Treatment Of Wastewater From Starch Producion By Three-Phase Biological Fluidized Bed Process

Three-phase biological fluidized bed is a new biological treatmenttechnology in wastewater treatment.It integrates conventional chemicalengineering fluidized technique and immobilized microorganism. Characterizedas^- high loading and high efficiency, it is regarded as one of the most prospectivebiological treatment technique in the field of water pollution control.A determination method on k_La in three-phase biological fluidized bedhad founded firstly according to the experiment in this paper. The effects ofscreen mesh, volumetric gas rate and carrier quantity on k_La were investigated.The result showed that the maximum volumetric mass transfer coefficient of thereactor is 0.0508 s^-1 and mass transfer efficiency (E_A) is 22.06％.Then studied on the producing wastewater of starch treatment bythree-phase biological fluidized bed.Through the formation of biofilm onbiology carrier and based on the theory of immobilized microorganism,reseached the impacts of carrier partical diameter, carrier quantity, volumetricgas rate, hydraulic retention time et al on the producing wastewater of starch.The experimental results show that after the formation of biofilm and running stably, the COD_Cr removal rate was 80％around when activated carbon quantitywas 10％(Ⅴ/Ⅴ), and activated carbon partical diameter was 0.5mm～1mm,andvolumetric gas rate was 100L/h, and hydraulic retention time was 90min.Else this paper studied the starch wastewater treatment by anaerobicpretreatment three-phase biological fluidized bed. On the condition that theCODcr of inflow was about 21000mg/L,the volume of anaerobic granular sludgewas 10％(Ⅴ/Ⅴ),the initial pH was about 7.5,the temperature was 40℃,HRT ofanaerobic was 24 hours at slow stir speed, the removal retio of COD_Cr ofoutflow was above 90％. The total removal retio of COD_Cr was 99％bythree-phase biological fluidized bed after anaerobic treatment.The experimentalresults show that the producing wastewater of the-starch treated by anaerobicpretreatment three-phase biological fluidized bed is acceptable on technology.