Electrode Biofilm Sbr Denitrification Experimental Research

A combined SBR-electrode-biofilm reactor was developed to improve the efficiency of denitrification in order to explore an effective method of ammonia nitrogen and nitrate nitrogen removal from Shenghua Oil Refinery wastewater pretreated trough airflow. The variation patterns of pH during the treating process were studied to provide reliable theoretical basis for achieving on-line fuzzy autocontrol.To obtain ideal total nitrogen removal efficiency, the denitrification reaction should be complete thoroughly. According to the basic theory of SBR and based on the proceeding pattern ,a anoxic period(just stirring at low speed) was added to the reaction process to activate denitrification ;The running parameters were tested for the selection of whole reaction cycle and each reaction period; The outlet water quality index were examined to evaluate their variation and characteristics ;The optimum procedure was established and achieved real-time automatic on-line control ;The method of hanging denitrification biofilm was verified ;The optimum micro-electrolysis condition was studied and the calculation method of the highest denitrification velocity was raised ;By comparing single SBR with electrode-biofllm-SBR ,the most effective and economic way and reasonable operating parameters of denitrification were posed ,With the contrasting of the variation curve of pH in typical cycle .the coincide points which can repeated very well in pH value and treating process were indicated to provide theoretical basis for on-line autocontrol through the variation of pH value which can synchronously represent the treating water quality ;The existed problem of working procedure and the reasonable resolving strategy were also summarized in this dissertation.The results of the experiment illustrate that (1)SBR is an ideal reactor for removal both of COD and ammonia nitrogen . On the condition of full oxic time,the efficiency of COD removal is up to 97% and the efficiency of ammonia nitrogen is up to 80%,respectively ;(2)The optimum cycle for simultaneously removal of COD and ammonia nitrogen from high concentration petrochemical industry wastewater comprises 8-10 inflating hours ,4 stirring hours and one settling hour ;In low concentration wastewater ,though the active sullage concentration reduced by the shortage of carbon resource which can lead microbe into inner respiration and eventually ,it can reach to a stable balanced stage ;(3) The denitrification of nitrate nitrogen cannot completethoroughly is the key link which result in the low efficiency of total nitrogen removal and the pivotal means of high efficiency for total nitrogen removal is to improve the efficiency of denitrification ;(4)On the appropriate condition of micro-electrolysis ,the biofilm denitrification efficiency of cathode biofilm in SBR system is fairly satisfied ,which can directly demonstrated with the striking removal of total nitrogen ( the efficiency of total removal has improved 48% and the efficiency of denitrification has improved 6 times .respectively .compared to single SBR ); (5) The suitable temperature of cathode biofilm denitrification is 20℃ to 35℃,where the average denitrification velocity can increase 0.54mg/L h and the ideal micro-electrolysis condition is that the electric current density equal to 0.30 mA/c m2 ; (6)Using VB source programme ,the operating system is designed as an common autocontrolling system by using real-time applied parameters which is more convenient and can save labor resource ; (7)The distinct points of pH which have special significance vary according to the removal of organic matters and can be feasibly used as on-line fuzzy process controlling parameters of organic matters ,nitrification and denitrification in a SBR process .The SBR wastewater treatment system has simple working procedure and low cost. Improving its capability of denitrification and efficiency of nitrogen removal .experimenting the controlling condition of long-period stability and selecting the parameters of automatic operation wi...