Effect of alternate dry-wet patterns on the performance of bioretention units for nitrogen removal

Wei, D; Singh, RP; Liu, J; Fu, D

HERO ID

3857483

Reference Type

Journal Article

Year

2017

HERO ID 3857483
In Press No
Year 2017
Title Effect of alternate dry-wet patterns on the performance of bioretention units for nitrogen removal
Authors Wei, D; Singh, RP; Liu, J; Fu, D
Journal Desalination and Water Treatment
Volume 59
Page Numbers 295-303
Abstract The removal rate of NO3- -N is a key indicator for the performance evaluation of nitrogen removal in bioretention units. At present, most studies show that setting the submerged area and adding carbon (C) source can improve denitrification effect and removal rate of NO3- -N in bioretention units. However, experiments show that the dissimilatory nitrate reduction to ammonium (DNRA) has a significant impact on the N cycle and C/N ratio determines the reduction pathway of NO3- -N. Based on earlier findings, current work aimed to investigate the DNRA process in bioretention system by alternate wetting and drying operation mode, considering Total Nitrogen, NO3- -N and NH4+ -N as assessment indices. Results show that after a prolonged drought period, bioretention unit was able to remove NO3- -N mainly through DNRA with addition of C source. NH4+ -N accumulation occurs in dry period and the removal rate of NH4+ -N was lower than that of with C source. This phenomenon indicates that carbon is the main factor to determine the reduction pathway of NH4+ -N. Results of the microbial sequencing analysis revealed the presence of six common DNRA bacteria in bioretention: Pseudomonas (Pseudomonas), Bacillus (Bacillus), Thiobacillus (Thiobacillus), E. coli (Escherichia), phosphorus Vibrio (Desulfovibrio) and Desulfuvibibrio, which proves the existence of DNRA process in bioretention units.
Doi 10.5004/dwt.2017.1822
Wosid WOS:000403563700034
Is Certified Translation No
Dupe Override No
Is Public Yes
Keyword Bioretention; DNRA; Nitrogen removal; Carbon source; Stormwater