Comparing results of cultured and uncultured biological methods used in biological phosphorus removal

Increasing attention has been paid to phosphate-accumulating organisms(PAOs)for their important role in biological phosphorus removal.In this study,microbial communities of PAOs cultivated under different carbon sources(sewage,glucose,and sodium acetate) were investigated and compared through culture-dependent and culture-independent methods,respectively.The results obtained using denaturing gradient gel electrophoresis(DGGE)of polymerase chain reaction-amplified 16S rDNA fragments revealed that the diversity of bacteria in a sewage-fed reactor(1#)was much higher than in a glucose-fed one(2#)and a sodium acetate-fed one(3#);there were common PAOs in three reactors fed by different carbon sources.Five strains were separated from three systems by using a phosphate- rich medium;they were from common bacteria isolated and three isolates could not be found in DGGE profile at all.Two isolates had good phosphorus removal ability.When the microbial diversity was studied,the molecular biological method was better than the culture-dependent one.When phosphorus removal characteristics were investigated,culture-dependent approach was more effective. Thus a combination of two methods is necessary to have a comprehensive view of PAOs.     

花状二维铜基卟啉气凝胶制备与气体吸附与分离性能研究

本研究针对混合气体选择性分离和二氧化碳捕获等问题,在小分子聚乙烯吡咯烷酮（PVP）和三氟乙酸的作用下控制纵向生长,通过金属铜离子与卟啉配体的自组装形成花状二维金属有机框架材料（2D Flower-like Cu-TCPP）,进一步冷冻干燥获得低密度纯2D Flower-like Cu-TCPP气凝胶.元素含量分析显示,2D Flower-like Cu-TCPP可以充分暴露金属活性位点,克服传统三维纳米材料内部位点难以被利用的缺点;比表面积（BET）分析显示,2D Flower-like Cu-TCPP比表面积为321.92 m²·g^-1,主要孔道尺寸分布在1.8 nm左右.由于充分暴露出金属活性位点Cu-O-Cu,对CO₂、N₂和CH₄表现出优异的吸附分离性能.根据Langmuir吸附等温线拟合得到,CO₂、CH₄和N₂的最大吸附量分别为7.357、2.852、2.002 mmol·g^-1.CO₂/N₂、CO₂/CH₄和CH₄/N₂的最大分离系数分别为9.86、2.52和4.00.2D Flower-like Cu-TCPP在碳捕获、混合气体选择性分离中具有较好的应用前景.     

整体式分子筛基催化剂制备及其微波催化燃烧VOCs

以整体式蜂窝状分子筛为载体,制备铜锰铈负载型催化剂,研究其微波辐照下对VOCs （甲苯、丙酮、乙酸乙酯）的催化活性及其稳定性,探究影响催化剂活性的因素,并通过测试床层温度分布进行分析.研究表明,微波功率1.3kW、催化剂体积300mm×300mm×300mm,固定床温度>300℃条件下,催化剂对初始浓度200~2000mg/m³的5m³/h VOCs气体的降解效率为80%~92%.温度是VOCs氧化降解的条件,但当床层温度超过了300℃（VOCs完全燃烧温度）之后,升温对VOCs降解效率的影响不再明显.表征可知,尖晶石态铜锰铈单金属氧化物及其复合氧化物是主要的催化活性组分.VOCs在催化剂表面进行准一级反应而被催化氧化;高温对催化剂结构有一定影响,但重复性试验证实了催化剂的高活性和良好的稳定性.     

热、热碱处理对污泥溶胞和溶解性有机物的影响

污泥有机物的水解是厌氧消化过程中的限速步骤,预处理可以有效地将污泥固体有机物转化为溶解态有机物,从而提高有机物降解速率和甲烷转化速率.本文研究了热、热碱处理(两种常用的预处理方法)对污泥溶胞释放溶解性有机物的组成、相对分子质量分布和结构的影响.结果表明,热、热碱处理均能大量释放溶解性有机物,相比对照组污泥,溶解性化学需氧量可分别增加21.9倍(热处理)和47.8倍(热碱处理).两种预处理会改变溶解性有机物相对分子质量分布,且含量最多的有机物相对分子质量减小.两种预处理均对污泥溶解性有机物中的主要组分(蛋白质)有水解作用,且热碱处理效果更显著.三维荧光光谱分析表明溶出的有机物中溶解性微生物副产物类物质和胡敏酸类物质难以被两种预处理进一步水解.另外,两种预处理不仅使污泥溶解性物质中出现新的有机结构,还会使原有的有机结构发生变化,甚至消失.     

高效除砷分子筛新型材料制备及其吸附特性研究

为提高4A分子筛(MS)对水溶液中砷的吸附性能,以MS为载体,采用浸渍法制备载铁分子筛(FMS)和铁锰分子筛(FMMS)作为除砷吸附剂,利用扫描电镜(SEM)、傅里叶红外光谱(FT-IR)、比表面积测试法(BET)等手段对MS和FMS微观结构特点进行表征,并开展批次试验考察FMS和FMMS对水中五价砷(As5+)和三价砷(As3+)的吸附效果,对FMS吸附As5+过程进行吸附动力学、等温吸附试验和吸附热力学等拟合.结果表明:①铁盐浸渍改性能有效提高MS比表面积、改善其表面结构,改性后FMS是一种窄孔径、尺寸均匀的介孔材料,比表面积和孔体积分别从27.38 m2/g和0.068 cm3/g增至281.25 m2/g和0.16 cm3/g,平均孔径由9.93 nm减至2.21 nm;MS微观结构由密实粗糙颗粒转变为疏松多孔隙结构.②FT-IR表明,铁盐浸渍形成的铁氧化物主要与MS结构中O—H、Al—O和Si—O结合;批次试验设定ρ(As5+)为4 mg/L,与MS相比FMS对As5+的去除率约提高70%.③吸附动力学结果显示,FMS对As5+的吸附过程符合准二级动力学模型,相关系数(R2)达0.99,反应过程中化学吸附起主要作用.④等温吸附试验表明,FMS对As5+吸附过程与Freundlich等温吸附模型拟合程度较高,相关系数(R2)达0.98,计算最大吸附容量为9.9 mg/g.⑤热力学参数ΔG、ΔH和ΔS计算表明,温度升高有利于FMS吸附砷,反应过程中FMS表面固体与溶液的混乱度上升.⑥与FMS相比,FMMS对As3+吸附性能有效提高,ρ(As3+/As5+)(As3+与As5+共存条件下溶液质量浓度)分别为2.0、4.0、6.0 mg/L下,FMMS去除率分别约提高26.34%、28.06%和28.09%.研究显示,利用铁盐浸渍法对MS改性可有效提升其对As5+和As3+的吸附容量,发挥材料的实际运用价值.      

O3-BAC深度处理石化废水厂尾水的特性及菌群结构分析

采用连续流O_3-BAC对华北某石化废水处理厂尾水进行了中试处理实验,研究了O_3氧化对COD及UV254处理效果的影响,同时对处理过程中有机物的变化特性及稳定运行30 d时BAC填料中的微生态环境进行了分析.结果表明,在O_3接触时间为40 min,O_3投加量为20 mg·L-1,BAC单元空床停留时间为1.5 h条件下,O_3-BAC工艺出水COD为24 mg·L-1,平均去除率为40.4%,相对于单独BAC工艺去除率提高10.0%,UV254的平均去除率为55.1%,且COD与UV254之间呈一定的相关性,相关系数R2为0.89;O_3氧化后相对分子质量1×103的比例由尾水中的69.0%提高到了87.0%,O_3-BAC工艺中NPOC的去除率为45.8%,较单独BAC工艺提高23.0%,且BAC单元去除的NPOC主要由相对分子质量1×103的组分所贡献;经GC-MS图谱及有机物统计分析,经O_3氧化后烷烃类、不饱和酯类及酚类等有机物得到明显的去除;O_3氧化后BAC单元的微生态环境得到明显改善,其中微生物种类(丰度在1.0%以上)由6种增加到了11种.O_3-BAC工艺可以有效应用于石化尾水的深度处理中.     

水生腐殖酸分子量分布研究——Ⅱ.腐殖酸凝胶色谱图峰加宽效应校正

研究了串联凝胶色谱系统的峰加宽效应.在该系统中,单分散标样的GPC谱图为低流出体积一侧较宽的不对称形式,以峰流出体积为界,这样的谱图可视作两个半侧正态函效的拼接.峰加宽效应还随淋出体积增大而加强,简单的直线方程可近似地描述分辨因子h随淋出体积的变化规律.在此基础上建立了腐殖酸GPC谱图峰加宽效应的校正方法.并根据实测结果计算了两个水生腐殖酸样品的分子量分布.     

Efficient removal of polybrominated diphenyl ethers from soil washing effluent by dummy molecular imprinted adsorbents: Selectivity and mechanisms

Surfactant enhanced elution is an effective method for removing hydrophobic organic pollutants from soils. The key to the development of leaching technology is selective removal of targeted pollutants in soil washing effluent and recycling of surfactant solutions. In this study, a molecular imprinting technique was applied to selectively sorb polybrominated diphenyl ethers (PBDEs) in soil washing effluent. The novel molecular imprinted polymers (MIPs) using different template molecules were synthesized by precipitation polymerization. Adsorption behaviors and mechanisms of MIPs were studied through experiments and theoretical calculations. The results show that 4-bromo-4′-hydroxybiphenyl and toluene can be effective imprinting molecule for MIPs synthesis. The maximal adsorption capacity of selected dummy molecular imprinted polymer (D₁-MIP) was 1032.36 µmol/g, and that of part molecular imprinted polymer (P-MIP) was 981.13 µmol/g. Their imprinting factors in 5 PBDEs adsorption ranged from 2.13 to 5.88, the recovery percentage of Triton X-100 can reach 99.09%, confirming the feasibility of reusing surfactant. Various PBDEs could be removed by MIPs, and Quantitative Structure Property Relationship analysis revealed that PBDEs’ molecular volume, planarity, polarity, and hydrophobicity have major influences on their adsorption performance. DFT calculation revealed that Van der Waals force and hydrogen bonding played important roles during selective adsorption. These results can provide effective theoretical guidance for surfactant enhanced soil elution in practical engineering applications.     

Mn-Co/MCM-41吸附剂表征及脱除烟气中单质汞研究

针对燃煤烟气中单质汞(Hg0)不溶于水而颇难去除的问题,采用浸渍法制备了不同Mn和Co物质的量比的Mn-Co/MCM-41介孔分子筛吸附剂,在固定床实验台架上考察了各吸附剂的脱汞效率.采用N2吸附/脱附、X射线衍射(XRD)、透射电子显微镜(TEM)、高分辨透射电子显微镜(HRTEM)、H2程序升温还原(H2-TPR)和X射线光电子能谱(XPS)等技术对吸附剂进行了物理化学性质表征.结果表明:Mn和Co复合后,吸附剂的脱汞效率显著提高.Mn/Co物质的量比为3/1时,吸附剂的脱汞效率最高,反应温度为150℃时,其脱汞效率高达90%.与单一组分Mn或Co负载MCM-41吸附剂相比,Co的掺杂不但使Mn和Co在MCM-41上的分散更均匀,还会促进Mn3+和Mn2+向Mn4+的转化和提高吸附剂的还原特性,增强吸附剂的脱汞性能.