fed by landfill leachate

A combined process consisting of a short-cut nitrification (SN) reactor and an anaerobic ammonium oxidation upflow anaerobic sludge bed (ANAMMOX) reactor was developed to treat the diluted effluent from an upflow anaerobic sludge bed (UASB) reactor treating high ammonium municipal landfill leachate.The SN process was performed in an aerated upflow sludge bed (AUSB) reactor (working volume 3.05 L),treating about 50% of the diluted raw wastewater.The ammonium removal efficiency and the ratio of NO 2 N to NOx-N in the effluent were both higher than 80%,at a maximum nitrogen loading rate of 1.47 kg/(m 3 ·day).The ANAMMOX process was performed in an UASB reactor (working volume 8.5 L),using the mix of SN reactor effluent and diluted raw wastewater at a ratio of 1:1.The ammonium and nitrite removal efficiency reached over 93% and 95%,respectively,after 70-day continuous operation,at a maximum total nitrogen loading rate of 0.91 kg/(m 3 ·day),suggesting a successful operation of the combined process.The average nitrogen loading rate of the combined system was 0.56 kg/(m 3 ·day),with an average total inorganic nitrogen removal efficiency 87%.The nitrogen in the effluent was mostly nitrate.The results provided important evidence for the possibility of applying SN-ANAMMOX after UASB reactor to treat municipal landfill leachate.     

高氮渗滤液短程深度脱氮及反硝化动力学

采用单级UASB-SBR生化系统处理实际高氮晚期渗滤液,重点研究了系统的有机物和氮去除特性,同时考察了SBR短程生物脱氮系统内微生物的反硝化动力学特性.试验结果表明,该生化系统能够高效、深度去除渗滤液内高浓度有机物和氮.UASB反应器的平均COD负荷为6.5 kg/(m3.d),去除速率为5.3 kg/(m3.d).在进水COD平均为6 537 mg.L-1,NH+4-N为2 021mg.L-1的条件下,出水分别为354 mg.L-1和2.8 mg.L-1以下,去除率分别为94.6%和99.8%,尤其是该系统获得了99.2%的TN去除率,出水TN20 mg.L-1,实现了深度脱氮的目的.SBR反应器实现并维持了稳定的短程硝化,通过90%以上的亚硝化率实现高效的氨氮去除,同时SBR系统内微生物的反硝化特性符合Monod动力学方程.     

Nitrogen removal via nitrite from municipal landfill leachate

A system consisting of a two-stage up-flow anaerobic sludge blanket (UASB), an anoxic/aerobic (A/O) reactor and a sequencing batch reactor (SBR), was used to treat landfill leachate. During operation, denitrification and methanogenesis took place simultaneously in the first stage UASB, and the e uent chemical oxygen demand (COD) was further removed in the second stage UASB. Then the denitrification of nitrite and nitrate in the returned sludge by using the residual COD was accomplished in the A/O reactor, and ammonia was removed via nitrite in it. Last but not least, the residual ammonia was removed in SBR as well as nitrite and nitrate which were produced by nitrification. The results over 120 d (60 d for phase I and 60 d for phase II) were as follows: when the total nitrogen (TN) concentration of influent leachate was about 2500 mg/L and the ammonia nitrogen concentration was about 2000 mg/L, the shortcut nitrification with 85%–90% nitrite accumulation was achieved stably in the A/O reactor. The TN and ammonia nitrogen removal e ciencies of the system were 98% and 97%, respectively. The residual ammonia, nitrite and nitrate produced during nitrification in the A/O reactor could be washed out almost completely in SBR. The TN and ammonia nitrogen concentrations of final e uent were about 39 mg/L and 12 mg/L, respectively.     

城市污水混合垃圾渗滤液脱氮试验研究

采用倒置A2/O工艺处理垃圾渗滤液与城市污水混合后的污水脱氮。正交试验得到,水力停留时间是影响混合污水脱氮和有机物去除的控制因素;理论最优运行参数是HRT为9 h、ρ(DO)为2 mg/L、R为80%、r为200%,该工况下COD、NH3-N和TN的平均去除率分别为77.4%、97.2%和62.4%,出水浓度可稳定地达到GB18918-2002《城镇污水处理厂污染物排放标准》一级A标准。     

碳氮比及HRT_S对交替缺氧/好氧CAST去除营养物的影响

以实际生活污水为处理对象,分别研究了碳氮比(COD/TN)为2.6、3.5及4.4时,HRTS(选择器水力停留时间)对交替缺氧/好氧(A/O)CAST工艺去除营养物性能的影响.结果表明,采用交替A/O运行方式,进水COD/TN比及HRTS的变化对COD去除性能影响不明显;而对脱氮性能影响较大.当进水COD/TN比分别为2.6和3.5时,系统氨氮去除率均维持在98%以上,TN去除率则随HRTS的增大而升高;HRTS由1.8h增至5h时,2种碳氮比下的TN去除率分别由62.9%、72.1%升至76.2%、84.6%.当进水COD/TN比为4.4时,HRTS由1.8h增至5h导致系统硝化不完全,TN去除率由86.3%降至58.2%.研究还发现,提高COD/TN比和增大HRTS均能改善系统的除磷性能.本研究中交替A/O运行方式下,进水COD/TN比为4.4(远低于一般城市生活污水的8～10),HRTS为1.8h时,CAST工艺获得较好的脱氮除磷效果,TN及磷的去除率分别为86.3%和93.8%,出水达到我国城镇污水处理厂污染物排放标准(GB18918-2002)一级A要求.     

SBR处理早期垃圾渗滤液中的COD和氨氮

采用SBR法对早期垃圾渗滤液进行好氧生物处理,探讨了进水COD负荷、pH值对COD、氨氮的处理效果和机理。实验结果表明:当运行周期为24 h时,好氧生物处理对早期的垃圾渗滤液有很好的处理效果,COD的去除率都能达到88%左右;出水的COD浓度随着进水COD浓度呈直线变化。pH一直保持在中性条件下,有利于COD的去除,但是对氨氮的去除却有一定的抑制作用。     

生活垃圾焚烧厂渗沥液厌氧氨氧化脱氮效能及微生物机理分析

生活垃圾焚烧厂渗沥液是一种含高氨氮高有机物浓度的难处理废水,目前渗沥液生物脱氮多采用多级硝化反硝化处理工艺,存在能耗大、效率低等不足。以厌氧氨氧化技术为核心,构建连续流厌氧消化-短程硝化-厌氧氨氧化三段式工艺,分析垃圾焚烧厂渗沥液的生物脱氮效果、有机物迁移转化规律、功能微生物活性及组成变化。结果表明:在进水ρ（NH₄+-N）为900~1800 mg/L,ρ（COD）为3000~20000 mg/L时,系统处理效果良好,稳定运行期间总无机氮和COD去除率分别为85%和77%。其中厌氧消化段可去除约45%的COD,短程硝化段NO₂--N积累率保持在97%以上,厌氧氨氧化段稳定运行期间总无机氮去除率约为85%,系统内也存在一定程度反硝化反应。接入渗沥液后,自养脱氮体系中功能微生物氨氧化菌（AOB）和厌氧氨氧化菌（Anammox）的活性均有不同程度的下降,采用宏基因组学结合16S rDNA高通量测序技术对比分析微生物的群落和功能组成变化,发现渗沥液中高浓度的有机物使短程硝化段和厌氧氨氧化段内异养反硝化菌相对丰度上升,Anammox受到难降解有机物抑制,其中Candidatus_Kuenenia菌属适应性较强,在驯化后仍然可以维持厌氧氨氧化系统较高的脱氮效果。     

晚期垃圾渗滤液厌氧氨氧化脱氮及其抑制动力学

采用晚期垃圾渗滤液对UASB反应器中无机环境培养条件下厌氧氨氧化菌进行驯化,探讨基质浓度和水力停留时间对系统运行性能的影响,通过批式试验分别对基质和垃圾渗滤液抑制厌氧氨氧化动力学进行测定并建立相应的动力学模型.结果表明,经过75d的运行,系统逐渐适应垃圾渗滤液并实现高效脱氮.基质的去除量随进水基质浓度的升高呈先升高后降低的变化趋势.随着HRT的延长,进水基质及渗滤液浓度逐渐升高,系统脱氮效果降低.厌氧氨氧化基质抑制的阈值是NH₄⁺-N浓度为489.03mg/L和NO₂^--N浓度为192.36mg/L.当以铵盐为抑制剂时,V_{max(NH4⁺-N)}为0.1893mg/(mg·d),半饱和常数为39.39mg/L,抑制动力学常数为3482.27mg/L.当以亚硝酸盐为抑制剂时,V_max(NO2^--N)为0.246mg/(mg·d),半饱和常数为43.19mg/L,抑制动力学常数为701.15mg/L.厌氧氨氧化受垃圾渗滤液影响尤为显著,垃圾渗滤液条件下厌氧氨氧化活性被完全抑制的浓度为1450.69mg/L (以COD计) .     

短程硝化-厌氧氨氧化组合工艺深度处理垃圾渗滤液

为解决垃圾渗滤液中高浓度污染物对微生物的毒性抑制、生物处理出水有机物或氮不达标及投加碳源成本高的问题,采用UASB(上流式厌氧污泥床)-A/O(缺氧/好氧)反应器-ANAMMOXR(厌氧氨氧化反应器)工艺,通过短程硝化-ANAMMOX(厌氧氨氧化)深度处理实际垃圾渗滤液与生活污水混和液(体积比为1∶10),其ρ(COD_Cr)、ρ(NH₄+-N)和ρ(TN)分别为(750±30)(290±10)和(300±10)mg/L,试验共进行90 d. 结果表明:COD_Cr、NH₄+-N和TN的去除率分别为88%±1%、95%±1%和91%±1%,最终出水质量浓度分别为(67±5)(15±2)和(35±5)mg/L,满足GB 16889—2008《生活垃圾填埋场污染控制标准》的排放要求. A/O反应器中的ρ(FA)(FA为游离氨)在0.21～1.38 mg/L之间,可抑制NOB(硝酸细菌),使AOB(氨氧化细菌)成为优势菌种,从而实现并维持NO₂--N积累率(70%～96%)较高的短程硝化,继而在ANAMMOXR中通过ANAMMOX去除残余NH₄+-N和NO₂--N,实现系统对氮的深度去除.      

免烧粉煤灰陶粒作为BAF填料处理城市污水

以电厂粉煤灰为主要试验原料,辅以外加药剂(水泥、石灰、石膏、水玻璃),经混合、成球、陈化和养护等工序,制得免烧粉煤灰陶粒,并将其作为曝气生物滤池(BAF)工艺的载体填料处理城市污水.待挂膜启动成功后,考察了水力停留时间( HRT)、COD负荷、氨氮负荷对COD和氨氮去除效果的影响.实验结果表明:在温度为18～21℃、气...     

一种沉淀法处理生活垃圾渗滤液的研究

生活垃圾渗滤液来源于生活垃圾的含水和地表径流和地下水的浸入。渗滤液是一种高浓度的有机废水。与工业废物一起填埋的垃圾渗滤液中还含有较多的重金属,垃圾浸滤液一旦控制不当,将会污染地下水,甚至对人体健康造成危害。目前研究垃圾浸滤液的方法已经成为水处理研究的热点,但研究生活垃圾浸出液中氨氮的去除比较少。本文首先介绍研究磷酸铵镁沉淀去除氨氮的原理,接下来讨论了磷酸铵镁沉淀法去除垃圾渗滤液中的氨氮的各种因素,分析了各种最佳条件的形成。在去除氨氮同时,对重金属也有很好的去除效果。磷酸铵镁沉淀法去除氨氮同时形成的是一种重要复合肥料。MAP法可降低垃圾渗滤液中COD浓度,改善其可生化性,并具有对NH3-N去除率高,无二次污染,受温度影响很小等特点。     

DPR-SNED系统处理低C/N城市污水与硝酸盐废水的运行特性

为实现低C/N城市污水与含硝酸盐废水的同步处理,采用SBR接种活性污泥,通过合理控制厌氧/缺氧/低氧时间和溶解氧(DO)浓度,实现了反硝化除磷耦合同步硝化内源反硝化(DPR-SNED)系统的启动,并对启动过程中系统的脱氮除磷特性进行了研究.结果表明采用厌氧/低氧的运行方式,控制厌氧时间为3 h,好氧段DO浓度为0. 5～1. 0 mg·L-1,60 d可实现同步硝化内源反硝化除磷(SNEDPR)系统的启动,出水PO_4~(3-)-P浓度0. 5 mg·L-1,系统氮磷去除率维持在90%以上,COD的去除率维持在80%以上,系统SNED率和CODins率分别维持在70%和95%左右;随后改变运行方式,采用厌氧/缺氧/低氧的方式运行,缺氧段前进含硝酸盐废水,45 d可实现DPR-SNED系统的启动,缺氧末PO_4~(3-)-P浓度1. 1 mg·L-1,出水PO_4~(3-)-P浓度0. 5 mg·L-1,系统磷、COD去除率均维持在90%以上,氮去除率维持在88%以上,系统SNED率和CODins率分别维持在62%和90%左右. DPR-SNED系统的成功启动后,厌氧段聚糖菌和聚磷菌对城市污水有限碳源的充分利用和强化储存,可为后续缺氧段及好氧段的脱氮除磷提供充足的内碳源.此外,DPR-SNED系统缺氧段内源短程反硝化的进行保障了系统在低C/N(4)条件下的高效脱氮.     

活性焦对垃圾渗滤液中难降解有机物的吸附及影响因素研究

垃圾渗滤液经预处理后与城市污水混合进行生物处理是较为有效的方法,但垃圾渗滤液中含大量难降解有机物,严重影响了城镇污水处理厂出水COD.因此,需强化垃圾渗滤液预处理过程,使其适用于生物处理.本研究采用活性焦吸附某垃圾焚烧发电厂垃圾渗滤液,发现活性焦对垃圾渗滤液中COD、色度、恶臭、TOC、TN等均具有良好的处理效果.通过对吸附性能的影响因素研究发现,活性焦种类、投加量、p H和吸附时间均会影响吸附效果,最佳活性焦投加量为20 g·L~(-1),酸性条件更有利于吸附,渗滤液中COD的去除主要发生在吸附过程的前1 h.活性焦吸附可提高垃圾渗滤液的可生化性,主要吸附垃圾渗滤液中难降解芳香族大分子有机物,其中,对溶解性有机物中疏水性有机酸组分的吸附效果最佳,使其出水适用于生物处理,从而保证污水处理厂COD可以稳定达标排放.     

UASB1-A/O-UASB2深度处理垃圾渗滤液

针对传统垃圾渗滤液生物处理TN去除率低、投加碳源成本高的问题,采用UASB1-A/O-UASB2(单级上流式厌氧污泥床+缺氧/好氧+后置上流式厌氧污泥床)工艺处理实际垃圾渗滤液,实现NH₄+-N和TN的同步深度脱除,并且定量解析了A/O反应器实现并维持稳定短程硝化的影响因素. 结果表明:以V(垃圾渗滤液)∶V(生活污水)为1∶5的混合液作为进水,其ρ(COD_Cr)、ρ(TN)和ρ(NH₄+-N)分别为1 700~1 800、660~700和650~680 mg/L,最终出水COD_Cr、TN和NH₄+-N去除率均在95%以上,出水ρ(TN)为38 mg/L,满足GB 16889—2008《生活垃圾填埋场污染控制标准》的排放要求. 在好氧反应器中,FA(游离氨)与FNA(游离亚硝酸)对NOB(硝化细菌)的联合抑制作用是实现NO₂--N积累率稳定在80%以上的主要原因,而产生的NO₂--N和NO₃--N可在UASB2中以难降解的有机物为碳源,通过反硝化途径被去除. 研究显示,组合系统可实现对TN的深度去除.      

广州垃圾填埋渗滤液中有机污染物的去除效果

采用同时好氧厌氧生物反应器处理广州市大田山垃圾填埋渗滤液,平均出水浓度COD_Cr为131mg·L^-1,氨氮为7mg·L^-1,达到了同类废水的国家二级排放标准.同时选择GC-MS联用仪对垃圾渗滤液中的有机物进行测定,测得有机污染物87种,其中16种有机污染物被列入美国EPA环境优先控制污染物,31种有机物被完全去除,14种有机物去除率可达80%以上,25种有机物去除率达50%以上.     

回流对陈垃圾生物反应器处理老年渗滤液污染物影响

为了研究回流对陈垃圾反应器处理老年渗滤液污染物的影响,构建了回流的陈垃圾生物反应器,试验了不同温度、负荷和回流比条件下反应器对污染物的去除效果。结果表明,在较低水力负荷12.8~25.5 L/(d.m2)的情况下,陈垃圾反应器对NH3-N、BOD5和COD等污染物的去除率分别达到90%、95%和70%以上。在不同温度下提高水力负荷,回流会抑制氨氮和COD的去除,但可显著提高TN的去除率,表明回流可作为提高老年渗滤液TN去除率的途径之一。利用氮同位素示踪技术发现反应器中有Anammox脱氮途径存在。但是可利用碳源的缺乏仍是提高老年渗滤液脱氮效率的限制因子。