Water Resources Research Act Program

Details for Project ID 2015ND293B

Contribution of Soluble Microbial Products on Dissolved Organic Nitrogen and its Biodegradability in Wastewater Effluent

Institute: North Dakota
Year Established: 2015 Start Date: 2015-03-01 End Date: 2016-02-29
Total Federal Funds: $8,292 Total Non-Federal Funds: $16,583

Principal Investigators: Halis Simsek

Abstract: Fargo, North Dakota, wastewater treatment plant removes ammonia from its influent to meet discharge limits by using a series of trickling filters as main biological treatment process. Residual nitrogen in treated effluent was found mostly in organic nitrogen form. Besides refractory organic compounds in wastewater influent, a part of effluent organic carbon and nitrogen has been suspected to be microbial products being released during secondary treatment unit. Therefore, in order to improve nitrogen removal efficiency in wastewater treatment plant, low level of effluent organic nitrogen must be maintained. Source of organic nitrogen during the operation of biological wastewater treatment need to be identified and characterized. However, source of dissolved organic nitrogen (DON) and its biodegradable form (BDON) in treated effluent from biofilm process is not known. Therefore, contribution of microbial products like soluble microbial products (SMP) released by wastewater biofilm on DON and BDON is crucial. Objectives of this study are: 1. To investigate the effect of hydrodynamic shear conditions on biofilm structure and influence on distribution of DON, extracellular polymeric substances (EPS) and soluble microbial products (SMP) in primary effluent, 2. To investigate wastewater characteristics on composition of DON and SMP in effluent, and 3. To investigate organic loading rate (OLR) effect on composition of DON and SMP in effluent. This study will provide important information on biofilm formation in trickling filter units to further understand the behavior of the microorganisms in trickling filter units. Additionally, investigation of EPS and SMP effect on DON removal will provide crucial information to understand biofilm formation created by bacteria on trickling filter media.