| The nitrifying process is one of important steps in the transformation of ammonium nitrogen, and the present researches mainly focus on the nitrifying characteristics and removal efficiency in the conventional activated sludge processes, which contains relative low ammonia concentration. However, few studies deal with such process as landfill leachate treatment in which there contains high-strength ammonium nitrogen and kinds of Xenobiotic organic compounds. The objectives of this dissertation are mainly about the acclimation characteristics of nitrifying sludge to Phenol or/and TCE (Trichloroethylene) added into the influents continuously under various conditions by using series of Membrane Bioreactors (MBRs). Here in order to obtain an stabilized operation timely to guarantee an accuracy of experimental data, we designed and assembled an MBR auto-controller by ourselves which was running stably and accepted as an National Patent successfully. The conclusions are as the followings:1 Auto-controller employed.In order to obtain a stable performance of Membrane Bioreactor (MBR) in a long period of operation, an auto controller, consisted of time relays, electromagnetic valves, and liquid level controller assembled into an integrated system, was designed for controlling influent, effluent and liquid level, aeration and backwashing, which has been patented nationally. The pumps employed in influent, effluent and aeration were periodically operated at a certain interval of time on and off controlled by Time relays to have enough time to rest. There are two functions in liquid level controller: one is to balance the influent and effluent approximately to equal by turning on and off the feeding pump; and the other is to start-up the backwashing system to eliminate cake layer formed on the membrane surface when effluent rate decreased significantly. During a long periods of operation of MBRs in activated sludge process, this auto controller showed high ability in controlling the parameters such as reaction volume, flux of membrane and pH value.2 The acclimation behavior of nitrifying sludge demonstrated.(1) The removal efficiency of ammonium nitrogen is about 30-50% under the condition of no pH control by nitrifying activated sludge, in which the pH of the mixed liquor in the vessels is maintained at the level of 5.4, lower to that of 7.6-8.0, favorable to the growth of nitrifying bacteria. The accumulation of hydrogen and nitrite ions produced by the nitrification process is responsible considerably for the low removal efficiency of ammonium nitrogen.(2) The influence of glucose, which is one of representative organic nutrients to microbes of sludge, on the nitrifying process, is investigated thoroughly. The results demonstrate that the nitrifying activity increases gradually at low concentration level of glucose, whereas the nitrifying activity decreases sharply at high concentration of glucose. However, along with an enhanced activity of organic-utilizing bacteria (heterotrophic bacteria ); From the facts observed, it indicates clearly that when plentiful organic carbon was added in influent, the heterotrophic bacteria seems to reproduce and grow rapidly, which growth rate is higher than that of nitrifying bacteria, and its number becomes dominant in the whole microbe of activated sludge to enhance the activity of organic compounds utilization which probably inhibits the activity of nitrifying bacteria. But a slow declination to the activity both for nitrifying bacteria and heterotrophic bacteria was observed in the delayed days. We explain that the accumulation of dissolved-and-high-molecular organic compounds captured by the membrane and no sludge renewal occurred timely due to the longer sludge retention time than usual were considerably responsible for the results mentioned above.(3) The inhibition characteristic of TCE and its cometabolic intermediate on nitrifying and heterotrophic bacteria was studied systematically with continuous, intermittent or no TCE addition. The results dem...
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