Triclosan in contact with activated sludge and its impact on phosphate removal and microbial community

Enhanced biological phosphorus removal (EBPR) activated sludge was operated in a laboratory-scale sequencing batch reactor (SBR) fed with acetate as the sole carbon source. The microbial community of the sludge was analyzed using the polymerase chain reaction (PCR) – denaturing gradient gel electrophoresis (DGGE) method for about 2 months of start-up period. As a result, the number of major bands decreased during the enrichment, indicating that the microbial community structure was getting simpler. Since the phosphate removal activity was maintained at a high level, the bacteria which still remained at the end can be considered as the important bacteria playing key roles in the present EBPR sludge, maybe polyphosphate accumulating organisms (PAOs). The dominant band in the last sample on the DGGE gel was excised and the DNA recovered from it was sequenced. The sequence was closely related to one of the putative PAOs group which Crocetti et al. (2000) and Hesselmann et al. (1999) have proposed. This PAOs group is closely related to the Rhodocyclus group (b-Proteobacteria). The fluorescence in situ hybridization (FISH) method with the probe specific for this PAOs group and the DAPI staining at a phosphate-probing concentration indirectly showed that these Rhodocyclus related bacteria really accumulated polyphosphate.

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Operational Results of the Wolfsburg Wastewater Treatment Plant

Water Science & Technology ◽

10.2166/wst.1992.0496 ◽

1992 ◽

Vol 25 (4-5) ◽

pp. 203-209 ◽

Cited By ~ 7

Author(s):

R. Kayser ◽

G. Stobbe ◽

M. Werner

Keyword(s):

Wastewater Treatment ◽

Activated Sludge ◽

Nitrogen Content ◽

Total Nitrogen ◽

Nitrogen Removal ◽

Wastewater Treatment Plant ◽

Treatment Plant ◽

Phosphate Removal ◽

Total Nitrogen Content ◽

Activated Sludge Process

At Wolfsburg for a load of 100,000 p.e., the step-feed activated sludge process for nitrogen removal is successfully in operation. Due to the high denitrification potential (BOD:TKN = 5:1) the effluent total nitrogen content can be kept below 10 mg l−1 N; furthermore by some enhanced biological phosphate removal about 80% phosphorus may be removed without any chemicals.

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The diversity of active microbial groups in an activated sludge process treating painting process wastewater

E3S Web of Conferences ◽

10.1051/e3sconf/202014801002 ◽

2020 ◽

Vol 148 ◽

pp. 01002

Author(s):

Herto Dwi Ariesyady ◽

Mentari Rizki Mayanda ◽

Tsukasa Ito

Keyword(s):

Wastewater Treatment ◽

Microbial Community ◽

16S Rrna ◽

16S Rrna Gene ◽

Activated Sludge ◽

Biological Treatment ◽

Rrna Gene ◽

Activated Sludge Process ◽

Painting Process ◽

Process Wastewater

Activated sludge process is one of the wastewater treatment method that is applied for many wastewater types including painting process wastewater of automotive industry. This wastewater is well-known to have high heavy metals concentration which could deteriorate water environment if appropriate performance of the wastewater treatment could not be achieved. In this study, we monitored microbial community diversity in a Painting Biological Treatment (PBT) system. We applied a combination of cultivation and genotypic biological methods based on 16S rRNA gene sequence analysis to identify the diversity of active microbial community. The results showed that active microbes that could grow in this activated sludge system were dominated by Gram-negative bacteria. Based on 16S rRNA gene sequencing analysis, it was revealed that their microbial diversity has close association with Bacterium strain E286, Isosphaera pallida, Lycinibacillus fusiformis, Microbacterium sp., Orchobactrum sp., Pseudomonas guariconensis, Pseudomonas sp. strain MR84, Pseudomonas sp. MC 54, Serpens sp., Stenotrophomonas acidaminiphila, and Xylella fastidiosa with similarity of 86 – 99%. This findings reflects that microbial community in a Painting Biological Treatment (PBT) system using activated sludge process could adapt with xenobiotics in the wastewater and has a wide range of diversity indicating a complex metabolism mechanism in the treatment process.

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Do initial concentration and activated sludge seasonality affect pharmaceutical biotransformation rate constants?

Applied Microbiology and Biotechnology ◽

10.1007/s00253-021-11475-9 ◽

2021 ◽

Author(s):

Tamara J. H. M. van Bergen ◽

Ana B. Rios-Miguel ◽

Tom M. Nolte ◽

Ad M. J. Ragas ◽

Rosalie van Zelm ◽

...

Keyword(s):

Microbial Community ◽

Activated Sludge ◽

Community Composition ◽

Rate Constants ◽

Wastewater Treatment Plants ◽

Microbial Community Composition ◽

Amplicon Sequencing ◽

Rrna Gene ◽

Initial Concentration ◽

Different Seasons

Abstract Pharmaceuticals find their way to the aquatic environment via wastewater treatment plants (WWTPs). Biotransformation plays an important role in mitigating environmental risks; however, a mechanistic understanding of involved processes is limited. The aim of this study was to evaluate potential relationships between first-order biotransformation rate constants (kb) of nine pharmaceuticals and initial concentration of the selected compounds, and sampling season of the used activated sludge inocula. Four-day bottle experiments were performed with activated sludge from WWTP Groesbeek (The Netherlands) of two different seasons, summer and winter, spiked with two environmentally relevant concentrations (3 and 30 nM) of pharmaceuticals. Concentrations of the compounds were measured by LC–MS/MS, microbial community composition was assessed by 16S rRNA gene amplicon sequencing, and kb values were calculated. The biodegradable pharmaceuticals were acetaminophen, metformin, metoprolol, terbutaline, and phenazone (ranked from high to low biotransformation rates). Carbamazepine, diatrizoic acid, diclofenac, and fluoxetine were not converted. Summer and winter inocula did not show significant differences in microbial community composition, but resulted in a slightly different kb for some pharmaceuticals. Likely microbial activity was responsible instead of community composition. In the same inoculum, different kb values were measured, depending on initial concentration. In general, biodegradable compounds had a higher kb when the initial concentration was higher. This demonstrates that Michealis-Menten kinetic theory has shortcomings for some pharmaceuticals at low, environmentally relevant concentrations and that the pharmaceutical concentration should be taken into account when measuring the kb in order to reliably predict the fate of pharmaceuticals in the WWTP. Key points • Biotransformation and sorption of pharmaceuticals were assessed in activated sludge. • Higher initial concentrations resulted in higher biotransformation rate constants for biodegradable pharmaceuticals. • Summer and winter inocula produced slightly different biotransformation rate constants although microbial community composition did not significantly change. Graphical abstract

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