Study On The Treatment Of Organic Wastewater Using RBC

Rotating biological contactors, one kind of biofilm wastewater treatment method, was usedfor the Petrochemical, dyeing, white and other wastewater treatment widely. Compared to theactive sludge process, the RBC had no recycled sludge, no aeration, energy-saving and a goodtreatment effect with a short contact time and other advantages.This paper included two parts, optimizing the plate materials of RBC and pollutants (aceticsodium) removed from the wastewater. The results were following:1.Optimizing of the plate materials: in this paper, it was studied on the performances of fivekinds of materials, including the wood, epoxy resins, quartz sand, polypropylene, active carbon.Synthetic wastewater was prepared with different influent concentrations of ammonia-nitrogenand COD. The results show that the effluent COD of the five plate materials are130,109,112,107,65.7mg/L and TN are 5.73,4.58,4.54,4.53,2.30mg/L respectively, when influentCOD is 600mg/L, TN is 30mg/L, rotating speed is 4 r/min, HRT is 12hours. The biomassattaching the plate was studied, the biomass net weight of wood, epoxy resins, quartz sands,polypropylene, active carbon are 17.6,30.3,28.4,32.2,44.5g/m2 respectively, after the RBC ranfor 30 days. There were some organics absorbed by the active carbon at the beginning of theRBC's first ran, due to the adsorption of active carbon. Experiments were carried out to certifythe role of the active carbon in the organics removal, and then it proved that the adsorption ofactive carbon has contributed for the removal COD, at the beginning of RBC ran. After 7 daysrunning, the bioactivity of active carbon contributed for the removal COD.2. The organics degradation: both the disc rotating speed and the HRT were importantparameters for the RBC. The experiments show that the optimum parameters for a three-stageRBC, which is installed the active carbon disc, are that the rotating speed is 4r/min and the HRTis 4h, so the following experiments were studied under these conditions. When the organic loadis 400,600,800mg/L, the effluent COD removal is 98,97,96% respectively and this result certifythat the RBC have a strong endurance of organic load. The COD:NH4+ ratio was important forthe TN removal. Under the condition that influent COD:NH4+ ratio is 160:5,140:5,120:5,100:5,the effluent TN was 2.09,3.06,3.94,5.36mg/L. Considered the effluent COD removal, theoptimum COD:NH4+ ratio is 120:5. The degradation of COD in RBC is first order reaction, therate constant of reaction is 0.216.