Hits:

Indexed by:Journal Papers

Date of Publication:2020-05-01

Journal:CHEMOSPHERE

Included Journals:PubMed、EI、SCIE

Volume:247

Page Number:125831

ISSN No.:0045-6535

Key Words:Moving-bed biofilm reactor (MBBR); Simultaneous nitrification and; denitrification (SND); Surface-modified carrier; Domestic wastewater; Low C/N ratio

Abstract:Moving-bed biofilm reactor (MBBR) is a well-established technology for simultaneous nitrification and denitrification (SND). In MBBR, biofilm development and pollutant removal performance are strictly governed by the physico-chemical properties of the carriers. In this study, novel surface-modified carriers with enhanced hydrophilicity (surface contact angle of 60.2 +/- 2.3 degrees) and positively-charged surfaces (+11.7 +/- 1.1 mV, pH 7.0) had been prepared successfully via polymer blending, and they had also been implemented in SND system for the treatment of real domestic wastewater. Results showed that accelerated startup of SND with more biomass on the carriers was observed in MBBR system filled with surface-modified carriers. At low DO level (0.6-0.8 mg L-1) and low C/N ratio (<= 5), highly efficient organics removal and SND performance could be achieved with COD removal, TN removal and SND efficiencies of 79.3-85.7%, 62.0-75.9% and 58.5-71.8%, respectively. The efficient performance of SND in MBBR system filled with surface-modified carriers was mainly attributed to the coexistence of enriched mixtrophic nitrifiers and denitrifiers like autotrophic nitrifers (Nitrosomonas, Nitrospira, Nitrobacter), heterotrophic nitrifers (Rudaea), aerobicdenitrifiers (Dokdonella, Terrimonas), anoxic denitrifiers (Gemmobacter, Ottowia, Methyloversatilis, Thermomonas) and N2O producer (Mesorhizobium). (C) 2020 Elsevier Ltd. All rights reserved.