[Effect of the influent COD and C/N ratio on phosphorus removal of UCT system].

UCT is deeply influenced by COD and C/N ratios.To check this infection,the UCT system was designed to run at variety of influent COD and C/N ratios.The results show that: when the influent C/N ratio is lower than 15,the high influent concentration of COD increases the proliferation of heterotrophic bacteria and decreases the phenomenon release rate.When the influent C/N ratio is higher than 20,the low influent concentration of TN decreases the proliferation of heterotrophic bacteria,the phenomenon release rate rise with the increase of COD.When the influent concentration of COD is lower than 350 mg/L,the phenomenon of denitrifying phosphorus-uptake is very remarkable.The phenomenon release is remarkable when the influent concentration of COD is higher than 350 mg/L.When the influent concentration of COD is lower than 350 mg/L,the promotion of C/N ratio which in the range of 10-20 is obvious,and the promotion decreases along with the increase of C/N ratio.The removal efficiency of total phosphorus achieve higher than 80% steadily when the influent concentration of COD in the range of 250-450 mg/L even in different influent C/N ratio.