Study On Calculation And Comparison Of Membrane Bioreactor For Bathing Wastewater

Membrane bioreactor (MBR) is a new technology, which combines biologicalwastewater treatment and membrane separation. It is a significant part of wastewaterreclamation technology. In China, MBR is supposed to be an effective way towastewater reclamation. Meanwhile, many progresses have been made in thisresearch field.Basing on the separation between sludge retention time (SRT) and hydraulicretention time (HRT) in MBR, this paper calculates MBR capacity by SRT and HRTrespectively. When SRT is 15 days, the 55th MBR capacity is worked out at 306m3according to SRT way;In the same condition of SRT, the 55th MBR capacity iscalculated as 125 m3 under the way of HRT, which is deduced by substance balanceof influent. In the aspect of standard oxygen supply, when SRT is set as 15 days, theratio of gas supply and designing water quantity is 9. Normally, membrane is requiredratio of gas supply and designing water quantity is 20 or more for the purpose ofreducing membrane fouling. Therefore, the final ratio of gas supply and designingwater quantity is 15 for considering these two factors.Under the comparative analysis among the three reclaimed system, this paper hasdrawn such conclusions as follows: the average chromaticity value of influentbetween the 55th and the Swimming pool reclaimed system is 273 and 207, and theeffluent is 22 and 9.5.The removal rate of turbidity goes to 96.5%~99.75% and91.18%~99.69% in 53rd and 55th reclaimed system. Moreover, the removal rate ofCODcr in the 53rd reclaimed system is 89.62% better than the 55th 81.61%,because itis designed a aerobic contact reactor that can increase the MLSS in this system andreduce the suspended active sludge in MBR. Besides, NH3-N in the 53rd fluctuatesbetween 2.39mg/L and 15.28 mg/L,but this value is 55th is 12.50~47.19 mg/L. Andthe removal rate of NH3-N is 92.1% in the 53rd reclaimed system and 72.4% in the55th. Finally, the average LAS density is 10.17 mg/L in the 53rd reclaimed systemand 8.26 mg/L in the 55th. This value in effluent is 0.27 mg/L and 0.48 mg/L in the53rd reclaimed system and the 55th respectively. Packing fixation in aerobic contactreactor may create a positive condition for some bacteria, which can remove LAS inhigh efficiency.It should be noted that the scum has a close relation with the influent quality and MLSSdensity in MBR. In order to reduce scum in MBR, some methods must be token such asincreasing MLSS, and reducing the density of LAS. When membrane module is chosen, properlyoperating mode should be some positive to reducing membrane fouling.