| Nowadays,for different types of industrial sewage and domestic sewage,the addition of magnetic field can improve the ability of sewage treatment system to degrade pollutants in water.At present,the combination of magnetic field and sewage treatment technology is a new technology which has the advantages of low energy consumption,cost,pollution,easy to operate and so on,and has a great development prospect.In this study,SBR process(sequencing batch activated sludge process)was selected.Several sets of permanent magnets are used as magnetic field generating devices.The magnetic induction intensity and magnetic field configuration were taken as variables.The effect of different external magnetic induction intensity and magnetic field configuration on the properties of activated sludge and the treatment effect of pollutants in SBR system was studied by using the electronic transfer system of iodinitrotetraazole(NT-ETS),dehydrogenase(TTC)activity,sludge settling rate,sludge morphology and other indicators to evaluate sludge activity.By adjusting the magnitude of magnetic induction intensity and the type of magnetic field configuration,the removal rate of COD,ammonia nitrogen,total phosphorus and other pollutants in sewage treatment system was studied.The results show that the removal effect of pollutants in the sewage treatment system can be improved under certain intensity of external magnetic field.The COD removal rate reaches the highest 95.2% at 1200 GS,which is 7.4% higher than that of the control group.The removal rate of ammonia nitrogen reached the highest 91.2% at 500 GS,which was 5.7% higher than that of the control group.The total phosphorus removal rate reached a peak of 88.78% at 700 GS,4.6% higher than that of the control group.In general,the optimal external magnetic induction intensity for COD removal is between 900 GS-1200 GS,the optimal external magnetic induction intensity for ammonia nitrogen removal is about 500 GS,and the optimal magnetic induction intensity for total phosphorus removal efficiency is about 700 GS.Through the comparison of the removal effect of the three pollutants under the condition of reaction system under the action of phase absorption and repulsion two magnetic field configurations,it can be seen that the overall trend of pollutant degradation is basically the same,but the overall effect of phase absorption magnetic field is better than that of repulsion magnetic field.In the magnetic field range set by the experiment,with the increase of magnetic induction intensity,the electronic transfer system of iodinitrotetrazolium and the dehydrogenase activity of sludge bacteria showed a significant increase trend.The dehydrogenase activity of activated sludge was increased by 43.7% under the condition of 1500 GS magnetic field,and the int-ets activity was increased by 33% when the magnetic induction intensity was 900 GS. |
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