Microbial Degradation of Quinoline: Kinetics Study With Burkholderia picekttii

Objective To investigate the kinetics of quinoline biodegradation by Burkholderia pickttii, a Gram negative rod-shaped aerobe, isolated in our laboratory. Methods HPLC (Hewlett-Packard model 5050 with an UV detector) was used for the analysis of quinoline concentration. GC/MS method was used to identify the intermediate metabolites of quinoline degradation. Results The biodegradation of quinoline was inhibited by quinoline at a high concentration, and the degradation process could be described by the Haldane model. The kinetic parameters based on Haldane substrate inhibition were evaluated. The values were v = 0.44 h-1,Ks=166.7 mg/L, Ki= 650 mg/L, respectively. The quinoline concentration to avoid substrate inhibition was inferred theoretically and determined to be 329 mg/L. Conclusion The biodegradation of quinoline conforms to the Haldane inhibition model and the main intermediate metabolite of quinoline biodegradation is 2-hydroxy-quinoline.

Experimental study on the simultaneous desulfurization and denitrification by duct injection

The highly active absorbent with oxidization based on fly ash, lime and additive was prepared. Experiments of simultaneous desulfurization and denitrification were carried out using fixture bed and duct injection. The influencial factors for the absorptive capacity of the absorbent were studied. The absorptive capacities of 120.7 mg for SO 2 and 43.7 mg for NOx were achieved at a Ca/(S+N) molar ratio 1.2, respectively, corresponding removal efficiencies of 87% and 76%, while spent absorbent appeared in the form of dry powder. The optimal temperature and humidity of flue gas treated with this process were shown to be approximately 50℃, and 5% respectively. The mechanism of removal for SO 2 and NOx was investigated. In comparison with traditional dry FGD, this process appears to have lower cost, less complicated configuration and simpler disposal of used absorbent. The valuable references can be provided for industrial application by this process. The foreground of application will be vast in China and in the world.

Improved Denitrification of Municipal Sludge in Biofilm-electrode Reactor

The denitrification of municipal sludge was improved by combining biofilm process with the electro-chemical effect in a single novel reactor. Experiments in this reactor[electric current 60 mA, hydraulic retention time(HRTs) 6.0 h] showed that the removal of COD_ Cr, ammonia nitrogen and total nitrogen in the biofilm-electrode reactor were 2.5%, 1.2%, 14.9%, respectively, higher than those in a traditional biofilm reactor.

Analysis of parental strain DNA fragments existing in GEMs-Fhhh

There were 6 target DNA fragments of the three parental strains existing in the cell of GEMs(genetically engineered microorganism strain) Fhhh measured in this research by PCR(polymerase chain reaction). The determination showed that GEMs Fhhh contained all the 6 target DNA fragments, mnp 1, mnp 2、 lip 1、 lip 2, FLO 1 and 16S rDNA, and had the molecular genetic stability. Meanwhile the PCR production of each parental strain could only had its target DNA fragments and was different from each other. It may illustrate that the technique of the inter kingdom protoplast fusion for the construction of GEMs Fhhh through the process of intercellular gene recombination could be used as a reliable bioengineering technique to create the specific functional stain for the pollution control.

Microbial Degradation of Aniline by Bacterial Consortium

Objective To investigate the characteristics of microbial degradation of aniline by a stable bacterial consortium. Methods The bacterial consortium was isolated from activated sludge treating chemical wastewater using aniline as the sole source of carbon and nitrogen by enrichment and isolation technique. The biomass was measured as optical density (OD) at 510 run using a spectrophotometer. Aniline concentrations were determined by spectrophotometer. The intermediates of aniline degradation were identified by GC/MS method. Results The bacterial consortium could grow at a range of aniline concentrations between 50 and 500 mg/L. The optimal pH and temperature for aniline degradation were determined to be 7.0 and 30, respectively. The presence of NH4NO3 as an additional nitrogen source (100-500 mg/L) had no adverse effect on bacterial growth and aniline degradation. The presence of heavy metal ions, such as Co2+, Zn2+, Ni2+, Mn2+ and Cu2+ had an inhibitory effect on aniline degradation. Conclusions The isolated bacterial consortium can degrade aniline up to 500 mg/L effectively and tolerate some heavy metal ions that commonly exist in chemical wastewater. It has a potential to be applied in the practical treatment of aniline-containing wastewater.

Precursors Revealed by the Multifractal Dimension Around Ordos Block,North China

Seismicity around the Ordos Block in the northern part of China has been studied by the multifractal dimensions with the help of complete data set of earthquakes with M≥2.5 since 1977. Seven regions around this block have been examined where the eight large earthquakes with M≥6.0 for the complete data occurred. In order to display the temporal distribution of the correlation dimension D 2, a moving window of fixed number of events is used in every of the seven regions. Except for two regions with less seismic activity, all other five regions have obviously been found to display sudden changes of the correlation dimension for the events with M≥4.5.

Quantitative structure activity relationship and toxicity mechanisms of chlorophenols on cells in vitro

dimethylthiazd-2-yl)-2,5-diphenylentra- zolium bromide (MTT) reduction assay was used to investi-gate the acute toxicity of 8 different chlorophenols (CPs) on rat connective tissue fibroblast L929 cells and human liver cancer HepG2 cells. Combined with the data from Quantita-tive Structure Activity Relationship (QSAR) approach of CPs by using the octanol-water partition coefficients (Kow), an effective model was deduced to evaluate the cytotoxicity of these chemicals. Furthermore, the relationship between the structures of CPs and their cytotoxicity was proposed. The results show that 2-chlorophenol (2-CP), 4-chlorophenol (4-CP), 2,6-dichlorophenol (2,6-DCP), 2,4-dichlorophenol (2,4-DCP), 2,4,6-trichlorophenol (2,4,6-TCP) and 2,3,4-tri- chlorophenol (2,3,4-TCP) induced apoptosis, whereas, 2,3,5,6- tetrachlorophenol (2,3,5,6-TeCP) and pentachlorophenl (PCP) demonstrated more characteristic of necrosis than apoptosis. These results establish a good experimental base both for developing the comparative evaluation of toxicity of CPs in vitro and for elucidating the toxicity mechanisms of them.