Design and study on hydraulics characteristic of multistage anaerobic granular sludge reactor

This article provides some ideas about several key parameters in design of multistage anaerobic granular sludge reactor （MA（iSR）, and an MAGSR was designed by these ideas. By experiment this paper studies the productivity of biogas and circulation flux of wastewater. The results indicate that in certain scope the circulation flux increases in linear with the biogas productivity rise. The result by the experiment and by the hydraulics model about the circulation flux is different. The circulation flux can be several or more than ten times of the influence.

Influence of Chemical Oxygen Demand Concentrations on Anaerobic Ammonium Oxidation by Granular Sludge From EGSB Reactor

Objective To investigate the effect of chemical oxygen demand （COD） concentrations on the anaerobic ammonium oxidation （ANAMMOX）. Methods An Expanded Granular Sludge Bed （EGSB） reactor was used to cultivate the granular sludge and to perform the ANAMMOX reaction in the bench scale experiment. NH4^＋-N and NO2^--N were measured by using colorimetric method. NO3^＋-N was analyzed by using the UV spectrophotometric method. COD measurement was based on digestion with potassium dichromate in concentrated sulphuric acid. Results When the COD concentrations in the reactors were 0 mg/L, 200 mg/L, 350 mg/L, and 550 mg/L, respectively, the NH4^＋-N removal efficiency was 12.5%, 14.2%, 14.3%, and 23.7%; the removal amount of NO2-N was almost the same; the nitrate removal efficiency was 16.8%, 94.5%, 86.6%, and 84.2% and TN removal efficiency was 16.3%, 50.7%, 46.9%, and 50.4%, moreover, the COD removal efficiency was 85%, 65.7%, and 60%; the COD removal rate was 27.42, 61.88, and 97.8 mg COD/（h·L）. Conclusion COD concentrations have a significant influence on anaerobic ammonium oxidation by granular sludge.

Inhibitory effect of ammonia nitrogen on specific methanogenic activity of anaerobic granular sludge

A series of batch experiments were conducted in 125 mL serum bottles to assess the toxicity of different concentrations of ammonia nitrogen to the specific methanogenic activity of anaerobic granular sludge from upflow anaerobic sludge bed（UASB） and expanded granular sludge bed（EGSB） reactors. The effects of pH value and temperature on toxicity of ammonia nitrogen to anaerobes were investigated. The results show that the specific methanogenic activity of anaerobic granular sludge suffers inhibition from ammonia nitrogen, the concentrations of ammonia nitrogen that produce 50 % inhibition of specific methanogenic activity for sludge from UASB and EGSB reactor are 2.35 and 2.75 g/L, respectively. Hydrogen utilizing methanogens suffers less inhibition from ammonia mtrogen than that of acetate utilizing methanogens. Hydrogen-producing acetogens that utilize propionate and butyrate as substrates suffer serious inhibition from ammonia nitrogen. The toxicity of ammonia nitrogen to anaerobic granular sludge enhances when pH value and temperature increase. Anaerobic granular sludge can bear higher concentrations of ammonia nitrogen after being acclimated by ammonia nitrogen for 7 d.

Production and application of anaerobic granular sludge produced by landfill

Sludge granulation is considered to be the most critical parameter governing successful operation of an upflow anaerobic sludge blanket and expanded granular sludge bed （EGSB） reactors. Pre-granulated seeding sludge could greatly reduce the required startup time. Two lab-scale and a pilot-scale EGSB reactors were operated to treat Shaoxing Wastewater Treatment Plant （SWWTP） containing wastewater from real engineering printing and dyeing with high pH and sulfate concentration. The microbiological structure and the particle size distribution in aerobic excess sludge, sanitary landfill sludge digested for one year, and the granular sludge of EGSB reactor after 400 d of operation were analyzed through scanning electron microscopy （SEM） and sieves. The lab-scale EGSB reactor seeded with anaerobic sludge after digestion for one year in landfill showed obviously better total chemical oxygen demand （TCOD） removal efficiency than one seeded with aerobic excess sludge after cation polyacrylamide flocculation-concentration and dehydration. The TCOD removed was 470.8 mg/L in pilot scale EGSB reactor at short hydraulic retention time of 15 h. SEM of sludge granules showed that the microbiological structure of the sludge from different sources showed some differences. SEM demonstrated that Methanobacterium sp. was present in the granules of pilot-scale EGSB and the granular sludge produced by landfill contained a mixture of anaerobic/anoxic organisms in abundance. The particle size distribution in EGSB demonstrated that using anaerobic granular sludge produced by sanitary landfill as the seeding granular sludge was feasible.

Microbiological Characteristics of Anaerobic Granular Sludge in Hybrid Anaerobic Baffled Reactor

Anaerobic granular sludge is of key importance for highly effective operation of hybrid anaerobic baffled reactor(HABR).An observation and analysis on the composition of anaerobic granular sludge in each separation compartment of HABR was conducted by using scanning electron microscope(SEM)and molecular biotechnology,and specific methanogenic activity(SMA)and coenzyme F420 content were determined.It was indicated that the disparity of microbial composition was significant among these separation compartments of HABR,and the HABR encouraged phase separation.The results show the understanding of microbiological characteristics of anaerobic granular sludge in HABR is helpful for cultivating granular sludge,which ensures the effective operation of the reactor.

Extracellular polymeric substances as paper coating biomaterials derived from anaerobic granular sludge

Recovering extracellular polymeric substances(EPS)from waste granular sludge offers a cost-effective and sustainable approach for transforming wastewater resources into industrially valuable products.Yet,the application potential of these EPS in real-world scenarios,particularly in paper manufacturing,remains underexplored.Here we show the feasibility of EPS-based biomaterials,derived from anaerobic granular sludges,as novel coating agents in paper production.We systematically characterised the rheological properties of various EPS-based suspensions.When applied as surface sizing agents,these EPS-based biomaterials formed a distinct,ultra-thin layer on paper,as evidenced by scanning electron microscopy.A comprehensive evaluation of water and oil penetration,along with barrier properties,revealed that EPS-enhanced coatings markedly diminished water absorption while significantly bolstering oil and grease resistance.Optimal performance was observed in EPS variants with elevated protein and hydrophobic contents,correlating with their superior rheological characteristics.The enhanced water-barrier and grease resistance of EPS-coated paper can be attributed to its non-porous,fine surface structure and the functional groups in EPS,particularly the high protein content and hydrophobic humic-like substances.This research marks the first demonstration of utilizing EPS from anaerobic granular sludge as paper-coating biomaterials,bridging a critical knowledge gap in the sustainable use of biopolymers in industrial applications.

Performance of Anammox granular sludge bed reactor started up with nitrifying granular sludge

The anaerobic ammonia oxidation(Anammox) granular sludge bed reactor was started up successfully with nitrifying granular sludge. During the operation, the nitrifying granular sludge was gradually converted into Anammox granular sludge with good settling property and high conversion activity. The Anammox reactor worked well with the shortest HRT of 2 43 h. Under the condition that HRT w as 6 39 h and influent concentration of ammonia and nitrite was 10 mmol/L, the removal of ammonia and nitrite was 97 17% and 100 00%, respectively. Corresponding volumetric total nitrogen loading rate and volumetric total nitrogen conversion rate were 100 83 mmol/(L·d) and 98 95 mmol/(L·d). The performance of Anammox reactor was efficient and stable.

Study of 4-t-octylphenol degradation and microbial community in granular sludge

In this study, the authors have investigated the effects of various factors on both aerobic and anaerobic degradation of 4-t-octylphenol （4-t-OP） in granular sludge. In comparison, the aerobic degradation rate was much higher than that of anaerobic degradation. The optimal pH values for 4-t-OP degradation in granular sludge were 9 and 7 under aerobic and anaerobic conditions, respectively. And the degradation rate decreased with an increase in the initial 4-t-OP concentration. Addition of yeast extract or homologous compounds such as phenol also enhanced the 4-t-OP degradation, especially under the aerobic condition. To investigate the bacterial community in this study, the denaturing gradient gel electrophoresis （DGGE） method was applied, based on the primers, for the 16S rDNA V3 region of bacteria, γ-proteobacteria and bacillus were identified as the major species of sludge.

Stability of expanded granular sludge bed process for terylene artificial silk printing and dyeing wastewater treatment

Terylene artificial silk printing and dyeing wastewater(TPD wastewater), containing averaged 710 mg/L terephthalic acid(TA) as the main carbon source and the character pollutant, was subjected to expanded granular sludge bed(EGSB) process. The stability of the EGSB process was firstly conducted by laboratory experiment. TA ionization was the predominated factor influencing the acid-base balance of the system. High concentration of TA in wastewater resulted in sufficient buffering capacity to neutralize the volatile fatty acids(VFA) generated from substrate degradation and provided strong base for anaerobic system to resist the pH decrease below 6.5. VFA and UFA caused almost no inhibition on the anaerobic process and biogas production except that pH was below 6.35 and VFA was at its maximum value. Along with the granulating of the activated sludge, the efficiency of organic removal and production rate of biogas increased gradually and became more stable. After start-up, the efficiency of COD removal increased to 57%—64%, pH stabilized in a range of 7.99—8.04, and production rate of biogas was relatively high and stable. Sludge granulating, suitable influent of pH and loading were responsible for the EGSB stability. The variation of VFA concentration only resulted in neglectable rebound of pH, and the inhibition from VFA could be ignored in EGSB. The EGSB reactor was stable for TPD wastewater treatment.

Niche Differentiation of Phenol-Degrading Microorganisms in UASB Granular Sludge as Revealed by Fluorescence in situ Hybridization

A microbial community structure of granules harvested from an anaerobic sludge blanket reactor treating phenolic wastewater was investigated using fluorescence in situ hybridization(FISH)and clone library construction.Clones of Syntrophorhabdaceae and Cryptanaerobacter were observed to be responsible for phenol degradation.For accurate taxonomic assignment of Cryptanaerobacter clones,phylogenetic analysis using nearly full-length 16S ribosomal RNA(rRNA)gene sequences was necessary.Three oligonucleotide probes were designed to detect the following three taxonomic groups:Syntrophorhabdaceae,Cryptanaerobacter,and Syntrophus.FISH analysis of thin sections of anaerobic granules showed a random distribution of bacteria and archaea.However,a well-defined distribution of Syntrophorhabdaceae,Cryptanaerobacter,and Syntrophus was observed.Cryptanaerobacter and Syntrophus were found on the outer layer of the granules and were closely associated with each other,while Syntrophorhabdaceae was located in the deeper part of the granules.Such specific distribution of the bacteria is most likely due to their metabolic association and affinity for the substrate.Phenol degradation in the granular sludge was observed to be carried out in the following way.First,Cryptanaerobacter converts phenol to benzoate,which is then degraded by Syntrophus into acetate.This syntrophic degradation of phenol occurs near the surface of the granule,where the phenol concen-tration is high.In the deeper part of the granule,where the phenol concentration is lower,Syntrophorhabdaceae degrades phenol into acetate.We observed that Syntrophorhabdaceae is less likely to produce benzoate as an intermediate to feed the neighboring organisms,which contradicts the theo-ries presented by previous studies.

低表观气速间歇曝气AGS-SBR系统处理实际生活污水

实验选用3个SBR反应器接种污水厂活性污泥,R1采用高表观气速(SGV)连续曝气,R2采用低SGV连续曝气,R3采用低SGV间歇曝气,在低碳氮比的实际生活污水中培养好氧颗粒污泥,探究不同SGV曝气条件对好氧颗粒污泥的形成及系统处理效果的影响.经过120d的培养,R1､R2和R3中颗粒粒径分别为(754±78),(812±86),(1183±93)μm,R3的脱氮除磷效果优于R1和R2.结果表明,应用低SGV间歇曝气策略在低碳氮比实际生活污水中培养的好氧颗粒污泥脱氮除磷性能良好,且系统中反硝化聚磷菌(DPAO)占聚磷菌(PAO)比例为24.75%.

内循环厌氧反应器处理猪场废水启动过程中AGS培养的试验研究

以猪场废水为基质,研究了内循环厌氧反应器(ICAR)启动中厌氧颗粒污泥(AGS)的驯化过程及对猪场废水的处理效果.结果表明,在逐渐加大进水流量和COD质量浓度来提高有机负荷的情况下,污泥床区逐渐充满沉降性能良好的AGS,到启动完成时,经历了62 d的时间.启动完成后,污泥床区中粒径大于1 mm的AGS量占81.3%,且污泥床区底部AGS粒径较大.通过镜检发现AGS表面丝状菌和短杆菌为优势菌,而内部则以球菌为主.在进水COD有机负荷(OLR)为20.6 kg.m-3.d-1,水力滞流期(HRT)不低于16 h时,COD去除率保持在90%以上.

Effect of inorganic carbon on anaerobic ammonium oxidation enriched in sequencing batch reactor

The present lab-scale research reveals the enrichment of anaerobic ammonium oxidation microorganism from methanogenic anaerobic granular sludge and the effect of inorganic carbon(sodium bicarbonate)on anaerobic ammonium oxidation.The enrichment of anammox bacteria was carried out in a 7.0-L sequencing batch reactor(SBR)and the effect of bicarbonate on anammox was conducted in a 3.0-L SBR.Research results,especially the biomass,showed first signs of anammox activity after 54 d cultivation with synthetic wast...

Startup and operation of anaerobic EGSB reactor treating palm oil mill effluent

A bench-scale expanded granular sludge bed （EGSB） reactor was applied to the treatment of palm oil mill effluent （POME）. The reactor had been operated continuously at 35℃ for 514 d, with organic loading rate （OLR） increased from 1.45 to 17.5 kg COD/（m^3·d）. The results showed that the EGSB reactor had good performance in terms of COD removal on the one hand, high COD removal of 91% was obtained at two days＇ of hydraulic retention time （HRT）, and the highest OLR of 17.5 kg COD/（m^3·d）. On the other hand, only 46% COD in raw POME was transformed into biogas in which the methane content was about 70% （V/V）. A 30-d intermittent experiment indicated that the maximum transformation potential of organic matter in raw POME into methane was 56%. Volatile fatty acid （VFA） accumulation was observed in the later operation stage, and this was settled by supplementing trace metal elements. On the whole, the system exhibited good stability in terms of acidity and alkalinity. Finally, the operational problems inherent in the laboratory scale experiment and the corresponding countermeasures were also discussed.

Treatment of methanol wastewater in external circulation anaerobic reactor with different inoculums

In order to guide the inoculums selection for the anaerobic treatment of methanol wastewater in the engineering application,two 7 L bench-scale external circulation (EC) anaerobic reactors were operated to investigate the inoculums of anaerobic granular sludge and anaerobic digested sludge,focusing on the efficiency and process stability.The effect of impact concentration and temperature on the performance was studied.The results demonstrated that anaerobic granular sludge as the inoculums could complete the start-up more rapidly than the anaerobic digested sludge,and above 90% COD removal were achieved at the organic loading rate of 10 to 15 kgCOD/(m3·d).The effect of impact COD on the methanogenic activity of sludge was weak and the removal efficiencies recovered gradually in the two reactors.The COD removal efficiencies reduced swiftly to 50%-60% due to the impact temperature.The results indicated that the complex bacterial groups in anaerobic digested sludge benefited to enhance the reactor's capacity for withstanding the temperature shock at some extent.

新型连续流系统中Anammox颗粒粒径控制策略研究

以具有自主专利的新型大/小双室自回流连续流反应器为平台,探究基于粒径回流的Anammox颗粒污泥粒径调控策略及调控机制.粒径回流策略通过改变内循环的位置,将不同粒径的污泥引入高基质浓度和高机械剪切区域进行粒径调控.结果表明,粒径回流策略能够提高Anammox颗粒粒径,并将其控制在合适的范围内.这一策略还增强了系统的污泥浓度、颗粒沉降性能和脱氮性能.其中大颗粒回流策略综合提升效果最佳,维持颗粒粒径在0.5~1.6mm范围内,中值粒径为948μm,污泥体积指数(SVI)为35.6mL/g,总无机氮(TIN)去除率为88.59%.胞外聚合物(EPS)分析和分层实验表明,紧密结合EPS(TB-EPS)中的蛋白质(PN)在粒径调控中起着关键作用,高浓度的外层污泥PN主导了颗粒的沉降性能,而内层紧实污泥的TB-EPS中的PN则增强了颗粒的结构强度.高通量测序结果表明,粒径循环策略能够大幅提高系统内厌氧氨氧化菌(AnAOB)Candidatus Kuenenia的丰度,在大颗粒回流时达到60.24%的峰值,并且AnAOB主要分布在颗粒污泥内层.

不同进水方式对污泥床膨胀的影响

为了探究不同进水方式对污泥膨胀床性能的影响,设计一种侧向进水物理模型和四种不同进水夹角的底部进水口的数值模型,对比分析计算流体力学的三维模拟与实物模型的运行状态。结果表明:侧向进水方式污泥床在进水时膨胀速率比底部进水方式快19%;进水流量对两种进水方式的污泥膨胀高度及死区面积的减少有显著影响,在模拟中倾角为15°时,流量提升2.7倍,死区面积减少87%;底部圆锥倾角的变化,对死区产生显著的影响;侧向进水时,流场分为左右两部分,未有明显的优先流,底部进水则存在沿中轴线前进的主流,两侧的速度场分布梯度较小。

Identical full-scale biogas-lift reactors(BLRs) with anaerobic granular sludge and residual activated sludge for brewery wastewater treatment and kinetic modeling

Two identical full-scale biogas-lift reactors treating brewery wastewater were inoculated with different types of sludge to compare their operational conditions, sludge characteristics, and kinetic models at a mesophilic temperature. One reactor （R1） started up with anaerobic granular sludge in 12 weeks and obtained a continuously average organic loading rate （OLR） of 7.4 kg chemical oxygen demand （COD）/（m3.day）, COD removal efficiency of 80%, and effluent COD of 450 mg/L. The other reactor （R2） started up with residual activated sludge in 30 weeks and granulation accomplished when the reactor reached an average OLR of 8.3 kg COD/（m^3·day）, COD removal efficiency of 90%, and effluent COD of 240 mg/L. Differences in sludge characteristics,biogas compositions, and biogas- lift processes may be accounted for the superior efficiency of the treatment performance of R2 over R1. Grau second-order and modified StoverKincannon models based on influent and effluent concentrations as well as hydraulic retention time were successfully used to develop kinetic parameters of the experimental data with high correlation coefficients （R2 〉 0.95）, which further showed that R2 had higher treatment performance than R1. These results demonstrated that residual activated sludge could be used effectively instead of anaerobic granular sludge despite the need for a longer time.

Influence of influent on anaerobic ammonium oxidation in an Expanded Granular Sludge Bed-Biological Aerated Filter integrated system

Shortcut nitrification-denitrification,anaerobic ammonium oxidation(ANAMMOX),and methanogenesis have been successfully coupled in an Expanded Granular Sludge Bed-Biological Aerated Filter(EGSB-BAF)integrated system.As fed different synthetic wastewater with chemical oxygen demand(COD)of 300-1200 mg·L^(-1)and NH_(4)^(+)-N of 30-120 mg·L^(-1)at the outer recycle ratio of 200%,the influence of influent on ANAMMOX in the integrated system was investigated in this paper.The experimental results showed that higher COD concentration caused an increase in denitrification and methanogenesis but a decrease in ANAMMOX;however,when an influent with the low concentration of COD was used,the opposite changes could be observed.Higher influent NH_(4)^(+)-N concentration favored ANAMMOX when the COD concentration of influent was fixed.Therefore,low COD=NH_(4)^(+)-N ratio would decrease competition for nitrite between ANAMMOX and denitrification,which was favorable for reducing the negative effect of organic COD on ANAMMOX.The good performance of the integrated system indicated that the bacterial community of denitrification,ANAMMOX,and methanogenesis could be dynamically maintained in the sludge of EGSB reactor for a certain range of influent.

Concept and application of anaerobic suspended granular sludge bed （SGSB） reactor for wastewater treatment

Bed expansion serves an important function in the design and operation of an upflow anaerobic reactor. An analysis of the flow pattern of expanded granular sludge bed （EGSB） reactors shows that most EGSB reactors do not behave as expanded bed reactors, as is widely perceived. Rather, these reactors behave as fluidized bed reactors based on the classic chemical reactor theory. In this paper, four bed expansion modes, divided as static bed, expanded bed, suspended bed, and fluidized bed, for bioreactors are proposed. A high-rate anaerobic suspended granular sludge bed （SGSB） reactor was then developed. The SGSB reactor is an upflow anaerobic reactor, and its expansion degree can be easily controlled within a range to maintain the suspended status of the sludge bed by controlling upfiow velocity. The results of the full-scale reactor confirmed that the use of SGSB reactors is advantageous. The full-scale SGSB reactor runs stably and achieves high COD removal efficiency （about 90%） at high loading rates （average 40 kg-COD·m^-3·d^-1, maximum to 52 kg·COD·m^-3 ·d^-1） based on the SGSB theory, and its expansion degree is between 22% and 37%.