煤矿酸性水中稀土元素的分布模式及影响因素

通过对山西省两个不同矿区的酸性矿井水、沉积物、围岩以及煤样中的稀土元素(REE)含量的测定,并结合吸附解吸实验和地球化学模拟软件(PHREEQC),研究了酸性矿井水中REE的分布模式及其主要的影响因素.研究表明:1)酸性矿井水中REE的含量很高,且呈典型的中稀土元素(MREE)富集模式分布;2)酸性水中的REE主要来源于围岩和黄铁矿的酸淋滤,而煤中REE的丰度相对较低;3)pH是影响酸性矿井水中REE含量及其分布模式最重要的因素;4)随着酸性矿井水pH的升高,Mn的氢氧化物沉淀对REE的含量影响最大,并且含铁沉积物优先吸附重稀土元素和中稀土元素;5)酸性矿井水中的REEs主要络合种类为REE(SO4)+(52.8%～79.4%),其次为REE(SO4)2-和REE3+.     

Characterization of tricalcium phosphate solubilization by Stenotrophomonas maltophilia YC isolated from phosphate mines

The phosphate solubilizing characteristics of a strain YC, which was isolated from phosphate mines (Hubei, China), were studied in National Botanical Research Institute’s phosphate (NBRIP) growth medium containing tricalcium phosphate (TCP) as sole phosphorus (P) source. The strain YC is identified as Stenotrophomonas maltophilia (S. maltophilia) based upon the results of morphologic, physiological and biochemical characteristics and 16S rRNA sequences analysis. The results show that the strain S. maltophilia YC can solubilize TCP and release soluble P in NBRIP growth medium. A positive correlation between concentration of soluble P and population of the isolate and a negative correlation between concentration of soluble P and pH in the culture medium are observed from statistical analysis results. Moreover, gluconic acid is detected in the culture medium by HPLC analysis. It indicates that the isolate can release gluconic acid during the solubilizing experiment, which causes acidification of the culture medium and then TCP solubilization. S. maltophilia YC has a maximal TCP solubilizing capability when using maltose as carbon source and ammonium nitrate as nitrogen source, respectively, in NBRIP growth medium. Foundation item: Project(2004CB619201) supported by the Major State Basic Research and Development Program of China; Project(Z200515002) supported by the Key Project Foundation of the Education Department of Hubei Province, China; Project(GCP200801) supported by the Open Research Fund of Key Laboratory for Green Chemical Process of Ministry of Education, China; Project(Q200811) supported by the Youths Science Foundation of Wuhan Institute of Technology, China     

基于15N质量平衡法研究养殖消化废水中氨氮的去除机理

为避免养猪场消化废水对环境造成的污染,利用微藻去除消化废水中营养物质的二次处理方法受到了广泛关注。采用¹⁵N质量平衡法研究了鞘藻去除氨氮的主要机理,重点研究了鞘藻生长与氨氮去除的关系以及氨氮去除的主要途径。经高压灭菌后的消化废水在鞘藻培养期的氨氮去除率为96.2%,鞘藻特定生长率为0.04~0.15;稀释后的原消化废水氨氮的去除率为94.1%,鞘藻特定生长率为-0.14~0.13。通过曝气的汽提效应对氨的去除有显著的促进作用,尤其在高pH值试验条件下更有利于脱氨。¹⁵N同位素质量平衡分析表明,原始消化废水中存在的细菌对氨氮的去除影响小,在鞘藻培养期去除原消化废水中氨氮的主要途径是鞘藻的吸收和气体的损失,分别占总氮量的40.97%和32.59%。氨氮的去除与主要影响因素间的回归和通径分析表明,要提高氨氮去除率,需要提高鞘藻Chl-a含量和DO浓度,同时限制或保持pH值在弱碱性状态。     

Enantiomeric separation of phenylsuccinic acid by cyclodextrin-modified reversed phase high-performance liquid chromatography

The chiral separation of phenylsuccinic acid (PSA) was studied by reversed phase high-performance liquid chromatography (RP-HPLC) with cyclodextrins (CDs) as chiral mobile phase additives. The effects of types of CDs, concentration of hydroxypropyl-β-cyclodextrin (HP-β-CD), percentage of organic modifier, pH value and column temperature on enantioselective separation were investigated. The quantification property of the developed RP-HPLC method was examined. The chiral recognition mechanism of PSA was also discussed. The results show that a baseline separation of PSA enantiomers is achieved on a Lichrospher C18 column (4.6 mm (inner diameter)×250 mm, 5 μm) with HP-β-CD as chiral mobile phase additive. The capacity factors of R-PSA and S-PSA are 3.94 and 4.80, respectively. The separation factor and resolution are respectively 1.22 and 8.03. The mobile phase is a mixture of acetonitrile and deionized water (20:80, volume ratio) containing 10 mmol/L HP-β-CD and 0.05% trifluoroacetic acid (pH 2.5, adjusted with triethylamine) with a flow rate of 1.0 mL/min. The ultraviolet (UV) detector is set at 254 nm. The likely roles are inclusion interaction, induction and hydrogen bonding between HP-β-CD and PSA enantiomers. Foundation item: Project(20776038) supported by the National Natural Science Foundation of China     

不同类型稻田亚硝酸型CH4厌氧氧化潜力的比较研究

甲烷(CH₄)厌氧氧化是稻田土壤中消减温室气体排放的重要过程.本试验选择内陆性南京稻田和滨海性上海崇明岛围垦稻田,比较研究稻田耕层(0～10 cm)和深层(50～60 cm)土壤中亚硝酸盐型CH₄厌氧氧化(n-DAMO)潜力的差异及其微生物驱动机制.结果表明,南京稻田耕层土壤的n-DAMO速率为3.51 nmol·g^-1·d^-1(以¹³CO₂计),显著高于围垦稻田耕层土壤(1.43 nmol·g^-1·d^-1).两种类型稻田耕层土壤的n-DAMO速率均显著高于深层土壤.南京稻田和围垦稻田M.oxyfera-like细菌的16S rRNA基因拷贝数分别为(2.31～4.82)×10⁷和(0.89～2.12)×10⁷ copies·g^-1,与亚硝酸盐型CH₄厌氧氧化速率显著正相关.相关性分析发现,土壤有机碳、总氮、无机态氮是稻田n-...