Correlations of nitrogen removal and core functional genera in full-scale wastewater treatment plants: Influences of different treatment processes and influent characteristics

2020 ◽  
Vol 297 ◽  
pp. 122455 ◽  
Author(s):  
Jiashun Cao ◽  
Teng Zhang ◽  
Yang Wu ◽  
Yaqing Sun ◽  
Yilei Zhang ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plants ◽  
Full Scale ◽  
Treatment Processes

scholarly journals Effect of COD:N ratio on biological nitrogen removal using full-scale step-feed in municipal wastewater treatment plants

2020 ◽  
Vol 30 (1) ◽  
Author(s):  
Supaporn Phanwilai ◽  
Pongsak Noophan ◽  
Chi-Wang Li ◽  
Kwang-Ho Choo
Keyword(s):  
Wastewater Treatment ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Full Scale ◽  
Biological Nitrogen Removal ◽  
Municipal Wastewater Treatment ◽  
Municipal Wastewater Treatment Plants ◽  
Scale Step ◽  
Biological Nitrogen

Abstract This study investigated the effect of low and high chemical oxygen demand (COD):N ratios on biological nitrogen removal and microbial distributions in full-scale step-feed (SF) municipal wastewater treatment plants (WWTPs) in Thailand (SF1) and Taiwan (SF2). The SF1 WWTP had a low COD:N (4:1) ratio, a long solids retention time (SRT) (> 60 d), and low dissolved oxygen (DO) conditions (0.2 mg L− 1 in anoxic tank and 0.9 mg L− 1 in aerobic tank). The total nitrogen (TN) removal efficiency was 48%. The SF2 WWTP had a high COD:N (10:1) ratio, a short SRT (7 d), and high DO (0.6 mg L− 1 in anoxic tank and 1.8 mg L− 1 in aerobic tank). The TN removal efficiency was 61%. The nitrification and denitrification rates from these two plants were inadequate. Using a quantitative polymerase chain reaction (qPCR) technique, the populations of ammonium oxidizing bacteria (AOB) and ammonium oxidizing archaea were quantified. Measurement of ammonia monooxygenase (amoA) gene abundances identified these AOB: Nitrosomonas sp., Nitrosospira sp., Nitrosoccus sp. and Zoogloea sp. Higher amounts of the archaeal-amoA gene were found with long SRT, lower DO and COD:N ratios. Abundance of Nitrobacter sp. was slightly higher than Nitrospira sp. at the SF1, while abundance of Nitrobacter sp. was two orders of magnitude greater than Nitrospira sp. at the SF2. More denitrifying bacteria were of the nirS-type than the nirK-type, especially at higher COD:N ratio. Most bacteria belong to the phyla Acidobacteria, Actinobacteria Bacteroidetes, Chloroflexi, Proteobacteria. The results from this work showed that insufficient carbon sources at the SF1 and high DO concentration in anoxic tank of SF2 adversely affected nitrogen removal efficiencies. In further research work, advanced techniques on the next generation sequencing with different variable regions should be recommended in full-scale WWTPs.

scholarly journals Comparison of Nitrogen Removal Efficiencies and Microbial Communities of Full-Scale Anaerobic, Anoxic and Aerobic Processes in Municipal Wastewater Treatment Plants having Low and High COD/TN Ratios

2021 ◽  
Author(s):  
Supaporn Phanwilai ◽  
Pongsak Noophan ◽  
Chi-Wang Li ◽  
Kwang-Ho Choo
Keyword(s):  
Wastewater Treatment ◽  
Microbial Communities ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Full Scale ◽  
Biological Nutrient Removal ◽  
Distribution Analysis ◽  
Microbial Distribution

Abstract Full-scale anaerobic, anoxic and aerobic (A2O) process is used worldwide for biological nutrient removal (BNR). However, operation parameters for nitrogen removals and information of microbial communities related to nitrogen removal in full-scale A2O wastewater treatment plants (WWTPs) having low and high COD/TN ratios are not available. Based on the analysis of four full-scale A2O WWTPs, it is suggested that maintaining longer SRT of ≥ 30 day and DO of ≥ 0.9±0.2 mg-O2 L-1 is needed to improve nitrogen removal efficiency under low COD/TN ratio (≤ 3.7). On other hand, at high COD/TN ratio (≥ 4.2), DO level of ≥ 2.6 mg-O2 /L and typical SRT of 19‒ 25 days would be suggested. It was confirmed that phosphorus removal efficiency significantly improved under BOD/TP ratio of > 20 for A2O process in these full-scale WWTP. Microbial distribution analysis showed that ammonia-oxidizing archaea (AOA) was abundant under conditions of low DO level, longer SRT, high temperature and low COD/TN ratio (≤ 3.7). Nitrosomonas sp. are mostly found in aerobic tank of full-scale A2O WWTPs. However, abundances of Nitrosomonas sp. are proportional to DO and NH4+ concentrations for WWTPs with high COD/TN ratio. Nitrosospira sp. are only found under operating condition of longer SRT for WWTPs with low COD/TN ratio. Abundances of Nitrobacter sp. are proportional to DO concentration and temperature rather than abundance of Nitrospira sp. Predominance of nosZ-type denitrifiers were found at low COD/TN ratio. Abundance of denitrifiers by using nirS genes was over abundance of denitrifiers by using nirK genes at high COD/TN ratios WWTPs.

Distribution of endotoxins in full scale pharmaceutical wastewater treatment plants and its relationship with microbial community structure

2018 ◽  
Vol 77 (10) ◽  
pp. 2397-2406 ◽  
Author(s):  
Xuemeng He ◽  
Lili Ding ◽  
Wenbo Su ◽  
Haijun Ma ◽  
Hui Huang ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Community Structure ◽  
Wastewater Treatment Plants ◽  
Anaerobic Treatment ◽  
Full Scale ◽  
Gram Negative Bacteria ◽  
Treatment Processes ◽  
Endotoxin Activity ◽  
Lal Assay ◽  
Pharmaceutical Wastewater Treatment Plants

Abstract Endotoxins are potential toxics impacting human health through respiration derived in wastewater treatment plants (WWTPs), yet the formation of endotoxins during wastewater treatment processes is still lacking research. In our study, the distribution of endotoxins and bacterial community structure in the wastewater of three full scale pharmaceutical WWTPs were explored using the limulus amebocyte lysate (LAL) test and MiSeq technique. Results showed that higher endotoxin activities in the influent of Plant A and Plant C (560 and 1140 EU/mL), stemming from the fermentation process, were found compared to that of Plant B (135 EU/mL), coming from the process of chemical synthesis. During the anaerobic treatment and the cyclic activated sludge system (CASS) in the three WWTPs, the endotoxin activity increased, while it declined in the aerobic treatment system. In all bioreactors, the relative abundance of Gram-negative bacteria accounted for 50.0–94.6%. Bacteria with high lipopolysaccharide (LPS) in LAL assay were found at the genus level of Bacteroides, Enterococcus, Desulfovibrio, and Megasphaera.

Elevational characteristics of the archaeal community in full-scale activated sludge wastewater treatment plants at a 3,660-meter elevational scale

2017 ◽  
Vol 76 (3) ◽  
pp. 531-541 ◽  
Author(s):  
Lihua Niu ◽  
Xue Zhang ◽  
Yi Li ◽  
Peifang Wang ◽  
Wenlong Zhang ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Archaeal Community ◽  
Full Scale ◽  
Anaerobic Reactors ◽  
Treatment Processes ◽  
Operational Variables ◽  
First Time ◽  
Archaeal Communities

Due to the important roles of archaea in wastewater treatment processes, archaeal communities have been studied extensively in various anaerobic reactors, but the knowledge of archaeal communities in full-scale activated sludge wastewater treatment plants (WWTPs) remains quite poor. In this study, 454-pyrosequencing was for the first time employed to investigate archaeal communities from 20 full-scale activated sludge WWTPs distributed at a 3,660-meter elevational scale in China. Results showed that archaeal communities from WWTPs were dominated by Methanosarcinales (84.6%). A core archaeal population (94.5%) composed of Methanosaeta, Methanosarcina, Methanogenium and Methanobrevibacter was shared among WWTPs. The elevational pattern of archaeal communities was observed in WWTPs, with an elevational threshold associated with archaeal community richness and structures at approximately 1,500 meters above sea level (masl). A declining trend in community richness with increasing elevation was observed at higher elevations, whereas no trend was presented at lower elevations. Spearman correlation analysis indicated that the archaeal community richness at higher elevations was associated with more environmental variables than that at lower elevations. Redundancy analysis indicated that wastewater variables were the dominant contributors to the variation of community structures at higher elevations, followed by operational variables and elevation.

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