Biodegradation of p-cresol by aerobic granules in sequencing batch reactor

The cultivation of aerobic granules in sequencing batch reactor for the biodegradation of p-cresol was studied. The reactor was started with 100 mg/L of p-cresol. Aerobic granules first appeared within one month of start up. The granules were large and strong and had a compact structure. The diameter of stable granules was in the range of 1-5 mm. The integrity coefficient and granules density was found to be 96% and 1046 kg/m³, respectively. The settling velocity of granules was found to be in the range of 2× 10^-2-6× 10^-2 m/sec. The aerobic granules were able to degrade p-cresol upto 800 mg/L at a removal efficiency of 88%. Specific p-cresol degradation rate in aerobic granules followed Haldane model for substrate inhibition. High specific p-cresol degradation rate up to 0.96 g p-cresol/(g VSS. day) were sustained upto p-cresol concentration of 400 mg/L. Higher removal efficiency, good settling characteristics of aerobic granules, makes sequencing batch reactor suitable for enhancing the microorganism potential for biodegradation of inhibitory compounds.     

活性污泥低温氨氧化功能的驯化与潜力研究

以强化低温污水生物处理系统的氨氮(NH4+-N)氧化功能为目标,采用序批式活性污泥反应器(SBR),通过逐步提高进水NH4+-N浓度的方式,在(15±1)℃的条件下对城镇污水处理厂的好氧活性污泥进行了驯化培育,并就其对生活污水和高氨氮废水的NH4+-N去除潜力进行了测试.结果表明,在(15±1)℃下,好氧活性污泥经适当驯化可获得良好的氨氧化能力.在初始NH4+-N浓度为46mg·L-1左右时,其NH4+-N去除速率和亚硝态氮(NO2--N)生成速率分别可达54.26g·kg-·1d-1(以MLSS计,下同)和29.07g·kg-·1d-1(以MLSS计,下同)左右.对NH4+-N浓度为47.19mg·L-1左右的城镇污水,其NH4+-N去除率可高达85%以上.初始NH4+-N浓度分别为91.01mg·L-1和163.37mg·L-1左右时,其最高NH4+-N去除速率分别可达52.54g·kg-·1d-1和111.97g·kg-·1d-1,具有处理高氨氮废水的潜力.     

厌氧-缺氧下反硝化除磷对低碳污水的处理性能研究

采用厌氧-缺氧条件运行的序批式移动床生物膜反应器,考察了NO3--N进水浓度及其投加方式对低碳废水(COD=200mg/L)反硝化除磷的影响.经驯化后,反硝化聚磷菌(DPB)在总聚磷菌的份额从15.7%增长到71.3%,富集了DPB.NO3--N的浓度对处理有较大影响.在NO3--N为30mg/L(即C/N=6.7:1)时,COD、PO43--P和NO3--N的去除率分别为97.8%、82.0%和81.2%,实现低碳污水的高效处理.NO3--N较低或较高浓度(20mg/L和40mg/L)时,缺氧段吸磷不充分,PHB由厌氧开始时的2.2mg/g左右分别积累至5.1mg/g和3.5mg/g,影响下一周期磷的释放.1次投加、2次投加和连续流加NO3--N,除对缺氧初期的反硝化吸磷速率有影响外,对反硝化除磷的效率影响不明显.     

Removal of veterinary antibiotics from anaerobically digested swine wastewater using an intermittently aerated sequencing batch reactor

A lab-scale intermittently aerated sequencing batch reactor(IASBR)was applied to treat anaerobically digested swine wastewater(ADSW)to explore the removal characteristics of veterinary antibiotics.The removal rates of 11 veterinary antibiotics in the reactor were investigated under different chemical organic demand(COD)volumetric loadings,solid retention times(SRT)and ratios of COD to total nitrogen(TN)or COD/TN.Both sludge sorption and biodegradation were found to be the major contributors to the removal of veterinary antibiotics.Mass balance analysis revealed that greater than 60%of antibiotics in the influent were biodegraded in the IASBR,whereas averagely 24%were adsorbed by sludge under the condition that sludge sorption gradually reached its equilibrium.Results showed that the removal of antibiotics was greatly influenced by chemical oxygen demand(COD)volumetric loadings,which could achieve up to 85.1%±1.4%at 0.17±0.041 kg COD/m-3/day,while dropped to 75.9%±1.3%and 49.3%±12.1%when COD volumetric loading increased to 0.65±0.032 and1.07±0.073 kg COD/m-3/day,respectively.Tetracyclines,the dominant antibiotics in ADSW,were removed by 87.9%in total at the lowest COD loading,of which 30.4%were contributed by sludge sorption and 57.5%by biodegradation,respectively.In contrast,sulfonamides were removed about 96.2%,almost by biodegradation.Long SRT seemed to have little obvious impact on antibiotics removal,while a shorter SRT of 30–40 day could reduce the accumulated amount of antibiotics and the balanced antibiotics sorption capacity of sludge.Influent COD/TN ratio was found not a key impact factor for veterinary antibiotics removal in this work.     

静态磁场对生物滴滤池强化的研究——以三氯乙烯废气的去除及细菌群落结构研究为例

构建了实验室规模磁场强化的生物滴滤池（MF-BTF）,并设对照生物滴滤池（S-BTF）,以火山石为载体,接种活性污泥,处理目标废气三氯乙烯（TCE）.研究了不同磁场强度下,2种生物滴滤池在稳定运行期间对TCE的去除效果,并采用高通量测序技术对滴滤池中细菌群落结构与功能进行了分析.实验结果表明：在好氧条件下,当空床停留时间（EBRT）为202.5s,苯酚浓度为0.20g/L,TCE浓度范围为53.6~337.1mg/m³时,对TCE的去除效果依次为MF-BTF（60.0mT） > MF-BTF（30.0mT） > S-BTF（0.0mT） > MF-BTF（130.0mT）,其去除率（RE）和最大去除容量（EC）分别为92.2%~45.5%,2656.8mg/（m³×h）;89.8%~37.2%,2169.1mg/（m³×h）;89.8%~29.8%,1967.7mg/（m³×h）;76.0%~20.8%,1697.1mg/（m³×h）.高通量测序结果表明：磁场强度为60.0mT时,细菌群落均匀度（Shannon index,Simpson index）及丰富度（OTUs,Chao1,ACE）均小于0.0mT的情况;但是60.0mT下优势门、纲、属为Proteobacteria,Gammaproteobacteria,Acinetobacter,丰度明显大于0.0mT,丰度分别为73.3%,36.8%,34.7%;69.6%,18.2%,10.9%.实验结果表明合适的磁场强度可以增大优势菌群的丰度,提高对TCE的去除效果.本实验为提高生物滴滤池的工业废气处理效果提供了有效的借鉴,具有广泛的应用前景.     

太湖不同湖区冬季沉积物细菌群落多样性

为了探究太湖不同营养水平湖区冬季沉积物细菌群落多样性,利用高通量测序对太湖水草区、湖心区和河口区共9个采样点表层沉积物细菌的16S rRNA基因进行序列测定.结果发现：不同湖区的物种丰富度和均匀度为水草区 > 湖心区 > 河口区;不同湖区优势细菌群落组成存在差异.其中,硝化螺旋菌门（Nitrospirae）和酸杆菌门（Acidobacteria）2类门水平优势细菌以及厌氧绳菌纲（Anaerolineae）和硝化螺菌纲（Nitrospira）2类纲水平优势细菌在不同湖区之间差异显著.冬季太湖沉积物细菌优势类群为绿弯菌门（Chloroflexi）、变形菌门（Proteobacteria）、蓝藻门（Cyanobacteria）和硝化螺旋菌门（Nitrospirae）;在属分类水平上,主要优势类群为unidentified_Chloroplast和微囊藻属（Microcystis）.Cyanobacteria和Microcystis在所有采样点均有检出,平均丰度均以湖心区最高.对沉积物细菌群落与环境因子的关系进行冗余分析,结果表明：营养盐水平、水温和pH值均能影响沉积物细菌群落结构,NO₃^--N和水温是Microcystis的主要影响因子.     

Effects of residual organics in municipal wastewater on hydrogenotrophic denitrifying microbial communities

Hydrogenotrophic denitrification is promising for tertiary nitrogen removal from municipal wastewater. To reveal the influence of residual organics in municipal wastewater on hydrogenotrophic denitrifiers, we adopted high-throughput 16S rRNA gene amplicon sequencing to examine microbial communities in hydrogenotrophic denitrification enrichments. Using effluent from a municipal wastewater treatment plant as water source, COD, nitrate and pH were controlled the same except for a gradient of biodegradable carbon (i.e., primary effluent (PE), secondary effluent (SE), or combined primary and secondary effluent (CE)). Inorganic synthetic water (IW) was used as a control. Hydrogenophaga, a major facultative autotroph, accounted for 17.1%, 5.3%, 32.7% and 12.9% of the sequences in PE, CE, SE and IW, respectively, implicating that Hydrogenophaga grew well with or without organics. Thauera, which contains likely obligate autotrophic denitrifiers, appeared to be the most dominant genera (23.6%) in IW and accounted for 2.5%, 4.6% and 8.9% in PE, CE and SE, respectively. Thermomonas, which is related to heterotrophic denitrification, accounted for 4.2% and 7.9% in PE and CE fed with a higher content of labile organics, respectively. In contrast, Thermomonas was not detected in IW and accounted for only 0.6% in SE. Our results suggest that Thermomonas are more competitive than Thauera in hydrogenotrophic denitrification with biodegradable organics. Moreover, facultative autotrophic denitrifiers, Hydrogenophaga, are accommodating to residual organic in effluent wastewater, thus we propose that hydrogenotrophic denitrification is amenable for tertiary nitrogen removal.     

武昌湖典型退化湿地菰草根际微生物群落结构

为研究淡水湖泊湿地微生物群落结构与退化湿地环境之间的关系,选取武昌湖湿地菰草根际水体、根际土壤、根下湖泊沉积物3组环境样本,提取样本微生物基因组DNA,并利用16S r DNA基因进行454高通量测序,共得到优质序列17 051条,产生2 062条OUTs。结果表明:武昌湖退化湿地菰草根际具有较为复杂的微生物群落结构,涉及15门48属,其中以变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)、酸杆菌门(Acidobacteria)和绿弯菌门(Chloroflexi)为主要门类;菰草根际不同微环境微生物群落结构存在明显差异,生物多样性指数Shannon、Chao、ACE指数及OTUs均呈现根际土壤湖泊沉积物根际水体的变化特征。探究湿地退化过程中植被菰草根际微生物群落结构特征,对揭示长江中下游浅水湖泊湿地退化机理具有重要意义。     

酸性矿山废水影响下水库细菌群落结构特征与环境因子关系

为揭示酸性矿山废水（Acid mine drainage,AMD）影响下水库水体中细菌群落结构特征及影响因子,对贵州省兴仁市3座受AMD影响与1座未受AMD影响水库样品进行了对比研究,利用16S rDNA高通量测序技术分析揭示细菌群落结构特征,并通过冗余分析（Redundancy analysis,RDA）探明影响水体细菌群落变化的主要环境因子.结果表明,受AMD影响水库水体中各主要阳离子（Ca²⁺、Na⁺、Mg²⁺、Fe²⁺、Mn²⁺、Cu²⁺、Zn²⁺、Ni²⁺）、SO₄^2-浓度及电导率值均高于未受AMD影响的水库,而DOC和pH值均低于未受AMD影响的水库.变形菌门（Proteobacteria）是受AMD影响水库水体的主要细菌门类,在3个受影响的水库中均占比95%以上.在属分类水平上,红杆菌属（Rhodobacter）、不动杆菌属（Acinetobacter）、假单胞菌属（Pseudomonas）和铁氧化细菌属（Ferrovum）是受AMD影响水库水体中的主要菌属;未受AMD影响水库水体细菌群落中,放线菌门（Actinobacteria）和变形菌门（Proteobacteria）为主要细菌门类,占比分别为48%和29%,主要菌属为发光杆菌属（Ilumatobacter）、不动杆菌属（Acinetobacter）.分析表明,受AMD影响水库细菌群落结构特征与未受AMD影响水库细菌群落存在明显差异,推测DOC、pH及Na⁺浓度对此差异起主导作用.本研究可为科学认识受AMD影响水体微生物群落与环境因子之间的关系提供依据.     

高温冲击对亚硝酸盐氧化过程中微生物菌群结构影响

为了进一步了解在亚硝酸盐氧化过程中,高温冲击对活性污泥微生物菌群结构的影响,本研究中,以在不同NO~-_2-N浓度条件下富集的硝化活性污泥为研究对象,利用16S rRNA高通量测序技术分析方法,通过改变环境温度考察活性污泥微生物菌群丰度变化及结构特征.高通量测序分析结果表明:25℃时易于微生物生长,系统活性污泥微生物菌群多样性最丰富.随着高温冲击试验进行,系统内菌群丰富度、均匀度和多样性呈下降趋势.此外,分析发现本系统主要硝化功能菌为Nitrospirae的Nitrospira,更适宜在35℃生长.且高温冲击试验同样引起了活性污泥中非硝化功能微生物(Bacteroidetes、Chloroflexi、Halomonas和Pseudomonas等)的菌群结构差异.试验结果可为高温冲击条件下亚硝酸盐氧化过程中微生物菌群分布特点的研究提供部分理论参考,并为相关高温冲击试验给予部分借鉴.