| With the rapidly development of economic and technological, more and more water bodies are subjected to the nitrogen pollution, especially the pollution from ammonia nitrogen wastewater with high concentration. Due to the ammonia nitrogen wastewater with high concentration have some characteristics, like wide origin, great damage to the environment, hardly to handle, etc, so water treatment technology for ammonia nitrogen wastewater with high concentration has been the focus with researchers.As a new highly water treatment technology, membrane bioreactor has many advantages, such as stable water quality of membrane effluent,less surplus sludge,strong impact load capacity,easy automatic operation,small footprint and so on, so the MBR is widely applied to water treatment. But compared to traditional water treatment technology, the total nitrogen removal in membrane bioreactor has little improvement. So in this topic selection, packing is put into the membrane bioreactor, the experiment choose carbon fiber which is provided by Capital Sunshine Environmental Protection Company. Carbon fiber has a lot of advantages with less environmental load,no secondary pollution,no species enroach,safety,light quality,good durability and effect significantly, etc. This experiment uses Hybrid Membrance Bioreator with carbon fiber to treat ammonia nitrogen wastewater with high concentration.The research results show that:(1) During the start-up period, the floating sludge concentration reduce firstly, and then grow rapidly, as the amount of microorganisms which adhering to carbon fiber grow rapidly. After the start-up period, the COD removal rate is about 95%, and the NH3-N removal rate is more than 75%. It means that the sludge domestication has been done and hanging membrane is completed successfully.(2) When the system operates under the stable conditions:the COD concentration is about 1000 mg/L and NH3-N is 500 mg/L in the inflow water,the sludge concentration is about 8000 mg/L in the bioreactor,adjusting DO concentration between 2 to 3 mg/L,controlling pH between 7 to 8,HRT is 12 hours and external environment temperature is between 20 to 35℃, the COD concentration in supernate water and membrane effluent are very low, the organic removal efficiency in the Hybrid Membrane Bioreactor is good, and the removal rate is about 95%.(3) It investigates the influence of the organic removal efficiency by dissolved oxygen hydraulic retention time and pH value, the results show that:①The COD concentration in effluent is very low, the organic removal efficiency in the Hybrid Membrane Bioreactor is good when DO concentration is more than 2.0mg/L;②The organic removal efficiency in the system is good when HRT is between 10 hours to 12 hours, and the COD removal rate has a little growth when HRT is increased;③pH value has little influence on organic removal efficiency, the organic removal efficiency in the Hybrid Membrane Bioreactor is the best when pH is neuter, and the organic removal rate reduces when pH value is lower or higher.(4) When the COD concentration is about 1000 mg/L and NH3-N is 500 mg/L in the inflow water,the sludge concentration is about 8000 mg/L in the bioreator,DO concentration is between 2 to 3 mg/L,adjusting pH value between 7 to 8,HRT is 12 hours and external environment temperature is between 20 to 35℃, the NH3-N concentration in supernate water and membrane effluent are low and the removal efficiency is good, the NH3-N and TN average removal rate are 89% and 81.02% respectively. Compared to common MBR which TN removal rate is only 50%-60%, the TN removal efficiency is better in Hybrid Membrane Bioreactor which adds carbon fiber in this experiment.(5) It investigates the influence of the NH3-N,TN removal efficiency and Simultaneous nitrification denitrifying efficiency by dissolved oxygen,hydraulic retention time and pH value, the results show that:①High dissolved oxygen is beneficial to NH3-N removal, On the contrary, Low dissolved oxygen is beneficial to TN removal, simultaneous nitrification denitrifying efficiency is better when DO concentration is 1.5mg/L, the TN removal rate is 82.06%;②Different C/N value has little influence on NH3-N removal, but great influence on TN removal, the effluent TN concentration decrease when the C/N value increase, the removal efficiency become higher, and simultaneous nitrification denitrifying efficiency become higher too;③The NH3-N and TN removal efficiency are good when HRT is 12 hours, the simultaneous nitrification denitrifying efficiency is the best, the TN removal rate is 80.34%;④The NH3-N and TN removal efficiency are good when pH is neutral partial alkali, the simultaneous nitrification denitrifying efficiency is the best.It adds carbon fiber to membrane bioreactor in this experiment, and treat high concentration ammonia-nitrogen wastewater in the Hybrid Membrane Bioreactor, the results confirm the NH3-N and TN removal efficiency are good. And it not only used to treat high ammonia nitrogen wastewater, but also provide practical process for efficient denitrification technology. |
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