Experimental Study on Single Factor, Orthogonal and Characteristics of SRB Particles Fixed by Biologically Activated Lignite

Aiming at the problems of insufficient supply of carbon source and toxic effect of heavy metal ions in the treatment of acid mine wastewater (AMD) by sulfate reducing bacteria (SRB), immobilized particles were prepared with Rhodopseudomonas spheroides, SRB and lignite as the main raw materials, and the optimal ratio of immobilized particles was determined based on single factor test and orthogonal test. The adsorption experiment of immobilized particles was carried out under the optimal ratio, the reaction kinetic process and adsorption capacity of immobilized particles for different ions were analyzed, and the action mechanism was studied. The results show that lignite not only has good adsorption performance, but also can be used as the carbon source of SRB after degradation by Rhodopseudomonas spheroides, so as to solve the problems of low removal efficiency of AMD by SRB and insufficient supply of carbon source. When the dosage of lignite, Rhodopseudomonas spheroides and SRB is 3%, 10% and 10% respectively, and the particle size of lignite is 200 mesh, the overall treatment effect is the best. The removal rates of SO42-, Zn2+ and Cu2+ are 83.21%, 99.59% and 99.93% respectively, the pH is increased to 7.43, the release of COD is 523 mg/L, and the ORP number is -134 mV. The reduction process of SO42- by immobilized particles conforms to the pseudo first-order kinetics, the isothermal adsorption of Zn2+ more conforms to the Freundlich isothermal adsorption equation, and the adsorption kinetics of Zn2+ more conforms to the pseudo second-order kinetic model.

Study on Rhodopseudomonas Spheroides as Coal Microbial Flocculant

Orthogonal test was employed to inspect the flocculation of Rhodopseudomonas spheroides in this text. The result showed that Rhodopseudomonas spheroides has good performance in flocculation effect of coal slurry. The hightest flocculation ratio is 93.4%. The optimum technological combination of flocculation test has been obtained:incubation time:12h,Coagulation aid dosage:2mL,Bacterium fluid amount:2mL,The categories of flocculants: the cell homogenates,pH:7.The FTIR analysis showed that the extractive of Rhodopseudomonas spheroides contain a large number of acidic Polysaccharides which has flocculent effect component.The main flocculation is “adsorption-bridge” between Molecular bioflocculant and coal slurry.

3-Hydroxyisobutyrate dehydrogenase, an impurity in commercial 3-hydroxybutyrate dehydrogenase

The enzymic determination of D-3-hydroxybutyrate and acetoacetate normally involves the use of 3-hydroxybutyrate dehydrogenase (HBDH, EC 1.1.1.30) of bacterial origin. We show that HBDH from Rhodopseudomonas spheroides (BCL, grade II) contains a 3-hydroxyisobutyrate dehydrogenase (HIBDH) activity: activity with 3-hydroxyisobutyrate as substrate was greater than 10% of that with 3-hydroxybutyrate. However, HBDH could be prepared essentially free of HIBDH activity by incubation at 37 degrees C in the presence of 1 mM-CaCl2, to produce an enzyme preparation that may be used for the specific determination of 3-hydroxybutyrate. Use of the purified enzyme preparations indicated that a major product of valine metabolism in hemidiaphragms from 40 h-starved rats was 3-hydroxyisobutyrate rather than 3-hydroxybutyrate.