Rotating Biological Contactor Process for Secondary Treatment and Nitrification Following a Trickling Filter

摘要

Typical Army wastewater treatment plants can be upgraded to secondary stadards for BOD5 by incorporation of the rotating biological contactor (RBC) process downstream of existing trickling filters. Existing trickling filter plants can also be upgraded for ammonia removal by using the RBC process for nitrification. In these studies both BOD5 removal and nitrification rates were affected by wastewater temperature. However, nitrification rates were more sensiive to low w astewater temperature than secondary treatment. Results indicate that chemical feed for elevated pH levels of about pH8.0 in the RBC influent increases the rate of nitrification and decreases RBC surface area requirements. The decrease in required RBC surface area for secondary treatment or nitrification will result in less costly upgrades for existing trickling filter wastewater treatment facilities. Increased rates of nitrification will also result in more consistent and reliable attainment of effluent standards. The RBC in this study received effluent from a high-rate trickling filter that performed at less than secondary effluent standards. Performance of the RBC was evaluated over a 2-year period without temperature control, in order to determine both summer and winter efficienc eis for BOD5 reduction and ammonia-nitrogen removal.