Study On The Effect Of Effective Organic Matter Biodegrating Bacteria On Treating Branch Creek River Water In Constructed Wetland

Effective organic matter biodegrating bacteria was chosen in order to make it attached on the fillers to form biofilm. It has been investigated in this research about the accuracy and feasibility of surveying the concentration changes of dissolved oxygen (DO) content, nitrate (NO3-), sulfate (SO42-), ferric ion (Fe3+) in one unit of time to reflect the biological activity. Additionally, in terms of the efficiency of degradation and biofilm formation as well as the degree of biofilm activity,the nitrification and denitrification intensity, it was evaluated about the biofilm of effective organic matter biodegrating bacteria on different fillers including haydite, zeolite and vermiculite, in order to select the best filler for effective organic matter biodegrating bacteria to form biofilm. Furthermore, study has been done about the impact of of effective organic matter biodegrating bacteria in the best filler constructed wetland system concerning branch creek water pollutant removal and distribution of different bacterial groups, as well as the study of the operating conditions on the impact of inoculation of effective organic matter biodegrating bacteria pollutant removal implemented in the constructed wetland. The main conclusions are drawn as follows:(1) Under diffident water quality,the result about utilization rate of different electron acceptors on biofilm which formed by effective organic matter biodegrating bacteria metabolic activity is shown below:(a).At the low concentration of organic matter,NO3-> SO42->O2>Fe3+;(b). At the high concentration of organic matter,O2>NO3> SO42-> Fe3+(c).In the anaerobic environment,NO3-> Fe3+> SO42-.(2) The order of its comprehensive performance from the test of effective organic matter biodegrating bacteria forming biofilm was haydite, zeolite, vermiculite. Haydite has the fastest speed for membrane formation and best biological activity, so it is an ideal filler for effective organic matter biodegrating bacteria. The beginging time of three fillers were4～6days,8days and11days respectively,and ending time were21days,25days and33days separately.(3) It was showed that inoculation of effective organic matter biodegrating bacteria could increase the quantity of artificial wetland denitrification bacteria which was10-100times higher than that in control group, raising pollutant removal rate, particularly the removal of CODMn was20%higher than that in control group, the nitrogen removal rate was10%higher than that in control group, and no significant difference on the phosphorus removal. There were significant correlations between ammonia nitrogen removal rate and nitrifying bacteria, as well as total nitrogen removal rate and denitrifying bacteria.(4) This wetland system was operated in a way of intermission:instantaneous inletâ†'test time (72h)â†'instantaneous outlet.It has shown that various kinds of pollutants removal rates different with the different residence time,48h>24h>12h,72h and48h had little difference. Regarding the changes of various kinds of pollutants removal rates,pH and DO after24hs, nitrification was weaken, while denitrification was strengthened, and the system achieved the denitrification intensity. In the condition of48h residence time,the content of CODMn and ammon nitrogen in the source water had some influence. When the influent CODMn was higher thanl5mg/L,CODMn removal rate decreased from62%to54%, when the ammonia nitrogen concentration of influent was higher than3mg/L, CODMn removal rate decreased from62%to48%.