膜生物反应器中生物铁对活性污泥性能的影响

污泥性能是决定污水处理效果的关键因素. 通过向膜生物反应器中添加生物铁来强化污水处理效果,研究膜生物反应器中生物铁对活性污泥性能的影响,比较普通膜生物反应器(普通MBR)和生物铁膜生物反应器(生物铁MBR)中的污泥指数(SVI)、污泥质量浓度〔ρ(MLSS)和ρ(MLVSS)〕、污泥的脱氢酶活性和耗氧活性. 结果表明,生物铁膜生物反应器中的污泥结构紧密,生物相丰富,污泥质量浓度比较稳定;生物铁MBR的SVI受进水负荷影响较小,能够克服污泥膨胀的影响;生物铁MBR污泥的脱氢酶活性和耗氧活性与普通膜生物反应器相似,随水力停留时间(HRT)的缩短或泥龄(SRT)的延长脱氢酶活性和耗氧活性呈下降趋势.      

膜生物反应器处理工业废水中膜污染及膜过滤特性研究

采用膜生物反应器(MBR)中试试验装置处理制革、印染工业园区混合废水,考察了悬浮污泥浓度(MLSS)、溶解性微生物产物(SMP)和松散型胞外聚合物(EPS)表征总量、胶体粒子等因素对膜污染发生的影响程度.结果表明,试验装置启动后的120 d内,发生轻度膜污染现象,过滤膜阻力R20从1.5×1012m-1增加至1.8×1012m-1.MBR池内胶体粒子浓度与膜过滤阻力变化呈现明显的线性相关,而MLSS、SMP和EPS表征总量等因素的变化与膜过滤阻力的变化不存在相关性.分析认为胶体粒子是引起该试验装置发生膜污染现象的主要因素,其成因可能是胶体粒子通过附着在膜表面,沉积堵塞膜孔,从而造成膜污染.     

UASB-膜生物反应器处理抗生素废水的研究

采用UASB-膜生物反应器对抗生素废水进行处理研究。结果表明,UASB具有很强的抗冲击能力,当UASB和膜生物反应器的容积负荷分别为10.9kgCOD/m3·d和4.62kgCOD/m3·d时,系统COD去除率仍有96.47%。污泥浓度对膜生物反应器的COD去除率有较大影响,当MLSS保持在3000～4000mg/L时,膜生物反应器COD去除率为85%左右,高于MLSS保持在7500～7800mg/L时为68%左右。在不排泥运行时膜生物反应器中MLVSS和MLSS比值比排泥运行时低。     

膜生物反应器处理高浓度含酚废水研究

将膜生物反应器(MBR)用于高浓度含酚废水的处理中,探讨了进水中苯酚浓度、水力停留时间和污泥浓度对膜生物反应器处理含酚废水效果的影响。实验结果表明:经过42d驯化后,可以在高浓度含酚废水中正常运行,MBR系统对COD和氨氮的去除率分别可达98%和80.6%。当苯酚浓度为134mg/L时,处理的最佳水力停留时间为3h,最佳污泥浓度(MLSS)为7367mg/L。     

污泥浓度对膜生物反应器运行效果的影响分析

考察了膜生物反应器处理洗浴废水时 ,污泥浓度对出水水质及膜通量的影响。结果表明 ,尽管试验中污泥沉降性能较差 ,但当污泥浓度大于 2 30 0mg/L时 ,出水仍能达到《城市污水再生利用　城市杂用水水质标准》(GB/T1892 0 -2 0 0 2 ) ;出水COD随污泥浓度升高而降低 ;膜通量与污泥浓度的对数值呈线性关系。由于处理效果和膜通量两方面的因素 ,对于本试验中的原水 ,MLSS的适宜范围为 2 30 0～ 5 0 0 0mg/L。     

生物强化序批式膜生物反应器处理溴氨酸废水

在序批式膜生物反应器(SMBR)中投加溴氨酸(BAA)高效降解菌鞘氨醇单胞菌QYY,对BAA 模拟废水进行了生物强化降解研究.在驯化过程中加入链霉素促进菌株QYY 在污泥中生长.结果表明,经过30d 驯化后,保持BAA 浓度550mg/L,系统处理效果稳定,MLSS 保持稳定,并能连续运行90d 以上;降解11h 时,脱色率为98%左右,COD 去除率50%左右.当BAA 浓度为200~2600mg/L 时,降解时间与BAA 浓度呈线性关系(R²=0.9968).核糖体基因间区序列分析(RISA)显示,稳定期活性污泥菌落生物多样性下降,菌株QYY 在污泥中已存活并可能成长为优势菌.     

平板膜在污泥浓缩消化处理中的应用研究

采用中试规模的反应器对平板膜-污泥浓缩消化(MSTD)工艺的污泥消化机制和膜污染机理进行了研究.结果表明,经过15d的运行,MSTD工艺的污泥浓度(MLSS)从最初的3.6g/L上升到约34.2g/L,MLVSS和MLSS的消解率分别达到52%和47%,实现了同步浓缩和消化.由于溶解氧的变化,MSTD工艺的消化机制分为好氧消化和类似的厌氧消化2个阶段,分别降解二价金属离子和铁离子连接的2类生物聚合物.在MSTD过程中,平板膜的截留和污泥消化导致污泥性质剧烈变化,从而造成膜过滤性能剧烈下降.MLSS、胞外聚合物(EPS)和溶解性微生物产物(SMP)均对膜污染有显著的影响.     

一体式膜-生物反应器同步硝化反硝化中试试验

当污泥浓度维持在19~20g/L时,一体式平板膜-生物反应器运行112d,通量稳定在25.2~25.7L/(m2.h),运行过程除正常曝气以保持对膜进行水力冲刷外没有进行任何物理和化学清洗。试验考察不同DO浓度对同步硝化反硝化效果的影响,结果表明,反应器内有较好的硝化反硝化效应,当温度在18~12℃变动时,膜生物反应器的硝化反硝化效果基本不受温度的影响。     

膜生物反应器膜污染的水力学控制实验研究

叙述了膜污染是影响膜-生物反应器处理技术推广应用的关键因素，采用水动力学方法是控制膜污染的有效方法。在不同污泥浓度条件下。对不同曝气强度下膜污染的发展速率及其形成机理进行了试验研究，研究结果表明：对应于不同污泥浓度均存在一个经济曝气强度，其大小随污泥浓度升高呈线性增加，膜生物反应器在经济曝气强度条件下运行可控制膜污染的发展；并从理论上推导出一个临界污泥浓度，其值为5．15g／L。对应于临界污泥浓度，并且污泥絮体在膜面可形成比较稳定的动态膜，膜过滤压差上升的速率最慢，膜生物反应器在此临界污泥浓度条件下运行膜污染发展最为缓慢。     

膜生物反应器处理生活污水的研究

考查了膜生物反应器处理生活废水的效果。研究了抽吸与暂停时间，温度，压力，进水浓度和污泥浓度等因素对出水水质的影响，得出最佳因素组合为时间抽吸12min，暂停2min。温度20℃左右，压力0.15MPa,MLSS3500mg/L时，进水浓度的变化对出水水质影响不大。     

A hybrid membrane process for simultaneous thickening and digestion of waste activated sludge

A hybrid membrane process for simultaneous sludge thickening and digestion (MSTD) was studied. During one cycle (15 d) of operation under a hydraulic retention time of 1 d, the concentration of mixed liquor suspended solids (MLSS) continuously increased from about 4 g·L⁻¹ to 34 g·L⁻¹, and the mixed liquor volatile suspended solids (MLVSS) increased from about 3 g·L⁻¹ to over 22 g·L⁻¹. About 42% of the MLVSS and 39% of the MLSS reduction were achieved. The thickening and digestion effects in the MSTD were further analyzed based on a mass balance analysis. Test results showed that biopolymers and cations of biomass were gradually released to the bulk solution during the process. It was also found that the capillary suction time, colloidal chemical oxygen demand, soluble microbial products, viscosity, and MLSS had significant positive correlations with the membrane fouling rate, whereas extracellular polymeric substances, polysaccharides, and proteins extracted from biomass had negative impacts on membrane fouling.     

浸没式膜生物反应器中生物质的增殖及其对运行效能的影响

研究了浸没式膜生物反应器(sMBR)中生物质的增殖过程及其对反应器运行效能的影响.采用可编程逻辑控制器(PLC)对sMBR实现过程控制,在不排泥的情况下运行20~40d,生物质浓度达到9670mg/L,出水的各项指标达到最佳,但随着生物质的继续增殖,污泥表观黏度急剧增加,引起F/M的降低和传质困难,最终导致污泥活性降低及出水效果恶化.表观黏度与MLSS、EPS的增长趋势一致,表明这2个因素与活性污泥的表观黏度有着密切关系.采用SEM/EDS方法对不同阶段膜表面进行了观察及表面元素分析,结果表明膜表层污染物中有机物占主要部分,无机成分所占比例较小.     

膜生物反应器PVDF膜和尼龙膜污染特性

分别采用PVDF膜（第1~219d）和尼龙（Nylon）膜（第220~360d）长期运行膜生物反应器（MBR）,分析MBR系统的脱氮性能和膜污染特性.结果表明,反应器最终在进水NH₄⁺-N和NO₂^--N浓度分别为400~740mg/L和460~790mg/L的条件下稳定运行112d,总氮去除率（TNRE）维持在86%左右,总氮去除负荷（NRR）为0.61~1.08kg N/（m³·d）.经过263d的运行,反应器中混合液悬浮固体浓度（MLSS）从4918mg/L增至7230mg/L,混合液挥发性悬浮固体浓度（MLVSS）从2585mg/L增加至4455mg/L,比厌氧氨氧化活性（SAA）最高达0.46g N/（d·gVSS）.无论是PVDF膜还是尼龙膜,Anammox-MBR系统在一个膜污染周期结束时,都是泥饼层阻力占主导,但二者的膜污染机制不同.与相同水力停留时间（HRT）下运行的PVDF膜相比,尼龙膜的膜污染发展速度显著减小.结合脱氮性能和膜污染情况,本实验条件下,MBR系统优先采用尼龙膜在HRT=1.5d运行.     

Simultaneous nitrogen and phosphor removal in an aerobic submerged membrane bioreactor

Simultaneous nitrification and denitrification （SND） effect and phosphor removal were investigated in a one-staged aerobic submerged membrane bioreactor on pilot-scale with mixed liquor suspended solids （MLSS） 19--20 g/L. The effects of DO concentration, sludge floc size distribution on SND were studied. Test results suggested that SND was successfully performed in the membrane bioreactor （MBR） and about 70% total nitrogen removal efficiency was achieved when DO concentration was set to 0.2-- 0.3 mg/L. The main mechanisms governing SND were the suitable sludge floc size and the low DO concentration which was caused by low oxygen transfer rate with such a high MLSS concentration in the MBR. In the meantime, phosphor removal was also studied with polymer ferric sulfate （PFS） addition and 14 mg/L dosage of PFS was proper for the MBR to remove phosphor. PFS addition also benefited the MBR operation owing to its reduction of extracellular polymer substances （EPS） of mixed liquor.     

SRT对UCT-MBR反硝化除磷性能与膜污染行为的影响

采用脱氮除磷膜生物反应器(UCT-MBR)工艺处理冀南地区城市污水,考察了SRT对UCT-MBR工艺反硝化除磷性能与膜污染行为的影响.结果表明:较短(15d)与较长(40d)SRT均不利于反硝化聚磷菌(DPAOs)的富集;SRT控制在25d时系统的反硝化除磷性能得到最大程度强化,反硝化聚磷菌(DPAOs)占聚磷菌(PAOs)的数量比例及缺氧除磷率达到最大值,分别稳定在50.9%和88%,并且此时系统总磷(TP)、总氮(TN)去除率也达到最大值91.7%、73.6%,出水浓度分别稳定在0.48, 13.3mg/L左右;SRT对系统COD、氨氮(NH₄⁺-N)的去除效能影响不大,COD、NH₄⁺-N平均去除率分别为89.8%、99.7%,出水浓度分别稳定在30.8, 0.15mg/L;随着SRT的延长,膜池混合液固体(MLSS)浓度升高,分子量大于100kDa、小于1kDa的溶解性微生物代谢产物(SMP)浓度和胞外聚合物(EPS)比污泥浓度升高及污泥粒径(PSD)减小,是导致膜池污泥可滤性变差的主要原因,从而致使系统膜渗透性加速降低、持续运行周期缩短,而红外光谱(FT-IR)分析表明SRT对膜污染物质的组成无显著影响,光谱折射率与SMP、EPS含量呈现一致性.     

Effect of components in activated sludge liquor on membrane fouling in a submerged membrane bioreactor

Introduction The membrane bioreactors (MBRs) have shown many advantages over conventional activated sludge processes, which apply membrane modules instead of the secondary settle tank to make a better separation of the solids and liquid and have been grea…     

好氧颗粒污泥膜生物反应器的运行特性

以人工合成模拟废水对好氧颗粒污泥膜生物反应器(MBR)的运行特性和膜污染进行了研究.结果表明:在HRT为6h,溶氧浓度为4～6mg.L^-1,COD的容积负荷为7.24kg·(m³·d)^-1的条件下,COD的去除率可达96%以上.当NH₃-N的容积负荷为0.17kg·(m³·d)^-1时,NH₃-N的去除率可达60%.COD/N比的变化,对好氧颗粒污泥MBR的COD及NH₃-N去除率基本没有影响.稳定运行过程时,MBR中好氧颗粒污泥浓度(MLSS)基本维持在14～16mg·L^-1.较高的污泥浓度和颗粒污泥内部缺氧和厌氧环境的存在,使MBR中硝化和反硝化过程能同时存在.同时,比较了2种不同形态的活性污泥(颗粒污泥和絮状污泥)在MBR运行过程中膜通量的变化趋势,结果表明,颗粒污泥MBR膜通量的下降速度明显比絮状污泥MBR的下降速度慢很多,且通过空气反冲或用水清洗即可使通量基本恢复.     

Effect of sludge retention time on sludge characteristics and membrane fouling of membrane bioreactor

Three identical membrane bioreactors (MBRs) were operated over 2 years at different sludge retention time (SRT) of 10 d, 40 d and no sludge withdrawal (NS), to elucidate and quantify the effect of SRT on the sludge characteristics and membrane fouling. The hydraulic retention times of these MBRs were controlled at 12 h. With increasing SRT, the sludge concentrations in the MBRs increased, whereas the ratio of volatile suspended solid to the total solid decreased, and the size of sludge granule diminished in the meantime. A higher sludge concentration at long SRT could maintain a better organic removal efficiency, and a longer SRT was propitious to the growth of nitrifiers. The performance of these MBRs for the removal of COD and NH₄⁺-N did not change much with different SRTs. However, the bioactivity decreased as SRT increase. The measurement of specific oxygen uptake rates (SOUR) and fluorescence in situ hybridization (FISH) with rRNA-targeted oligonucleotide probes testified that SOUR and the proportion of the bacteria-specific probe EUB338 in all DAPI-stainable bacteria decreased with increasing SRT. The concentrations of total organic carbon, protein, polysaccharides and soluble extracellular polymeric substance (EPS) in the mixed liquor supernatant also decreased with increasing SRT. The membrane fouling rate was higher at shorter SRT, and the highest fouling rate appeared at a SRT of 10 d. Both the sludge cake layer and gel layer had contribution to the fouling resistance, but the relative contribution of the gel layer decreased as SRT increase.     

Control of membrane fouling during hyperhaline municipal wastewater treatment using a pilot-scale anoxic/aerobic-membrane bioreactor system

Membrane fouling limits the effects of long-term stable operation of membrane bioreactor (MBR). Control of membrane fouling can extend the membrane life and reduce water treatment cost effectively. A pilot scale anoxic/aerobic-membrane bioreactor (A/O-MBR, 40 L/hr) was used to treat the hyperhaline municipal sewage from a processing zone of Tianjin, China. Impact factors including mixed liquid sludge suspension (MLSS), sludge viscosity (μup), microorganisms, extracellular polymeric substances (EPS), aeration intensity and suction/suspended time on membrane fouling and pollution control were studied. The relationships among various factors associated with membrane fouling were analyzed. Results showed that there was a positive correlation among MLSS, sludge viscosity and trans-membrane pressure (TMP). Considering water treatment efficiency and stable operation of the membrane module, MLSS of 5 g/L was suggested for the process. There was a same trend among EPS, sludge viscosity and TMP. Numbers and species of microorganisms affected membrane fouling. Either too high or too low aeration intensity was not conducive to membrane fouling control. Aeration intensity of 1.0 m³/hr (gas/water ratio of 25:1) is suggested for the process. A long suction time caused a rapid increase in membrane resistance. However, long suspended time cannot prevent the increase of membrane resistance effectively even though a suspended time was necessary for scale off particles from the membrane surface. The suction/suspended time of 12 min/3 min was selected for the process. The interaction of various environmental factors and operation conditions must be considered synthetically.