| Because of the pollution of surface water and sewage of small towns sewage treatment ecological engineering technology, artificial rapid infiltration system (CRI for short) is in the rapid infiltration system (RI) based on the establishment of a new sewage ecological treatment technology, is becoming the focus of domestic research and application. It has been proved in practice that the technology in the processing of small town sewage and polluted surface water has a significant effect, the CODcr removal rate 85-90%, of ammonia nitrogen removal rate reached more than 90%, of SS and Las removal rate reached more than 95%, covers an area of relative to traditional land treatment technology is relatively small, simple process, low investment, less operation cost, etc., to our country small town domestic sewage and polluted surface water treatment has important application value and obvious advantages. But its total nitrogen(TN), total phosphorus(TP) removal rate is low, the removal rate of 10%-30% is TN, the removal rate of TP is 30%-55%, which is not up to the standard. Therefore, studying the mechanism of aerobic denitrification of CRI system, the research results can enrich and develop the theory of artificial rapid infiltration system ecological engineering treatment of sewage, has important scientific significance and academic value.In this paper, the aerobic denitrification bacteria were extracted from the CRI simulation column, and the best operating conditions were studied by controlling the external conditions (pH, C/N, inoculation amount, temperature) to study the denitrification performance of aerobic denitrification bacteria. Enrichment culture of aerobic denitrifying bacteria inoculation to CRI simulation column, in the aerobic denitrifying bacteria under the optimum conditions, the operation system, the study found after inoculation of CRI system off performance of nitrogen increased, especially for TN removal efficiency is greatly improved. In order to provide reference for the development of the theory of artificial rapid infiltration system for ecological engineering treatment of sewage.The results showed that:1. Success extract 4 strains of aerobic denitrifying bacteria from CRI simulation column, through the study on the strain LJ11, LJ12, LJ13 and LJ14 the morphological, physiological and biochemical characteristics, further combined with 16SrDNA sequence analysis and phylogenetic tree construction, determine the lichens Bacillus genera. The identified strains LJ11 belonged to the genus Bacilluslicheniformis, the strain LJ12 and LJ13 belong to the genus Bacilluspumilus, and the strain LJ14 belongs to Pseudomonas.2. Neutral and alkaline environment (pH 7.0-7.5) is beneficial for strains LJ12 and LJ13 exert aerobic denitrification effect; The removal efficiency of TN, NH+-N and COD was best when LJ12 C/N is 9 were LJ13 C/N is 12 respectively, and the best aerobic denitrification performance was played out; The optimal inoculation amount range of 5%-7% for strain LJ12 and LJ13; The optimum temperature of aerobic denitrification of strain LJ12 and LJ13 was about 30 centigrade.3. CRI system COD removal rate has reached a higher level, inoculated with aerobic denitrifying bacteria LJ12 on COD removal rate promotion effect is small, the average increase of 1.5%; CRI ammonia nitrogen removal rate has reached a higher level, inoculated with aerobic denitrifying bacteria LJ12 of COD and ammonia nitrogen removal rate to improve the effect is small, with an average increase of 2.1%.4. The removal rate of the control experiment in LJ12 TN strains, inoculated with aerobic denitrifying bacteria on the removal rate of TN increased evidently, the average increase of 40%. It can be seen from this experiment that the inoculation of aerobic denitrification bacteria has a significant effect on improving the removal rate of TN, which shows that the strain LJ12 has a good denitrification effect in the CRI system. To lay the foundation for the study of the industrial application of CRI system. |
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