scholarly journals Denitrification Process Enhancement and Diversity of the Denitrifying Community in the Full Scale Activated Sludge System after Adaptation to Fusel Oil

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5225
Author(s):  
Przemysław Kowal ◽  
Sławomir Ciesielski ◽  
Jeremiah Otieno ◽  
Joanna Barbara Majtacz ◽  
Krzysztof Czerwionka ◽  
...  
Keyword(s):  
Community Structure ◽  
Carbon Source ◽  
Bacterial Community ◽  
Activated Sludge ◽  
Bacterial Community Structure ◽  
Experimental Period ◽  
Process Rate ◽  
Fusel Oil ◽  
Operational Costs ◽  
Denitrification Process

Implementation of anaerobic digestion of primary sludge in modern wastewater treatment plants (WWTPs) limits the availability of organic carbon for denitrification in conventional nitrification-denitrification (N/DN) systems. In order to ensure efficient denitrification, dosage of the external carbon source is commonly undertaken. However, application of commercial products, such us ethanol or acetate, greatly increases operational costs. As such, inexpensive and efficient alternative carbon sources are strongly desirable. In this study, the use of the fusel oil, a by-product from the distillery industry, was validated in terms of the denitrification process enhancement and impact on the activated sludge bacterial community structure. The experiment was conducted at a full scale biological nutrient removal facility (210,000 PE), in the set of the two technological lines: the experimental line (where fusel oil was introduced at 45 cm3/m3 dose) and the reference line (without an external carbon source addition). During the experimental period of 98 days, conventional nitrate utilization rate (NUR) measurements were carried out on a regular basis in order to assess the biomass adaptation to the fusel oil addition and denitrification process enhancement. While the NURs remained at a stable level in the reference line (1.4 ± 0.1 mg NO3-N/g VSS·h) throughout the entire duration of the experiment, the addition of fusel oil gradually enhanced the denitrification process rate up to 2.7 mg NO3-N/g VSS·h. Moreover, fusel oil contributed to the mitigation of the variability of NO3-N concentrations in the effluent from the anoxic zone. The bacterial community structure, characterized by 16S rRNA PCR—DGGE and the clone libraries of the genes involved in the denitrification process (nirS and nirK), was comparable between the reference and the experimental line during the entire experimental period. In both analyzed lines, the most frequent occurrence of denitrifiers belonging to the genera Acidovorax, Alcaligenes, Azoarcus, Paracoccus and Thauera was noticed. Our results proved that fusel oil would a valuable substrate for denitrification. The addition of fusel oil enhances the process rate and does not reflect a severe selection pressure on the bacterial community at applicable doses. Practical application of fusel oil generates opportunities for the WWTPs to meet effluent standards and reduce operational costs, as well as optimizing waste management for the distillery industry.

scholarly journals Influence of Diclofenac on Activated Sludge Bacterial Communities in Fed-Batch Reactors

2020 ◽  
Vol 58 (4) ◽  
Author(s):  
Barbara Kraigher ◽  
Ines Mandic-Mulec
Keyword(s):  
Community Structure ◽  
Carbon Source ◽  
Bacterial Community ◽  
Activated Sludge ◽  
Bacterial Community Structure ◽  
Batch Reactors ◽  
Fed Batch ◽  
Nitrification Activity ◽  
Community Profiling ◽  
Taxonomic Affiliation

Research background. The occurrence and environmental toxicity of pharmaceuticals have recently attracted increasing attention. Diclofenac is a highly consumed non-steroidal anti-inflammatory drug, which is often detected in wastewaters, but investigations of its influence on bacteria are scarce. Experimental approach. We investigated the influence of this pharmaceutical on bacterial community in activated sludge exposed to increasing concentrations of diclofenac in fed-batch reactors over 41 days. Nitrification activity of the activated sludge was measured and changes in bacterial community structure were followed using culture-independent molecular method (terminal restriction fragment length polymorphism, T-RFLP) and by the cultivation approach. Results and conclusions. Nitrification activity was not detectably influenced by addition of diclofenac, while the main change of the bacterial community structure was detected only at the end of incubation (after 41 days) when diclofenac was added to artificial wastewater as the only carbon source. Changes in community composition due to enrichment were also observed using cultivation approach. However, taxonomic affiliation of isolates did not match taxons identified by T-RFLP community profiling. Isolates obtained from inoculum activated sludge belonged to five genera: Comamonas, Arthrobacter, Acinetobacter, Citrobacter and Aeromonas, known for their potential to degrade aromatic compounds. However, only Pseudomonas species were isolated after the last enrichment step on minimal agar plates with diclofenac added as the sole carbon source. Novelty and scientific contribution. Our results suggested that the selected recalcitrant and commonly detected pharmaceutical does not strongly influence the sensitive and important nitrification process of wastewater treatment neither. Moreover, the isolated strains obtained after enrichment procedure that were able to grow on minimal agar plates with diclofenac added as the only carbon source could serve as potential model bacteria to study bacterial diclofenac degradation.

The effects of ibuprofen on activated sludge: Shift in bacterial community structure and resistance to ciprofloxacin

2017 ◽  
Vol 340 ◽  
pp. 291-299 ◽  
Author(s):  
Madars Davids ◽  
Dita Gudra ◽  
Ilze Radovica-Spalvina ◽  
Davids Fridmanis ◽  
Vadims Bartkevics ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Activated Sludge ◽  
Bacterial Community Structure

Assessment and characterization of the bacterial community structure in advanced activated sludge systems

2019 ◽  
Vol 282 ◽  
pp. 254-261 ◽  
Author(s):  
Paolo Cinà ◽  
Giovanni Bacci ◽  
Walter Arancio ◽  
Giuseppe Gallo ◽  
Renato Fani ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Activated Sludge ◽  
Bacterial Community Structure ◽  
Activated Sludge Systems

scholarly journals Analysis of Bacterial Community Structure of Activated Sludge from Wastewater Treatment Plants in Winter

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Shuang Xu ◽  
Junqin Yao ◽  
Meihaguli Ainiwaer ◽  
Ying Hong ◽  
Yanjiang Zhang
Keyword(s):  
Wastewater Treatment ◽  
Community Structure ◽  
Bacterial Community ◽  
Activated Sludge ◽  
Bacterial Community Structure ◽  
Redundancy Analysis ◽  
Wastewater Treatment Plants ◽  
Effluent Treatment ◽  
Autonomous Region ◽  
Sludge Bulking

Activated sludge bulking is easily caused in winter, resulting in adverse effects on effluent treatment and management of wastewater treatment plants. In this study, activated sludge samples were collected from different wastewater treatment plants in the northern Xinjiang Uygur Autonomous Region of China in winter. The bacterial community compositions and diversities of activated sludge were analyzed to identify the bacteria that cause bulking of activated sludge. The sequencing generated 30087–55170 effective reads representing 36 phyla, 293 families, and 579 genera in all samples. The dominant phyla present in all activated sludge were Proteobacteria (26.7–48.9%), Bacteroidetes (19.3–37.3%), Chloroflexi (2.9–17.1%), and Acidobacteria (1.5–13.8%). Fifty-five genera including unclassified_f_Comamonadaceae, norank_f_Saprospiraceae, Flavobacterium, norank_f_Hydrogenophilaceae, Dokdonella, Terrimonas, norank_f_Anaerolineaceae, Tetrasphaera, Simplicispira, norank_c_Ardenticatenia, and Nitrospira existed in all samples, accounting for 60.6–82.7% of total effective sequences in each sample. The relative abundances of Saprospiraceae, Flavobacterium, and Tetrasphaera with the respective averages of 12.0%, 8.3%, and 5.2% in bulking sludge samples were higher than those in normal samples. Filamentous Saprospiraceae, Flavobacterium, and Tetrasphaera multiplied were the main cause for the sludge bulking. Redundancy analysis (RDA) indicated that influent BOD5, DO, water temperature, and influent ammonia had a distinct effect on bacterial community structures.

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