SO2-4,HCO-3和Cl-对UV/TiO2降解矿井水中CODCr的影响

探讨SO^2-₄,HCO^-₃和Cl^{-对TiO₂光催化降解矿井水的化学耗氧量(用Cr法测)(COD_Cr)性能的影响. 用阴离子树脂充分过滤掉矿井水中阴离子, 将Na₂SO₄,NaHCO₃和NaCl分别配成在矿井水中单一存在的溶液和复合存在的溶液, 使用自制的TiO₂在紫外灯照射下光催化降解矿井水中COD_Cr. 当3种离子单独存在时, 它们均使光催化COD_Cr的降解率下降, 影响大小依次是HCO-₃>SO2-₄>Cl-; 当3种离子两两复合时, 在HCO-₃分别与SO2-₄和Cl-的复合实验中， 当HCO-₃浓度较低时， HCO-₃和SO2-₄,或Cl-共同影响使COD_Cr降解率下降， HCO-₃起主要作用； 当HCO-₃浓度较高时，HCO-₃起主要作用. 在SO2-₄,和Cl-的复合实验中, Cl-浓度为4.45 mmol/L, 可轻微促进COD_Cr降解率的提高, 当Cl-浓度高于此浓度时， Cl-和SO2-₄有协同作用并使COD_Cr降解率下降, 且降解率均低于Cl-和SO2-₄ ,单独存在时的降解率.}

Isolation and Identification of a Mesophilic Bacteria ZW2531-1 Producing a Novel Amylase

Twelve amylase producing mesophilic strains, newly isolated from Chinese soil were screened according to their ability of starch digestion by clear zone method. Among them, strain ZW2531-1 showed high amylase producing ability, and its amylase could catalyze the degradation of starch to produce several oligosccharides including maltose, maltotriose and a large amount ofisomaltotriose and isomaltotetraose, without glucose. Strain ZW2531-1 was bacilliform, a spore forming bacterium under an electron microscope. To explorethe phylogenetic position of strain ZW2531-1, its 16S rRNA gene was amplified, sequenced, and then was compared with those of standard bacteria available in Genebank databases. Further, the phylogenetic tree including strain ZW2531-1 was built. All the results regarding strain ZW2531 1 support that bacterium ZW2531-1 belongs to genus Bacillus, therefore, it could be proposed as Bacillus sp. ZW2531-1.