| In this dissertation, biological aerated filter (BAF) was applied in industrial wastewater treatment. Taking saline exhausted lye as the study object, the application feasibility of BAF for the treatment of high salinity wastewater was investigated. The treatment efficiency of a combined ozonization-biological process was also studied in the advanced treatment, which took cassava alcohol wastewater as the study object. BAF showed good performance during the experimental period and the results were satisfactory.The dissertation is divided mainly into two sections:In the first section, saline exhausted lye from an ethylene plant was treated by use of BAF, and a salt-tolerance test of the treatment system was carried out on the basis of proper sludge acclimation. The results showed that, under the conditions that temperature was 20-25℃and hydraulic retention time was 9h, when the salt concentration was less than 6%, a stable COD removal rate of 85% could be achieved. When the salt concentration reached 8%, microbial activity was restrained but still a high COD removal rate of above 75% was attained.In the second section, an advanced treatment of cassava alcohol wastewater by coupling BAF and ozonization was conducted. The effects of different operation conditions such as the hydraulic retention time, the ozone dosage and the circulation ratio were investigated. Experimental results showed that under certain conditions, when the contents of the influent COD was 168-230mg/L and the colority was 80-125 times, the average COD and colority of the effluent could be reduced to less than 100mg/L , 30 times , respectively, which met the discharge standards.
|
PDF Full Text Request