Investigates of substrate mingling ratio and organic loading rate of KOH pretreated corn stover and pig manure in batch and semi-continuous system:Anaerobic digestion performance and microbial characteristics

The effects of substrate mingling ratio(SMR)(1:1,1:2,1:3,3:1,and 2:1)and organic loading rate(OLR)(50-90 g total solids per liter per day)on anaerobic co-digestion performance and microbial characteristics were investigated for pig manure(PM)and pretreated/untreated corn stover in batch and semicontinuous anaerobic digestion(AD)system.The results showed that SMR and pretreatment affected co-digestion performance.The maximum cumulative methane yield of 428.5 ml·g^(-1)(based on volatile solids(VS))was obtained for PCP13,which was 35.7%and 40.0%higher than that of CSU and PM.In the first 5 days,the maximum methane yield improvement rate was 378.1%for PCP13.The daily methane yield per gram VS of PCP13 was 11.4%-18.5%higher than that of PC_(U)13.Clostridium_sensu_stricto_1,DMER64,and Bacteroides and Methanosaeta,Methanobacterium,and Methanospirillum had higher relative abundance at the genus level.Therefore,SMR and OLR are important factor affecting the AD process,and OLR can affect methane production through volatile fatty acids.

Transformation and performance of granular sequence batch reactor under conventional organic loading rate condition

Laboratory experiments were conducted to investigate the transformation and performance of a granular sequence batch reactor(SBR) under the conventional organic loading rate(OLR) condition.Aerobic granules were successfully cultivated in a SBR by means of alternative feeding load combined with reducing settling time after 60 d operational period.Subsequently,the black fungal granules were presented in reactor because of the filamentous overgrowth on the surface of aerobic granules.A small amount of fungal granules had no effect on the performance of granular SBR.Aerobic granules completely vanished and fungal granules eventually became the dominant species in subsequent 90 d operation after granulation.The three-dimensional excitation emission matrix(EEM) spectra result shows that the extracellular polymeric substances(EPS) component in both granules has no much difference,whereas the content of EPS in fungal granules is higher than that in bacterial granules.Due to their low bioactivity,the chemical oxidation demand(COD) and NH4-N removal efficiencies gradually decrease from 90.4%–96.5% and 99.5% to 71.8% and 32.9% respectively while the fungal granules become dominant in the SBR.

The Effect of Hydraulic Retention Times and Loading Rates on the Removal of Pollutants from Fish Processing Wastewater by Anaerobic Process

Anaerobic treatment model treats fish processing wastewater to be necessary for a small and medium factory that is very popular in Vietnam and other countries.Several techniques have been proposed.However,they are quite expensive and hard to operate,especially in remote areas.In this study,the hydraulic retention times(HRT)including 3,5,and 7 hours with a various organic loading rate of 1.5 to 6.5 kg COD/m3/day were investigated.Biomass concentration as mix-liquor volatile suspended solid(MLVSS)in the model is at 6,000 to 9,000 mg/L.On the basis of the result the optimal HRT with a 4.0 kg COD/m3/day organic loading rate was 8 hours which BOD5,COD removal efficiency were 92.18,87.36 percent respectively.By the end of the optimal hydraulic retention times,the total methane gas volume as a by-product was collected with 2.6 liters.

利用OLR和pH调控快速建立生物制氢反应器

以连续流搅拌槽式反应器(CSTR)作为反应装置,以糖蜜废水为底物利用活性污泥制取氢气,着重对有机负荷(OLR)和pH调控下生物制氢反应器乙醇型发酵的快速启动进行了研究。结果表明,在污泥接种量(以VSS计)为17.74g/L、温度为35℃±1℃、水力停留时间(HRT)为6h的条件下,通过调节进水化学需氧量(COD)质量浓度和系统pH值,约12d就可以快速实现生物制氢反应器中微生物的主要代谢类型为乙醇型发酵,实现稳定的氢气生产。

OLR对UASB运行特性的影响及丙酸氧化菌群的演替

考察有机负荷率(OLR)的提高对升流式厌氧污泥床(UASB)反应器运行特性及丙酸氧化菌群的影响。结果表明,OLR由6 kg COD/(m3·d)逐步提高到54 kg COD/(m3·d)时,UASB的COD去除率可保持在92%以上,厌氧污泥的比产甲烷速率和比COD去除速率分别由130 L CH4/(kg VSS·d)和0.3 kg COD/(kg VSS·d)提高到827 L CH4/(kg VSS·d)和1.8 kg COD/(kg VSS·d)。随着OLR的逐步提高,系统中丙酸氧化菌群发生明显演替,其中,具有较低比生长速率(μ)和最大比降解速率(Umax)的Syntrophobacter wolinii和Pelotomaculum propionicicum被先后淘汰,而具有较高μ、Umax的P.schinkii逐渐成为系统的优势菌,具有较高μ、Umax的丙酸氧化菌的逐步富集可显著提高系统降解丙酸的能力,促进产甲烷菌群的增殖和代谢,使系统的整体处理效能得到显著提升。

qPCR揭示丙酸降解菌群随OLR提高的演替规律

为探讨有机负荷率(OLR)对升流式厌氧污泥床(UASB)反应器运行效能的影响及互营丙酸降解菌群的响应,以稀释的制糖废水为底物,考察了OLR升高对UASB处理效能的影响,并采用实时荧光定量PCR技术(qPCR)分析了互营丙酸降解菌群随OLR提高的演替规律.结果表明,在OLR为6.0～54.0kg COD/(m^3·d)的范围内,UASB处理制糖废水取得了良好的效果,其COD去除率为92.0%以上.qPCR检测结果表明,至少有3种已鉴定的丙酸氧化菌(Pelotomaculum schinkii,P.propionicum和Syntrophobacter sulfatireducens)存在于UASB反应器中.其中,S.sulfatireducens是主要的丙酸氧化菌,其数量为126～1.2×10~3 16S rRNA基因拷贝数/ng DNA,约占检测到丙酸氧化菌总数的47.9%～58.6%.OLR从6.0提高至54.0kg COD/(m^3·d)导致所有丙酸氧化菌数量显著减少.Methanospirillum hungatei和Methanosaeta concilii是该UASB系统中的主要氢营养型产甲烷菌和乙酸营养型产甲烷菌.与丙酸氧化菌的变化趋势相反,这两种产甲烷菌的数量均随OLR的提高而显著增加,并在OLR54.0kg COD/(m^3·d)条件下达到最大值.

餐厨垃圾厌氧消化快速启动特性的研究

为明确餐厨垃圾快速启动过程的厌氧消化特性,通过半连续搅拌反应器系统,监测了有机负荷(Organic Loading Rate,OLR)为1.5、2.0、2.5和3.0 gVS·L^(-1)d^(-1)运行过程中沼气产量和甲烷含量、沼液pH值、挥发性脂肪酸(VFA)、碱度和氨氮等参数的变化情况。研究结果表明:OLR从1.5 gVS·L^(-1)d^(-1)提高至3.0 gVS·L^(-1)d^(-1)时,容积产气率提高到2.12±0.05 L·L^(-1)d^(-1),比甲烷产量稳定在273.2±7.8 mLCH_(4)·g^(-1)VS,系统产气性能良好且稳定;挥发性脂肪酸浓度维持较低水平(650 mg·L^(-1)左右),主要成分是乙酸。氨氮含量随着OLR的提升不断增加,最高达到4171 mg·L^(-1),游离氨增加至300~350 mg·L^(-1),对产气性能产生轻微抑制作用;微生物群落分析表明厌氧消化过程主要细菌菌群是Firmicutes、Bacteroidota和Synergistota,优势产甲烷菌群主要以Methanosarcina、Methanobacterium和Methanosaeta为主。厌氧消化启动阶段在有机负荷达到3.0 gVS·L^(-1)d^(-1)时可以稳定运行,反应器成功启动。

厌氧消化技术在处理有机废弃物方面的应用现状

本研究聚焦于评估厌氧消化技术在处理有机废弃物、转化为再生能源和有机肥料方面的应用,并探讨了其对环境影响的减缓作用。采用文献综述方法,深入分析了温度、碳氮比、有机负荷率、挥发性脂肪酸、水力停留时间和pH等因素如何影响厌氧消化过程的效率与稳定性。研究表明,这些参数对促进微生物活动、加快有机物分解以及维持系统稳定运行均具有显著影响。通过对玉米秸秆、畜禽粪便和厨余垃圾等典型有机废弃物的案例分析,验证了厌氧消化技术的有效性,并详细阐述了该过程中关键微生物群落的结构和功能,包括细菌和古菌在不同阶段如水解、酸化、乙酸化和产甲烷中的作用机制。此外,文章还讨论了有毒物质生成问题及其管理策略。最终,文章建议通过提升厌氧消化效率、开发新型反应器技术以及加强微生物种群研究,将有助于使厌氧消化技术在未来实现更高效、稳定且广泛的运用。

不同OLR对流固共筑生物膜ABR生物制氢系统影响

以启动成功的厌氧折流板生物制氢反应器(ABR)作为实验装置,并以配置不同有机负荷质量浓度的红糖废水作为实验底物,通过分阶段调控水力停留时间(HRT)和进水COD质量浓度的方式研究了5,6.7,10,12,14,16 kg/(m^3·d)6种不同有机负荷对ABR系统的影响。实验结果表明,当受到一定范围内的有机负荷冲击时,ABR系统经过2—5 d的适应期可以恢复稳定,且适应期随反应的进行逐渐缩短,说明在一定范围内随着有机负荷的提高,ABR系统的稳定性能逐渐增强;当HRT为12 h、进水COD质量浓度达到8000 mg/L时[有机负荷(COD)约16 kg/(m^3·d)],有机负荷超出ABR系统承受能力并导致系统发生酸化,pH值最低降低到3.98,COD去除率及总产氢速率降低。本研究为ABR反应器在实际中的运用提供了理论基础。

有机负荷率对新型厌氧/好氧/缺氧工艺的影响机制探究

为了探究进水有机负荷对新型厌氧/好氧/缺氧工艺(AOA)工艺的影响,构建了新型AOA生物脱氮除磷反应器,通过控制进水COD考察了有机负荷率(OLR)对AOA工艺对污染物和营养盐去除的影响,并通过分析不同OLR工况影响下污泥特征及胞内聚合物的变化规律、微生物群落特征揭示了OLR对AOA工艺的影响机制。结果表明进水OLR由200 mg/L提高至400 mg/L,AOA工艺具有良好的去除效率,COD、TN和SOP的去除效率分别达到93.6%~96.2%、82.45%~85.1%和94.2%~98.5%。进水OLR提高了污泥往胞外聚合物含量,且显著提高了PN含量。在进水OLR为400 mg/L时,聚羟基脂肪酸酯(PHA)最大积累量为5.98 mmol/g,糖原质含量下降至6.03 mmol/g。OLR能影响AOA工艺内微生物群落结构,适量提高OLR促进了Proteobacteria和Firmicutes在污泥内的占比。研究结果为AOA工艺处理不同进水OLR的废水提供一定的数据支撑和理论依据。

Studies of Heterogeneous Hydrothermal Stripping from Iron-loaded Naphthenic Acid-Alcohol-Kerosen

The technique of hydrothermal stripping from mixed aqueous-organic systems is a promising method for synthesizing oxide ceramic powders for high-performance applications. Some factors influencing heterogeneous hydrothermal stripping with water from iron-loaded organic phase of naphthenic acidisooctyl alcoholkerosene, such as initial concentrations of iron and naphthenic acid, concentration of Fe2O3 搒eed, temperature and time, were investigated. Based on the experimental results, the rate equation was established. Nano-ferric oxide powders were obtained by the technique of hydrothermal stripping from the iron-loaded organic phase. The results suggest that the heterogeneous hydrothermal stripping proceeds in 3 steps: adsorption of naphthenic acid dimers and naphthenic complex of iron onto the surface of seed? hydrolysis of adsorbed complex of iron, and condensation of hydrolyzed complex. The process activation energy is 115 kJ/mol and the heterogeneous hydrothermal stripping is controlled by a chemical reaction (the hydrolysis of naphthenic complex of iron).

有机负荷率对颗粒污泥处理高浓度畜禽养殖废水影响

通过改变进水有机负荷率(OLR)在序批式反应器内考察了OLR对颗粒污泥处理畜禽养殖废水去除污染物、颗粒化进程及微生物群落结构的影响。结果表明,适当提高OLR利于颗粒污泥去除畜禽废水内污染物并加速颗粒化进程,当OLR为3.0 kg/(m^(3)·d)时,COD和溶解性磷酸盐的去除效率分别高达92.6%~95.2%和92.6%~95.2%,均显著高于低OLR工况,且在此OLR下,污泥浓度最高,沉降性好,污泥粒径在0.3~0.7 mm占比69.8%,胞外聚合物(EPS)含量低至72.5 mg/g,但EPS内蛋白质/多糖的比值高达2.02。高OLR降低颗粒污泥处理畜禽养殖废水的效能并导致部分颗粒污泥解体。OLR同样能影响颗粒污泥内微生物多样性及群落结构,适当提高OLR增加了微生物多样性,并提高Proteobacteria和Bacteroidetes的相对丰度但降低了Planctomycetes的相对丰度,利于有机质和营养盐去除。本研究结果拓展了颗粒污泥的应用范围,并为颗粒污泥的快速启动提供一定技术支撑和理论依据。

有机负荷对餐厨垃圾厌氧消化性能影响及动力学分析

为探究有机负荷对餐厨垃圾厌氧消化系统的影响,在50 L全混合式厌氧消化反应器(CSTR)进行进料负荷从0.72增至3.86 kgVS·m^(-3)d^(-1)的梯度实验。同时采用Modified Gompertz模型研究不同进料负荷(1、2、3、4、5 kgVS·m^(-3)d^(-1))产甲烷动力学特性,开展生化产甲烷潜力(BMP)试验。结果表明,日产气量和挥发性脂肪酸(VFA)随着负荷的增加而波动上升,而吨VS产气量和碱度则随之下降;在负荷3.15 kgVS·m^(-3)d^(-1)阶段,VFA为2000 mg·L^(-1)左右,酸碱比在0.13左右,容积产气率在2.25 L·L^(-1)左右,系统稳定性强且厌氧消化效率高,此负荷为最佳负荷。BMP试验显示Modified Gompertz模型适合描述餐厨垃圾厌氧消化过程,最大产甲烷量和最高产甲烷率均随着负荷的增加而提高。

高含油餐厨垃圾厌氧消化最佳负荷及油脂积累的解除

高含油餐厨垃圾具有高负荷、高产气、易积累油脂的特点,为探究高含油餐厨垃圾厌氧消化的最佳有机负荷(OLR)及油脂积累恶化条件下的有效除油方法,以剩余污泥为接种物、餐厨垃圾为原料,启动中温湿式厌氧消化。系统油脂积累后,从活性炭、氯化钙、膨润土中优选出脱除长链脂肪酸(LCFAs)的添加剂,协同脂肪酶降解餐厨油脂并解除中间产物LCFAs的抑制作用。结果表明,高含油餐厨垃圾中温厌氧消化系统最佳OLR为4.54 g/(L·d)(VS),此时产气率为3.878 L/(L·d),甲烷产量为565.6 mL/g(VS),脂肪酶是脱除LCFAs的最佳添加剂,和氯化钙可协同脱除LCFAs并解除系统内的油脂积累。

Microbial community dynamics at high organic loading rates revealed by pyrosequencing during sugar refinery wastewater treatment in a UASB reactor

The performance and rnicrobial community structure in an upflow anaerobic sludge blanket reactor （UASB） treating sugar refinery wastewater were investigated. The chemical oxygen demand （COD） removal reached above 92.0% at organic loading rates （OLRs） of 12.0-54.0 kgCOD/（m^3· d）. The volatile lhtty acids （VFAs） in effluent were increased to 451.1 mg/L from 147.9 mg/L and the specific methane production rate improved by 1.2 2.2-1bid as the OLR increased. The evolution of microbial comnmnities in anaerobic sludge at three different OLRs was investigated using pyrosequencing. Operational taxonomic units （OTUs） at a 3% distance were 353,337 and 233 for OLRI2, OLR36 and OLR54, respectively. When the OLR was increased to 54.0 kgCOD/（m^3· d） from 12.0 kgCOD/ （m^3· d） by stepwise, the microbial community structure were changed significantly. Five genera （Bacteroides, Trichococcus, Cho,seobacterium, Longilinea and Aerococcus） were the dominant fermentative bacteria at the OLR 12-0 kgCOD/（m^3· d）. However, the sample of OLR36 was dominated by Lacmcoccus, Trichococcus, Anaer-arcus and Veillonella. At the last stage （OLR = 54.0 kgCOD/ （m^3· d）, the diversity and percentage of femlentative bacteria were markedly increased. Apart from fermentative bacteria, an obvious shift was observed in hydrogen-producing acetogens and non- acetotrophic methanogens as OLR increased. Svntrophohacter, Geobacter and Methanomethylovor- ans were the dominant hydrogen-producing acetogens and methylotrophic methanogens in the samples of OLRI2 and OLR36. When the OLR was increased to 54.0 kgCOD/（m^3· d）, the mare hydrogen-producing acetogens and hydrogenotrophic methanogens were substituted with Destd/bvi- brio and Methanospillum. However, the composition of acetotrophic methanogens （Methanosaeta） was relatively stable during the whole operation period of the UASB reactor.

Spatial distribution of bacterial community in EGSB reactor treating synthetic sulfate-containing wastewater at low organic loading rate

Given that the consumption of organic substances entails costly biodesulfurization,the characteristics of the bacterial community in a reactor should be determined to increase the desulfurizing rate under low organic loading condition.In this study,the bacterial community distribution in the expanded granular sludge bed reactor used to treat sulfate-containing wastewater with low organic loading rate was determined by polymerase chain reaction-denaturing gradient gel electrophoresis(PCRDGGE)and 16S rDNA clone library analyses.DGGE results showed that the predominant bacteria were stable and accounted for*90%sulfate removal efficiency.Differences in band positions and intensities indicated that the distribution and abundance of bacteria were affected by their positions in the reactor.Typical bands were identified in the bacterial community comprising Desulfovibrio,Desulfomicrobium,Thiomonas,Acinetobacter,Bacteroidetes,and Chloroflexi.Their functions in the reactor were also discussed.The possible links between the functional and microbial responses were also investigated based on the characteristic and spatial distribution of each bacterium in consortium.

大中型湿垃圾半干法全混式厌氧反应器的运行性能、微生物特性及经济性评价

随着湿垃圾产生量的持续增加,大中型高效湿垃圾厌氧发酵工程发展迅速。以上海某生态园有机质固废处理项目为研究对象,对项目中有效容积分别为7160、4150 m^(3)的大型、中型半干法全混式厌氧反应器(CSTR)的运行性能及微生物群落结构特征等进行了系统研究。结果表明,稳定运行期间,大型、中型半干法CSTR平均有机负荷总体接近,平均值分别为2.02、2.04 kg/(m^(3)·d);大型半干法CSTR平均产沼率为914 Nm^(3)/t(以进料中单位质量挥发性固体(VS)产生的标况下沼气体积计,下同),显著高于中型半干法CSTR的696 Nm^(3)/t(P<0.01)。两种规模CSTR中的污泥浓度、上清液溶解性化学需氧量(SCOD)和挥发性脂肪酸等均无显著差异,SCOD去除率均可达90%以上。两种规模的CSTR中,微生物在门水平上的多样性分布无显著差异(P>0.05),均以厚壁菌门、盐杆菌门、拟杆菌门为主。大型、中型半干法CSTR进料收益分别为91.3、62.8元/m^(3),随着反应器规模的扩大,经济效益明显提升。

温度与有机负荷对猪粪厌氧发酵过程的影响

为提高畜禽养殖场沼气工程能源利用效率,降低工程运行成本。该文通过全混式半连续试验,以猪粪为发酵原料,研究不同温度(20、28、38℃)和有机负荷(0.3、1.3、2.3、3.3、4.3kg/(m3·d))条件下,甲烷产率、挥发性脂肪酸(volatile fattyacid,VFA)及总无机碳(total inorganic carbon,TIC)的变化特征。结果表明:20℃条件下,反应器启动缓慢,甲烷产率低。当有机负荷增加至1.3kg/(m3·d)以上时,反应器运行不稳定,需外加NaHCO3调节pH值;在28℃与38℃条件下,各有机负荷甲烷产率无明显差异,但是在较高有机负荷3.3和4.3kg/(m3·d)下运行时,28℃条件下产生挥发性脂肪酸积累的现象,系统缓冲能力缺乏,VFA/TIC值分别达到0.4和0.6。当实际沼气工程低负荷率运行时,可选择28℃作为发酵温度,以达到节省能源、提高沼气工程经济效益的目的。该研究可为实际沼气工程运行管理提供数据参考。

有机负荷对厨余垃圾常温厌氧发酵产甲烷的影响

为了考察在不同有机负荷下厨余常温厌氧发酵产甲烷的特性,试验以厨余垃圾为原料,在常温(27℃)条件下,采用40L厌氧反应器进行连续式厌氧消化。结果表明,当有机负荷率控制在3.89～6.49kg/(m3.d)之间,池容产气率可稳定在2.5～4.5L/(L.d),原料挥发性固体产甲烷率为300.59～488.52L/kg,平均甲烷体积分数为54.05%～56.04%,挥发性固体物去除率为55.12%～89.58%;因此,将有机负荷率控制在3.89～6.49kg/(m3.d)之间,厨余垃圾在常温下厌氧消化可达到较高的原料产甲烷率和稳定的产甲烷过程。

MBR工艺处理含50%海水的污水试验研究

采用MBR工艺对含50%海水的污水生物处理进行了试验研究。实验条件为进水COD为300～2 600 mg/L,NH3-N为50～300 mg/L,pH值为6～9,混合液污泥浓度为7 000 mg/L,溶解氧浓度为2～4 mg/L,温度为20～25℃。试验结果表明,系统的最佳运行条件为：有机负荷〈3.2 kg COD/（m^3·d）,氨氮负荷〈0.35 kg/（m^3·d）,pH值在7.5～8.5之间,HRT〉12 h。在此条件下,COD与氨氮的去除率可同时达到90%。高盐环境下微生物所分泌的大量胞外多聚物是造成MBR工艺处理含盐废水过程中膜污染的主要原因。