气提式内循环膜生物反应器试验研究

针对膜生物反应器存在的膜污染和能耗高的问题，结合气提式内循环和一体式膜生物反应器处理废水的工艺特点，提出圆柱形套筒气提式内循环膜生物反应器。试验结果表明，同等曝气强度和曝气方式下，气提式内循环膜生物反应器中氧传质系数（KLa）高于一般膜生物反应器；膜间水流流速是一般膜生物反应器的1.53～2.44倍，提高了膜面的水力冲刷作用，可减缓膜污染；对反应器膜过滤性能的考察，表明气提式内循环膜生物反应器较一般膜生物反应器有更好的膜过滤性能和抗污染能力。反应器中添加内循环，污泥活性有所下降，但对实际废水的去除效果影响不大，污泥活性较为稳定。     

悬浮填料生物膜反应器处理黑水的启动挂膜

采用自然挂膜法在低碳氮比的黑水中启动悬浮填料生物膜反应器,探讨了进水有机物和氨氮负荷率对挂膜启动的影响,分析了挂膜过程中溶解性化学需氧量(SCOD)、氨氮(NH+4-N)和总氮(TN)的去除转化规律及填料上附着生物量和填料生物相的变化规律。研究结果表明,在DO为1.5~2.5 mg/L、温度为(21±2)℃等条件下可快速(43 d)启动生物硝化挂膜,SCOD、NH+4-N和TN去除率分别可达到84%、62%和46%,单个填料上的生物膜量达到0.49 g/个。进水SCOD、NH+4-N负荷率明显影响硝化细菌在填料上的成膜和生物硝化效率。研究认为,进水SCOD、NH+4-N负荷率分别保持5.34g/(m2·d)、1.44 g/(m2·d)左右,能够促快速挂膜并获得良好的短程硝化和同步硝化反硝化效果。     

气升式内循环蜂窝陶瓷反应器高效快速修复地表水的研究

采用新型蜂窝陶瓷载体气升式内循环反应器(IAL-CHS)对受污染的城市地表水进行生物修复,该反应器能快速有效地修复受污染水体.考查了氨氮的变化历程、HRT与氨氮去除率间的关系,确定了最佳HRT为20 min.在HRT为20 min、接触反应时间仅为14 min条件下,该反应器对氨氮、TP、COD、TOC、浊度、UV254的去除率分别为86.7%～96.2%、4.5%～34.4%、15.5%～63.6%、5.8%～38.1%、9.4%～88.3%、3.8%～48.5%.     

亲水性多孔载体在流化床中的生物膜形成过程分析

采用实验制备的一种新型亲水性多孔聚合物作为流化床反应器中生物膜附着生长的载体,实现流态化水力条件下的生物挂膜过程.在3个结构尺寸相同的流化床反应器中考察了接种污泥浓度、进水有机负荷及载体粒径对亲水性多孔载体生物挂膜量的影响,试验结果表明,接种污泥浓度为30 g VSS/L、进水TOC值为350 mg/L、载体粒径为5～8 mm时载体表面的附着生物量最大,反应器运行12 d的载体附着生物量达到4.45 g VSS/L,膜结构稳定,表现出较活性污泥法更高的活性.在进水TOC、氨氮浓度分别为350 ms/L、50 mg/L,HRT为6 h的情况下,两者的去除率分别达到了97.1%和64.3%,表明载体上的生物膜对污水中TOC及氨氮的去除表现出高效率.挂膜后载体表面上的微生物以丝状菌为主,孔壁上的微生物以球菌和杆菌为主要生物相,证明载体内外表面皆适宜微生物的生长,并且形成合理的生物相分布.     

好氧颗粒污泥的特点及其研究进展

综述了好氧颗粒污泥的基本特征和微生物相、好氧颗粒污泥形成的主要影响因素及其颗粒化反应器等。好氧颗粒污泥是近几年发现的在好氧条件下自发形成的细胞自身固定化过程 ,是生物膜特殊的生长形式。颗粒污泥具有良好的沉降性能、较高的生物量和在高容积负荷条件下降解高浓度有机废水的良好生物活性。污泥颗粒化过程是一个多阶段的过程 ,取决于废水组成及其操作条件的选择。在气提式内循环间歇反应器 (internalcirculatesequencingbatchairliftreac tor ,ICSBAR )中易于培养出性能良好的好氧颗粒污泥。     

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。     

高效脱氮菌增强膜曝气生物反应器处理市政污水

利用自行筛选的好氧反硝化菌(Pseudomonas sp.)添加到膜曝气生物反应器构建高效脱氮菌群增强膜曝气生物反应器来处理市政污水。研究表明,对于高效脱氮菌的附着下形成的增强型膜曝气生物反应器,在COD负荷为7.6 g COD·(m~2·d)~(-1),水力停留时间为5 h下,可使污染物的COD、氨氮及总氮的去除率分别保持在87%、98%和85%以上。总氮去除率比平行对比的传统型膜曝气生物反应器高出10%。DGGE分析显示,筛选菌种在增强型膜曝气生物反应器中比平行膜曝气生物反应器明显增多,从微观上证明了菌种发挥了重要作用。本工艺在生活污水脱氮处理方面有良好的应用前景。     

好氧颗粒污泥的特点及其研究进展

综述了好氧颗粒污泥的基本特征和微生物相、好氧颗粒污泥形成的主要影响因素及其颗粒化反应器等。好氧颗粒污泥是近几年发现的在好氧条件下自发形成的细胞自身固定化过程，是生物膜特殊的生长形式。颗粒污泥具有良好的沉降性能、较高的生物量和在高容积负荷条件下降解高浓度有机废水的良好生物活性。污泥颗粒化过程是一个多阶段的过程，取决于废水组成及其操作条件的选择。在气提式内循环间歇反应器(intemal circulate sequencing batch airlift reaclor，ICSBAR)中易于培养出性能良好的好氧颗粒污泥。     

复合耐盐微生物菌剂强化MBBR工艺处理高盐废水

在移动床生物膜反应器(MBBR)中接种SEM复合耐盐微生物菌剂,研究5％ ～ 10％盐度条件下悬浮填料的挂膜启动及其对高盐废水的强化处理效果.实验结果表明,MBBR在高盐环境下能够顺利挂膜,其挂膜效果受盐度及无机盐种类的影响:较高盐度下成功挂膜所需的周期更长,同一盐度下NaCl体系挂膜效果优于Na2SO4体系.MBBR处理羧甲基纤维素生产废水效果优于活性污泥法:进水盐浓度均为5％～7％,当进水COD 5 343 mg/L时,MBBR出水COD小于300mg/L,经絮凝后低于100 mg/L,容积负荷高达2.67 kg COD/(m3·d),而活性污泥法在进水COD 3 563 mg/L时,出水COD小于400 mg/L,经絮凝后低于150 mg/L,容积负荷仅为1.68 kg COD/(m3·d).MBBR生物膜处理体系稳定性及去除能力更高,能够抵抗较高盐度范围波动、有机负荷等的冲击.     

ABR反应器的两种快速启动方法对比

ABR反应器的启动是ABR反应器能否高效稳定运行的关键，其影响因素很多。为了更好地实现ABR反应器的启动，提出了通过2种不同启动方法的对比，即1^#反应器采用好氧预挂膜的方法，2^#反应器采用低负荷启动法，得出的结论为，好氧预挂膜启动法的启动时间短，COD去除率高，出水pH稳定，颗粒状污泥生长情况较好，是一种可推广的启动方法。     

Effect of formaldehyde on biofilm activity and morphology in an ultracompact biofilm reactor for carbonaceous wastewater treatment.

The effects of formaldehyde on biofilm morphology and biomass activity were investigated in an ultracompact biofilm reactor (UCBR) for carbonaceous wastewater treatment. The wastewater contained a fixed amount of glucose (with a chemical oxygen demand concentration of 600 mg/L) and an increasing concentration of formaldehyde (ranging from 21.4 to 271.1 mg/L). An influent formaldehyde concentration higher than 75 mg/L could facilitate filamentous growth (on biofilm) control and lead to a higher biofilm density, which is desirable as it enhanced the UCBR performance stability. However, at an influent formaldehyde concentration higher than 214.4 mg/L, biomass production was inhibited and deteriorations of biofilm morphology and biomass activity were observed. This study showed that it was desirable to maintain an influent formaldehyde concentration lower than 202.2 mg/L, as this concentration could achieve a good biofilm morphology while not inhibiting its microbial activity.     

添加NaOH对水生植物固体厌氧发酵产甲烷的作用

为了提高木质纤维素生物质的甲烷产率,固体厌氧发酵以及预处理技术得到了广泛应用。本研究以水生植物菹草为例,探讨了厌氧固体发酵同步碱处理提高甲烷产率的可行性。采用2种来源的微生物(厌氧污泥和牛粪),初始生物质浓度为20%TS(total solid,总固体重量),考察不同的NaOH添加量(基于反应体系总TS 0%、2.0%、3.5%和5.0%)对菹草厌氧发酵产气和固体水解效率的影响。结果表明,与对照实验组相比,初始NaOH加入量为3.5%时,接种污泥和牛粪的实验组中甲烷总产量分别为787.1 mL和1 165.4 mL,与对照实验组相比(619.1 mL和834.8 mL),分别提高了27.1%和39.6%,而且接种牛粪的实验组中单位挥发性固体(VS)产甲烷率最高,为186.5 mL/g。对发酵后的木质纤维素残渣组分进行分析,结果表明,NaOH有助于促进菹草中纤维素及半纤维素的分解,以及木质素结构的破坏,从而提高了菹草厌氧发酵产气产甲烷效率。     

Comparison of different packing materials for the biofiltration of air toxics

Four different biofilter packing materials (two porous ceramics, perlite, and open pore polyurethane foam) were compared for the removal of toluene vapors. The focus was on evaluating performance at relatively short gas retention time (13.5 and 27 sec). The reactors were initially operated as biotrickling filters with continuous feeding and trickling of a nutrient solution. After significant plugging of the biotrickling filter beds with biomass was observed, the operation mode was switched to biofiltration with only periodic supply of mineral nutrients. This resulted in stable conditions, which allowed detailed investigations over > 6 months. The reactor packed with cattle bone Porcelite (CBP), a ceramic material containing some macronutrients and micronutrients, exhibited the highest performance. The critical load (i.e., load at which 95% removal occurred) was 29 g m(-3) hr(-1) at a gas retention time of 13.5 sec and 66 g m(-3) hr(-1) at a gas retention time of 27 sec. After the long-term experiment, the packing materials were taken from the reactors and examined. The reactors were divided into three sections, top, middle, and bottom, to determine whether spatial differentiation of biomass occurred. The assays included a double-staining technique to count total and live microorganisms and determination of moisture, protein, and dry weight contents. Microbial community analysis was also conducted by denaturing gradient gel electrophoresis. The results showed that most reactors had a significant fraction of inactive biomass. Comparatively, the CBP biofilter held significantly higher densities of active biomass, which may be the reason for the higher toluene removal performance. The analyses suggest that favorable material properties and the nutrients slowly released by the CBP provided better environmental conditions for the process culture.     

Decoloration of textile dyes by alginate-immobilized Trametes versicolor

Alginate-immobilized Trametes versicolor decolorized Amaranth at similar rates in repeated batch culture when the dye was present in either (i) modified Kirk's medium containing 0.22 gl(-1) ammonium tartrate, (ii) the same buffer, thiamine, trace elements and glucose concentrations as in the modified Kirk's medium, or (iii) glucose alone at either 1, 5 or 10 gl(-1). With glucose alone (0.5 gl(-1)), Amaranth, Reactive Black 5, Reactive Blue 19 and Direct Black 22 had first-order decoloration rate constants of 0.56, 0.76, 0.52, and 0.15 h(-1), respectively. Mixtures of these dyes were also completely decolorized. After four successive decolorations, beads were kept in storage solutions for 48 d at 6 degrees C. CaCl2 (1g l(-1)) was the best storage solution as the beads were easier to handle and had the fastest decoloration rates after storage. Decoloration rates were faster with lower viscosity (less than 2000 cps) alginates and with softer beads which had a lower resistance to compression. Fungal colonization of the beads resulted in higher biomass concentrations with a corresponding higher decoloration rate but the beads became larger, had a lower resistance to compression and a higher percentage of bead breakage in a stirred tank reactor. Biomass, recovered from beads in which there was no growth, could be dispersed while the biomass from colonized beads formed a hollow, spherical shell due to growth on and near the bead surface and no growth in the bead interior. If alginate-immobilized T. versicolor is to be used in a stirred tank reactor, a high biomass loading during the immobilization phase and no fungal growth in the beads is recommended to have high decoloration rates and low bead breakage.     

Recovery potential of aerobic sludge biomass from Co (II) stress in sequencing batch reactors

Heavy metals in higher concentrations are often encountered in domestic sewage of developing and under-developed countries. High metallic concentrations can stress reactor sludge biomass morphology impeding its performance in organics reduction. However, the extent of damage and ability of sludge biomass to recover from the metallic stress is not fully understood. Also, there is no protocol to identify and prevent the sludge biomass from metallic stress in fully functional sewage treatment plants (STPs). This study investigates performance, metabolic activity, morphology, and settling characteristics of the sludge biomass under different Co(II) stress conditions. The extent of recovery in biomass, when the supply of Co(II) metal ion was discontinued in the inlet stream, was explored. The study also proposed a protocol based on simple settling characteristics of sludge biomass to get an early indication of metal infiltration to prevent potential damage to the biomass morphology. Four sequencing batch reactors (SBRs) with Co(II) ion concentrations of 0 (designated as RCo0), 5 (RCo5), 25 (RCo25), and 75 mg/L (RCo75) in the feed were operated with a cycle time of 12 h. Reactors were operated for 35 days with Co(II) in the feed (termed as stressed phase operation) followed by 24 days of operation without Co(II) in the feed (termed as recovery phase operation). Results show that COD removal in reactor RCo75 reduced to 48% on the 10th day of stressed phase operation, showing a lag in COD removal due to metallic stress. The activity of biomass in reactors RCo5, RCo25, and RCo75 was reduced by 39%, 45%, and 49%, respectively, in the stressed phase compared to the biomass in control reactor. Recovery in COD removal efficiency and specific biomass activity were observed in all the reactors after the removal of metallic stress. The settleability of sludge biomass in reactors RCo25 and RCo75 was significantly affected. Transformation in the shape of flocs in reactor RCo25 and RCo75 biomasses revealed the prolonged effect of metallic stress, which was observed to be irreversible even during the recovery phase operation.

     

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。     

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.     

Comparison of Different Packing Materials for the Biofiltration of Air Toxics

Abstract

Four different biofilter packing materials (two porous ceramics, perlite, and open pore polyurethane foam) were compared for the removal of toluene vapors. The focus was on evaluating performance at relatively short gas retention time (13.5 and 27 sec). The reactors were initially operated as biotrickling filters with continuous feeding and trickling of a nutrient solution. After significant plugging of the biotrickling filter beds with biomass was observed, the operation mode was switched to biofiltration with only periodic supply of mineral nutrients. This resulted in stable conditions, which allowed detailed investigations over >6 months. The reactor packed with cattle bone Porcelite (CBP), a ceramic material containing some macronutrients and micronutrients, exhibited the highest performance. The critical load (i.e., load at which 95% removal occurred) was 29 g m^?3 hr^?1 at a gas retention time of 13.5 sec and 66 g m^?3 hr^?1 at a gas retention time of 27 sec. After the long-term experiment, the packing materials were taken from the reactors and examined. The reactors were divided into three sections, top, middle, and bottom, to determine whether spatial differentiation of biomass occurred. The assays included a double-staining technique to count total and live microorganisms and determination of moisture, protein, and dry weight contents. Microbial community analysis was also conducted by denaturing gradient gel electrophoresis. The results showed that most reactors had a significant fraction of inactive biomass. Comparatively, the CBP biofilter held significantly higher densities of active biomass, which may be the reason for the higher toluene removal performance. The analyses suggest that favorable material properties and the nutrients slowly released by the CBP provided better environmental conditions for the process culture.     

Improvement of upflow anaerobic sludge bed performance using chitosan.

Chitosan, with a degree of deacetylation of 85% and a molecular weight of 2.5 x 10(5) Da, yielding high flocculation efficiency (85 to 100% flocculation) and a broad flocculation region (2 to 45 mg/g suspended solids), was selected for accelerating granulation in a 30-L upflow anaerobic sludge bed (UASB) used to treat wastewater from a tropical fruit-processing industry. Compared with other studies, smaller amounts of chitosan were applied (two injections with 2 mg chitosan/g suspended solids in the reactor at each injection). Comparison with the UASB without chitosan addition, the UASB had a 24 to 37% larger particle size and a 6 to 41% longer solids retention time. In addition, the reactor performances were also enhanced. The UASB with chitosan addition had a 9 to 59% lower effluent chemical oxygen demand (COD), 4 to 10% higher COD removal, up to 35% higher biogas production rate, and a 16 to 68% lower biomass washout. The paired t-test analysis indicated that these performance parameters were significantly different (P < 0.05).     

不同温度下有机负荷对厌氧折流板反应器污泥颗粒化的影响

采用2个相同的厌氧折流板反应器（ABR）研究不同温度、有机负荷对ABR启动过程中胞外聚合物（EPS）产生的影响，以及各隔室优势菌种。结果表明，高温和较高的有机负荷（OLR）促进EPS的产生，而EPS有利于颗粒污泥的形成。较高温度也有利于反应器承受更高的有机负荷。启动结束后，沿着水流方向，隔室中的污泥发生变化，由水解酸化菌演替为产甲烷优势菌。