CSTR和ABR甲烷发酵系统运行特征比较

厌氧发酵技术是解决环境污染及能源需求问题的重要途径。针对常见的连续流搅拌槽式反应器(CSTR)和厌氧折流板反应器(ABR)存在的甲烷发酵技术问题,开展了产甲烷系统的调控技术研究。在特定条件下,比较CSTR和ABR两类反应器的甲烷发酵系统效能。结果表明,在进水COD为4 000 mg/L、HRT为24 h条件下,CSTR系统运行73 d后可形成完整甲烷发酵,对COD的去除率维持在70%左右,但系统运行不够稳定。在接种污泥、进水COD、HRT等相同的情况下,ABR系统运行17 d后,对COD的去除率即可达到74%;保持有机负荷为4 kg/(m3·d)不变,通过调控ABR进水COD浓度、HRT等后,对COD的去除率可达到90%以上。与CSTR相比,ABR通过生物相的分离(产酸发酵菌群、产氢产乙酸菌群和产甲烷菌群等沿程分布于各格室并呈现不同的优势度),增强了产氢产乙酸作用,使系统去除效能更高、抗冲击负荷能力更强,运行也更稳定。     

厌氧折流板反应器处理精细化工废水的试验研究

采用厌氧折流板反应器(ABR)处理生产合成医药及农药中间体、光固化引发剂等精细化学品过程中产生的混合废水,结果表明,在ABR反应器的上流室中悬挂纤维填料可以防止污泥流失并提高ABR反应器的处理效率;当混合废水的COD＜7 600 mg/L时其具有良好的厌氧生化处理活性,在ABR反应器中能形成分级厌氧菌落.研究还发现该废水的碱度不足,需要额外投加2～2.5 g/L的Na2CO3或NaHCO3,以防止挥发性脂肪酸在前两个格室内积累;在水力停留时间为48 h、容积负荷为1.5～3.8 kgCOD/(m3·d)的条件下,ABR反应器对COD的去除率可达50%.     

3种有机废水的酸化发酵产氢特性研究

利用厌氧消化污泥对含糖废水、淀粉废水和养殖废水的酸化发酵产氢特性进行了研究。试验结果表明,以含糖废水为基质时的最大产氢能力为4.2m3/(m3·d),氢气最大含量为58.4%,运行参数应分别控制在pH值为4.3～5、HRT为3.5～5.0h、有机负荷为15～40kgCOD/(m3·d),稳定运行期间COD去除率为20%～30%。淀粉废水酸化产氢适宜的HRT(4.5～7h)大于含糖废水,而养殖废水的酸化发酵气体中始终未检测到氢气。     

两相厌氧工艺处理高盐纤维素醚废水的研究

采用接种特定污泥的两相厌氧反应器处理高盐纤维素醚废水,重点考察了启动过程及其处理效果。试验结果表明,当产酸相的HRT为18 h时,其所能承受的最大容积负荷为8.18kg/(m3.d),此时其对COD的去除率为20%左右;当产甲烷相的HRT为24 h时,其所能承受的最大容积负荷为5.5 kg/(m3.d),此时其对COD的去除率为35%左右;产甲烷相对COD的去除率与产酸相出水的酸化度呈显著正相关。在产酸相进水COD为6 000 mg/L、产甲烷相进水pH值为7的条件下,当产酸相进水pH值为6、HRT为18 h及产甲烷相的HRT为48 h时,系统的处理效果较佳,出水COD为1 800 mg/L,对COD的总去除率可达70%左右。     

中药废水两相厌氧生物处理工艺的工程调试

中药生产废水具有污染物浓度高、可生化性差、水质水量波动大等特点,属于高浓度难降解有机工业废水。采用具有专利技术的两相厌氧生物处理工艺处理中药废水,调试结果表明,通过选取适当的接种污泥和制定合理的调试运行方案,可以保证两相厌氧工艺在3个月内完成工程调试,最终产酸相反应罐容积负荷为30～45kgCOD/(m3.d),COD去除率稳定在15%～20%;产甲烷相反应池容积负荷为8～10kgCOD/(m3.d),COD去除率稳定在90%～95%。     

中温两相厌氧消化工艺处理混合污泥的效能

采用中温(35℃)两相厌氧消化工艺处理初沉污泥与剩余污泥的混合样(1∶1),以实现污泥的稳定化。结果表明,在水力停留时间约为10 d、有机负荷为2.75 kgVS/(m3.d)时,对TCOD的去除率可达46%,对VS的去除率为41%;产甲烷相反应器的最大比产甲烷活性为0.19LCH4/(gVS.d),并保持相对稳定;两相反应器内污泥的比脱氢酶活性都出现了增长,并维持在25~32μgINTF/(mgVS.h)之间;经消化后污泥的沉降性和脱水性变差。     

餐厨废水强化EGSB反应器处理焦化废水的启动

为确定餐厨废水强化EGSB反应器处理焦化废水的快速启动和污泥颗粒化可行性,对驯化阶段的挥发性脂肪酸(VFA)、产甲烷活性和污泥颗粒化程度(SGR)等指标进行分析。结果表明,在初始有机负荷为1.76 kg COD/(m~3·d)、中温条件下,采用逐步提高有机负荷和投加少量餐厨废水的方式可以加速反应器的启动,EGSB经过69 d即成功启动,容积负荷可达2.66 kg COD/(m~3·d),对COD的去除率为34%;焦化废水对颗粒污泥活性的毒性抑制作用是可逆的,随着微生物逐渐适应焦化废水,产甲烷菌的活性得到部分恢复;成熟颗粒污泥以小粒径颗粒污泥居多,SGR由接种颗粒污泥的91.12%降为86.63%。     

EGSB工艺在VC生产废水处理中的应用

采用中温EGSB工艺处理VC生产废水,考察了碱度、抑制物浓度、有机负荷、上升流速等因素对反应器处理效果的影响.结果表明:当进水碱度>800 mgCaCO3/L、上升流速为2.5m/h时,COD容积负荷最终稳定在16.3 kg/(m3·d),对COD的去除率>75%,水质得到极大改善;试验结束时,颗粒污泥的沉降速率为50.9 m/h、比产甲烷活性为244.11 mL/(gVSS·d)、污泥负荷为2.34 gCOD/(gVSS·d).     

微波预处理对厌氧颗粒污泥发酵产氢的影响

以高浓度有机废水为发酵底物,接种颗粒污泥进行厌氧发酵制氢,研究不同的微波预处理时间对颗粒污泥发酵产氢的影响。结果表明:最佳的微波预处理时间为6 min,此时的比产氢速率高达8.03 mmolH2/(gCOD.d);随着预处理时间的增加,对COD的去除率逐步提高,但也不宜过长,否则将会杀灭产酸菌芽孢,导致去除率降低;系统启动完成后,出水pH值稳定在4.5左右,对COD的去除率约为40%,颗粒污泥的VSS/SS值为83.0%,沉降速率为23.5 m/h。     

外循环厌氧反应器处理啤酒废水的启动研究

研究了外循环(EC)厌氧反应器处理啤酒废水的启动过程.结果表明:在以颗粒污泥进行接种的情况下,EC反应器可在23d内完成启动,容积负荷可达6.39kgCOD/(m3·d),对COD的去除率>85%;出水回流可使反应器内混合液的pH和颗粒污泥分布均匀,有利于产甲烷反应的高效进行,提高了反应器的容积利用率;启动结束后粒径为0.9-2mm的颗粒污泥由接种前的22.28%增加到35.5%,颗粒污泥比产甲烷活性达到接种时的2.38倍;VSS/SS由接种时的0.77增加到0.86.     

ABR中厌氧颗粒污泥的微生物学特性

了解厌氧折流板反应器(ABR)内厌氧颗粒污泥的微生态结构对于颗粒污泥的培养具有指导意义，为此对ABR各隔室中厌氧颗粒污泥的微生物组成进行扫描电镜观察，并测定了其在不同基质中的比产甲烷活性和辅酶F420的含量。结果表明，ABR各隔室颗粒污泥的微生物组成差异较大，1^#隔室颗粒污泥表面以产酸菌为主，内部以产甲烷杆菌为主，2^#、3^#隔室的颗粒污泥中没有明显的优势菌，菌群多样复杂，4^#隔室颗粒污泥中的优势菌是索氏甲烷菌；1^#隔室颗粒污泥利用葡萄糖、乙酸的产甲烷活性较低，利用丙酸的产甲烷活性最高，2^#、3^#、4^#隔室颗粒污泥利用葡萄糖、乙酸的产甲烷活性较高，利用丙酸的产甲烷活性较低。ABR中颗粒污泥的辅酶F420沿隔室逐渐升高，与产甲烷活性的变化一致，也就是说F420可以反映颗粒污泥的产甲烷活性。     

Psychrophilic and mesophilic anaerobic digestion of brewery effluent: a comparative study

Two expanded granular sludge bed-anaerobic filter (EGSB-AF) bioreactors (3.38 l active volume) were used to directly compare psychrophilic (15 degrees C), anaerobic digestion (PAD) to mesophilic (37 degrees C) anaerobic digestion (MAD) for the treatment of a brewery wastewater (chemical oxygen demand (COD) concentration of 3,136+/-891 mg l(-1)). Bioreactor performance was evaluated by COD removal efficiency and biogas yields at a range of hydraulic and organic loading rates. Specific methanogenic activity (SMA) assays were also employed to investigate the activity of the biomass in the bioreactors. No significant difference in the COD removal efficiencies (which ranged from 85-93%) were recorded between PAD and MAD during the 194-d trial at maximum organic and hydraulic loading rates of 4.47 kg m(-3) day(-1) and 1.33 m(3) m(-3) day(-1), respectively. In addition, the methane content (%) of the biogas was very similar. The volumetric biogas yield from the PAD bioreactor was approximately 50% of that from the MAD bioreactor at an organic loading rate of 4.47 kg COD m(-3) day(-3) and an applied liquid up-flow velocity (V(up)) of 2.5 m h(-1). Increasing the V(up) in the PAD bioreactor to 5 m h(-1) resulted in a volumetric biogas production rate of approximately 4.1 l d(-1) and a methane yield of 0.28 l CH(4) g(-1) COD d(-1), which were very similar to the MAD bioreactor. Significant and negligible biomass washout was observed in the mesophilic and psychrophilic systems, respectively, thus increasing the sludge loading rate applied to the former and underlining the robustness of the latter, which appeared underloaded. A psychrotolerant mesophilic, but not truly psychrophilic, biomass developed in the PAD bioreactor biomass, with comparable maximum SMA values to the MAD bioreactor biomass. PAD, therefore, was shown to be favourably comparable to MAD for brewery wastewater treatment and biogas generation.     

微电解/水解酸化/SBR工艺处理化学制药废水

采用微电解/厌氧水解酸化/SBR组合工艺处理难生物降解的化学制药废水.结果表明:微电解/厌氧水解酸化预处理可大大提高化学制药废水的可生化性,其BOD_5/COD由0.13增至0.64.在SBR处理系统中,当污泥负荷控制在0.5 kgCOD/(kgMLSS·d)、曝气为10～12 h时,对COD的去除率可达到85%以上,污泥增长速率约为1.5 kg/(m~3·d).     

好氧颗粒污泥技术用于味精废水处理的研究

以厌氧颗粒污泥为接种污泥,采用人工模拟废水在SBR反应器内培养好氧颗粒污泥,35 d后颗粒污泥成熟,反应器对COD和NH4+-N的去除率分别高于95%和99%。采用该反应器处理味精废水,当COD、NH4+-N的容积负荷分别为2.4、0.24 kg/(m3.d)时,对COD、NH4+-N和TN的去除率分别在90%、99%和85%左右,且颗粒污泥未出现解体的现象。以厌氧颗粒污泥为接种污泥、味精废水为进水,在与上述相同条件下培养好氧颗粒污泥,经过60 d的培养,反应器内的污泥以絮状污泥为主,该系统对COD、NH4+-N和TN的去除率分别为85%、99%和70%。     

Methanogenic granular sludge as a seed in an anaerobic baffled reactor

This paper reviews the importance of phase separation in anaerobic wastewater treatment, characteristics of anaerobic baffled reactor (ABR), properties of anaerobic granular sludge, granulation process and advantages of granular sludge over nongranular sludge. The performance data of ABR and its modified configurations with regard to carbonaceous matter removal by using various seed sludges are compared. It is concluded that enhanced wastewater treatment efficiencies can be achieved with methanogenic granular seed sludge in an ABR because of a number of advantages associated with granular biomass over nongranular aggregates.     

环境温度下DASB预处理脱墨废水的研究

降流式厌氧污泥床反应器(DASB)作为一种新型厌氧处理工艺,具有生物截留能力强、泥水混合效果好、运行管理方便、性能可靠等优点。采用DASB对造纸脱墨废水进行预处理,研究了其影响因素和水解酸化效果。试验结果表明,pH值、HRT和容积负荷对DASB的运行效果有一定的影响,当出水pH值为7.0～7.2、HRT为22.4 h、容积负荷为2.15 kg/(m3.d)时,运行效果最好;在最佳运行条件下,当进水BOD5/COD值在0.38左右时,出水BOD5/COD值可提高到0.50左右,脱墨废水的可生化性大大提高。     

间歇膨胀复合厌氧工艺用于处理抗生素废水

采用间歇膨胀复合厌氧/A-O-SBR工艺处理高浓度制药废水,在进水有机负荷为2.134～11.488 kgCOD/(m3.d)、pH值为4.5～6的常温条件下,厌氧反应器COD去除率>70%,容积负荷可达到9.075 kgCOD/(m3.d)。厌氧出水经A-O-SBR及混凝气浮处理后,出水COD、氨氮、总磷、pH值分别为130 mg/L、4.4 mg/L、2.39 mg/L、7.8,完全满足企业所在地的纳管排放要求。     

Performance characteristics of the anaerobic baffled reactor

An anaerobic sludge blanket process, termed the anaerobic baffled reactor (ABR), has been developed and shows promise for industrial wastewater treatment. It combines the advantages of high stability and reliability with a high void volume. The risk of clogging and sludge bed expansion with resulting high microbial losses is reduced and there is no need for special gas collection or biological solids separation systems. Organic loadings as high as 36 g COD l^?1day^?1 have been achieved with COD removal rates of more than 24 g COD l^?1 day^?1 and methane production rates exceeding 6 volumes per day per unit volume of reactor. The hypothesis, that the ABR may be adequately modeled as a fixed-film reactor, has been supported. Therefore, a unified approach, based on fundamentals of bacterial kinetics and mass transport, appears useful for modeling this and similar systems. Pilot plant studies are necessary to determine the scaling factors of the system as well as the overall efficiency and costs.     

Performance of UASB reactor treating leachate from acidogenic fermenter in the two-phase anaerobic digestion of food waste

This study was conducted to investigate the performance of the upflow anaerobic sludge blanket (UASB) reactor treating leachate from acidogenic fermenter in the two-phase anaerobic digestion of food waste. The chemical oxygen demand (COD) removal efficiency was consistently over 96% up to the loading rates of 15.8 g COD/l d. The methane production rate increased to 5.51/l d. Of all the COD removed, 92% was converted to methane and the remaining presumably to biomass. At loading rates over 18.7 g COD/l d, the COD removal efficiency decreased due to sludge flotation and washout in the reactor, which resulted from short HRT of less than 10.6 h. The residual propionate concentration was the highest among the volatile fatty acids (VFA) in the effluent. The specific methanogenic activity (SMA) analysis showed that the VFA-degrading activity of granule was the highest for butyrate, and the lowest for propionate. Typical granules were found to be mainly composed of microcolonies of Methanosaeta. The size distribution of sludge particles indicated that partially granulated sludge could maintain the original structure of granular sludge and continue to gain size in the UASB reactor treating leachate from acidogenic fermenter.