ABSTRACT
Denaturing gradient gel electrophoresis analysis of polymerase chain reaction-amplified genes coding for 16s rDNA was used to assess changes of biodiversity in a biotrickling filter used to treat waste air containing toluene. The results shown that along with gradually increase of removing capacity for toluene, microbial community structure in packing materials sampled from biotrickling filter also changed markedly over periods of experiment. Under selective pressure of toluene, the number of microbial species decreased but relative abundance of some predominant species increased,and microbial spatial location along the height of biotrickling filter tend to be identical.
ABSTRACT
A new species of genus shewarella Shewanellade decolorations S12, was isolated from activated sludge of a textile-printing waste-water treatment plant. In the anaerobic condition, S12 could conserve energy for growth by using Fe3 + as the terminal electron acceptor. At the optimal condition of pH8, temperature 30℃, ferric citrate 800mg/L, sodium lactate 2g/ L, yeast extract 0. 5g/ L , the cell growth increased with the raise of the amount of the Fe3+ reduction in 8k The effect of different carbon soucres, nitrogen sources, pH values and growth temperatures on the anaerobic Fe3 + reduction of Shewanella decolorations S12 was investigated. LB was favorable for Fe3 + reduction. Glucose and sodium lactate also were favorable for Fe3+ reduction. The cell growth and Fe3 + reduction increased with the raise of the amount of the yeast extract from 0 to 4g/L The amounts of the sodium lactate of 6g/ L and ferric citrate of 800mg/L were suitable for strain S12 growth and Fe3+ reduction. In the optimum initial pH value range of 6 -8 for Fe3+ reduction, strain S12 growth increased with the raise of the pH val- ue. Strain S12 could growth and reduce Fe3+ at the temperature range of 20 -40℃. The best temperature for strain S12 growth and Fe3 + reduction was 301.
ABSTRACT
A laboratory scale combination process of anaerobic baffled reactor(ABR) with sequencing batch reactor(SBR) for treatment of real dyeing wastewater was studied.The effects of operational conditions were investigated.The results demonstrated that removal rates of COD,colour and aniline were 32%~95%,89%~99% and 50%~98%,respectively,the effluents of COD were 30.0 ~97.1mg/L,colour were 8 ~40 times dilution ratio,concentration of aniline were 0.20 ~0.95 mg/L,which could meet the National Discharge Criteria(GradeⅠ) under the operational conditions of HRTs of 24~36 h,organic loading rates of 0.43 ~2.46 kg COD/(m~(3)?d),the influent pH values of 6.5~8.0,ambient temperatures of 20℃~35℃ at the ABR stage and DOs of 2 mg/L,reaction times of 3~10h,settle times of 2 h at the SBR stage.
ABSTRACT
A pilot-scale research on purification of odorous gas emitted from wastewater treatment plant using a biofilter was conducted. The aim of this study is to check on the performance of biofilter running in various conditions and the effect of pH fluctuations on the performance of biofilter. The relation between distribution of microorganism and removal of odorous gases were also discussed here. The experimental results show that the predominant odor-causing gas can be efficiently eliminated by a biofilter inoculated with deodoring microorganism which were isolated previously. Moreover the biofilter had been proved having good tolerance to shocking loads of pollutant and can operate well in the condition of low pH.