Influence of external circulation on sludge characteristics during start-up of internal circulation reactor

The start-up of external circulationadded internal circulation(IC) reactor was finished in 26 d, 32 d fewer than that of IC reactor. To evaluate the influence of the added external circulation on the development of granular sludge, the characteristics of the granular sludge taken from the two tested laboratory-scale reactors during start-up were studied. The results show that the added external circulation can enhance biomass granulation, accelerate granule development and improve sludge characteristics. At the end of start-up, the granular size of sludge in external circulation-added IC reactor greatly increases with a size distribution much better than that of sludge in IC reactor. The granular sludge originated from external circulationadded IC reactor contains more extracellular polymers and has a greater settling velocity than that from IC reactor. Methanogenic activity of the granular sludge from the external circulationadded IC reactor started 26 d ago reaches 358.23mL·g -1 ·d -1 , 1.66 and 1.20 times as great as that of the sludge from the IC reactor started 26 d and 58 d ago respectively.

Treatment of methanol wastewater in external circulation anaerobic reactor with different inoculums

In order to guide the inoculums selection for the anaerobic treatment of methanol wastewater in the engineering application,two 7 L bench-scale external circulation (EC) anaerobic reactors were operated to investigate the inoculums of anaerobic granular sludge and anaerobic digested sludge,focusing on the efficiency and process stability.The effect of impact concentration and temperature on the performance was studied.The results demonstrated that anaerobic granular sludge as the inoculums could complete the start-up more rapidly than the anaerobic digested sludge,and above 90% COD removal were achieved at the organic loading rate of 10 to 15 kgCOD/(m3·d).The effect of impact COD on the methanogenic activity of sludge was weak and the removal efficiencies recovered gradually in the two reactors.The COD removal efficiencies reduced swiftly to 50%-60% due to the impact temperature.The results indicated that the complex bacterial groups in anaerobic digested sludge benefited to enhance the reactor's capacity for withstanding the temperature shock at some extent.

Treatment of methanol wastewater with two-stage and two-phase anaerobic process

The two-stage and two-phase anaerobic process (TSTP) composed of hydrolytic acidification reactor,first-order and second-order external circulation anaerobic reactors (EC) was taken to treat methanol wastewater. Test results show that TSTP process is quick start-up in 51 d, and the maximum VFA of hydrolytic acidification reactor effluent reaches 876 mg/L. Under the condition of volume loading of 6.56 kgCOD/m3·d, COD removal rate of the first-order EC reactor is about 85%, and under the condition of volume loading of 1.02 kgCOD/m3·d, COD removal rate of the second-order EC reactor is about 50%. When the inflow COD of TSTP process is between 7000-11000 mg/L, its effluent COD is lower than 600 mg/L. In the biological conversion process of methanol into methane,the production of acetic acids as an intermediate product can be ignored and the direct production of methane from methanol is predominant.

Insights into sludge granulation during anaerobic treatment of high-strength leachate via a full-scale IC reactor with external circulation system

In this study, a full-scale internal circulation（IC） reactor coupled with an external circulation system was developed to treat high-strength leachate from a municipal solid waste（MSW）incineration plant, in which anaerobic sludge granulation was intensively investigated. Results showed that the IC reactor achieved excellent treatment performance under high organic loading rates（OLR） of 21.06–25.16 kg chemical oxygen demand（COD）/（m3？ day）. The COD removal efficiency and biogas yield respectively reached 89.4%–93.4% and 0.42–0.50 m3/kg COD.The formation of extracellular polymeric substances（EPS） was closely associated with sludge granulation. Protein was the dominant component in sludge EPS, and its content was remarkably increased from 21.6 to 99.7 mg/g Volatile Suspended Solid（VSS） during the reactor operation. The sludge Zeta potential and hydrophobicity positively correlated with the protein/polysaccharide ratio in EPS, and they were respectively increased from-26.2 m V and 30.35% to-10.6 m V and 78.67%, which was beneficial to microbial aggregation. Three-dimensional fluorescence spectroscopy（3 D-EEM） and Fourier transform infrared spectroscopy（FT-IR）analysis further indicated the importance of protein-like EPS substances in the sludge granulation. Moreover, it was also found that the secondary structures of EPS proteins varied during the reactor operation.

IC厌氧反应器处理技术的应用研究及发展

IC厌氧反应器是第三代厌氧反应器,已广泛应用于高浓度有机废水处理。介绍了厌氧生物处理技术的特点及厌氧生物反应器的发展,重点介绍了IC厌氧反应器的构造、反应原理、特点、应用现状及发展趋势等,以期为IC厌氧反应器的应用提供参考。

IC厌氧反应器处理OCC废水运行效率研究

某OCC制浆造纸企业新建了一座容积2900 m^(3)的IC厌氧反应器,并引入来自同类废水的厌氧颗粒污泥。启动21天后,IC厌氧反应器运行效果达到设计负荷,OCC制浆造纸废水处理量为15000 m^(3)/d,CODCr处理量为50000 kg/d,CODCr去除率72%~86%,出水挥发性脂肪酸稳定保持在30~110 mg/L,IC厌氧反应器在较短时间内完成效率提升。

IC厌氧-两级AO工艺处理白酒废水工程实例

针对白酒废水中有机物含量高、可生化性较好、色度高、悬浮物浓度高等特点,某企业设计采用IC厌氧-两级AO-深度处理组合工艺进行处理,工程运行结果表明,在综合废水进水ρ(COD_(Cr))≤11750 mg/L、ρ(BOD_(5))≤5875 mg/L、ρ(NH_(3)-N)≤60 mg/L,处理后出水ρ(COD_(Cr))≤30 mg/L、ρ(BOD_(5))≤6 mg/L、ρ(NH_(3)-N)≤1.5 mg/L,满足GB 3838—2002《地表水环境质量标准》中Ⅳ类标准要求,其他指标满足GB/T 18920—2020《城市污水再生利用城市杂用水水质》中城市绿化及道路清扫水质要求。

IC+SBR工艺处理养猪场废水的研究

针对河北省阜平县某大型养猪场废水处理设备老化严重、处理能力不足、出水水质不达标等问题,采用“IC+SBR”组合工艺对养猪场废水进行处理,设计此工艺的处理能力为600 m^(3)/d。介绍了该项目的工艺流程和主要设计参数,考察了该处理工艺对养猪场废水的处理效果,并且分析了其前期投资和运行费用。结果显示:该项目对废水处理后的水质有显著的改善作用,对于废水中主要污染物COD的平均去除率为96.36%,BOD_(5)的平均去除率为96.76%,SS的平均去除率为92.72%,NH_(3)-N的平均去除率为90.87%。出水中各主要污染物指标均满足GB 18596—2001《畜禽养殖业污染物排放标准》的排放规定。

污水厌氧生物处理的新工艺—IC厌氧反应器

对IC反应器的结构、原理进行了简要介绍,并结合其工艺思想及应用实例指出IC反应器是对现代高效厌氧反应器的一种突破,具有处理效率高,抗冲击能力强等特点,有着重大的理论意义和实用价值.

IC反应器技术的发展

扼要介绍 IC反应器的基本结构和原理 ,并从工艺思想的角度对该反应器进行了分析 ,即 IC反应器是现有废水处理工艺成果与内循环技术相结合的产物。最后总结了

外循环对IC反应器运行效果的影响

为改善已形成颗粒污泥的IC反应器运行性能,增设外循环装置,并在回流比分别为0、1.0、2.0、3.0、4.0的情况下,进行了系统运行稳定性研究。与无外循环的情况相比,在设定的回流比范围内,附加外循环不会破坏反应器内部厌氧条件,反应器运行稳定;在进水COD为6000 mg·L-1左右,系统HRT约为10 h,容积负荷为14 kg·m-3·d-1的情况下,系统污泥MLSS有所增加,COD去除率随回流比的增大而增加,最高可达97.3%,出水COD低至160 mg·L-1;随回流比的增大,产气总量逐渐增加且最终可达171.2 L·d-1,甲烷产量先增加后趋于稳定,在回流比为2.0时可达到91.7 L·d-1;增加外循环运行一段时间后,厌氧颗粒污泥生物相更为丰富,产甲烷优势菌由甲烷杆菌转变为甲烷八叠球菌。结合能耗和去除效率等考虑,回流比为2.0时最佳。

生产性IC反应器厌氧颗粒污泥的生物学特征

IC反应器以絮状污泥接种用于处理酒糟废水,运行至第180d时分别测定反应器第1、第2反应室颗粒污泥的VSS、产甲烷活性、胞外多聚物和辅酶F420等各项生物学指标。结果表明反应器内颗粒污泥具有较强活性,反应器COD去除率基本稳定在95%以上,出水COD不超过1000mg/L。

IC反应器处理维生素制药废水的启动试验研究

采用IC反应器处理维生素制药废水,废水水质COD为9000mg·L-1,BOD为3500mg·L-1,pH为3～4。通过中试启动研究,结果表明,当IC反应器接种污泥浓度为17g·L-1时,启动试验成功,启动周期为91d,COD去除率达到90%以上,运行稳定。

IC反应器处理低浓度有机废水的启动实验研究

对内循环厌氧反应器(IC反应器)在(33±0.5)℃下处理低浓度有机废水的启动特性进行了实验研究。结果表明:反应器经过59 d启动成功;当进水COD浓度为411.6 mg/L,HRT为0.8 h,相应的有机负荷COD为12.3 kg/(m3.d)时,其COD去除率能稳定在87%左右,日产气率15 m3/(m3.d)左右,出水VFA浓度HAc为41.2～43.6 mg/L;污泥床反应区COD去除量占总COD去除量的77%以上,远大于精细处理区;启动完成后,反应器底部形成了颗粒污泥,镜检发现颗粒污泥表面分布着丝状菌,内部则以杆菌和球菌为主。

IC反应器水力特性实验研究

利用模拟实验的方法,从水力学的角度对压力、沼气产率以及温度与反应器内循环水流量的关系进行了实验研究。研究表明,压力变化是影响内循环水流量的最主要因素;反应器产气率对循环水流量的作用也非常显著,而且在一定范围内,反应器的循环水流量随产气率成线性关系变化;温度对反应器循环水流量的影响相对比较复杂,且与产气速率有很大关系;摩擦力对内循环水流量存在一定程度的影响,在反应器设计过程中不能忽略该因素。

内循环(IC)厌氧反应器在几种高浓度废水中的工程应用及发展

内循环(IC)厌氧反应器是在上流式厌氧污泥床(UASB)的基础上研制开发而成的第三代高效厌氧反应器,具有负荷高、效率高、能耗低、占地少、投资省和运行稳定等优点。随着对该反应器技术研究的不断深入和完善,它在工程上也得到了越来越广泛的推广和应用。文章对IC厌氧反应器在不同种类废水处理工程中的应用实例进行了分析研究,并介绍了由国内环保单位自行开发的多级内循环(MIC)厌氧反应器技术在工程中的应用情况。

IC厌氧反应器的内循环装置

通过模拟实验 ,对IC厌氧反应器中内循环装置进行了研究 。

IC厌氧反应器在外循环状态下启动的试验研究

为提高IC厌氧反应器在启动初期的上升流速,改善其传质作用,在回流比3∶1的条件下,启动运行IC反应器。结果显示,反应器能够在较短的时间内达到较高的COD去除率。在COD为8 000 mg/L时,反应器产气效率和产甲烷效率达到最大,分别为0.43、0.21 m3/(kg.d);出水pH在6.0～7.5,出水ORP在-300 mV左右,出水碱度大于进水碱度,成功培育出了颗粒污泥。

高浓度氨氮对IC厌氧反应器运行的抑制性研究

在中温（35±1）℃条件下，以葡萄糖为有机碳源，研究氨氮对IC厌氧反应器运行的影响。实验结果表明，氨氮浓度超过3036mg／L时对反应器的运行有抑制作用，随着氨氮浓度的增加，抑制作用更加明显，氨氮对系统的IC50为4500mg／L；系统运行过程中VFA低于400mg／L，pH值和碱度分别维持在7．21～7．62之间和2356～3065mg／L之间；反应器对氨氮的平均去除率为12．67％。在毒性恢复实验中，7d后COD去除率恢复到93．01％；恢复期系统VFA逐渐降低，从第6d开始维持在152～162mg／L之间；出水碱度和pH值维持在1769～2298mg／L和7．09～7．27之间，系统运行稳定。

附加外循环IC反应器启动试验

在启动期,IC反应器产气量很小,尚不能形成对颗粒污泥的有效搅动,传质过程主要受水力上升流速的控制。由于启动期的IC反应器只能以较低的容积负荷运行,进水流量受到限制,水力上升流速很难达到传质作用的要求,因此IC反应器也像其他类型厌氧装置一样,同样存在着启动周期较长,启动期运行不够稳定的问题。为改善启动期IC反应器的传质作用,本研究对IC反应器进行了改造,增加了外循环装置。通过处理啤酒配水的比较试验,发现在启动期附加外循环可有效强化传质过程,提高IC反应器内的泥水混合程度,大大缩短启动周期。附加外循环IC反应器的整个启动过程只用了26天,比未附加外循环装置的IC反应器缩短了32天。