An evaluation of full-scale activated sludge dynamics using microbial fatty acid analysis

2006 ◽  
Vol 54 (1) ◽  
pp. 11-19 ◽  
Author(s):  
A.G. Werker

Patterns of microbial fatty acids (MFAs) from activated sludge samples were analyzed over one year's operation at the Hamilton Woodward municipal wastewater treatment plant in Canada. The objective was to examine community structure dynamics and to consider the potential for interrelationships between the population dynamics and treatment performance. With the exception of a higher than normal solids discharge on one day, the treatment plant operations were otherwise stable during the year. As such, wastewater temperature appeared to be the dominant influence on the observed dynamics of the MFA community structure. MFA monitoring and analysis was demonstrated as a practical diagnostic tool in community structure trend monitoring. While the findings did suggest potential for full-scale treatment process monitoring, further development is required. Advancement in technique and greater insight for the data interpretation will be made with historical data from continued case studies. In future studies, selective sub-sampling of biomass fractions (settling and dispersed fauna), evolution in the compositional analysis methods, and, ideally, complementary genotypic and classical microscopic analyses on select samples are recommended.

2018 ◽  
Vol 78 (11) ◽  
pp. 2256-2269 ◽  
Author(s):  
Alan Werker ◽  
Simon Bengtsson ◽  
Leon Korving ◽  
Markus Hjort ◽  
Simon Anterrieu ◽  
...  

Abstract Production of polyhydroxyalkanoate (PHA) biopolymers by mixed microbial cultures concurrent to wastewater treatment is a valorization route for residual organic material. This development has been at pilot scale since 2011 using industrial and municipal organic residuals. Previous experience was the basis for a PHA production demonstration project: PHARIO. PHARIO was centred on processing surplus activated sludge biomass from the Bath full-scale municipal wastewater treatment plant in the Netherlands to produce PHA. Full-scale surplus activated sludge was fed to a pilot facility to produce PHA rich biomass using fermented volatile fatty acid (VFA) rich liquors from industry or primary sludge sources. A PHA rich biomass with on average 0.41 gPHA/gVSS was obtained with reproducible thermal properties and high thermal stability. A routine kilogram scale production was established over 10 months and the polymer material properties and market potential were evaluated. Surplus full-scale activated sludge, over four seasons of operations, was a reliable raw material to consistently and predictably produce commercial quality grades of PHA. Polymer type and properties were systematic functions of the mean co-polymer content. The mean co-polymer content was predictably determined by the fermented feedstock composition. PHARIO polymers were estimated to have a significantly lower environmental impact compared to currently available (bio)plastics.


2016 ◽  
Vol 7 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Abdelsalam Elawwad ◽  
Mohamed Zaghloul ◽  
Hisham Abdel-Halim

In developing countries, and due to the high cost of treatment of industrial wastewater, municipal wastewater treatment facilities usually receive a mixture of municipal wastewater and partially treated industrial wastewater. As a result, an increased potential for shock loads with high pollutant concentrations is expected. The use of mathematical modelling of wastewater treatment is highly efficient in such cases. A dynamic model based on activated sludge model no. 3 (ASM3) describing the performance of the activated sludge process at a full scale wastewater treatment plant (WWTP) receiving mixed domestic–industrial wastewater located in an arid area is presented. ASM3 was extended by adding the Arrhenius equation to respond to changes in temperature. BioWin software V.4 was used as the model platform. The model was calibrated under steady-state conditions, adjusting only three kinetic and stoichiometric parameters: maximum heterotrophic growth rate (μH = 8 d−1), heterotrophic aerobic decay rate (bH, O2 = 0.18 d−1), and aerobic heterotrophic yield (YH,O2 = 0.4 (gCOD/gCOD)). ASM3 was successful in predicting the WWTP performance, as the model was validated with 10 months of routine daily measurements. ASM3 extended with the Arrhenius equation could be helpful in the design and operation of WWTPs with mixed municipal–industrial influent in arid areas.


Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 527
Author(s):  
Mengmeng Liu ◽  
Meixue Chen ◽  
Rong Qi ◽  
Dawei Yu ◽  
Min Yang ◽  
...  

Aiming at providing cost-effective approach for upgrading the existing municipal wastewater treatment plants in the cold region of China to meet more stringent discharge standards of nitrogen removal, a full-scale sewage treatment plant with the CASS process was selected through focusing on biological process, key equipment and hydrodynamics in bioreactors by the activated sludge model 1 (ASM1) and computational fluid dynamics (CFD) model. Influent COD fractions and the key characteristic parameters (YH and bH) of the activated sludge were determined through the respirometry at temperatures of 10 °C and 20 °C, respectively. The layout of submerged agitator installation in the bioreactor of the CASS process was optimized through CFD simulation. The calculation of the average relative deviation (less than 20%) between simulated data and the operation data, demonstrated that the ASM1 model could be reasonably used in the wastewater treatment plant simulation. The upgrade solution based on modelling of ASM1 and CFD was successfully applied in practice, which not only made the effluent COD, NH4+-N and TN concentrations meet with the discharge standard of Grade I-A, but also reduced the energy consumption by 25% and 16.67% in summer and winter, respectively. After upgrading, microbial diversity increased in both summer and winter, with an especially significant increase of the relative abundance of denitrifying bacteria.


2007 ◽  
Vol 73 (6) ◽  
pp. 1952-1960 ◽  
Author(s):  
A. Schlüter ◽  
R. Szczepanowski ◽  
N. Kurz ◽  
S. Schneiker ◽  
I. Krahn ◽  
...  

ABSTRACT The erythromycin resistance plasmid pRSB105 was previously isolated from an activated sludge bacterial community of a municipal wastewater treatment plant. Compilation of the complete pRSB105 nucleotide sequence revealed that the plasmid is 57,137 bp in size and has a mean G+C content of 56.66 mol%. The pRSB105 backbone is composed of two different replication and/or partitioning modules and a functional mobilization region encoding the mobilization genes mobCDE and mobBA. The first replicon (Rep1) is nearly identical to the corresponding replication module of the multiresistance plasmid pRSB101 isolated from an unknown activated sludge bacterium. Accordingly, pRSB101 and pRSB105 are sister plasmids belonging to a new plasmid family. The second replicon (Rep2) of pRSB105 was classified as a member of the IncP-6 group. While Rep1 confers replication ability only in γ-proteobacteria, Rep2 extents the host range of the plasmid since it is also functional in the β-proteobacterium Ralstonia eutropha. Plasmid pRSB105 harbors the macrolide resistance genes mel and mph, encoding, respectively, a predicted ABC-type efflux permease and a macrolide-2′-phosphotransferase. Erythromycin resistance is mainly attributed to mel, whereas mph contributes to erythromycin resistance to a lesser extent. The second resistance region, represented by an integron-containing Tn402-like element, includes a β-lactam (oxa10) and a trimethoprim (dfrB2) resistance gene cassette. In addition to antibiotic resistance modules, pRSB105 encodes a functional restriction/modification system and two nonresistance regions of unknown function. The presence of different mobile genetic elements that flank resistance and nonresistance modules on pRSB105 indicates that these elements were involved in acquisition of accessory plasmid modules. Comparative genomics of pRSB105 and related plasmids elucidated that pRSB105 evolved by integration of distinct modules from different plasmid sources, including Pseudomonas aeruginosa plasmids, and thus represents a mosaic plasmid.


1992 ◽  
Vol 25 (6) ◽  
pp. 167-183 ◽  
Author(s):  
H. Siegrist ◽  
M. Tschui

The wastewater of the municipal treatment plants Zürich-Werdhölzli (350000 population equivalents), Zürich-Glatt (110000), and Wattwil (20000) have been characterized with regard to the activated sludge model Nr.1 of the IAWPRC task group. Zürich-Glatt and Wattwil are partly nitrifying treatment plants and Zürich-Werdhölzli is fully nitrifying. The mixing characteristics of the aeration tanks at Werdhölzli and Glatt were determined with sodium bromide as a tracer. The experimental data were used to calibrate hydrolysis, heterotrophic growth and nitrification. Problems arising by calibrating hydrolysis of the paniculate material and by measuring oxygen consumption of heterotrophic and nitrifying microorganisms are discussed. For hydrolysis the experimental data indicate first-order kinetics. For nitrification a maximum growth rate of 0.40±0.07 d−1, corresponding to an observed growth rate of 0.26±0.04 d−1 was calculated at 10°C. The half velocity constant found for 12 and 20°C was 2 mg NH4-N/l. The calibrated model was verified with experimental dam of me Zürich-Werdhölzli treatment plant during ammonia shock load.


2003 ◽  
Vol 48 (8) ◽  
pp. 9-18 ◽  
Author(s):  
C. Fux ◽  
K. Lange ◽  
A. Faessler ◽  
P. Huber ◽  
B. Grueniger ◽  
...  

Separate biological elimination of nitrogen from the digester supernatant of a municipal wastewater treatment plant (WWTP) was investigated in pilot and full-scale plants. Denitrification mainly via nitrite was achieved in a sequencing batch reactor (SBR) and a continuous flow reactor (CSTR or SHARON). Suppression of nitrite oxidation in the SBR was feasible at short aerobic/anaerobic intervals allowing for immediate denitrification of the produced nitrite. Nitrate production could also be stopped by exposing the biomass to anaerobic conditions for 11 days. Temporarily high concentrations (up to 80 gNH3-Nm-3) of free ammonia could not be considered as the major reason for inhibiting nitrite oxidation. In a full-scale SBR plant 90% of the nitrogen load was denitrified in a total hydraulic retention time (HRT) of 1.6 days and with a sludge age between 15 and 20 days. Ethanol and methanol were used for denitrification. The specific average substrate consumption was 2.2 gCODdosedg-1Nremoved with an effective biomass yield of 0.2 gCODbiomassg-1CODdosed. No dosing with base was required. In the SHARON process full nitrogen elimination was achieved only with a total HRT greater than 4 days at 29°C. The overall costs were estimated at €1.4 kg-1Nremoved for the SBR and €1.63 kg-1Nremoved in SHARON mode, respectively. The SHARON process is simple in operation (CSTR) but the tank volume has to be significantly greater than in SBR.


Sign in / Sign up

Export Citation Format

Share Document