外循环式UASB反应器处理高浓度酒精废水

利用改进型上流式厌氧污泥床反应器在中温条件下处理高浓度酒精废水,研究反应器的启动影响因素及颗粒污泥形成过程,分析反应器运行特性。在容积负荷为10.39 kg COD/(m3.d),COD去除率达90.2%,VFA在300 mg/L以下,平均产气率为0.328 m3/kg COD,取得最佳的运行效果,为高浓度酒精废水的处理应用提供科学依据。     

Oily wastewater treatment using a novel hybrid PBR-UASB system

In this study, anaerobic treatability of oily wastewater was investigated in a hybrid reactor system consisting of a packed bed reactor (PBR) followed by an upflow anaerobic sludge blanket (UASB) reactor at 35 degrees C. The system was operated using real pet food wastewater at different hydraulic retention times and loading rates for 165 d. The PBR was packed with sol-gel/alginate beads containing immobilized enzyme which hydrolyzed the oil and grease (O&G) into free long chain fatty acids, that were biodegraded by the UASB. The hybrid system was operated up to an oil loading rate of 4.9 kg O&Gm(-3)d(-1) (to the PBR) without any operational problems for a period of 100 d, with COD and O&G removal efficiencies above 90% and no sludge flotation was observed in the UASB. Beads supplement to the PBR was less than 2 g d(-1) and the relative activity was about 70%. Further increment in O&G loading to 18.7 kg O&Gm(-3)d(-1) caused destabilization of the system with 0.35% (v float/v feed) sludge float removed from the UASB.     

Study on hydrogen production with hysteresis in UASB

This paper uses a 10-l UASB (upflow anaerobic sludge blanket) bench-scale reactor to treat the esterification wastewater of a polyethylene terephthalate manufacturing plant. Two organic loading rates are used to evaluate the effect on H2 production of temperature gradually step-down and step-up in the range of 11-25 degrees C. Experimental results show that H2 production is positively related to temperature. H2 production increases with temperature at the higher organic loading rate (4.5 kg COD m(-3)d(-1)). However, the H2 produced does not go back to its original concentration but rather follows a hysteresis curve. This hysteresis also occurs in the corresponding concentrations of COD, acetate, propionate and butyrate. As in the H2 profiles, these parameter curves return clockwise during the temperature step-up. At the lower organic loading rate (2.2 kg COD m(-3)d(-1)), no obvious hysteresis is observed for H2 curve. The pattern of other parameters, except for the propionate, returns counterclockwise resulting in the hysteresis phenomena.     

Influence of the organic loading rate on the performance and the granular sludge characteristics of an EGSB reactor used for treating traditional Chinese medicine wastewater

The effects of the organic loading rate (OLR) on the performance and the granular sludge characteristics of an expanded granular sludge bed (EGSB) reactor used for treating real traditional Chinese medicine (TCM) wastewater were investigated. Over 90 % of the COD removal by the EGSB reactor was observed at the OLRs of 4 to 13 kg COD/(m³ day). However, increasing the OLR to 20 kg COD/(m³ day) by reducing the hydraulic retention time (HRT 6 h) reduced the COD removal efficiency to 78 %. The volatile fatty acid (VFA) concentration was 512.22 mg/L, resulting in an accumulation of VFAs, and propionic acid was the main acidification product, accounting for 66.51 % of the total VFAs. When the OLR increased from 10 to 20 kg COD/(m³ day), the average size of the granule sludge decreased from 469 to 258 μm. There was an obvious reduction in the concentration of Ca²⁺ and Mg²⁺ in the granular sludge. The visible humic acid-like peak was identified in the three-dimensional excitation-emission matrix (EEM) fluorescence spectra of the soluble microbial products (SMPs). The fatty acid bond, amide II bond, amide III bond, and C–H bond bending were also observed in the Fourier transform infrared (FTIR) spectra of the SMPs. Methanobacterium formicicum, Methanococcus, and Bacteria populations exhibited significant shifts, and these changes were accompanied by an increase in VFA production. The results indicated that a short HRT and high OLR in the EGSB reactor caused the accumulation of polysaccharides, protein, and VFAs, thereby inhibiting the activity of methanogenic bacteria and causing granular sludge corruption.     

内循环厌氧反应器的启动及影响因素

采用内循环(IC)厌氧反应器,以生产淀粉和酒精的混合废水为处理对象,研究了中温条件下IC反应器的启动及影响因素。结果表明:接种厌氧消化污泥进行培养,逐渐提高进水有机负荷,运行105 d后,可实现IC反应器的启动;当进水COD浓度为11 500 mg/L,有机容积负荷为6.13 kg COD/(m3·d),COD去除率能到达95%左右;水力停留时间对启动过程没有影响,而温度和温度波动影响COD去除率;VFA比pH更能准确快速地反眏出反应器内部环境的变化,防止反应器的酸化;反应器内污泥实现颗粒化,并且具有良好的沉降性。     

Effect of recycle-to-influent ratio on activities of nitrifiers and denitrifiers in a combined UASB-activated sludge reactor system

A laboratory study using a combined upflow anaerobic sludge bed (UASB)-activated sludge (AS) reactor system was undertaken to explore the effect of recycle-to-influent ratio (R(e)=1, 2, and 3) on the activities of nitrifiers and denitrifiers. Suspended-solids pre-settled piggery wastewater was used as the substrate-feed wastewater. At the R(e) of 1-3, the combined reactor system achieved efficient removal of COD (96-97%), TKN (100%) and total nitrogen TN (54-77%). Methanogenesis occurred with nearly-complete denitrification in the UASB reactor, whereas complete nitrification took place in the AS reactor. A higher R(e) (i.e., accompanied with a shorter solids retention time) resulted in a larger amount of high-activity denitrifiers and thereby achieved a higher TN removal efficiency. Compact granules and a high biomass concentration in the UASB reactor were observed. At the R(e) of 1-3, the maximum specific reaction rate of nitrifiers (0.45-0.49 NH(4)(+)-NmgVSS(-1)d(-1)) and the specific nitrification rates of mixed culture (0.18-0.22mg NH(4)(+)-NmgVSS(-1)d(-1)) in the AS reactor varied slightly; whereas the maximum specific reaction rate of denitrifiers (0.18-0.27mg NO(x)(-)-NmgVSS(-1)d(-1)) and the specific denitrification and COD removal rates of mixed culture (0.025-0.050mg NO(x)(-)-NmgVSS(-1)d(-1); 0.24-0.31mgCODmgVSS(-1)d(-1)) in the UASB reactor increased with increasing R(e). The primary finding of the study is that the combined UASB-AS reactor system should be operated at a higher R(e) to maintain high-activity denitrifiers to remove organic materials and nitrogen from piggery wastewater.     

Anaerobic bioconversion of carbon dioxide to biogas in an upflow anaerobic sludge blanket reactor

The increasing concentration of carbon dioxide (CO2)--the most dominant component of greenhouse gases--in the atmosphere has been of growing concern for many years. Many methods focus on CO2 capture and storage and there is always the risk of CO2 release to the environment. In this study, a new method to convert CO2 to biogas with a high content of methane (CH4) in an anaerobic system with a lab-scale upflow anaerobic sludge blanket reactor at 35 degrees C was developed. In a series of experiments, the reactor was run with and without CO2-saturated solutions including volatile fatty acids (VFAs) as sources of hydrogen. The concentration of dissolved CO2 in the influent solutions was 2.2-6.1 g/L, with corresponding chemical oxygen demand (COD) values of 2.6-8.4 g/L for the solutions. Overall CO2 removal values of 2.7-20 g/day (49-88% conversion) were obtained for the organic loading rates (OLR) and CO2 loading rates of 8-36 gCOD/L day and 6-26 gCO2/L x day, respectively with CH4 purity of above 70%. Also, VFA and COD removal were in the range of 79-95% and 75-90%, respectively. Methanogenic activities of the cultures with the concentrations measured as volatile suspended solids (VSSs) were 0.12-0.40 L CH4/gVSS x d with the highest value for the system containing acetic acid. This anaerobic method can be applied to reduce CO2 emitted to the atmosphere from a wide variety of industrial point sources with a value-added product, CH4.     

Biological treatment of dye wastewaters using an anaerobic-oxic system

Three dye solutions, namely, C.I. Acid Yellow 17, C.I. Basic Blue 3, and C.I. Basic Red 2, were treated in an upflow anaerobic sludge blanket (UASB) reactor followed by a semi-continuous aerobic activated sludge tank. When hydraulic retention time was about 12 hours, no significant color removal was observed in the aerobic stage. In the anaerobic stage, Acid Yellow 17, Basic Blue 3, and Basic Red 2 were removed by 20%, 72%, and 78%, respectively. To treat wastewater from a dye manufacturing factory with COD concentration of 1200 mg/l and Color of 500 degree (dilution factor), an UASB reactor (4.5 liters) and an activated sludge tank (5 liters, adjustable), COD and color were removed by more than 83% and 90% at a COD loading rate of 5.3 kg COD/m³-day in the anaerobic stage, and at the hydraulic retention time of 6-10 hours for the anaerobic stage and 6.5 for the aerobic stage. The anaerobic stage of the A/O system removes both color and COD. In addition, it also improves biodegradability of dyes for further aerobic treatment.     

EGSB反应器运行中的床层流态行为及其控制

生物量流失是EGSB反应器在高负荷状态下稳定运行面临的主要问题。利用实验室EGSB反应器在中温条件下处理高浓度葡萄糖废水,研究EGSB反应器在高负荷状态下的床层流态行为及其受影响因素。结果表明,在该反应器结构形式下,当有机负荷达到23-26 kg COD/（m3·d）,水力上升流速在约3.0 m/h,气体上升流速在约1.3 m/h状态下运行时,床层易发生剧烈流化现象,并导致颗粒污泥的解体和流失。降低反应器回流比、减小反应器内水力上升流速,控制床层在悬浮状态时可以有效降低高负荷状态下生物量的流失,并取得了有机负荷46 kg COD/（m3·d）,COD去除率97%以上的处理效果。     

Simultaneous nitrification and denitrification in an aerobic reactor with granular sludge originating from an upflow anaerobic sludge bed reactor.

Anaerobic granular sludge, obtained from an upflow anaerobic sludge bed reactor at a brewery waste treatment station, was cultured for 3 months under aeration conditions until the diameter of sludge was in the range 1.8 to 2.6 mm. The aerobic granular sludge gathered acquired the ability of catalyzing simultaneous nitrification and denitrification (SND) and was applied in the study of the process of nitrogen removal in a bioreactor. The ratio between chemical oxygen demand (COD) and ammonium-nitrogen (NH4(+)-N) concentration in the influent was found to be an important factor influencing the process of SND. The final percentage removal of NH4(+)-N reached 100% under the optimal condition of 500 mg/L COD and 0.39 NH4(+)-N/COD. Intermediate products, such as nitrite-nitrogen and nitrate-nitrogen, were also analyzed to clarify the SND process with the aerobic granular sludge.     

2种UASB的ANAMMOX与反硝化协同作用对比研究

采用2套UASB-ANAMMOX反应器处理垃圾渗滤液,其中反应器2具有生物膜,对反应器在有机环境下的ANAMMOX与反硝化协同作用进行对比研究。在稳定期,反应器1和反应器2对氨氮、亚硝氮、TIN、COD的平均去除率分别为95.7%、95.9%、77.3%、70.3%和97.4%、96.4%、87.2%、74.8%。反应器1对TIN和COD最大容积去除率为112.2和107.7 g/(m3.d),反应器2对TIN和COD最大容积去除率为120.5和119.9 g/(m3.d)。结果表明,过高的负荷会对反应器产生抑制作用,且当抑制产生后协同作用难以恢复到原来水平。在厌氧氨氧化与反硝化协同作用良好时,pH值和碱度均存在特征性变化。总体上,反应器2比反应器1具有更强的厌氧氨氧化与反硝化协同作用和抗负荷冲击能力。     

EGSB反应器处理城市生活垃圾沥滤液

采用膨胀颗粒污泥床(EGSB)反应器对城市生活垃圾焚烧厂产生的垃圾沥滤液进行处理。实验结果表明:中温条件下,当COD浓度为55 000 mg/L左右,有机容积负荷(OLR)为22.8 kg COD/(m3.d)时,EGSB对垃圾沥滤液具有较好的的处理效果,COD去除率可达94.2%。当进水COD为72 000 mg/L左右时,为保证反应器的稳定运行,OLR应降低至18.2 kg COD/(m3.d),此时COD去除率可以达到88%左右,出水COD平均为9 103 mg/L。垃圾沥滤液和EGSB处理出水均以小分子量有机物为主,其中<4 kDa的有机物分别占76.5%和74.4%。EGSB对整个分子量区间的溶解性有机物都有较好的处理效果,其中对大分子有机物的处理效率相对更高。     

外循环式UASB反应器处理槟榔废水

在中温（35±2℃）条件下,利用外循环式UASB反应器处理中高有机浓度的槟榔加工废水,并着重探讨了水力停留时间（HRT）对厌氧消化的影响。研究表明,当反应器稳定运行,水力停留时间为1 d,进水COD浓度5 000 mg/L左右,容积负荷在2.53-5.25 kg COD/（m3·d）时,COD去除率在38%以上,出水COD〈3 000 mg/L,平均产气率为0.41 m3/kg COD;若水力停留时间延长至4 d,容积负荷为1.26-1.30 kg COD/（m3·d）,COD去除率可以达到79%,出水COD〈1 200 mg/L,出水可生化性下降,BOD5/COD平均为0.28,实验取得了良好的处理效果,为利用厌氧技术处理槟榔加工废水提供了设计依据。     

摇动床生物膜反应器和活性污泥法组合技术处理高浓度有机废水的研究

利用摇动床生物膜反应器(简称摇动床)技术具有的容积负荷高与污泥产量低的优点,在普通活性污泥池的前部填充高性能丙烯酸树脂纤维(Biofringe)填料,研究了摇动床和活性污泥法组合技术处理高浓度有机废水的有效性。结果表明,该组合技术具有很强的有机物去除能力,当进水COD平均质量浓度由1500mg/L上升到2514mg/L时,出水COD的平均去除率基本保持在96%以上;整个运行阶段的出水COD浓度均满足《污水综合排放标准》(GB8978—1996)的二级标准;当进水NH4+-N浓度增加时,NH4+-N的去除率由99.7%降低到76.5%,但是在试验运行的整个阶段,摇动床和活性污泥法组合技术系统都表现出较强的硝化能力;活性污泥池中最高的混合液悬浮固体(MLSS)质量浓度为10625mg/L,最高MLSS约为普通活性污泥法的4倍;运行结束后的污泥产率为0.186,污泥产率仅为普通活性污泥法的50%左右。     

降低负荷以提高反硝化颗粒污泥的稳定性

在上流式污泥床反应器（USB）内，接种好氧活性污泥，以甲醇为碳源，NO-3为电子受体，经过40多d培养，得到良好的反硝化颗粒污泥，粒径2～3 mm，MLSS为36 g/L，氮去除速率和COD去除速率分别在0.15 g NO₃-N/(g VSS·d)和0.8 g COD/(g VSS·d)。当负荷提高至6.44 g NO₃-N/(L·d)继续运行1周后，观察到反应器内颗粒污泥出现上浮，浓度降低，颗粒粒径多数在3～5 mm，外观呈乳白色。为恢复反应器稳定运行，当负荷降至3.86 g NO₃-N/(L·d)时，上浮现象减轻，当负荷降至2.57 g NO₃-N/(L·d)时，上浮现象消失，颗粒污泥密度由不稳定时的1.0018 g/cm³提高到1.0126 g/cm³，颗粒粘连现象基本消失，污泥氮去除速率在0.19 g NO₃-N/(g VSS·d)，连续运行30 d，系统保持稳定。分析认为，颗粒污泥表面微生物生长速度过快是导致不稳定的主要因素，较长的泥龄有利于系统稳定。     

Comparative mesophilic and thermophilic anaerobic digestion of palm oil mill effluent using upflow anaerobic sludge blanket

The effects of organic loading rate and operating temperature on the microbial diversity and performances of upflow anaerobic sludge blanket (UASB) reactors treating palm oil mill effluent (POME) were investigated. The following two UASB reactors were run in parallel for comparison: (1) under a mesophilic condition (37 degrees C) and (2) under a mesophilic condition in transition to a thermophilic condition (57 degrees C). A polymerase chain reaction (PCR)-based denaturing gradient gel electrophoresis (DGGE) analysis showed that the microbial population profiles significantly changed with the organic loading rate (OLR) and the temperature transition from the mesophilic to the thermophilic condition. Significant biomass washout was observed for the mesophilic UASB when operating at a high organic loading rate (OLR) of 9.5 g chemical oxygen demand (COD)/L.d. In contrast, the thermophilic UASB can be operated at this OLR and at a temperature of 57 degrees C with satisfactory COD removal and biogas production. The PCR-based DGGE analysis suggested that the thermophilic temperature of 57 degrees C was suitable for a number of hydrolytic, acidogenic, and acetogenic bacteria.     

Microbial activity in a combined UASB-activated sludge reactor system

A combined upflow anaerobic sludge bed-activated sludge (UASB-AS) reactor system with consistently wasting of excess biomass was used to treat suspended-solids pre-settled piggery wastewater (COD=2000 mg l(-1), total Kjeldahl nitrogen TKN=400 mg l(-1), suspended solids=250-400 mg l(-1)). Thus, the activity of nitrogen-related microbial groups in each individual bioreactor was investigated. When the granules retention time (GRT) of 20-50 d in the UASB reactor, the solids retention time (SRT) of 10-25 d in the AS reactor and the recycle-to-influent ratio (Re) of 1 were maintained, the combined system removed 95-97% of chemical oxygen demand (COD), 100% of TKN and 54-55% of total nitrogen (TN). Denitrification and methanogenesis occurred in the UASB reactor so that both biochemical processes contributed to most of the COD removal and, complete nitrification (most of the TKN removal) occurred in the AS reactor. Compact granules with good settling abilities developed in the UASB reactor, and rapid rates of granulation of break-up granules in the UASB reactor were confirmed by experiments. The activity of nitrifiers and denitrifiers (an=0.68-0.87; adn=0.55-0.70) and the calculated specific nitrification and denitrification rates (qn=0.26-0.47 mg NH4+ -N mg VSS(-1)d(-1); qdn=0.046-0.076 mg NOx- -N mg VSS(-1)d(-1)) significantly increased with decreasing SRT and GRT, respectively. Accordingly, the combined UASB-AS reactor system should be regarded a promising alternative for the removal of organic carbon and nitrogen from piggery wastewater.     

新型高效生物反应器类型和应用

近年来高效生物反应器得到不断发展,出现了多种新型生物反应器.从厌氧升流式生物反应器发展的经验和反应器的特点出发,提出了升流式反应器的结构、三相分离器的形式和污泥颗粒化现象等3个新概念是高效新型反应器的基础,进而在广义升流式污泥床反应器概念的基础上,提出具有传质效率高、处理能力强、有机负荷高以及抗冲击负荷能力强等优点的第三代高效生物反应器概念.     

新型高效生物反应器类型和应用

近年来高效生物反应器得到不断发展，出现了多种新型生物反应器。从厌氧升流式生物反应器发展的经验和反应器的特点出发，提出了升流式反应器的结构、三相分离器的形式和污泥颗粒化现象等3个新概念是高效新型反应器的基础，进而在广义升流式污泥床反应器概念的基础上，提出具有传质效率高、处理能力强、有机负荷高以及抗冲击负荷能力强等优点的第三代高效生物反应器概念。     

Influence of nutrients on biomass evolution in an upflow anaerobic sludge blanket reactor degrading sulfate-laden organics.

This paper describes the effect of the nutrients iron (Fe), nickel (Ni), zinc (Zn), cobalt (Co), and molybdenum (Mo) on biomass evolution in an upflow anaerobic sludge blanket (UASB) reactor metabolizing synthetic sulfate-laden organics at varying operating conditions during a period of 540 days. A bench-scale model of a UASB reactor was operated at a temperature of 35 degrees C for a chemical oxygen demand-to-sulfate (COD/SO4(2-)) ratio of 8.59 to 2.0, a sulfate loading rate of 0.54 to 1.88 kg SO4(2-)/m3 x d, and an organic loading rate of 1.9 to 5.75 kg COD/m3 x d. Biomass was characterized in terms of total methanogenic activity, acetate-utilizing methanogenic activity, total sulfidogenic activity, acetate-utilizing sulfidogenic activity, and scanning electron microscopy (SEM). Nickel and cobalt limitation appears to affect the activity of hydrogen-utilizing methane-producing bacteria (HMPB) significantly without having an appreciable effect on the activity of acetate-utilizing methane-producing bacteria (AMPB). Nickel and cobalt supplementation resulted in increased availability and, consequently, restoration of biomass activity and process performance. Iron limitation and sulfidogenic conditions resulted in the growth of low-density, hollow, fragile granules that washed out, causing process instability and performance deterioration. Iron and cobalt supplementation indicated significant stimulation of AMPB with slight inhibition of HMPB. Examination of biomass through SEM indicated a population shift with dominance of sarcina-type organisms and the formation of hollow granules. Granule disintegration was observed toward the end of the study.