不同驯化方式对以苯酚为基质的微生物燃料电池产电性能的影响

以厌氧污泥作为初始接种体,构建了单室微生物燃料电池（MFCs）,考察了梯度驯化、直接驯化和间接驯化3种不同驯化方式对MFC降解苯酚及产电性能的影响。结果表明,MFC在闭路状态下对苯酚的降解速率比MFC在开路状态下的苯酚降解速率加快10%～20%,说明MFC在产电的同时,可加速苯酚的降解。当以600 mg/L的苯酚溶液为单一燃料,反应68 h后,3种驯化方式下的MFC对苯酚降解率都达到90%以上。相对于其他2种驯化方式,梯度驯化条件最有利于MFC产电性能的提高及苯酚的降解,其最大输出功率为31.3 mW/m2,降解速率提高了7%～20%。     

富含腐殖酸还原混合菌的污泥厌氧降解对乙酰氨基酚的机制

以杭州市四堡污水处理厂的厌氧污泥为接种污泥,驯化富集了厌氧腐殖酸还原混合菌,加入不同的腐殖酸和碳源以优化驯化条件.结果表明,利用驯化厌氧污泥降解对乙酰氨基酚,1周降解时间内,驯化1个月的含腐殖酸还原混合菌群污泥比普通厌氧污泥降解率高34%,驯化半年的成熟厌氧污泥降解效果更好,降解率达90%以上.驯化厌氧污泥的最佳pH为7.0,Fe3 与腐殖酸同时存在时能进一步提高对乙酰氨基酚的厌氧生物降解效果.     

序批式反应器生物强化处理苯酚废水的研究

将4株高效苯酚分解菌湿菌体分3批投加于序批式反应器(SBR),对活性污泥进行生物强化试验,分析活性污泥状态与性能变化,测定生物强化后对苯酚的降解能力.结果表明,随着生物强化过程的进行,沉降性能改善,污泥颗粒化趋势明显;生物强化后,活性污泥对苯酚降解能力、降解速率及对苯酚的耐受性明显提高:苯酚质量浓度为730～960mg/L时,苯酚完全降解时间可由正常的6h缩短至2h;6h内可完全降解苯酚的质量浓度由原来的880mg/L提高到2080mg/L,处理能力提高了1.36倍;当进水苯酚质量浓度增加到2400mg/L时,6h内污泥对苯酚的降解率仍达到60.1%.     

土霉素对剩余污泥中温厌氧消化的短期和长期影响

在中温(35℃)条件下,考察了土霉素(OTC)对剩余污泥厌氧消化的短期和长期影响。在短期影响实验中,采用间歇实验装置研究了OTC浓度为5、50和500 mg/L时对累计甲烷产气量的影响。结果表明,50 mg/L的OTC短期暴露下中温厌氧消化污泥的产甲烷活性会受到急性抑制,但经过141 h的驯化后系统能够恢复产气,表明中温厌氧污泥经过驯化后,可处理含高浓度OTC的剩余污泥。采用完全混合反应器进行了为期230 d的OTC长期影响实验,反应器进泥中OTC浓度从0 mg/L逐步提高为40、200和1 000 mg/L,通过定期监测产气量、甲烷含量和挥发性脂肪酸等指标来表征反应器的运行状况。当OTC浓度≤200 mg/L时系统产气量和气体中甲烷含量稳定并且消化液中挥发性脂肪酸未出现累积,表明厌氧系统未受到影响。但在OTC浓度为1 000 mg/L时运行43 d(2个污泥停留时间)后,污泥中发酵产酸细菌类群代谢活性受到抑制,导致系统产气量下降。上述结果表明,经过驯化,中温厌氧消化系统可处理OTC浓度≤200 mg/L的剩余污泥。     

一株苯酚降解菌的筛选及降解动力学特性

利用富集驯化的培养方法,从首钢焦化厂废水处理系统中的二沉池出水中,分离筛选出一株能够高效降解苯酚的菌株B3对其16S rDNA序列进行分析,并选择Monod方程和Andrews方程分别研究该菌在不同苯酚浓度条件下的降酚动力学模式。结果表明,B3为蜡状芽孢杆菌(Bacillus cereus);苯酚浓度较低时,苯酚对菌株的生长基本不产生抑制作用,用Monod模型对B3降酚动力学过程进行拟合,其动力学参数V max=0.03 h-1,K s=25.53 mg/L;苯酚浓度较高时,按照Andrews模型对B3降酚动力学过程进行非线性最小二乘曲线拟合,其动力学参数V max=0.08 h-1,K s=147.52 mg/L,K i=384.96 mg/L。根据动力学方程,推论菌株B3降解对于浓度238.30 mg/L的苯酚具有最佳降解效果。     

厌氧颗粒污泥反应器对丙酸和丁酸冲击负荷变化的响应研究

采用升流式厌氧污泥床（UASB）反应器,对增大进水浓度和增大进水流量过程中,颗粒污泥对丙酸和丁酸冲击负荷变化响应进行了研究。实验表明,进水浓度从2 000 mg COD/L提高到5 000 mg COD/L,丙酸去除率骤降,而丁酸降解相对稳定;在保持进水浓度为3 000 mg COD/L的条件下,增大进水流量,负荷从7.5 kg COD/（m3.d）升高到15 kg COD/（m3.d）时,丙酸降解率骤降,丁酸降解率仍然相对稳定。实验结果符合降解热力学理论和传统抑制动力学的未解离挥发性脂肪酸理论,并发现改变反应器运行条件能够加剧未解离酸的抑制作用。同时提出了探讨厌氧过程中丙酸积累导致厌氧反应器运行失败的基础理论原因。     

三氯乙烯在苯酚菌中的共代谢降解性能研究

通过生物降解实验考察三氯乙烯(TCE)在苯酚驯化微生物中的共代谢降解性能,并进行动力学分析。结果表明,苯酚是TCE-苯酚共代谢过程必不可少的共代谢基质;TCE的共代谢降解与苯酚和TCE初始浓度有关。TCE在降解初期会出现一个短暂的迟滞期,TCE的大量降解要在苯酚被利用后才发生;高质量浓度TCE(>9mg/L)对共代谢降解有抑制作用。苯酚/TCE(质量比)在10～15以上时,苯酚菌对TCE的去除率较大。Haldane模型能够很好地拟合苯酚和TCE的比降解速率。动力学分析表明,微生物对苯酚的亲和力要大于TCE,苯酚对TCE共降解具有竞争性抑制作用,TCE对微生物存在毒性抑制作用;结果证实了生物降解实验的结论。     

以两种酚类有机物为基质的微生物燃料电池产电特性

以城市污水处理厂的厌氧污泥为接种微生物,在外电阻为1900Ω下,采用双室微生物燃料电池(MFC)分别对以难降解的有毒有机物2,4-二氯苯酚(DCP),对硝基苯酚(PNP),对硝基苯酚和2,4-二氯苯酚为基质时进行有机物降解和产电性能的研究。实验结果表明以DCP(50 mg/L)为单一基质时,MFC的运行周期长达225 h左右,负载两端的最大电压值达393.7 mV,库仑效率为13.73%;而以PNP和DCP为混合基质时,PNP明显促进DCP的降解,使得DCP的去除率高达64.52%,同时PNP的去除率也达到94.47%。实验最终表明,MFC能够以2,4-二氯苯酚和对硝基苯酚为基质,在实现DCP和PNP降解的同时可稳定高效地向外输出电能。     

腐植酸强化苯酚厌氧发酵降解

在无外加电子受体的条件下,首次研究了腐植酸对活性污泥厌氧降解苯酚的影响。研究结果表明,腐植酸Suwannee River Humic Acid Standard(SR-HA)、Leonardite Humic Acid Standard(L-HA)和Pahokee Peat Humic Acid(PP-HA)作为氧化还原介体能够提高苯酚的厌氧发酵降解效率。其中腐植酸PP-HA对苯酚的厌氧降解表现出了最为明显的强化效果,反应进行36 h后,苯酚去除率提高了18.5%。当单独投加的PP-HA浓度在0至100 mg/L范围内,苯酚的厌氧降解效率随着腐植酸浓度增加而逐渐提高,而浓度大于100 mg/L后,腐植酸对苯酚降解效率的促进作用随着PP-HA浓度的增加逐渐减缓。除此之外,当低浓度的蒽醌-2-磺酸钠(AQS)(0.02 m M)和PP-HA(20 mg/L)在反应体系中共存时,相比于无介体存在的对照组,苯酚厌氧降解效率提高了约1.4倍。产物分析结果表明,乙酸和CH4作为苯酚发酵降解的重要产物被检测出来。最后,在氧化还原介体腐植酸的存在下,初步探讨了苯酚厌氧发酵降解的代谢途径。     

用驯化的活性污泥强化修复氯酚污染土壤的试验

以接种驯化的活性污泥为生物强化手段，通过摇瓶反应模拟生物泥浆反应器的运行，研究了受氯酚污染土壤的修复特性。结果表明，接种驯化的活性污泥可以大大加快邻氯苯酚（2-CP）的降解速率，对2-CP初始污染浓度为500 mg/kg干土的土壤，接种1%活性污泥 （w∶w）后反应11 h降解率即可达到96.4%。最适的反应条件为：活性污泥接种量1%，水土比2∶1，温度25 ℃，摇床转速200 r/min。2-CP的降解符合表观一级动力学方程；且当初始浓度为50～500 mg/kg干土时，2-CP降解速率常数随着初始浓度的增大而减小。     

Comparative granule characteristics and biokinetics of sucrose-fed and phenol-fed UASB reactors

Two upflow anaerobic sludge bed (UASB) reactors were fed with a non-inhibitory substrate sucrose and an inhibitory substrate phenol, respectively, to compare granule characteristics and biokinetics. The average size of biomass granules in the sucrose-fed UASB reactor was slightly larger than that of the phenol-fed reactor. The average microbial density was significantly higher in the phenol-fed reactor. The intrinsic biokinetics of sucrose-acidogenesis and phenol-acidogenesis followed Monod and Haldane kinetics, respectively. By comparing half-saturation constants for sucrose and phenol (Ks1,s; Ks1,p), the affinity of phenol to the granule should be much higher. The mass fraction of methanogens (f) in the sucrose-fed reactor decreased with increasing volumetric loading rate (VLR) because of the accumulation of volatile fatty acids (VFAs); the f of the phenol-fed reactor decreased with increasing VLR because acidogenesis was the rate-limiting step. The mass transfer resistance in overall substrate removal in the sucrose-fed reactor was greater than that in the phenol-fed reactor.     

高氯离子味精尾母液废水厌氧处理研究

味精尾母液废水COD浓度极高同时含有大最氯离子.采用UASB反应器对味精尾母液废水进行处理,其中接种污泥来自啤酒厂UASB反应器.实验表明:当氯离子浓度在4 500 mg/L以下时,对厌氧微生物没有明礁的抑制作用;5 000 mg/L的氯离子浓度可以看作一个抑制限值,但经过驯化后,仍可获得较好的COD去除效果;当氯离子浓度达到8 000mg/L左右时,COD平均去除率在80%以上.     

UASB反应器处理链霉素废水启动及运行性能

采用上流式厌氧污泥床(UASB)反应器处理链霉素生产废水,研究了中温条件下反应器启动和稳定运行中废水处理性能及厌氧污泥颗粒化过程。结果表明,通过逐步提高链霉素废水进水比例和负荷,可以实现UASB反应器的启动和稳定运行,并对高浓度链霉素实际废水具有良好的处理性能,COD去除率稳定在80%以上,COD去除负荷达7.2 kg/(m3·d),CH4产生量达到6.2 L/d。UASB反应器启动运行过程中,链霉素废水对污泥活性具有抑制影响,造成短期反应器运行性能明显下降,而后很快恢复。同时高负荷链霉素废水造成甲烷产率降低。污泥性状变化显著,污泥形态逐渐转变为颗粒态,污泥粒径增大,出现大量0.5~1.0 mm颗粒污泥,污泥VSS/SS比值升高,污泥沉降性明显增强,比产甲烷活性显著升高,表明污泥开始实现颗粒化。     

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。     

Phenol degradation and microbial characteristics in upflow anaerobic sludge blanket reactors at ambient and mesophilic temperatures

A synthetic wastewater containing phenol as sole substrate was respectively treated at temperatures of 26±1°C and 37±1°C in 2.8 litre upflow anaerobic sludge blanket (UASB) reactors. At the two temperatures, pH 7.0–7.5, with a 1:1 effluent recycle ratio, phenol in wastewater was efficiently degraded in a UASB reactor. Microbial community analysis using denaturing gradient gel electrophoresis (DGGE) showed that less shift in the microbial community occurred with the temperature changing. Phenol degradation in wastewater was recommended to select ambient temperature in UASB reactors. The optimal HRT was 12 to 16 hours corresponding to 6.0–4.5 g COD/(l.d) loading rate at ambient temperature in UASB reactors. The distribution of archaeal and bacterial populations in the UASB granular consortium was revealed using fluorescence in situ hybridisation (FISH) technique.     

Effect of limited aeration on the anaerobic treatment of evaporator condensate from a sulfite pulp mill

Serious inhibition was found in the regular up-flow anaerobic sludge blanket (UASB) reactor in treating the evaporator condensate from a sulfite pulp mill, which contained high strength sulfur compounds. After applying the direct limited aeration in the UASB, the inhibition was alleviated gradually and the activity of the microorganisms was recovered. The COD removal rate increased from 40% to 80% at the organic loading rate of 8kgCODm(-3)d(-1) and a hydraulic retention time of 12h. Limited aeration caused no oxygen inhibition to the anaerobic microorganisms but instigated sulfide oxidization and H(2)S removal, which was beneficial to the methanogens. The experiment confirmed the feasibility of applying limited aeration in the anaerobic reactor to alleviate the sulfide inhibition. It also proved that the anaerobic system was actually aerotolerant. SEM observation showed that the predominant microorganisms partly changed from rod-shaped methanogens to cocci after the UASB reactor was aerated.     

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。     

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.     

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.     

五氯苯酚在厌氧颗粒污泥中的吸附研究

在血清瓶中进行的分批实验中,研究了UASB和EGSB反应器厌氧颗粒污泥对五氯苯酚(PCP)的吸附、解吸规律.结果表明,吸附和解吸在接触PCP 2.5 h内达到平衡,吸附和解吸过程都符合Freundich等温方程,PCP的吸附机制为恒定的分配吸附.来自UASB反应器中活的颗粒污泥吸附能力大于灭活的颗粒污泥,Freundich等温方程吸附常数K值分别为0.557 0和0.037 9.UASB反应器颗粒污泥对PCP的吸附能力大于EGSB反应器颗粒污泥,Freundich等温方程吸附常数K值分别为0.557和0.263.