Abstract
Abstract In this study, a sequential process (heterotrophic up-flow column and completely mixed membrane bioreactors) was proposed combining advantages of the both processes. The system was operated for 249 days with simulated and real groundwater for nitrate removal at concentrations varying from 25 to 145 mg·L−1 NO3−-N. The contribution of heterotrophic process to total nitrate removal in the system was controlled by dozing the ethanol considering the nitrate concentration. By this way, sulfur based autotrophic denitrification rate was decreased and the effluent sulfate concentrations were controlled. The alkalinity requirement in the autotrophic process was produced in the heterotrophic reactor, and the system was operated without alkalinity supplementation. Throughout the study, the chemical oxygen demand in the heterotrophic reactor effluent was (23.7 ± 22) mg·L−1 and it was further decreased to (7.5 ± 7.2) mg·L−1 in the system effluent, corresponding to a 70% reduction. In the last period of the study, the real groundwater containing 145 mg·L−1 NO3−-N was completely removed. Membrane was operated without chemical washing in the first 114 days. Between days 115–249 weekly chemical washing was required.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
