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关键词： 厌氧消化   厌氧膜生物反应器   城市污水   运行效果   物料平衡  

摘要： 为推进节能减排低碳化社会的进程,验证了利用厌氧消化新技术处理城市污水的可行性,在日本仙台市搭建并成功运行了目前世界上最大的中试浸没型一体式厌氧膜生物反应器,实现了在25℃左右的常温条件下对实际城市污水的高效厌氧处理。该中试反应器从2019年5月运行至2020年1月,历时217 d,最短水力停留时间缩短至6 h,COD去除率高达90%以上,BOD5去除率为95%。1 m^(3)城市污水中可回收沼气0.09~0.10 m^(3),每处理1 g COD可回收沼气约0.25 L,沼气中甲烷平均含量可达到75%。每处理1g COD中有0.19~0.26 g转化为污泥,污泥产率小于传统好氧活性污泥法。研究采用的微滤膜可实现最大膜通量为17.75 L/(m^(2)·h),稳定运行最大跨膜压量可达到23.5 kPa。该中试工程的成功运行再次验证了厌氧消化技术与膜分离技术结合在低浓度城市污水处理中的可能性与实用性,实现了节能减排与生物质能源利用,是一项可持续性发展的革新工艺。研究在大型中试规模实现了厌氧膜生物反应器的长期稳定运行,也为后续污水处理研究提供了基本运行参数和工程可靠性基础。

关键词： 接骨木   扦插   生根剂   基质  

摘要： [目的]研究不同浓度生根剂及基质类型对接骨木扦插生根的影响,以筛选出提高接骨木扦插育苗的技术。[方法]以接骨木为试材,采用3种不同浓度GGR6号生根粉(激素)和4种不同扦插基质对接骨木进行了硬枝扦插生根试验。[结果]扦插前采用200 mg/L的GGR6号处理接骨木硬枝,并在泥炭土∶珍珠岩=1∶3混合基质中进行扦插,比在其他种类基质中扦插的生根率都高。[结论]筛选出了一套生根效果好的技术方法,以期提高接骨木的繁殖效率。

关键词： 等P/V   生物反应器   缩小模型   CHO细胞  

摘要： 目的应用3 L生物反应器,基于等P/V策略建立生产规模450 L生物反应器的缩小模型。方法应用3 L生物反应器,按照生产工艺培养稳定表达抗CD20人鼠嵌合单克隆抗体的CHO细胞,培养16 d应用亲和层析纯化抗CD20单克隆抗体,分子排阻法分析抗体聚体,弱阳离子高效液相色谱法分析抗体的酸性峰和碱性峰含量,2-AB标记法检测抗体糖型含量,mini-tab软件对结果进行双单侧检验(Two One-Sided Test,TOST)分析。结果与生产规模相比,缩小规模细胞生长、二氧化碳分压(pCO_(2))水平及主要代谢产物乳酸和铵离子水平基本一致,抗体表达量、聚体含量、糖型结果及酸性峰和碱性峰含量经分析,均具有等价性。结论基于等P/V缩小原则成功建立了生产规模生物反应器的缩小模型。

关键词： 菌藻生物反应器   泥/藻质量比   生活污水   细菌群落组成  

摘要： 利用污水处理厂好氧池活性污泥和来自二沉池壁的藻类构成菌藻生物反应器用以处理实际生活废水,探讨了不同泥藻接种比对废水处理效果的影响,并分析了稳定运行后的微生物群落组成。结果表明:泥/藻质量比为1∶0.75的混合系统对污染物质(COD、TN和TP)的去除效率最高;当HRT为2 d时,按泥/藻质量比为1∶0.75接种的光生物反应器(初始TSS为1.12 g·L^(−1))在搅拌和太阳光照射的条件下,对NH_(4)^(+)-N的去除率可达99.7%,对PO_(4)^(3-)的去除率约为70%。利用高通量测序技术对运行42 d后反应器内(SRT为15 d)的细菌群落进行分析发现,优势细菌为厚壁菌门的微小杆菌属(Exiguobacterium),蓝菌门的光合产氧蓝细菌属(Cyanobium)和变形菌门α-变形菌纲的不产氧光合好氧异养固氮红杆菌属(Rhodobacter),其相对丰度分别为23.32%、15.23%和5.77%。同时,反应器内还存在氧化亚硝酸盐的硝化螺旋菌(Nitrospira),以及除磷的不动杆菌(Acinetobacter)和能进行好氧反硝化的副球菌(Paracoccus),其相对丰度分别为1.19%、0.58%和0.35%。

关键词： Carbon dioxide   Methane   Gravity flow of denitrification bioreactor   Folded plate denitrification bioreactor   Waste sawdust   Industrial sludge  

摘要： Carbon dioxide (CO2) and methane (CH4) produced by denitrification bioreactors in processing agricultural surface runoff have contributed to increasing proportion of greenhouse gases (GHG) emissions. It is the first time to monitor and quantify the emission flux of CO2 and CH4 produced by laboratory-scale denitrification bioreactors which recycled waste Cunninghamia lanceolata sawdust (CLS) and industrial sludge (IS) as fillers to process simulated agricultural surface runoff. Sludge-water ratio, inflow rate and water flow direction are used as experimental factors to study the effect on the emission flux of CO2 and CH4. Results show that emission flux of CO2 from denitrification bioreactors with different sludge-water ratio approached 20 mg m- 2h-1, simultaneously the average emission flux of CH4 produced by all bioreactors was 1.785 mg m- 2h-1. The addition of sludge increased the emission flux of CH4 and had no significant effect on the emission flux of CO2. Increasing the inflow rate reduced the CO2 emission flux from 21.57 to 1.27 mg m- 2h-1, and at the same time increased the CH4 emission flux from 0.007 to 9.54 mg m- 2h- 1. The gravity flow of wastewater reduced the emission flux of CO2 and CH4. The emissions of CO2 and CH4 from folded plate denitrification bioreactor with CLS and industrial sludge with a volume ratio of 1:2 can be reduced by 24.67% and 73.3%, respectively. There was no need to add special gas collection and treatment devices because CO2 and CH4 emission fluxes produced by the folded plate denitrification bioreactor and gravity denitrification bioreactor are not enough to increase the greenhouse effect. This study quantified the CO2 and CH4 produced by denitrification bioreactors filling CLS and IS, and provided a reference for future research on the gases produced by the denitrification process.

关键词： 城市污泥   厌氧消化   厌氧膜生物反应器   膜污染  

摘要： 利用厌氧消化技术处理城市污泥等有机废弃物,可以生成以甲烷为主要成分的沼气,同时实现废弃物减量化。传统的污泥厌氧消化技术存在水力停留时间长,处理水质差,反应器对环境变动敏感,运行不稳定等缺陷。使用有效体积15 L的实验室规模厌氧膜生物反应器(AnMBR)对初沉污泥与剩余污泥混合的城市污水厂污泥进行高浓度厌氧消化处理。AnMBR通过膜过滤方式将悬浮固体(SS)截留在反应器内,增强了反应器运行的稳定性并促进有机物的分解。AnMBR反应器在中温35℃,HRT为15 d,有机负荷为4.66 g-COD/(L·d)的条件下进行了为期155 d的长期运行实验。实验过程中,反应器运行稳定,没有出现氨氮抑制和挥发性脂肪酸的积累。沼气收率为0.48 L/g-VS,甲烷平均含量为63.32%。膜过滤水中COD浓度为0.77 g/L,COD去除率高达98%以上。通过物质衡算,基质总COD的54.38%转化为甲烷,仅有0.6%残留在膜过滤水中。在保持反应器污泥浓度25 g/L的高浓度条件下,实现了工作模式为4 min抽吸,1 min休息,平均膜通量9.6 L/(m^(2)·h)的连续稳定运行。通过膜阻力抵抗值的计算,污染膜总阻力为11.87×10^(12)/m,其中附着在膜表面的泥饼层和导致膜孔闭塞的有机层为膜污染形成的主要因素。通过长期连续实验的产甲烷情况及膜过滤效果,验证了AnMBR在有机废弃物减量化和能源回收应用上的可行性。

关键词： Deodorization   Wastewater treatment   Microbial community structure   Keystone species   Ecological mechanism  

摘要： Although activated sludge (AS) diffusion is promising for odor control, disagreement still exists on its treatment efficiency of varying odorants, and its microbiological mechanisms remain largely unknown. Herein, we investigated the deodorization efficiency, wastewater treatment performance, and microbiological and ecological effects of AS diffusion in two in situ membrane bioreactors (MBRs). AS diffusion removed ? 94.7% of H2S and 100% of NH3, while other odorants were released at low concentrations. The odor-diffused system also achieved appreciable wastewater treatment performance (effluent phosphate at 0.13 ? 0.12 mg/L, COD at 12.1 ? 1.8 mg/ L, and total nitrogen at 5.9 ? 1.8 mg-N/L), while membrane fouling was mitigated. Notably, influent wastewater substrates and nutrients, other than MBR system settings, significantly affected system performance, main functional taxa and bacterial community dynamics. Ecological null model and network analysis revealed that odor diffusion strengthened the niche-based deterministic processes (i.e., environmental selection) and caused more negative and intense microbial interactions. Organics competition was enhanced, and some hydrolytic bacteria correspondingly became keystone taxa in the odor-diffused system. The findings provide valuable guidance in establishing efficient AS systems for integrated wastewater and odor treatment.

关键词： 序批式生物反应器(SBR)   提盐速率   短程硝化   胞外聚合物   微生物群落结构  

摘要： 使用序批式生物反应器驯化耐盐活性污泥,探究提盐速率对污染物去除效果、活性污泥特性和微生物群落结构的影响.结果表明,快速提升盐度至30‰(30 d内提升盐度),COD和NH^(+)_(4)-N去除率均出现明显下降,由最初的85.5%和98.5%,分别降低至72.2%和81.7%;缓慢提升盐度至30‰(90 d内提升盐度),COD和NH^(+)_(4)-N去除率受盐度影响较小,表现出良好的去除性能.在缓慢提升盐度过程中,盐度为20‰,出水NO_(2)--N升高至11.13 mg·L^(-1),NO^(-)_(3)-N降低为0.56 mg·L^(-1),实现短程硝化;盐度为30‰,亚硝酸盐积累率约为90%,TN去除率升高至75%左右.随着盐度升高,胞外聚合物中多糖和蛋白质的含量不断增加,当盐度高于15‰时,多糖明显增加.高通量测序结果表明,经快速提盐和缓慢提盐驯化,微生物多样性明显下降,Shannon指数由8.06分别降为4.34和6.17.随着盐度增加,Micropruina、Denitromonas、TM7a和Marinicella表现出良好的耐盐特性.经快速提盐驯化后,Denitratisoma、Defluviimonas、Arenimonas和Denitromonas等反硝化菌的相对丰度明显减少.

关键词： Brine management   Nitrate removal   Batch bioreactors   Denitrification efficiency  

摘要： Woodchip bioreactors are widely known as a best management practice to reduce excess nitrate loads that are discharged with agricultural leachates. The aim of this study was to evaluate the performance of citrus woodchip bioreactors for denitrification of brine (electrical conductivity ?17 mS cm-1) from groundwater desalination plants with high nitrate content (NO3 --N ?48 mg L-1) in the Campo de Cartagena agricultural watershed, one of the main providers of horticultural products in Europe. The performance was evaluated relative to seasonal changes in temperature, dissolved organic carbon (DOC) provided by woodchips, hydraulic residence time (HRT) and woodchip aging. Bioreactors (capacity 1 m3) operated for 2.5 years (121 weeks) in batch mode (24 h HRT) with three batches per week. Denitrification efficiency was modulated by DOC concentration, temperature, hydraulic residence time and the drying-rewetting cycles. High salinity of brine did not prevent nitrate removal from occurring. The high DOC availability (>25 mg C L-1) during the first ?48 weeks resulted in high nitrate removal rate (>75%) and nitrate removal efficiency (until ?25 g N m- 3 d-1) regardless of temperature. Moreover, the high DOC contents in the effluents during this period may present environmental drawbacks. Denitrification was still high after 2.5 years (reaching ?9.3 g N m- 3 d-1 in week 121), but dependence on warm temperature became more apparent with woodchips aging from week ?49 onwards. Nitrate removal efficiency was highest on the first weekly batch, immediately after woodchips had been unsaturated for four days. It was attributable to a flush of DOC produced by aerobic microbial metabolism during drying that stimulated denitrification following re-saturation. Hence, alternance of drying-rewetting cycles is an operation practice that increase bioreactors nitrate removal performance.

关键词： Anaerobic digestion   Adaptive model predictive control   Fuzzy supervisory control  

摘要： In the present work, a fuzzy supervisory control approach combined with an adaptive model predictive controller (AMPC), has been proposed to maximize the productivity of an anaerobic digestion (AD) process, while keeping the operation stable. In the proposed hierarchal control strategy, the set-point of the inner loop is provided by a supervisory controller. In the inner loop an AMPC has been applied to achieve the desired methane production rate by manipulating the feed flow rate. The AMPC is designed based on the auto-regressive moving average (ARMA) model whose parameters are updated at each sampling time to make the controller more robust against uncertainties and external loads. In the supervisory level, a fuzzy logic system is utilized to adjust the set-point of the lower level controller based on the measurement of total concentration of the volatile fatty acids (VFA). To prevent VFA accumulation, an override control strategy is used to bring the total VFA concentration to its safe level when it exceeds a predetermined level. To simulate the AD process, the well-established Anaerobic Digestion Model No.1 (ADM1) has been used. Through simulation study, the performance of the proposed control strategy has been evaluated. Simulation results indicate that the proposed control strategy could maximize the methane production rate in presence of different external disturbances and model mismatch. (C) 2021 Elsevier Ltd. All rights reserved.