Two biological nutrient removal （BNR） wastewater treatment plants （WWTPs） in Thailand were selected for study： the Nonghkaem WWTP and the Suvarnabhumi Airport WWTP. For each site the influents, effluents, and sup...Two biological nutrient removal （BNR） wastewater treatment plants （WWTPs） in Thailand were selected for study： the Nonghkaem WWTP and the Suvarnabhumi Airport WWTP. For each site the influents, effluents, and supernatant liquids from anaerobic sludge digesters were analyzed for total Kjeldahl nitrogen （TKN）, total nitrogen （TN）, total chemical oxygen demand （TCOD）, biodegradable chemical oxygen demand （bCOD）, and biochemical oxygen demand （BOD）. Nitrogen removal efficiencies in the Nonghkaem WWTP and the Suvarnabhumi Airport WWTP were evaluated. Inadequate nitrogen removal at the Nonghkaem centralized WWTP was found during the summer period. Influent ratios of bCOD：N at the Nonghkaem plant and the Suvarnabhumi Airport plant were 2.42：1-5.45：1 and 4.1：1-6.5：1, respectively. The efficacy of addition of molasses as a carbon source for enriched denitrifying culture in a BNR process at Nonghkaem was studied. Fluorescent in situ hybridization technique （FISH） was used to identify specific nitrifying bacteria （Nitrosomonas spp., Nitrobacter spp. and Nitrospira spp.）. Nitrospira spp. was the most prevalent species in the aeration tank at the Nonghkaem WWTP. This result from FISH suggests that there were significantly low oxygen and nitrite concentration in the aeration tank at the Nonghkaem WWTP during a period of low nitrogen removal.展开更多
文摘Two biological nutrient removal （BNR） wastewater treatment plants （WWTPs） in Thailand were selected for study： the Nonghkaem WWTP and the Suvarnabhumi Airport WWTP. For each site the influents, effluents, and supernatant liquids from anaerobic sludge digesters were analyzed for total Kjeldahl nitrogen （TKN）, total nitrogen （TN）, total chemical oxygen demand （TCOD）, biodegradable chemical oxygen demand （bCOD）, and biochemical oxygen demand （BOD）. Nitrogen removal efficiencies in the Nonghkaem WWTP and the Suvarnabhumi Airport WWTP were evaluated. Inadequate nitrogen removal at the Nonghkaem centralized WWTP was found during the summer period. Influent ratios of bCOD：N at the Nonghkaem plant and the Suvarnabhumi Airport plant were 2.42：1-5.45：1 and 4.1：1-6.5：1, respectively. The efficacy of addition of molasses as a carbon source for enriched denitrifying culture in a BNR process at Nonghkaem was studied. Fluorescent in situ hybridization technique （FISH） was used to identify specific nitrifying bacteria （Nitrosomonas spp., Nitrobacter spp. and Nitrospira spp.）. Nitrospira spp. was the most prevalent species in the aeration tank at the Nonghkaem WWTP. This result from FISH suggests that there were significantly low oxygen and nitrite concentration in the aeration tank at the Nonghkaem WWTP during a period of low nitrogen removal.
