Screening COD Degrading Bacteria from Soil of Constructed Wetland and Technical Conditions Optimization of Construction Sprains

Abstract

The utilization of bioaugmentation in constructed wetland can enhance the effect of organic matter removal from wastewater. Obtaining effective COD degrading bacteria plays a key role in bioaugmentation. In this paper, in order to improve the capacity of organic matter removal of constructed wetland, four kinds of effective COD degrading sprains (A2,A11,B1,C4) were obtained from soil of constructed wetland by the way of segregation, primary screening and secondary screening. Through the test of microorganism construction to acquire matching groups with better growth situation and the test of technical conditions optimization inspecting the influence of PH, temperature and rotate speed of incubator shaker on COD converting rates, group A2A11,A11B1,A11C4 and B1C4 were acquired, among which the group B1C4 had the highest COD converting rates (73.74%) when PH was 6.8, temperature was 20 and rotate speed was 100r/min. Using the method of 16S rDNA sequence determination, we observed that sprain B1 had the most similarity with Bacillus simplex (T); DSM1321T; AJ439078, 99%, belonging to bacillus, and sprain C4 had the most similarity with Pseudomonas stutzeri (T); ATCC 17588; AF094748, 97%, belonging to Pseudomonas.