The Research On Optimal Operation Parameters Of Cast Process

Combined with the design of municipal wastewater treatment plant in Jiangyan city, the operation parameters of CAST process were studied in this paper, and the effects of aeration time, HRT, DO, activated sludge load, temperature on treatment results were discussed.The results prove that it is feasible to treat municipal wastewater with CAST process. This process is characterized by steady treatment effects and sustainability at shock loading.The longer aeration time is useful for removal of NH₄⁺-N, COD. 3h of aeration time is chosen for better treatment effects.Removal rates of COD,NH₄⁺-N are improved with HRT increase. 18h of HRT is preferential for its economical and steady characters.For the purpose of fluent nitrification, DO of bulk reaction tank should be controlled above 3mg/L during aeration phase. Activated sludge goes into anaerobic phase after having been precipitated for 10 min.COD removal rate is above 87% when the activated sludge load is more than 0.31kgCOD/(kgMLSS. d).CAST process is able to reach good treatment effects in dealing with municipal wastewater which is discharged unsteadily.