Response of nitrite accumulation and microbial community to free ammonia and dissolved oxygen treatment of high ammonium wastewater

Abstract

The effects of free ammonia (FA) and dissolved oxygen (DO) on nitrite accumulation in the treatment of high ammonium wastewater and on the evolution of the microbial community were investigated. Under high DO conditions (3.75±0.49 mg/L), FA as high as 10.61±2.89 mg NH 3 /L maintained stable nitrite accumulation rate (NAR) of 84 % with NH 4 + -N load of 2.05 kg N/(m 3 day) at sludge retention time (SRT) of 15-18 days. After 56 days of operation, Proteobacteria and Nitrosomonas were the dominant phylum and genus, respectively; Nitrosomonas increased from 21.14 to 54.57 %. By contrast, under relative low DO and low FA, nitrite-oxidizing bacteria (NOB) were nearly eliminated (NOB/AOB of 0; ammonium-oxidizing bacteria (AOB)), and NAR of 94 % was achieved with lower NH 4 + -N load of 0.48 kg N/(m 3 day). DO correlated with AOB and NOB abundance, and FA decreased NOB activity and the NOB/AOB ratio. In conclusion, high FA and high DO conditions are optimal for efficient nitrite accumulation.

Gut Microbiota and Relevant Metabolites Analysis in Alcohol Dependent Mice

“…The species composition of the three groups could be separated clearly by PCA (Principal Component Analysis) ( Figure 6A ). Circos ( Sui et al, 2016 ) is a visual loop diagram that describes the correspondence between a sample and a species ( Figures 6B,C ), which suggested that Bacteroidetes , Firmicutes , Proteobacteria and Deferribacteres had a high abundance in the three groups and each group had different abundance in the four dominant species, and also indicated changes in Clostridiales and Bacteroidales , the two orders with the highest abundance. Ratio of Firmicutes to Bacteroidetes was increased in the experimental group, abundance of Clostridiales was also observed higher in FDG than that in CT group.…”

Enhancement of surface flow constructed wetlands performance at low temperature through seasonal plant collocation

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Combined impact of TiO2 nanoparticles and antibiotics on the activity and bacterial community of partial nitrification system

“…The amounts of Chloroflexi , Acidobacteria , and Chlorobi enhanced after autotrophic domestication. It has been reported that these three phyla are frequently detected in PN systems [ 5 , 46 , 47 ] and several members of them are identified as autotrophic bacteria [ 48 ]. In addition, the abundance of Chloroflexi , the second most dominant phylum, increased under erythromycin shock.…”