scholarly journals Enrichment of phosphate-accumulating organisms (PAOs) in a microfluidic model biofilm system by mimicking a typical aerobic granular sludge feast/famine regime

Author(s):  
Edina Klein ◽  
Janek Weiler ◽  
Michael Wagner ◽  
Minja Čelikić ◽  
Christof M. Niemeyer ◽  
...  

Abstract Wastewater treatment using aerobic granular sludge has gained increasing interest due to its advantages compared to conventional activated sludge. The technology allows simultaneous removal of organic carbon, nitrogen, and phosphorus in a single reactor system and is independent of space-intensive settling tanks. However, due to the microscale, an analysis of processes and microbial population along the radius of granules is challenging. Here, we introduce a model system for aerobic granular sludge on a small scale by using a machine-assisted microfluidic cultivation platform. With an implemented logic module that controls solenoid valves, we realized alternating oxic hunger and anoxic feeding phases for the biofilms growing within. Sampling during ongoing anoxic cultivation directly from the cultivation channel was achieved with a robotic sampling device. Analysis of the biofilms was conducted using optical coherence tomography, fluorescence in situ hybridization, and amplicon sequencing. Using this setup, it was possible to significantly enrich the percentage of polyphosphate-accumulating organisms (PAO) belonging to the family Rhodocyclaceae in the community compared to the starting inoculum. With the aid of this miniature model system, it is now possible to investigate the influence of a multitude of process parameters in a highly parallel way to understand and efficiently optimize aerobic granular sludge-based wastewater treatment systems.Key points• Development of a microfluidic model to study EBPR.• Feast-famine regime enriches polyphosphate-accumulating organisms (PAOs).• Microfluidics replace sequencing batch reactors for aerobic granular sludge research.

2019 ◽  
Vol 70 (1) ◽  
pp. 283-285
Author(s):  
Elena Elisabeta Manea ◽  
Costel Bumbac

Increasing the efficiency and capacity of existing wastewater treatment plants can be carried out by using intensive biological processes. One of the currently studied biological solutions consists in using aerobic granular sludge in order to achieve both organics and nutrients removal simultaneously in one tank and with high efficiency. Aerobic granular sludge is currently used at full scale in sequential batch reactors, research for identifying the optimal solutions for continuous flow systems being carried out worldwide. The paper summarizes the results obtained for two continuous flow configurations with aerobic granular sludge, in terms of organics and nutrients removal for synthetic wastewater in laboratory conditions. Both experimental setups led to wastewater treatment efficiencies, with values ranging between 80 and 99% for COD, 85 and 99% for BOD5, 52 and 98% for NH4+ and 5 to 87% for TP.


Author(s):  
Syahira Ibrahim ◽  
Norhaliza Abdul Wahab ◽  
Aznah Nor Anuar ◽  
Mustafa Bob

This paper proposes an improved optimisation of sequencing batch reactors (SBR) for aerobic granular sludge (AGS) at high temperature-low humidity for domestic wastewater treatment using response surface methodology (RSM). The main advantages of RSM are less number of experiment required and suitable for complex process. The sludge from a conventional activated sludge wastewater treatment plant and three sequencing batch reactors (SBRs) were fed with synthetic wastewater. The experiment were carried out at different high temperatures (30, 40 and 50°C) and the formation of AGS for simultaneous organics and nutrients removal were examined in 60 days. RSM is used to model and to optimize the biological parameters for chemical oxygen demand (COD) and total phosphorus removal in SBR system. The simulation results showed that at temperature of 45.33°C give the optimum condition for the total removal of COD and phosphorus, which correspond to performance index R<sup>2</sup> of 0.955 and 0.91, respectively.


2017 ◽  
Vol 68 (8) ◽  
pp. 1723-1725
Author(s):  
Elena Elisabeta Manea ◽  
Costel Bumbac ◽  
Olga Tiron ◽  
Razvan Laurentiu Dinu ◽  
Valeriu Robert Badescu

Using aerobic granular sludge for wastewater treatment has multiple advantages compared to conventional activated sludge systems, most important being the ability of simultaneous removal of the pollutants responsible for eutrophication: organic load, compounds of nitrogen (NH4+; NO3-) and phosphorus (PO43-). The advantages are currently exploited for developing the next generation of wastewater treatment systems while the identified limitations are approached by experimental and theoretical researches worldwide. The aim of the study consists in evaluating the possibility of predicting the system�s response to different changes in the influent wastewater loadings. The paper presents simulations results backed up by experimental data for pollutants removal efficiencies evaluation for a sequential batch reactor (SBR) with aerobic granular sludge. The mathematical model is based on the activated sludge model no. 3, which was updated by considering the simultaneous biological nitrification (NH4+NO3) and denitrification (NO3-N2) processes, thus complying with the biochemical reactions occurring in aerobic granular sludge sequential batch reactors. The model developed was validated by the experimental results obtained on a laboratory scale SBR monitored for over a month.


2021 ◽  
Vol 12 ◽  
Author(s):  
Jannie Munk Kristensen ◽  
Caitlin Singleton ◽  
Lee-Ann Clegg ◽  
Francesca Petriglieri ◽  
Per Halkjaer Nielsen

Microbial communities in water resource recovery facilities encompass a large diversity of poorly characterized lineages that could have undescribed process-critical functions. Recently, it was shown that taxa belonging to “Acidobacteriota” are abundant in Danish full-scale activated sludge wastewater treatment plants (WWTP), and here we investigated their diversity, distribution, and functional potential. “Acidobacteriota” taxa were identified using a comprehensive full-length 16S rRNA gene reference dataset and amplicon sequencing surveys across 37 WWTPs. Members of this phylum were diverse, belonging to 14 families, eight of which are completely uncharacterized and lack type strains. Several lineages were abundant, with relative abundances of up to 5% of the microbial community. Genome annotation and metabolic reconstruction of 50 high-quality “Acidobacteriota” metagenome-assembled genomes (MAGs) from 19 WWTPs showed high metabolic diversity and potential involvement in nitrogen and phosphorus removal and iron reduction. Fluorescence in situ hybridization (FISH) using newly-designed probes revealed cells with diverse morphologies, predominantly located inside activated sludge flocs. FISH in combination with Raman microspectroscopy revealed ecophysiological traits in probe-defined cells from the families Holophagaceae, Thermoanaerobaculaceae, and Vicinamibacteraceae, and families with the placeholder name of midas_f_502, midas_f_973, and midas_f_1548. Members of these lineages had the potential to be polyphosphate-accumulating organisms (PAOs) as intracellular storage was observed for the key compounds polyphosphate and glycogen.


2014 ◽  
Vol 54 ◽  
pp. 337-346 ◽  
Author(s):  
Adriana Maria Lotito ◽  
Marco De Sanctis ◽  
Claudio Di Iaconi ◽  
Giovanni Bergna

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