Improved Method of Activated Sludge Biomass Determination

1994 ◽  
Vol 29 (7) ◽  
pp. 7-13 ◽  
Author(s):  
M. Liebeskind ◽  
M. Dohmann
Keyword(s):  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Biomass Estimation ◽  
Acid Extraction ◽  
Calibration Data ◽  
Colour Reaction ◽  
Reproducible Method ◽  
Unknown Composition ◽  
Biomass Determination

With the development of kinetic models and new design criteria for activated sludge systems, biomass determination becomes important. Various methods can be used to estimate the amount of biomass. Most of these methods are only applicable to pure culture studies. The activated sludge of wastewater treatment plants contains not only biomass, but also a high content of dead organic and inorganic material of unknown composition. Distinguishing between these sludge constituents is difficult. The best and most reproducible method for biomass estimation is often described as the determination of DNA content. This method includes the acid extraction of DNA, the quantitative determination of deoxyribose sugar by a colour reaction with diphenylamine, the calibration with standard DNA and the mathematical conversion into biomass. This study shows that the conventional method is strongly affected by unknown activated sludge constituents and in particular iron. The interference can be overcome by EDTA treatment. Inconsistencies in published calibration data are overcome.

scholarly journals Quantification of nosZ genes and transcripts in activated sludge microbiomes with novel group-specific qPCR methods validated with metagenomic analyses

2019 ◽  
Author(s):  
DaeHyun D. Kim ◽  
Doyoung Park ◽  
Hyun Yoon ◽  
Taeho Yun ◽  
Min Joon Song ◽  
...  
Keyword(s):  
Activated Sludge ◽  
De Novo ◽  
Wastewater Treatment Plants ◽  
Batch Reactor ◽  
Amino Acid Sequences ◽  
Sewage Sample ◽  
Metagenome Analysis ◽  
Continuous Stream ◽  
Reliable Quantification

AbstractSubstantial N2O emission results from activated sludge nitrogen removal processes. The importance of N2O-reducers possessing NosZ-type N2O reductases have been recognized as the only N2O sink in situ key to determination of the net N2O emissions; however, reliable quantification methods for nosZ genes and transcripts have yet to be developed. Here, nosZ genes and transcripts in activated sludge tank microbiomes were analyzed with the group-specific qPCR assays designed de novo combining culture-based and computational approach. A sewage sample was enriched in a batch reactor fed continuous stream of N2 containing 20-10,000 ppmv N2O, where 14 genera of potential N2O-reducers were identified. All available amino acid sequences of NosZ affiliated to these taxa were grouped into five subgroups (two clade I and three clade II groups), and primer/probe sets exclusively and comprehensively targeting the subgroups were designed and validated with in silico PCR. Four distinct activated sludge samples from three different wastewater treatment plants in Korea were analyzed with the qPCR assays and the results were validated by comparison with the shotgun metagenome analysis results. With the validated qPCR assays, the nosZ genes and transcripts of six additional activated sludge samples were analyzed and the results of the analyses clearly indicated the dominance of two clade II nosZ subgroups (Flavobacterium-like and Dechloromonas-like) among both nosZ gene and transcript pools.

scholarly journals In situ continuous monitoring of nitrogen with ion-selective electrodes in a constructed wetland receiving treated wastewater: an operating protocol to obtain reliable data

2018 ◽  
Vol 77 (6) ◽  
pp. 1706-1713 ◽  
Author(s):  
Sandrine Papias ◽  
Matthieu Masson ◽  
Sébastien Pelletant ◽  
Stéphanie Prost-Boucle ◽  
Catherine Boutin
Keyword(s):  
Continuous Monitoring ◽  
Wastewater Treatment Plants ◽  
Treated Wastewater ◽  
Ion Selective Electrodes ◽  
Calibration Data ◽  
Effluent Quality ◽  
Evaluation Of Performance ◽  
Real Performance

Abstract Constructed wetlands receiving treated wastewater (CWtw) are placed between wastewater treatment plants and receiving water bodies, under the perception that they increase water quality. A better understanding of the CWtw functioning is required to evaluate their real performance. To achieve this, in situ continuous monitoring of nitrate and ammonium concentrations with ion-selective electrodes (ISEs) can provide valuable information. However, this measurement needs precautions to be taken to produce good data quality, especially in areas with high effluent quality requirements. In order to study the functioning of a CWtw instrumented with six ISE probes, we have developed an appropriate methodology for probe management and data processing. It is based on an evaluation of performance in the laboratory and an adapted field protocol for calibration, data treatment and validation. The result is an operating protocol concerning an acceptable cleaning frequency of 2 weeks, a complementary calibration using CWtw water, a drift evaluation and the determination of limits of quantification (1 mgN/L for ammonium and 0.5 mgN/L for nitrate). An example of a 9-month validated dataset confirms that it is fundamental to include the technical limitations of the measuring equipment and set appropriate maintenance and calibration methodologies in order to ensure an accurate interpretation of data.

Application of ionic liquids for the removal of heavy metals from wastewater and activated sludge

2012 ◽  
Vol 65 (10) ◽  
pp. 1765-1773 ◽  
Author(s):  
Maria Fuerhacker ◽  
Tadele Measho Haile ◽  
Daniel Kogelnig ◽  
Anja Stojanovic ◽  
Bernhard Keppler
Keyword(s):  
Heavy Metals ◽  
Ionic Liquids ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Industrial Effluents ◽  
Acid Extraction ◽  
Removal Of Heavy Metals ◽  
A New Technique ◽  
Wastewater Samples ◽  
Standard Solutions

This paper presents the results of adsorption studies on the removal of heavy metals (Cr, Cu, Cd, Ni, Pb and Zn) from standard solutions, real wastewater samples and activated sewage sludge using a new technique of liquid–liquid extraction using quaternary ammonium and phosphonium ionic liquids (ILs). Batch sorption experiments were conducted using the ILs [PR4][TS], [PR4][MTBA], [A336][TS] and [A336][MTBA]. Removal of these heavy metals from standard solutions were not effective, however removal of heavy metals from the industrial effluents/wastewater treatment plants were satisfactory, indicating that the removal depends mainly on the composition of the wastewater and cannot be predicted with standard solutions. Removal of heavy metals from activated sludge proved to be more successful than conventional methods such as incineration, acid extraction, thermal treatment, etc. For the heavy metals Cu, Ni and Zn, ≥90% removal was achieved.

Respirometry for determination of the influents SS-concentration

1996 ◽  
Vol 33 (1) ◽  
pp. 311-323 ◽  
Author(s):  
A. Witteborg ◽  
A. van der Last ◽  
R. Hamming ◽  
I. Hemmers
Keyword(s):  
Experimental Design ◽  
Activated Sludge ◽  
Substrate Concentration ◽  
Full Scale ◽  
Activated Sludge Process ◽  
Respiration Rates ◽  
On Line ◽  
Large Measurement ◽  
Set Up

A method is presented for determining influent readily biodegradable substrate concentration (SS). The method is based on three different respiration rates, which can be measured with a continuous respiration meter which is operated in a cyclic way. Within the respiration meter nitrification is inhibited through the addition of ATU. Simulations were used to develop the respirometry set-up and decide upon the experimental design. The method was tested as part of a large measurement programme executed at a full-scale plant. The proposed respirometry set-up has been shown to be suitable for a semi-on-line determination of an influent SS which is fully based on the IAWQ #1 vision of the activated sludge process. The YH and the KS play a major role in the principle, and should be measured directly from the process.

Quantification of the kinetic differences between communities isolated from completely mixed activated sludge systems operated with or without a selector using a novel respirometric method

1994 ◽  
Vol 30 (11) ◽  
pp. 255-261 ◽  
Author(s):  
Barth F. Smets ◽  
Timothy G. Ellis ◽  
Stephanie Brau ◽  
Richard W. Sanders ◽  
C. P. Leslie Grady
Keyword(s):  
Oxygen Consumption ◽  
Activated Sludge ◽  
Physiological Changes ◽  
Biodegradation Kinetics ◽  
Substrate Removal ◽  
Biomass Yields ◽  
Selection For ◽  
Single Oxygen ◽  
Activated Sludge Systems

This study quantified the kinetic differences in microbial communities isolated from completely mixed activated sludge (CMAS) systems that were operated either with or without an aerobic selector preceding the main reactor. A new respirometric method was employed that allowed the determination of biodegradation kinetics from single oxygen consumption curves, thereby minimizing physiological changes to the examined communities during the assay. Results indicated that increased values for Ks and μmax for acetate, phenol, and 4-chlorophenol degradation were measured in the CMAS system operated with a selector. The biomass yields on acetate, phenol, and 4-chlorophenol were very similar in both systems. These findings indicate that the operation of CMAS systems with aerobic selectors may result in the selection for degrading populations with higher Ks and μmax values for both biogenic and xenobiotic organic compounds, and that substrate storage in the selector only partially contributes to increased substrate removal rates.

Urban Wastewater Discharge and Bacteriological Quality of Receiving Coastal Waters: Processes and Modelling

1993 ◽  
Vol 27 (12) ◽  
pp. 223-226
Author(s):  
J.-F. Guillaud ◽  
M. Pommepuy ◽  
E. Dupray ◽  
J.-C. Salomon ◽  
B. Thouvenin
Keyword(s):  
Coastal Zone ◽  
Coastal Waters ◽  
Wastewater Treatment Plants ◽  
Enteric Bacteria ◽  
Wastewater Discharge ◽  
Urban Wastewater ◽  
Bacteria Transport

The aim of this paper is to present some results of bacterial studies which were developed by IFREMER in coastal discharge areas of urban wastewaters; they are focused on the determination of bacterial inputs by wastewater treatment plants, the role of environmental factors on the enteric bacteria survival in the coastal zone, and the modelling of bacteria transport and disappearance in order to provide useful management information for minimizing faecal pollution in the coastal zone.

Operational Determination of the Activated Sludge Process Using Neural Networks

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2461-2464 ◽  
Author(s):  
R. D. Tyagi ◽  
Y. G. Du
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Steady State ◽  
Activated Sludge ◽  
Feedforward Neural Network ◽  
Training Data ◽  
Activated Sludge Process

A steady-statemathematical model of an activated sludgeprocess with a secondary settler was developed. With a limited number of training data samples obtained from the simulation at steady state, a feedforward neural network was established which exhibits an excellent capability for the operational prediction and determination.

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