Study of aeration rate effects on total nitrogen removal from domestic wastewater

Nitrogen removal from wastewater often requires a highly cost of chemical treatment to prevent over loading of nutrient in effluent discharge to the surface water body. Therefore, an alternative low-cost treatment method for removing nitrogen from wastewater is urgently needed. Hence, the present st...

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Bibliographic Details
Main Authors: Ibrahim, Izzati Izwanni, Hamdan, Rafidah
Format: Conference or Workshop Item
Published: 2013
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Online Access:http://eprints.uthm.edu.my/4558/
http://eprints.uthm.edu.my/4558/1/MEO35.pdf
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Summary:Nitrogen removal from wastewater often requires a highly cost of chemical treatment to prevent over loading of nutrient in effluent discharge to the surface water body. Therefore, an alternative low-cost treatment method for removing nitrogen from wastewater is urgently needed. Hence, the present study of a pilot-scale vertical aerated rock filter (VARF) was principally design to remove ammoniacal nitrogen from domestic wastewater. To develop the most favorable environment for nitrification to take place, the influence of aeration flow rate at different filters depth of 0.5m and 1.0m has been studied. Wastewaters from Universiti Tun Hussein Onn Malaysia wastewater treatment plant have been collected to operate the VARF. Throughout the experimental period, the VARF influent and effluent samples have been sampling and analyzed for total nitrogen, ammoniacal nitrogen, biochemical oxygen demand, chemical oxygen demand, suspended solid, turbidity, dissolved oxygen and pH to monitor the filter effectiveness. From this, it was indicated that most of ammoniacal nitrogen were converted to nitrate-nitrogen in the highly aerated VARF system. More than 90% of ammoniacal nitrogen were converted to NO3-N in the system at the filter depth of 0.75m and 1.0 m. Results from this study show that at the filter depth of 0.75m and air flow rate of 10 L/min has efficiently remove 50.4%, 51.9%, 74.7%, 99.2%, 96.2%, and 97.1% of chemical oxygen demand, biochemical oxygen demand, total nitrogen, ammoniacal nitrogen, suspended solid, and turbidity respectively compared to the air flow rate of 20 L/min at the same filter depth which is remove 42%, 72.1%, 54%, 95.1%, 92.4%, and 83.5% respectively. For pH and dissolved oxygen profiles, the effluent values was found to be higher at the air flow rate of 10 L/min, which is range between 8.4 to 9.5 and 7.6, 8.3 and 8.5 mg/L respectively. Meanwhile at air flow rate of 20 L/min is about 8.2 to 8.4 and 7.3, 8.1 and 7.0 mg/L respectively. By complying with Malaysian Environment Quality (sewage) Regulations 2009, the sample treated for all parameters are within permissible limit of standard B.