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。     

AFB-SBR工艺处理蓝皮制革工业废水

采用厌氧流化床(AFB)-序批式反应器(SBR)工艺处理蓝皮制革工业废水。分别考察了水力停留时间(HRT)、容积负荷对厌氧流化床以及曝气时间、污泥浓度、溶解氧浓度对SBR反应器处理效果的影响。试验结果表明,AFB将实验废水的BOD_5/COD(B/C)值由0.19～0.26提高至0.35～0.42,有效提高了其可生化性;在进水COD浓度为1 700～1 890 mg/L、HRT为1 d、容积负荷为1.792 kg COD/(m~3·d)时,COD去除率达65.2%～68.5%,且具有良好的抗冲击负荷能力。SBR在进水COD浓度为628～712 mg/L、污泥浓度为2.9 g/L、曝气时间为10 h、溶解氧浓度为2 mg/L工况下,COD去除率达87.6%,NH_3-N去除率达93.6%,处理后出水水质符合污水综合排放标准(GB 8978-1996)中的一级标准要求。     

UASB启动及不同HRT对老龄垃圾渗滤液处理效果的影响

在UASB反应器中接种好氧污泥培养厌氧颗粒污泥进行启动,研究不同HRT对老龄(13年)垃圾渗滤液对处理效果的影响情况。通过保持进水COD浓度不变、逐步缩短HRT从而提高容积负荷到40 g COD/(L.d)的方法,可以培育出直径为1～3 mm颗粒污泥,最终产气量稳定在100 L/d,甲烷含量在60%～70%之间,COD去除率保持在90%左右,污泥层最底部MLSS为81 g/L。逐步提高HRT依次为6、12、24、48和72 h考察其对处理效果的影响,当HRT为24 h时处理效果最好,COD去除率最高达到35%左右。     

厌氧—好氧反应系统处理含酚废水的研究

利用好氧污泥转厌氧驯化方法在厌氧复合床内接种培养，处理浓度为1000mg／L左右的含酚废水。研究结果表明，在水力停留时间1d，酚容积负荷1．06kg／（m3·d）的条件下，厌氧复合床内培养出颗粒污泥，处理效果明显提高，本酚去除率达98．7％，COD去除率达98．3％。此时后接一个好氧接触氧化柱，最终出水中检不出酚。     

厌氧折流板反应器处理邻苯二甲酸二丁酯废水

采用南京江心洲污水处理厂的厌氧消化污泥作为厌氧折流板反应器（ABR）的接种污泥,研究室温（25±5）℃条件下ABR对邻苯二甲酸二丁酯（DBP）降解的运行特性。结果表明,ABR在室温、容积负荷为0.9-1.8 kg/（m3·d）条件下启动运行30 d可以达到运行稳定,其COD去除率在90%左右。在负荷提高阶段,当水力停留时间（HRT）为12 h,容积负荷为2.0-6.8 kg/（m3·d）时,反应器对COD平均去除率大于85%;当HRT为12 h,容积负荷6.8 kg/（m3·d）时,COD去除率达90.7%,DBP降解率达87.3%。     

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.     

Fluorescence-based monitoring of tracer and substrate distribution in an UASB reactor

In this work, rhodamine-related fluorescence was measured on-line at four reactor heights in order to study hydrodynamics within an upflow anaerobic sludge bed reactor. A linear dependence of the dispersion coefficient (D) on the upflow velocity was observed, while the influence of the organic loading rate (OLR) was insignificant. Furthermore, the Bodenstein number of the reactor loaded with granulated sludge was found to be position-dependent with the largest values measured at the bottom of the sludge bed. This trend was not observed in the reactor without sludge. Chemical oxygen demand (COD) and volatile fatty acid (VFA) concentrations were measured at the same reactor heights as in rhodamine tests using conventional off-line analytical methods and on-line multiwavelength fluorometry. Significant spatial COD and VFA gradients were observed at organic loading rates above 6g COD l(R)(-1)d(-1) and linear upflow velocities below 0.8m h(-1).     

Treatment of carbofuran-bearing synthetic wastewater using UASB process

In the present study, fate of carbofuran in anaerobic environments and the adverse effects of carbofuran on conventional anaerobic systems were evaluated. Carbofuran degradation studies were carried out in batch reactors with varying carbofuran concentrations of 0 to 270.73 mg/L corresponding to a sludge-loading rate (SLR) of 2.12 x 10(-6) to 3.83 x 10(-3) g of carbofuran/g of volatile suspended solids (VSS)/d. Carbofuran concentration was reduced to undetectable levels at the end of 8 and 13 days in the batch reactors operated with a SLR of 2.12 x 10(-6) and 3.33 x 10(-5) g of carbofuran/g of VSS/d, respectively. Performances of two anaerobic reactors i.e. upflow anaerobic sludge blanket (UASB) and modified UASB (with tube settlers) were evaluated in the presence and absence of carbofuran using synthetic wastewater. In the absence of carbofuran, the soluble chemical oxygen demand (COD) removal efficiency in the conventional UASB reactor at 8 h and 6 h hydraulic retention time (HRT) was nearly 88% and 76%, respectively, whereas in modified UASB reactor it was increased to 90% at 8 h HRT and 78% at 6 h HRT. When 28 mg/L (SLR of 1.19 x 10(-2) g of carbofuran/g of VSS/d) of carbofuran was introduced in the reactors, the COD removal efficiency was reduced to 41% and 44% in conventional and modified UASB reactors respectively. However, the reactor could maintain around 80% COD removal efficiency at a carbofuran concentration of 7.84 mg/L (SLR of 3.64 x 10(-3) g of carbofuran/g of VSS/d). The reactor efficiency was also measured in terms of specific acetoclastic methanogenic activity (SMA). The toxic effect of carbofuran was reversible to a certain extent. Carbofuran removal efficiency in the conventional UASB reactor at carbofuran concentrations of 7, 13 and 28 mg/L were 40 +/- 3%, 27 +/- 3%, and 11 +/- 3%, respectively. In modified UASB reactor, carbofuran removal efficiency was almost uniform at 7 and 13 mg/L but it was reduced nearly by 56% at 28 mg/L. The major metabolite of carbofuran i.e. 3-keto carbofuran was found in all the reactors.     

The inhibitory effects of lindane in batch and upflow anaerobic sludge blanket reactors

In this study, the inhibitory effects of lindane (LIN) on originally unacclimated mixed anaerobic cultures were investigated by anaerobic toxicity assay (ATA) experiments. ATA experiments revealed that 10 mg/l LIN exerted inhibitory effects on anaerobic cultures, which was recoverable. Continuous reactor experiments conducted to determine the inhibitory effects of LIN and the maximum LIN loading rate achievable in two-stage upflow anaerobic sludge blanket (UASB) reactors indicated that anaerobic granular cultures were successfully acclimated to 30 mg/l LIN. The maximum LIN loading rate and minimum hydraulic retention time (HRT) possible for the UASB system were 10 mg/l day and 18 h, respectively, which resulted in the overall chemical oxygen demand (COD) removal efficiency of 89%.     

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。     

常温下ABR处理低浓度废水性能及污泥特性

研究了常温(17~25℃)下4隔室厌氧折流板反应器(ABR)处理低浓度废水的运行效果及污泥特性。在水力停留时间(HRT)为24 h,进水COD浓度为1 500、1 000和500 mg/L左右时,平均COD去除率分别为94%、93%和87%。进水COD浓度保持在500 mg/L左右,将HRT降为12 h和8 h,COD的去除率仍达到83%以上。厌氧污泥性质测定结果表明,最后隔室中的污泥浓度、颗粒化程度及产甲烷活性与其他隔室相比明显较低,说明低浓度进水对最后隔室厌氧污泥的性质影响较大。颗粒污泥扫描电镜观察显示,各隔室颗粒污泥内部微生物组成差异较大,第1隔室颗粒污泥以产甲烷球菌为主,第2隔室颗粒污泥中没有明显的优势菌,但杆状菌比第1隔室明显较多,第3、4隔室颗粒污泥中以索氏甲烷丝菌为优势菌。     

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。     

炭纤维载体固定床厌氧发酵启动运行效果实验

以开发高效率、抗冲击性能强的高浓度有机废水沼气发酵技术为目的,用传统的 UASB反应器作为对照,研究了以炭纤维为生物膜载体的固定床厌氧反应器的启动运行效果。反应器进口废水 COD 为 5 000 mg/L, 水力停留时间 (HRT) 由213 h 逐步缩短为35 h,进水有机容积负荷(OLR)由0.56 kg COD/ (m³·d)提到3.45 kg COD/(m³·d)。结果表明,固定床反应器厌氧发酵的效率比对照高,出水 pH 值也比对照稳定;运行到第 50 d 时,固定床厌氧反应器和对照的 COD去除率分别由第 7 d 的36.56%和33.58%上升到87.9%和62.6%;固定床厌氧反应器的容积比产气率最高为1.16 m³/(m³·d),累计产气量为415.59 L,而对照的容积比产气率最高值仅为0.31 m³ /(m³·d),累计产气量为 71.66 L,前者最高容积比产气率和累计产气量分别是后者的3.74倍和5.78倍。固定床厌氧反应器的启动速度、COD 去除率和产甲烷效率显著地高于对照反应器。     

苯酚的厌氧生物处理

采用不断增加苯酚浓度而降低葡萄糖浓度的方法可驯化厌氧污泥中的微生物,使厌氧污泥最终以苯酚为唯一碳源生长,可显著提高厌氧污泥降解苯酚的能力;对苯酚间歇厌氧降解过程进行了分析。苯酚浓度在0～1.680 mg/L范围内,其厌氧降解过程符合一级动力学。Aiba模型、Haldane模型和Teisser 模型均可很好地描述处于对数期时厌氧污泥的比生长速率与初始底物浓度之间的关系,其中以Teisser 模型模拟的效果最好。将驯化污泥接种于UASB中可实现对含酚废水处理的连续运行,最大的有机负荷达2 g COD/（L·d）,稳定运行时苯酚的去除率可维持在96%以上。     

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.     

UASB处理硫酸盐有机废水的启动

为了考察上流式厌氧污泥床反应器(UASB)处理含硫酸盐有机废水的特性,采用有效容积为10 L的UASB,研究了启动运行过程中COD和SO2-4降解情况、出水VFA和pH值、产气量及颗粒污泥比产甲烷活性(SMA)变化状况。结果表明,接种厌氧颗粒污泥,保持进水COD为1 500 mg/L,SO2-4浓度为100 mg/L,将HRT由24 h缩短至12 h以提高负荷,经历55 d成功启动了UASB反应器;当HRT为12 h,进水COD和SO2-4负荷为3.0 kg/(m3·d)和0.20 kg/(m3·d),COD和SO2-4的去除率分别达到80%和89%,出水VFA为3 mmol/L,产气量达9.5 L/d,颗粒污泥的SMA为86.4 mL/(g VSS·d)。     

厌氧-好氧接触氧化处理汽车脱脂废水研究

采用厌氧UASB-好氧接触氧化工艺对汽车脱脂废水进行连续处理实验研究。结果表明,在脱脂废水进水COD浓度为6 000 mg/L,厌氧水力停留时间为3.4 d,好氧水力停留时间为2.5 d条件下,COD总去除率平均为93%,厌氧段平均值为38%。厌氧段可以提高出水的可生化性,厌氧-好氧接触氧化工艺效果要明显优于好氧工艺。     

啤酒废水常温厌氧消化启动及运行实验

采用自行设计的复合式厌氧反应器在常温下对啤酒废水进行了厌氧发酵产沼气的实验研究,将进水COD控制在5 000 mg/L左右,采取逐步缩短HRT的方法来提高进水有机负荷,结果表明,启动运行41 d之后,产气量上升速度加快,反应器成功启动运行;在稳定运行过程中,随着负荷的升高,产气量呈阶梯式渐次上升,COD去除率保持在90%以上,出水pH值维持在7.0左右,TSS去除率达到60%以上,出水水质较好,说明该反应器具有较好的厌氧消化处理有机废水的能力。     

Characteristics of granular sludge developed in an upflow anaerobic sludge fixed-film bioreactor treating palm oil mill effluent.

In the present study, characteristics of the granular sludge (including physical characteristics under stable conditions and process shocks arising from suspended solid overload, soluble organic overload, and high temperature; biological activity; and sludge kinetic evaluation in a batch experiment) developed in an upflow anaerobic sludge blanket fixed-film reactor for palm oil mill effluent (POME) treatment was investigated. The main aim of this work was to provide suitable understanding of POME anaerobic digestion using such a granular sludge reactor, particularly with respect to granule structure at various operating conditions. The morphological changes in granular sludge resulting from various operational conditions was studied using scanning electron microscopy and transmission electron microscopy images. It was shown that the developed granules consisted of densely packed rod- (Methanosaeta-like microorganism; predominant) and cocci- (Methanosarsina) shaped microorganisms. Methanosaeta aggregates functioned as nucleation centers that initiated granule development of POME-degrading granules. Under the suspended solid overload condition, most of the granules were covered with a thin layer of fiberlike suspended solids, so that the granule color changed to brown and the sludge volume index also increased to 24.5 from 12 to 15 mL/g, which caused a large amount of sludge washout. Some of the granules were disintegrated because of an acidified environment, which originated from acidogenesis of high influent organic load (29 g chemical oxygen demand [COD]/L d). At 60 degrees C, the rate of biomass washout increased, as a result of disintegration of the outer layer of the granules. In the biological activity test, approximately 95% COD removal was achieved within 72 hours, with an initial COD removal rate of 3.5 g COD/L d. During POME digestion, 275 mg calcium carbonate/L bicarbonate alkalinity was produced per 1000 mg COD(removed)/ L. A consecutive reaction kinetic model was used to simulate the data obtained from the sludge activity in the batch experiment. The mathematical model gave a good fit with the experimental results (R2 > 0.93). The slowest step was modeled to be the acidification step, with a rate constant between 0.015 and 0.083 hours(-1), while the rate constant for the methanogenic step was obtained to be between 0.218 and 0.361 hours(-1).     

城市垃圾焚烧渗沥液中Ca2＋对厌氧EGSB处理效果的影响

研究了城市生活垃圾焚烧厂渗沥液中Ca2＋对厌氧颗粒污泥膨胀床反应器（EGSB）处理效果的影响,并采用静态实验方法考察了Ca2＋对厌氧颗粒污泥产甲烷活性的影响。实验结果表明,进水COD为17000mg／L的条件下,当Ca2＋浓度低于6000mg／L时,EGSB对COD去除率达93％以上;当Ca2＋浓度高于6000mg／L时,COD去除率随运行时间明显下降,并在污泥中形成大量沉淀。静态实验结果表明,废水中低浓度Ca2＋促进了厌氧颗粒污泥的产甲烷活性,但高浓度Ca2＋明显抑制了其产甲烷活性,这是导致高Ca2＋浓度条件下EGSB对COD去除率降低的主要原因。研究表明,颗粒污泥产甲烷活性恢复程度随Ca2＋浓度增加而减弱。