The Research On Municipal Wastewater Treatment By The Integrative Wastewater Reactor Based On A/O Technology With The Magnetic Biofilm Packing

With the rapid development of Chinese social economy and urbanization, the population of the towns and villages keep concentrating, the enterprises in towns and villages’keep developing rapidly. There is much more wastewater from towns and villages has been produced. Generally speaking, the characteristics of these wastewater are disperseding widely, relatively discharging not much, the wastewater’s quality and quantity changing unpredictably. It’s a hard to work to col-lect all of these wastewater together. The wastewater cann’t been collected or cann’t easy been collected by municipal network called distributed wastewater. According to statistics, 30% -60% of the total pollution of water bodies from distributed wastewater. At present, for our national conditions, develops an integrative wastewater reactor to purify local water efficiently with low energy is an important ways to deal with distributed wastewater. In recent years, it’s a very active direction in researching magnetic effects on water treatment. Because of the wastewater treatment is usually tremendous, a external magnetic field is too difficult to add on it. Magnetic materials as a new technology, it’s the magnetic biofilm packing in wastewater treatment,which make each of the magnetic biofilm packing to become a mini magnetic field generator. To use of the magnetic effect, the metabolism or co-metabolism’s effect can change the surface wettability and mass transfer perfor-mance of the magnetic biofilm packing, short the period to attain the stable treatment performance, improve wastewater treatment effect.In this study, combined with the above background, develops the integrative wastewater reactor base on the A/O technology with the magnetic biofilm packing. In terms of the biofilm packing, makes use of the chemical coprecipitation to produce the magnetic nanoparticles. Nutshell activated carbon as a carrier to attach to mag-netic nanoparticles, makes the magnetic nutshell activated carbon with MnFe2O4 magnetic nanoparticles attached. By SEM, XRD, magnetic susceptibility, BET and the total pore volume analysis, MnFe2O4 magnetic nanoparticles attachs on nutshell activated carbon successfully. The composites material in favor of the microbial growth and biofilm formation, because it possesses both magnetic and rough and porous structure as activated carbon. On the Reactor hand, based on traditional A/O process, develops a reactor with biodegradable pollutants, nitrification - denitrifica-tion, physical entrapment, adsorption and sludge sedimentation and other processes in one integrated A/O integrated reactor.The reactor starts up with granular sludge inoculation. In the granular sludge inoculation experiments,the integrated reactor stars up with both the magnetic bio film packing and the ordinary bio film packing. The magnetic biofilm packing in the bio-film speed and the removal rate of COD and NH4+-N performances better than the ordinary biofilm packing. In the 8th day, the reactor with the magnetic biofilm packing keeps the removal rate of COD stable about 83.3%. In the 12th day the re-actor with the ordinary biofilm packing keeps the removal rate of COD stable about 81.5%. In the 8th day, the reactor with the magnetic biofilm packing keeps the re-moval rate of NH4+-N stable about 86%. In the 13th day the reactor with the ordinary biofilm packing keeps the removal rate of COD stable about 72.2%.The reactor runs at different factors such as:HRT, reflux ratio, dissolved oxygen, temperature. Then researchs the removal rate of COD, NH4+-N, TN at different fac-tors. The optimal HRT, reflux ratio, dissolved oxygen, temperature is:10h,200%, 2.5-4mg/L, 25℃-30℃. Based on kinetical model of the plug reactor:xAf=1-e-kT to build kinetical equationthe of the removal rate of COD(x) and HRT(T) is x=1-e-0.1566T-0.7446,R2=0.9631; kinetical equationthe of the removal rate of NH4+-N (x) and HRT(T) is:x=1-e-0.1566T-0.7446, R2=0.9673; kinetical equationthe of the removal rate of TN (x) and HRT(T) is:x=1-e-0.0953T-0.0916, R2=0.9787.Under the optimal conditions, takes campus municipal wastewater runs contin-uously 20d. Reactor for COD, NH4+-N, TN has a better removal, COD removal rate is 85.5%, ammonia nitrogen removal rate is 82.8%, TN removal rate is 53.2%. The wa-ter quality of effluent has reached the national discharge standard of pollutants for municipal WWTP(Class 1st B standard).