Biosorption Behavior and Mechanism of Lead(II) from Aqueous Solution by Aerobic Granules(AG) and Bacterial Alginate(BA)

Lead(Pb) and its compounds are common pollutants in industrial wastewaters.To develop appropriate Pb 2+ treatment technologies,aerobic granules(AG) and bacterial alginates(BA) were studied as alternative biosorbents to remove Pb 2+ from aqueous solutions.The biosorption mechanism of AG and BA were further analyzed to determine which functional groups in AG and BA are active in Pb 2+ biosorption.In this paper,the Pb 2+ biosorption behavior of AG and BA was respectively investigated in batch experiments from the perspectives of the initial pH,contact time,and initial Pb 2+ concentration.The results showed that biosorption of Pb 2+ by AG and BA occurred within 60min at the initial Pb 2+ concentrations(0 150 mg L-1).The actual saturated Pb 2+ biosorption capability of AG was 101.97 mg g-1(dry weight of aerobic granular biomass).When the initial pH was 5,the biosorption capability of AG and BA was highest at the initial Pb 2+ concentrations(0 20mg L-1).During the process of Pb 2+ biosorption,K +,Ca 2+,and Mg 2+ were released.The Ion Chromatography(IC) and Fourier Transform Infrared Spectroscopy(FTIR) further highlighted the main role of ion exchange between Ca 2+ and Pb 2+ and sequestration of Pb 2+ with carboxyl(-COO) of AG and BA.This analogical analysis verifies that BA is responsible for biosorption of Pb 2+ by AG.At the same optimal pH,AG cultivated with different carbon source has different Pb 2+ biosorption capacity.The Pb 2+ biosorption by AG with sodium acetate as the sole carbon source is higher than AG with glucose as carbon source.

Storage and Subsequent Reactivation of Phosphate-Accumulating Aerobic Granules

Phosphate-accumulating aerobic granules cultivated in a sequencing batch reactor were composed of inner rod-shaped bacteria aggregates and outer twining filamentous bacteria. The influence of two-month storage under dif- ferent conditions on the storage and subsequent reactivation performance of aerobic granules was investigated. After two-month storage the granules sealed at 4 ~C in distilled water or normal saline （named granules A and granules B, respectively） could maintain their characteristics as before, while the granules idled in the reactor at room temperature （named granules C） exhibited decreased properties. During reactivation, granules A and granules B presented almost identical recovery performance, faster than granules C, in terms of phosphorus removal efficiency, mixed liquor sus- pended solids （MLSS）, phosphate release and accumulating ability. The results suggest that hermetical storage at low temperature promoted the maintenance of the granular properties and the reviving behaviors of phosphateaccumulating aerobic granules, and storage medium had little influence on the storage and recovery perfomlance.

絮凝剂硫酸铝强化AGS处理建筑涂料废水的探究

为了缩短好氧颗粒污泥(AGS)颗粒化时间并提高AGS处理建筑涂料废水的效能,通过向活性污泥内投加絮凝剂硫酸铝(AS),研究了AS对AGS颗粒化进程的影响,并探究了AS诱导形成的AGS处理建筑涂料废水的效能。结果表明,AS快速造粒形成的AGS结构紧密,生物量高、沉降性能好并缩短AGS颗粒化时间约10 d。AS提高了AGS内胞外聚合物(EPS)含量,并同步提高蛋白质(PN)和多糖(PS)含量,在AS组别内,PN/PS高于空白组。AS诱导形成的AGS强化处理建筑涂料废水,AS组别内COD去除效率均超过90%。AS浓度由20 mg/L增加至100 mg/L时,总氮去除效率由62.4%~64.8%升高至67.9%~69.4%。各组内氨氮去除效率均较理想。研究结果为AGS快速颗粒化提供备选条件,并为建筑涂料废水的高效处理提供技术支撑。

Influence of different substrates on the formation and characteristics of aerobic granules in sequencing batch reactors

The effects of different substrates on the aerobic granulation process were studied using laboratory-scale sequencing batch reactors （SBRs）. Four parallel granules sequencing batch reactors （GSBR）： R1, R2, R3, and R4 were fed with acetate, glucose, peptone and fecula, respectively. Stable aerobic granules were successfully cultivated in R1, R2, R4, and smaller granules less than 500 μm were formed in R3. Morphology and the physic-chemical characteristics of aerobic granules fed with different carbon substrates were investigated by the four reactors operated under the same pressure. The aerobic granules in the four reactors were observed and found that peptone was the most stable one due to its good settleability even after a sludge age as short as 10 d. A strong correlation was testified between the characteristics of aerobic granules and the properties of carbon substrates. The stability of aerobic granules was affected by extracellular polymer substances （EPS） derived from microorganism growth during feast time fed with different carbon substrates, and the influence of the property of storage substance was greater than that of its quantity. Optimal carbon substrates, which are helpful in the cultivation and retention of well-settling granules and in the enhancement of the overall ability of the aerobic granules reactors, were found.

Cultivation of aerobic granules for simultaneous nitrification and denitrification by seeding different inoculated sludge

Cultivation of aerobic granules for simultaneous nitrification and denitrification in two sequencing batch airlift bioreactors was studied. Conventional activated floc and anaerobic granules served as main two inoculated sludge in the systems. Morphological variations of sludge in the reactors were observed. It was found that the cultivation of aerobic granules was closely associated with the kind of inoculated sludge. Round and regular aerobic granules were prevailed in both reactors, and the physical characteristics of the aerobic granules in terms of settling ability, specific gravity, and ratio of water containing were distinct when the inoculate sludge was different. Aerobic granules formed by seeding activated floc are more excellent in simultaneous nitrification and denitrification than that by aerobic granules formed from anaerobic granules. It was concluded that inoculated sludge plays a crucial role in the cultivation of aerobic granules for simultaneous nitrification and denitrification.

Performance Characteristics for Nitrogen Removal in SBR by Aerobic Granules

The sequencing batch reactor (SBR) was started up by seeding the anaerobic granular sludge and the aerobic granular sludge was successfully cultivated. The performance characteristic of the aerobic granules for nitrogen removal was investigated in detail. The experimental results demonstrated the relationship between operational parameters [dissolved oxygen (DO) and pH] and variation of chemical oxygen demand (COD), ammonium (NH4+-N)and total nitrogen (TN). In continuous flow pattern, COD was too low in the reactor at the later stage of a cycle,which restrained denitrification and decreased the removal of nitrogen, while in discontinuous flow pattern, the carbon source could be supplemented in time, which improved denitrification and increased the removal of TN from 66% to 81%.

Start-up and contaminants removal characteristics of aerobic granules-membrane bioreactor at low temperature

In order to understand the effect of low temperature on the formation process of aerobic granules and contaminants removal characteristics,the aerobic granules-membrane bioreactor (AGS-MBR) has been started up and operated at low temperature using the carbon resource of sodium acetate. Aerobic granules cultivated in AGS-MBR possess smooth surface and compact structure in morphology as well as better settling property and higher biomass after 38 days. The average parameters of aerobic granules are: diameter 3. 1 mm,wet density 1. 041 g/mL,sludge volume index 42. 35 mL/g and settling velocity 20. 6 - 45. 2 cm/min. During the start-up of AGS-MBR,the respectively average contaminants removal efficiencies at low temperature are 91. 9% for chemical oxygen demand (COD) ,89. 2% for NH4 + -N and 86. 3% for PO43- -P,and the overgrowth of filamentous bacteria has been well controlled. In addition,the hollow fiber microfiltration (MF) membrane fouling is light and the regime membrane layer is capable of enhancing membrane filtration as well as the average growth of trans-membrane pressure (TMP) is 1. 07 kPa/d. Compared with the conventional cultivation of aerobic granules,the sludge granulation time significantly decreases from 73 days to 38 days by the application of microfiltration membrane at low temperature.

Characteristics of aerobic granules grown on glucose a sequential batch shaking reactor

Aerobic heterotrophic granular sludge was cultivated in a sequencing batch shaking reactor(SBSR) in which a synthetic wastewater containing glucose as carbon source was fed. The characteristics of the aerobic granules were investigated. Compared with the conventional activated sludge flocs, the aerobic granules exhibit excellent physical characteristics in terms of settleability, size, shape, biomass density, and physical strength. Scanning electron micrographs revealed that in mature granules little filamentous bacteria could be found, rod-shaped and coccoid bacteria were the dominant microorganisms.

Influence of temperature on the characteristics of aerobic granulation in sequencing batch airlift reactors

Aerobic granular sludge was cultivated in sequencing batch airlift reactors （SBAR） at 25, 30, and 35℃, respectively. The effect of temperature on the granules characteristics was analyzed and the microbial community structures of the granules were probed using scanning electron microscope （SEM） and polymerase chain reaction-denaturing gradient gel electrophoresis （PCR-DGGE）. The results showed that 30℃ is optimum for matured granule cultivation, where the granules had a more compact structure, better settling ability and higher bioactivity, the oxygen utilization rate （OUR） reached 1.14 mg O2/（g MLVSS.min） with COD removal rate of 97% and TP removal rate of 75%. The removal efficiency of NH3-N increased from 68.5% to 87.5% along with the temperature increment from 25 to 35℃. The DGGE profiles revealed that the microbial community structure at 25℃ showed the least similarity with those at other temperatures. The sequencing results indicated that the majority of dominant microbes belonged to Actinobacteria and Proteobacterium. Thermomonas sp., Ottowia sp. and Curtobacteriurn ammoniigenes might play important roles at different temperatures, respectively.

Characteristics of extracellular fluorescent substances of aerobic granular sludge in pilot-scale sequencing batch reactor

The aerobic granular sludge was cultivated in a pilot-scale sequencing batch reactor （SBR）, and some of the granules were stored at 8 ℃ for 150 d. Extracellular polymeric substances （EPS） of sludge samples were extracted and analyzed during the granulation and storage process. The results show that the contents of protein and EPS increase along with the granulation process, while polysaccharides remain almost unchanged. The content of protein in EPS is almost two-fold larger than that of polysaccharides in granular sludge cultivated with municipal wastewater. Moreover, some of the granules disintegrate during storage, corresponding to the decrease of protein contents in EPS. Three peaks are identified in three-dimensional excitation emission matrix （EEM） fluorescence spectra of the EPS in the aerobic granules. Two peaks （A and B） are attributed to the protein-like fluorophores, and the third （peak C） is related to visible fulvic-like substances. Peak A gradually disappears during storage, while a new peak related to ultraviolet fulvic acid （peak D） is formed. The formation and the stability of aerobic granules are closely dependent on the quantity and composition of EPS proteins. Peak C has no obvious changes during granulation, while the fulvic-like substances present an increase in fluorescence intensities during storage, accompanied with an increase in structural complexity. The fulvie-like substances are also associated with the disintegration of the aerobic granules.

加味七方胃痛颗粒含药血清抑制人胃癌AGS细胞铁死亡的机制研究

目的 探讨加味七方胃痛颗粒抑制胃癌细胞铁死亡效应机制。方法 选取Wistar大鼠制备含药血清;胃癌AGS细胞分为AGS组、空白血清组和含药血清组。含药血清组大鼠以19.4 g/(kg·d)的换算方法灌胃加味七方胃痛颗粒7 d制备含药血清。空白血清组大鼠常规喂养制备空白血清。干预2 d后检测各组细胞活性和形态,比色法检测丙二醛(MDA)、谷胱甘肽(GSH)含量,RT-q PCR、Western blot检测SLC7A11、P53、GPX4 mRNA含量及蛋白表达水平。结果 含药血清组细胞增殖率低于空白血清组(P<0.05)。含药血清组SLC7A11、GPX4 mRNA的含量低于空白血清组,P53 mRNA含量高于空白血清组(P<0.01)。含药血清组SLC7A11、GPX4的蛋白表达水平低于空白血清组,P53的蛋白表达水平高于空白血清组(P<0.01)。含药血清组MDA含量低于空白血清组,GSH含量高于空白血清组(P<0.01)。结论 七方胃痛颗粒可抑制胃癌细胞增殖,其效应可能与抑制细胞铁死亡信号有关。

Shut-cut nitrification characteristics of aerobic granule in a sequencing batch airlift reactor at low temperature

To investigate the shut-cut nitrification characteristics of aerobic granule,an aerobic granular sequencing batch airlift reactor(AG-SBAR) was carried out with mixed carbon sources of sodium acetate and glucose at 10±1 ℃.Results indicated that ammonia oxidizing bacteria was accumulated inside the aerobic granules and the reactor performed stably with shut-cut nitrification for a long term at low temperature.During the stable operation period,the effluent ammonia nitrogen concentration was maintained at 13.6 mg/L without nitrate and nitrite when the COD/N ratio was 20:1.However,the effluent concentration of ammonia nitrogen was below 0.5 mg/L with effluent nitrosation ratio of 96.7% on average when the COD/N ratio was reduced to 15:1 and 10:1.And the effluent phosphorus concentration was less than 0.4 mg/L during the stable period with the sludge retention time of 30 d.The phosphorus removal efficiency was not strongly influenced by the adjustment of COD/N ratio in this experiment.The removal efficiencies for COD,NH4+-N and PO43--P were 91.3%-94.6%,97.9%-99.7% and 97.1%-99.5%,respectively.

Effects of extracellular polymer substances on aerobic granulation in sequencing batch reactors

The effects of extracellular polymeric substances (EPS) on aerobic granulation in sequencing batch reactors (SBR) were investigated by evaluating the EPS content, and the relationship between EPS composition and surface properties of glucose-fed aerobic granules. The results show that aerobic granular sludge contains more EPS than seed sludge, and it is about 47 mg/gMLSS. Corresponding to the changes of EPS, the surface charge of microorganisms in granules increases from -0.732 to -0.845 meq/gMLSS, whereas the hydrophobicty changes significantly from 48.46% to 73.16%. It is obviously that changes of EPS in sludge alter the negative surface charge and hydrophobicity of microorganisms in granules, enhance the polymeric interaction and promote the aerobic granulation. Moreover, EPS can serve as carbon and energy reserves in granulation, thus the growth between the interior and exterior bacteria is balanced, and the integrality of granules is maintained. SEM observation of the granules exhibits that EPS in granules are ropy; by mixing with bacteria, compact matrix structure can be formed. The distribution of EPS in granules profiles the importance of EPS storage. It can be concluded that EPS play a crucial role in aerobic granulation.

Comparison of aerobic conjunctival bacterial flora in pregnant, reproductive-aged and postmenopausal women

AIM: To evaluate the effect of hormonal status on aerobic conjunctival flora in women. METHODS: One hundred fifty-eight women [reproductive-aged (n=55), pregnant (n=51), and postmenopausal (n=52)] who admitted to outpatient clinic of Obstetrics and Gynecology Department of Denizli State Hospital were enrolled. Age, body-mass index (BMI), obstetric history, cigarette smoking, drug usage, presence of systemic disease, and intraocular pressure (IOP) were recorded for each patient. The samples were taken from the lower fornix with two culture swabs and directly incubated in culture containing 5% sheep blood, eosin-methylene blue and chocolate agar. The other swab specimen was Gram stained. All growths and microscopic results were analyzed. RESULTS: The coagulase-negative Staphylococcus was the predominant organism isolated in the conjunctival samples in both three groups. The aerobic microorganism growth rate for all isolated aerobic organisms revealed no significant change in the three groups (P>0.05). The conjunctival culture positivity rates were similar in the three groups (49% in reproductive-aged, 57% in pregnant and 58% in postmenopausal women) (P>0.05). Age, IOP, BMI, gravidity, parity, cigarette smoking, drug usage, and presence of systemic diseases did not have an effect on culture positivity in three groups. CONCLUSION: Results of this study showed that conjunctival aerobic flora and bacterial colonization did not differ between reproductive-aged, pregnant and postmenopausal women.

lncRNA MAFG-AS1通过调控miR-11181-3p/GLG1轴促进胃癌AGS细胞迁移、侵袭和有氧糖酵解

目的:探讨lncRNA MAFG-AS1/miR-11181-3p/GLG1分子轴对胃癌(gastric cancer,GC)细胞迁移、侵袭和有氧糖酵解的影响及其可能的机制。方法:选取MAFG-AS1相对高表达的GC细胞系AGS作为研究对象,采用qPCR法检测其MAFGAS1、miR-11181-3p、GLG1的RNA表达水平,Transwell实验、糖酵解分析等检测细胞迁移、侵袭和有氧糖酵解的变化,利用生物信息学分析及双荧光素酶报告基因验证MAFG-AS1、miR-11181-3p、GLG1之间的相互作用关系。结果:敲减MAFG-AS1显著上调miR-11181-3p及下调GLG1的表达(均P<0.01),并可显著抑制GC细胞迁移、侵袭和有氧糖酵解(均P<0.01);荧光素酶报告基因证实MAFG-AS1竞争性吸附miR-11181-3p(P<0.01);抑制miR-11181-3p或过表达GLG1可部分逆转敲减MAFG-AS1对GC细胞迁移、侵袭和有氧糖酵解的抑制作用(均P<0.05或P<0.01)。结论:MAFG-AS1通过miR-11181-3p/GLG1分子轴增强GC迁移、侵袭和有氧糖酵解,可能是GC诊疗的潜在分子靶点。

七方胃痛颗粒对H.pylori感染的AGS细胞TFF1表达及ERK/NF-κB信号通路的影响

目的:探讨七方胃痛颗粒对幽门螺杆菌(Helicobacter pylori,H.pylori)感染的人胃腺癌AGS细胞三叶因子1(trefoil factor family1,TFF1)的表达及其细胞外信号调节激酶(extracellular signal-regulated kinase,ERK)/核因子κB(nuclearfactor-κB,NF-κB)信号通路的调控机制.方法:采用实时荧光定量PCR(RFQ-PCR)法检测TFF1 mRNA的表达,Western blot法检测TFF1、磷酸化ERK及NF-κB蛋白的表达水平;同时采用U0126抑制ERK信号通路后,观察AGS细胞TFF1蛋白表达的变化.结果:10%、20%、30%浓度七方胃痛颗粒药物血清作用H.pylori感染的AGS后,TFF1mRNA表达量为271±33、305±23、327±13,显著高于实验对照组的187±30,(P<0.05);TFF1、p-ERK及NF-κB蛋白表达量分别为271±22、358±31、428±34;175±9、141±3、107±15;116.0±2.6、83±2、53.0±6.6;与实验对组的210±13比较,差异具有统计学意义(均P<0.05).加入U0126阻断ERK信号通路后,TFF1蛋白表达量为115±6,与实验对照组的210±13比较,差异具有统计学意义(P<0.05).结论:七方胃痛颗粒可能通过抑制ERK/NF-κB信号通路参与调控H.pylori诱导的AGS细胞TFF1表达,促进上皮修复,是其防治H.pylori诱发胃癌可能的机制之一.

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%.

Unifying concepts in methanogenic,aerobic,and anammox sludge granulation

The retention of dense and well-functioning microbial biomass is crucial for effective pollutant removal in several biological wastewater treatment technologies.High solids retention is often achieved through aggregation of microbial communities into dense,spherical aggregates known as granules,which were initially discovered in the 1980s.These granules have since been widely applied in upflow anaerobic digesters for waste-to-energy conversions.Furthermore,granular biomass has been applied in aerobic wastewater treatment and anaerobic ammonium oxidation(anammox)technologies.The mechanisms underpinning the formation of methanogenic,aerobic,and anammox granules are the subject of ongoing research.Although each granule type has been extensively studied in isolation,there has been a lack of comparative studies among these granulation processes.It is likely that there are some unifying concepts that are shared by all three sludge types.Identifying these unifying concepts could allow a unified theory of granulation to be formed.Here,we review the granulation mechanisms of methanogenic,aerobic,and anammox granular sludge,highlighting several common concepts,such as the role of extracellular polymeric substances,cations,and operational parameters like upflow velocity and shear force.We have then identified some unique features of each granule type,such as different internal structures,microbial compositions,and quorum sensing systems.Finally,we propose that future research should prioritize aspects of microbial ecology,such as community assembly or interspecies interactions in individual granules during their formation and growth.

木犀草素抑制有氧糖酵解对胃癌AGS细胞凋亡的影响

目的:观察木犀草素通过下调胃癌AGS细胞有氧糖酵解水平,抑制有氧糖酵解相关蛋白表达,进而诱导胃癌AGS细胞凋亡过程。方法:Annexin V-FITC/PI双染法,流式细胞术检测木犀草素诱导细胞凋亡的作用;测定细胞培养基中葡萄糖及乳酸含量,计算葡萄糖消耗率及乳酸产量,评价不同浓度木犀草素(20、40、80μmol/L)对胃癌AGS细胞有氧糖酵解的影响;免疫印迹法(Western Bolt)检测各组细胞有氧糖酵解及凋亡相关蛋白表达的影响。结果:木犀草素对胃癌AGS细胞IC_(50)值为55.64μmol/L;随着木犀草素浓度增大,胃癌AGS细胞凋亡率升高(P<0.0001),葡萄糖消耗率及乳酸产量升高(P<0.01,P<0.001,P<0.0001),Caspase-3、HKⅡ、GLUT1、PKM2表达降低(P<0.01,P<0.001,P<0.0001),Cleaved Caspase-3表达升高(P<0.001,P<0.0001)。结论:木犀草素可诱导胃癌AGS细胞凋亡,其机制可能通过抑制胃癌AGS细胞有氧糖酵解途径有关。

Walking and Aerobic Capacity in Old Adults after Concentric and Eccentric Endurance Exercise at Self-Selected Intensities

Self-selected exercise intensity can be a useful exercise prescription tool for older adults;however, it is not known if it can elicit improvements in walking and aerobic capacity. In older adults, effects of concentric or eccentric endurance exercise at self-selected walking speed were examined on 1-mile indoor walk performance, predicted maximum oxygen uptake and physiological parameters. Twenty-four older adults (67 ± 4 years) completed 3 × 30 min treadmill walks per week for 12-weeks on level (LTW, n = 11, 0%) or downhill (DTW, n = 13, ﹣10%) treadmill gradient at a self- selected speed, which progressed every 4 weeks. Maximal oxygen uptake was predicted using a 1-mile walk at 4-week intervals with physiological responses recorded using a portable metabolic system. One-mile walking speed increased from baseline following 8- and 12-weeks (12 weeks: LTW: 13% ± 6%, DTW: 14% ± 9%,