Implementation of glycogen accumulating bacteria in treating nutrient-deficient wastewater

2002 ◽  
Vol 46 (1-2) ◽  
pp. 185-190 ◽  
Author(s):  
A. Jobbágy ◽  
B. Literáthy ◽  
G. Tardy
Keyword(s):  
Activated Sludge ◽  
Analytical Data ◽  
Carbon Sources ◽  
Experimental System ◽  
Full Scale ◽  
Extracellular Polysaccharides ◽  
Excess Carbon ◽  
Biomass Structure ◽  
Scale Experiment ◽  
Activated Sludge Systems

Activated sludge treatment of nutrient-deficient wastes may lead to severe slime formation and consequent biomass separation difficulties. The purpose of this paper has been to show that bioreactor arrangement essentially influences the manner of biological excess carbon removal. In a comparative lab-scale experiment two differently arranged activated sludge systems were operated simultaneously: an aerated CSTR with an aerobic selector and an aerated CSTR with an anaerobic selector. The seed derived from an anaerobic/aerobic activated sludge plant of a winery. The model wastewater contained wine, sugar and acetic acid as organic carbon sources and lacked nutrients regarding both N and P, similarly to the influent of the full-scale plant. During the 52 days of the experiment the SVI values of the fully aerated system increased up to 600–800 cm3 g−1 whereas those of the anaerobic/aerobic system remained below 250 cm3 g−1. The SVI values showed a strict correlation with the amount of extracellular polysaccharides. In the anaerobic/aerobic experimental system, the high (40% of MLSS) intracellular polysaccharide content of the seed could be maintained. Besides the analytical data, also the microscopic observations of the biomass structure referred to the presence of glycogen accumulating organisms in both the lab- and full-scale anaerobic/aerobic systems.

scholarly journals SEM-EDS for determining the phosphorus content in activated sludge EPS

2001 ◽  
Vol 43 (6) ◽  
pp. 105-112 ◽  
Author(s):  
D. J. Oosthuizen ◽  
T. E. Cloete
Keyword(s):  
Activated Sludge ◽  
Energy Dispersive Spectrometry ◽  
Extracellular Polysaccharides ◽  
In Situ Characterization ◽  
Cell Clusters ◽  
Polyphosphate Accumulating Organisms ◽  
Shed Light ◽  
Activated Sludge Systems

Not all phosphorus removed in activated sludge systems can be accounted for by polyphosphate accumulating organisms (PAO). A method for the qualitative and quantitative in situ characterization of PAO cell clusters and closely associated extracellular polysaccharides (EPS) is described. X-ray microanalysis was performed on samples from four activated sludge plants situated in Pretoria, South Africa. Analyses were done by means of Scanning Electron Microscopy (SEM) combined with Energy Dispersive Spectrometry (EDS). Cell clusters with associated EPS on average contained between 57 and 59% phosphorus, while EPS alone contained on average between 23 and 30% phosphorus. Results suggest that phosphorus removal in activated sludge might be due not only to PAO, but also by EPS acting as a phosphorus reservoir. Extraction of EPS from two different activated sludge plants yielded different amounts of EPS, which, in combination with SEM-EDS, may shed light on different phosphate uptake abilities of different activated sludges.

The development and use of real-time PCR for the quantification of nitrifiers in activated sludge

2002 ◽  
Vol 46 (1-2) ◽  
pp. 267-272 ◽  
Author(s):  
S.J. Hall ◽  
P. Hugenholtz ◽  
N. Siyambalapitiya ◽  
J. Keller ◽  
L.L. Blackall
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Real Time ◽  
Real Time Pcr ◽  
Wastewater Treatment Plants ◽  
Quantitative Polymerase Chain Reaction ◽  
Analytical Data ◽  
Full Scale ◽  
Rrna Gene ◽  
Dna Templates

Chemical analytical data has long been used to monitor the performance of activated sludge plants even though the process relies on the performance of microorganisms. It is now evident that a rapid and reliable quantitative method is required, to be able to monitor the organisms responsible for nutrient transformation and their activities, allowing avenues for more efficient nutrient removal. The development of real-time or quantitative polymerase chain reaction (PCR) also known as TaqMan® or 5′-nuclease assay has allowed the rapid, quantitative analysis of DNA templates, eliminating some of the variability traditionally associated with other quantitative techniques. In this study analysis of Nitrospira spp., one of the key organisms in nitrite oxidation in wastewater treatment, was used to validate real-time PCR for the their quantification in activated sludge. A probe and primer set, targeting the 16S rRNA gene of Nitrospira spp. was designed according to the constraints of the TaqMan® specifications. Samples used to evaluate the method included DNA from the sludge from full-scale wastewater treatment plants and laboratory scale systems. The reproducibility, quantitative efficiency and specificity were assessed in the evaluation. It was concluded that the method is sensitive and reproducible but has some constraints on the quantitative efficiency. A survey of full-scale systems for Nitrospira spp. was carried out and the results are presented here.

Quantification of ammonia-oxidizing bacteria populations in full-scale sewage activated sludge systems and assessment of system variables affecting their performance

2006 ◽  
Vol 54 (1) ◽  
pp. 91-99 ◽  
Author(s):  
T. Limpiyakorn ◽  
F. Kurisu ◽  
O. Yagi
Keyword(s):  
Activated Sludge ◽  
Real Time ◽  
Real Time Pcr ◽  
Full Scale ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Ammonia Oxidizing Bacteria ◽  
Primer Sets ◽  
Activated Sludge Systems ◽  
Pcr Primer

This study carried out quantification of ammonia-oxidizing bacteria (AOB) populations in 12 full-scale sewage activated sludge systems that were different in ammonia removals and treatment processes during three different seasons. Experiment was divided into 3 parts: 1) analysis of AOB communities by PCR-DGGE-cloning-sequencing of 16S rRNA genes; 2) development of four real-time PCR primer sets for quantification of the particular AOB of interest; and 3) quantification of AOB populations by using the newly developed real-time PCR primer sets. The results suggested that all the primer sets gave good reproducibility and specificity for PCR amplification with the detection limits of 102 copies/PCR reaction. Although the 12 systems were different in several aspects, one of the identified sequence types of Nitrosomonas oligotropha cluster was the dominant AOB in every system and every season studied. However, the other sequence type of this cluster was not significantly involved in ammonia removals in the systems. The occurrence of N. communis cluster in the systems seemed to depend on the remaining oxygen concentrations in the sludge floc and thus the activity of aerobic heterotrophs in the aeration tanks. N. europaea–Nitrosococcus. mobilis solely existed in one A2O system of which the influent contained twice the chloride concentrations than those of other systems.

scholarly journals Metagenomic insights into mixotrophic denitrification facilitated nitrogen removal in a full-scale A2/O wastewater treatment plant

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0250283
Author(s):  
Shulei Liu ◽  
Yasong Chen ◽  
Lin Xiao
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Sulfate Reduction ◽  
Nitrogen Removal ◽  
Carbon Sources ◽  
Full Scale ◽  
Sulfur Species ◽  
Sulfur Oxidizing ◽  
Reduced Sulfur ◽  
Denitrification Process

Wastewater treatment plants (WWTPs) are important for pollutant removal from wastewater, elimination of point discharges of nutrients into the environment and water resource protection. The anaerobic/anoxic/oxic (A2/O) process is widely used in WWTPs for nitrogen removal, but the requirement for additional organics to ensure a suitable nitrogen removal efficiency makes this process costly and energy consuming. In this study, we report mixotrophic denitrification at a low COD (chemical oxygen demand)/TN (total nitrogen) ratio in a full-scale A2/O WWTP with relatively high sulfate in the inlet. Nitrogen and sulfur species analysis in different units of this A2/O WWTP showed that the internal sulfur cycle of sulfate reduction and reoxidation occurred and that the reduced sulfur species might contribute to denitrification. Microbial community analysis revealed that Thiobacillus, an autotrophic sulfur-oxidizing denitrifier, dominated the activated sludge bacterial community. Metagenomics data also supported the potential of sulfur-based denitrification when high levels of denitrification occurred, and sulfur oxidation and sulfate reduction genes coexisted in the activated sludge. Although most of the denitrification genes were affiliated with heterotrophic denitrifiers with high abundance, the narG and napA genes were mainly associated with autotrophic sulfur-oxidizing denitrifiers. The functional genes related to nitrogen removal were actively expressed even in the unit containing relatively highly reduced sulfur species, indicating that the mixotrophic denitrification process in A2/O could overcome not only a shortage of carbon sources but also the inhibition by reduced sulfur of nitrification and denitrification. Our results indicate that a mixotrophic denitrification process could be developed in full-scale WWTPs and reduce the requirement for additional carbon sources, which could endow WWTPs with more flexible and adaptable nitrogen removal.

Incidence of Sphaerotilus Natans in Laboratory Scale Activated Sludge Systems

1989 ◽  
Vol 21 (4-5) ◽  
pp. 29-41 ◽  
Author(s):  
D. M. D. Gabb ◽  
G. A. Ekama ◽  
D. Jenkins ◽  
G. v. R. Marais
Keyword(s):  
Activated Sludge ◽  
Surface Area ◽  
Volume Ratio ◽  
Full Scale ◽  
Laboratory Scale ◽  
Sphaerotilus Natans ◽  
Attached Growth ◽  
Mixed Liquor ◽  
Activated Sludge Systems

Bulking in activated sludge systems due to proliferation of Sphaerotilus natans is very common in laboratory-scale but rare in full-scale systems. From two laboratory-scale studies it is concluded that a cause for proliferation was attached growth of S.natans on the walls of the feed lines and reactor surfaces continuously seeding the mixed liquor. It is suggested that S.natans bulking in laboratory-scale systems is common compared to full-scale systems because the surface area/volume ratio of the former is orders of magnitude higher than that of the latter so that the potential for seeding from attached growths in laboratory-scale plants is correspondingly higher. It would appear that in laboratory-scale activated sludge systems regular cleaning of the feed lines and daily scrubbing of the reactor and other wetted surfaces will eliminate S.natans bulking due to seeding of the mixed liquor from these surfaces.

scholarly journals Removal of bacterial and viral indicator organisms in full-scale aerobic granular sludge and conventional activated sludge systems

2020 ◽  
Vol 6 ◽  
pp. 100040 ◽  
Author(s):  
Mary Luz Barrios-Hernández ◽  
Mario Pronk ◽  
Hector Garcia ◽  
Arne Boersma ◽  
Damir Brdjanovic ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Granular Sludge ◽  
Full Scale ◽  
Aerobic Granular Sludge ◽  
Indicator Organisms ◽  
Conventional Activated Sludge ◽  
Activated Sludge Systems

Nitrogen transformations and mass balances in anaerobic/anoxic/aerobic batch experiments with full-scale biomasses from BNR activated sludge systems

2009 ◽  
Vol 60 (9) ◽  
pp. 2463-2470 ◽  
Author(s):  
J. Mękinia ◽  
H. D. Stensel ◽  
K. Czerwionka ◽  
J. Drewnowski ◽  
D. Zapero
Keyword(s):  
Activated Sludge ◽  
Organic Nitrogen ◽  
Full Scale ◽  
Aerobic Denitrification ◽  
Batch Reactors ◽  
Chemical Pretreatment ◽  
Mass Balances ◽  
Nitrogen Transformations ◽  
N Losses ◽  
Activated Sludge Systems

The aim of this study was to investigate nitrogen mass balances occurring inside full-scale BNR activated sludge systems, with special attention to colloidal and dissolved organic nitrogen (CON and DON) transformations. For this purpose, laboratory experiments were carried out using process biomass from two large BNR plants in northern Poland. Two parallel batch reactors were operated in a 3-phase (anaerobic/anoxic/aerobic) cycle. In one reactor, the settled wastewater without any pretreatment was used, whereas the settled wastewater after coagulation-flocculation (to remove colloidal and particulate fractions) was added to another reactor. The chemical pretreatment of settled wastewater with ZnSO4 did not adversely affect the observed nitrification rates in the (last) aerobic phase. It caused, however, a reduction of denitrification rates in the anoxic phase. Moreover, the chemical pretreatment did not appear to generally decrease DON but decreased CON. DON was explicitly produced in the aerobic phase and organic nitrogen conversion also occurred at a significant rate in the anoxic phase with biodegradable COD consumption and solids hydrolysis. The inorganic N mass balances revealed N losses up to approximately 10% which could be attributed to a few novel pathways of nitrogen removal, most likely aerobic denitrification or simultaneous nitrification/denitrification.

The influence of PAX-14 on activated sludge systems and in particular on Microthrix parvicella

2002 ◽  
Vol 46 (1-2) ◽  
pp. 487-490 ◽  
Author(s):  
T. Roels ◽  
F. Dauwe ◽  
S. Van Damme ◽  
K. De Wilde ◽  
F. Roelandt
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Wastewater Treatment Plants ◽  
Full Scale ◽  
Morphological Properties ◽  
Eu Directive ◽  
Solids Separation ◽  
Microthrix Parvicella ◽  
Separation Problems ◽  
Activated Sludge Systems

The amount of wastewater treatment plants (WWTP) dealing with solid separation problems has significantly increased since the new requirements of the EU Directive 271/91 on nutrient removal. In Flanders a number of the nutrient removal WWTP are affected by solid separation problems mostly attributed to Microthrix parvicella being the most common dominant species. The effect of dosing polyaluminium chloride (PAX-14) on activated sludge is illustrated for WWTP solids separation problems, in particular because of Microthrix parvicella. The effects of the addition of PAX-14 on the microbiology and the morphology of Microthrix parvicella were studied in 9 full-scale WWTPs. PAX-14 succeeded in reducing high SVI-values and controlled foaming problems whenever caused by Microthrix parvicella. Laboratory trials have shown that the dosage of PAX-14 should be less than 150 μL/L or 7 g Al3+/kg MLSS. At a dosage higher than 250 μL/L, an increase of free bacteria and a decrease of the protozoa activity are observed. In full-scale, PAX-14 is dosed at a concentration of 1.5 to 4.5 g Al3+/kg MLSS. Before addition, the mixed liquor scum layer – if present – should be removed. In our experience, the dosing should last for at least 3 weeks. During the first week, no drastic changes occur. At the end of the first week, an increase of SS and SVI is possible. The SVI and scum start to decrease after 10 to 15 days. The amount of filaments is reduced after 3 to 3½ weeks. The morphological properties of Microthrix parvicella change, while other filaments such as Nostocoida limicola and Nocardia spp. are not affected. This study proves that PAX-14 is effective in controlling bulking and foaming problems at WWTPs when they are due to Microthrix parvicella. Prediction of when the SVI will decrease and when addition should be stopped is possible.

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