Effects of influent loads on performance and microbial community dynamics of aerobic granular sludge treating piggery wastewater

Abstract

BACKGROUND Understanding how influent loads affect the microbial community may promote applications of aerobic granular sludge (AGS). Herein, performance and microbial community dynamics of the AGS were assessed with stepwise increasing influent loads. RESULTS AGS exhibited good structure stability and effective removal efficiency; when the influent load increased from 6.5 kg COD m‐3 d‐1 (0.255 NH4+‐N m‐3 d‐1) to 10.1 kg COD m‐3 d‐1 (0.455 kg NH4+‐N m‐3 d‐1). COD and NH4+‐N removal efficiencies reached 97.1–97.9% and 84.5–98%, respectively. As indicated from the PCR‐DGGE results, the microbial community and dominant species in the AGS also gradually evolved along with the increase of influent loads. A coincidence was observed, namely, three main distinct clusters of the phylogenetic tree appeared respectively in the three stages of influent loads. The microbial diversity attained a maximum in the medium loads stage. The identified bacteria mainly belonged to Proteobacteria, Actinobacteria, Bacteroidetes and Firmicutes. The dominant species were responsible for the AGS stability and pollutant removal. CONCLUSION Variation in the influent load strongly affected the microbial community dynamics, and hence the AGS performance. These results and understanding could lead to potential improvements in guiding AGS wastewater treatment. © 2017 Society of Chemical Industry

Insights into function of hydrocyclone separator and modified volcanic rock coagulant on formation of aerobic granular sludge

“…Specifically, the lowest COD loading rate of 0.13 kg/(m 3 ·day) contributed to the high SVI of 165.0 ml/g and MLSS dropping to the lowest value of 0.2 g/L. Also, Chen et al (2018) reported that the augmentation of organic loading rate favours the granulation effect. For example, after a period of adaptation, when the COD increased to 5.1 g/L, the MLSS increased to 13.8 g/L, and the SVI decreased to 15.0 ml/g.…”

Characterization of Microbial Communities, Identification of Cr(VI) Reducing Bacteria in Constructed Wetland and Cr(VI) Removal Ability of Bacillus cereus

“…Fungal communities were characterized by nested PCR amplification using primers ITS1/ITS4 (5′-TCC GTA GGT GAA CCT GCG G-3′/5′-TCC GTA GGT GAA CCT GCG G-3′) and ITS1GC/ITS2 (5′-CGC CCG CCG CGC GCG GCG GGC GGG GCG GGG GCA CGG GGG G TCC GTA GGT GAA CCT GCG G-3′/5′-GCT GCG TTC TTC ATCG ATG C-3′) as the first and second round primers, respectively 26,27 . The temperature cycling conditions of nested PCR were as follows: 94 °C for 5 min, 35 cycles (94 °C for 30 s; 50 °C (ITS1/ITS4) or 56 °C (ITS1GC/ITS2) for 30 s; 72 °C for 1 min), and 72 °C for 10 min.…”

Demystifying polyphosphate-accumulating organisms relevant to wastewater treatment: A review of their phylogeny, metabolism, and detection

“…The nirK gene encodes a copper-containing enzyme found in low-oxygen environments, whereas nirS encodes a cytochrome cd1-containing enzyme found in high-oxygen environments [ 68 , 69 ]. Next, nitric oxide reductase (gene nor ) catalyzes the reduction of NO to nitrous oxide (N 2 O) [ 70 ]. In the final step, the nitrous oxide reductase (gene nos ) reduces N 2 O to N 2 and completes denitrification [ 71 ].…”