Change in metabolism of PHA accumulation by activated sludge modifying operating conditions

2002 ◽  
Vol 46 (1-2) ◽  
pp. 353-356 ◽  
Author(s):  
L.S. Serafim ◽  
P.C. Lemos ◽  
M.A.M. Reis
Keyword(s):  
Activated Sludge ◽  
Phosphorus Removal ◽  
Operating Conditions ◽  
Reactor Operation ◽  
Operational Conditions ◽  
Removal Process ◽  
Phosphorus Accumulation ◽  
Aerobic Dynamic Feeding ◽  
Substrate Feeding

In the present work, sludge from a stable and efficient phosphorus removal process was used to evaluate the change in the metabolism when the reactor operation was modified from anaerobic/aerobic to aerobic dynamic substrate feeding. The change in operational conditions allowed the population to modify the metabolism of phosphorus and polyhydroxyalkanoates (PHA) accumulation. Under aerobic dynamic feeding, phosphorus accumulation was almost hindered while the amount of PHA accumulation increased significantly. After ten days of operation under dynamic substrate feeding, the reactor operation turned back to anaerobic/aerobic cycles and the metabolism of phosphorus was progressively recovered

Understanding the contribution of biofilm in an integrated fixed-film-activated sludge system (IFAS) designed for nitrogen removal

2015 ◽  
Vol 71 (10) ◽  
pp. 1500-1506 ◽  
Author(s):  
P. Moretti ◽  
J. M. Choubert ◽  
J. P. Canler ◽  
O. Petrimaux ◽  
P. Buffiere ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Loading Rate ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Biofilm Growth ◽  
Operational Conditions ◽  
Solids Concentration ◽  
Fixed Film ◽  
Autotrophic Biomass

The objective of this study is to improve knowledge on the integrated fixed-film-activated sludge (IFAS) system designed for nitrogen removal. Biofilm growth and its contribution to nitrification were monitored under various operating conditions in a semi-industrial pilot-scale plant. Nitrification rates were observed in biofilms developed on free-floating media and in activated sludge operated under a low sludge retention time (4 days) and at an ammonia loading rate of 45–70 gNH4-N/kgMLVSS/d. Operational conditions, i.e. oxygen concentration, redox potential, suspended solids concentration, ammonium and nitrates, were monitored continuously in the reactors. High removal efficiencies were observed for carbon and ammonium at high-loading rate. The contribution of biofilm to nitrification was determined as 40–70% of total NOx-N production under the operating conditions tested. Optimal conditions to optimize process compacity were determined. The tested configuration responds especially well to winter and summer nitrification conditions. These results help provide a deeper understanding of how autotrophic biomass evolves through environmental and operational conditions in IFAS systems.

Development and application of 16S rRNA-targeted oligonucleotide probe for detection of the phosphate-accumulating bacterium microlunatus phosphovorus in an enhanced biological phosphorus removal process

1998 ◽  
Vol 37 (4-5) ◽  
pp. 481-484 ◽  
Author(s):  
Mamoru Kawaharasaki ◽  
Takahiro Kanagawa ◽  
Hideo Tanaka ◽  
Kazunori Nakamura
Keyword(s):  
16S Rrna ◽  
Activated Sludge ◽  
Phosphorus Removal ◽  
Oligonucleotide Probe ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Phylogenetic Groups ◽  
Removal Process ◽  
Biological Phosphorus ◽  
Total Bacteria

A 16S rRNA-targeted oligonucletide probe (MP2) specific for the phosphate-accumulating bacterium (PAB) M. phosphovorus was designed and applied to a sludge from an enhanced biological phosphorus removal (EBPR) process. Probes specific for defined phylogenetic groups and the polyphosphate staining dye, DAPI (4′, 6-diamidino-2-phenylindol dihydrochloride) were also used to analyze the activated sludge community. M. phosphovorus was about 3% of the total bacteria in the EBPR sludge used. Proteobacteria belonging to the beta subclass were the most abundant. Many coccoid bacteria similar to M. phosphovorus were stained with DAPI. The percentage of PABs detected by DAPI stain was about 9% of the total bacteria.

scholarly journals An improved ASM-GDA approach to evaluate the production kinetics of loosely bound and tightly bound extracellular polymeric substances in biological phosphorus removal process

RSC Advances ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 2495-2506
Author(s):  
Hai Cui ◽  
Shan-Shan Yang ◽  
Ji-Wei Pang ◽  
Hai-Rong Mi ◽  
Chen-Chen Nuer ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Phosphorus Removal ◽  
Extracellular Polymeric Substances ◽  
Biological Phosphorus Removal ◽  
Activated Sludge Model ◽  
Removal Process ◽  
Degradation Processes ◽  
Production Kinetics ◽  
Biological Phosphorus ◽  
Kinetics Of

An extended activated sludge model no. 2 provides a new recognition of the contributions of both loosely- and tightly-bound EPS into phosphorus removal by incorporating their formation and degradation processes during the anaerobic–aerobic cycle.

Microscopic Evaluation of Carbon and Phosphorus Accumulation in Nutrient Removal Activated Sludge Plants

1988 ◽  
Vol 20 (4-5) ◽  
pp. 37-49 ◽  
Author(s):  
Laurraine H. Lötter ◽  
Margaret Murphy
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Phosphorus Removal ◽  
Start Up ◽  
Microscopic Evaluation ◽  
Phosphorus Accumulation ◽  
Rapid Formation ◽  
Large Clusters ◽  
Aerobic Zone ◽  
Extracellular Slime

Successful phosphorus removal by a nutrient removal activated sludge plant, depends ultimately on the ability of the biomass to store carbon in the form of polyhydroxybutyrate and phosphate as polyphosphate. This study has shown that floc-forming cells in the aerobic zone of an efficient phosphorus removing plant contain large polyphosphate inclusions, and are usually larger in size than anaerobic zone cells. Monitoring the development of biomass in a new activated sludge plant by seeding with mixed liquor from the Johannesburg Goudkoppies Works, demonstrated the rapid formation of a typical activated sludge floc. The distinct differences between polyhydroxybutyrate and polyphosphate storage in the anaerobic, anoxic and aerobic zones observed in Goudkoppies sludge were however, not evident in the new plant until two weeks after start-up and the large clusters of polyphosphate containing bacteria were not observed until even later. The formation of large clusters of bacteria observed in phosphorus removing plants was considered contingent on the production of extracellular slime. This was borne out by the examination of various plants for the presence of extracellular slime, which revealed that the presence of this material correlates well with satisfactory phosphorus removal.

Nitrification studies on fertilizer wastewaters in activated sludge and biofilm reactors

1995 ◽  
Vol 32 (12) ◽  
pp. 141-148 ◽  
Author(s):  
Ferhan Çeçen ◽  
Elvan Orak ◽  
Pinar Gökçin
Keyword(s):  
Dissolved Oxygen ◽  
Activated Sludge ◽  
Continuous Flow ◽  
Removal Rate ◽  
Ammonia Concentration ◽  
Biofilm Reactor ◽  
Operating Conditions ◽  
Nitrite Accumulation ◽  
Operational Conditions ◽  
Oxygen Concentrations

Nitrification characteristics of a high-strength fertilizer wastewater were studied in a batch activated sludge and a continuous-flow biofilm reactor. In a batch activated sludge system one of the most decisive factors was the pH control. The results in terms of ammonium decrease and nitrite build-up were fitted to kinetic models and it was shown that in the absence of inhibitory factors like high free ammonia or nitrous acid build-up the behaviour was similar to that in the case of low-strength wastes. Continuous-flow studies in the biofilm reactor at different loading rates and dissolved oxygen concentrations indicated that such a biofilm reactor could be employed in the treatment of highly nitrogenous fertilizer wastes. Depending on operating conditions such as dissolved oxygen concentration and loading rate an effluent ammonia concentration as low as 4 mg NH4−N/L could be achieved. In the dissolved oxygen ranges of 3.2 mg/L–3.5 mg/L the system reached the maximum removal rate of 0.17 kg NH4−N/m3.d. When the dissolved oxygen was increased to 4.9 mg/L, removal rates as high as 0.41 kg NH4−N/m3.d could be obtained. Also in continuous-flow operation nitrite accumulation reached in some cases a considerable degree depending on the bulk nitrogen and dissolved oxygen concentrations. The nitrite accumulation in the effluent stream varied from 4–180 mg NO2−N/L depending on operational conditions.

Behaviour of Alkylphenol Polyethoxylate Surfactants and of Nitrilotriacetate in Sewage Treatment

1987 ◽  
Vol 19 (3-4) ◽  
pp. 449-460 ◽  
Author(s):  
W. Giger ◽  
M. Ahel ◽  
M. Koch ◽  
H. U. Laubscher ◽  
C. Schaffner ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Sewage Treatment ◽  
Operating Conditions ◽  
Municipal Sewage ◽  
Sludge Treatment ◽  
Loading Rates ◽  
Treatment Conditions ◽  
Physico Chemical ◽  
Treated Sewage ◽  
Removal Efficiencies

Effluents and sludges from several municipal sewage treatment plants in Switzerland were analyzed for nonylphenol polyethoxylates (NPnEO, n=3-20), nonylphenol mono- and diethoxylate (NPlEO, NP2EO), corresponding nonylphenoxy carboxylic acids (NP1EC, NP2EC) and nonylphenol (NP). These chemicals derive from nonionic surfactants of the NPnEO-type, and specific analitical techniques were used to study their behaviour during mechanical-biological sewage and subsequent sludge treatment. The parent NPnEO-surfactants, with concentrations in raw and mechanically treated sewage from 400-2200 mg/m3, were relatively efficiently removed by the activated sludge treatment. The abundances of the different metabolites varied depending on treatment conditions. The refractory nature of NPl/2EO, NP and NPl/2EC was recognized. Both biotransformations and physico-chemical processes determine the behaviour and fate of nonylphenolic substances in sewage treatment. Nitrilotriacetate (NTA) was found in primary effluents at concentrations between 430 and 1390 mg/m3. The various treatment plants showed different removal efficiencies for NTA depending on the operating conditions. Activated sludge treatment with low sludge loading rates and nitrifying conditions removed NTA with efficiencies between 95 and 99%. High sludge loading caused a decrease in NTA removal efficiencies from 70% to 39%.

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