Energy savings by reduced mixing in aeration tanks: results from a full scale investigation and long term implementation at Avedoere wastewater treatment plant

2011 ◽  
Vol 64 (5) ◽  
pp. 1089-1095 ◽  
Author(s):  
A. K. Sharma ◽  
T. Guildal ◽  
H. R. Thomsen ◽  
B. N. Jacobsen
Keyword(s):  
Wastewater Treatment ◽  
Flow Velocity ◽  
Wastewater Treatment Plant ◽  
Energy Savings ◽  
Treatment Plant ◽  
Full Scale ◽  
Long Term Results ◽  
Treatment Efficiency ◽  
Negative Effect

The aim of this project was to investigate the potential of reducing number of mixers in the biological treatment process and thereby achieve energy and economical savings and contribute to cleaner environment. The project was carried out at Avedoere wastewater treatment plant and a full scale investigation was conducted to study the effect of reduced mixing on flow velocity, suspended solid sedimentation, concentration gradients of oxygen and SS with depth and treatment efficiency. The only negative effect observed was on flow velocity; however the velocity was above the critical velocity. The plant has been operating with 50% of its designed number of mixers since September 2007 and long term results also confirm that reduced mixing did not have any negative effect on treatment efficiency. The estimated yearly electricity saving is 0.75 GWh/year.

Sludge reduction in a small wastewater treatment plant by electro-kinetic disintegration

2015 ◽  
Vol 72 (3) ◽  
pp. 364-370 ◽  
Author(s):  
Agostina Chiavola ◽  
Alessandra Ridolfi ◽  
Emilio D'Amato ◽  
Simona Bongirolami ◽  
Ennio Cima ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Flow Rate ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Full Scale ◽  
Sludge Reduction ◽  
Treatment Efficiency ◽  
Biological Sludge ◽  
Sludge Production

Sludge reduction in a wastewater treatment plant (WWTP) has recently become a key issue for the managing companies, due to the increasing constraints on the disposal alternatives. Therefore, all the solutions proposed with the aim of minimizing sludge production are receiving increasing attention and are tested either at laboratory or full-scale to evaluate their real effectiveness. In the present paper, electro-kinetic disintegration has been applied at full-scale in the recycle loop of the sludge drawn from the secondary settlement tank of a small WWTP for domestic sewage. After the disintegration stage, the treated sludge was returned to the biological reactor. Three different percentages (50, 75 and 100%) of the return sludge flow rate were subjected to disintegration and the effects on the sludge production and the WWTP operation efficiency evaluated. The long-term observations showed that the electro-kinetic disintegration was able to drastically reduce the amount of biological sludge produced by the plant, without affecting its treatment efficiency. The highest reduction was achieved when 100% return sludge flow rate was subjected to the disintegration process. The reduced sludge production gave rise to a considerable net cost saving for the company which manages the plant.

Packed-Cage RBC with Combined Cultivation of Suspended and Fixed-Film Biomass

1990 ◽  
Vol 22 (1-2) ◽  
pp. 101-111 ◽  
Author(s):  
J. Wanner ◽  
M. Sýkora ◽  
M. Kos ◽  
J. Miklenda ◽  
P. Grau
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Random Medium ◽  
Treatment Plant ◽  
Mixing Effect ◽  
Scale Unit ◽  
Fixed Film ◽  
Rotating Biological Contactors ◽  
Bod Removal

The situation in the treatment of wastewaters from small sources in Czechoslovakia has been discussed and two types of manufactured rotating biological contactors have been described. The evaluation of RBCs' operation showed the main disadvantages of the contactors with conventional discs, viz. the low 0C and low mixing effect. In a newly designed RBC, the discs or packets of discs were replaced by a cage packed with a random medium. The cage was equipped with tubular aeration and mixing elements. The long-term tests with a pilot-plant and a full-scale unit using synthetic as well as municipal wastewaters proved the ability of the packed-cage RBC to achieve a low effluent BOD with such organic loadings when the effluent from the conventional RBCs already deteriorated. Besides the BOD removal the 0C of the packed-cage RBCs was tested to verify the possibility of the combined cultivation of suspended and fixed-film biomass. On the basis of results presented here, a new package wastewater treatment plant for about 500 PE will be designed.

Management of toxicity effects in a large wastewater treatment plant

1997 ◽  
Vol 36 (2-3) ◽  
pp. 1-8 ◽  
Author(s):  
P. Grau ◽  
B. P. Da-Rin
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Severe Case ◽  
Treatment Efficiency ◽  
Filamentous Bulking ◽  
Biological Phenomena ◽  
Inhibition Of Nitrification ◽  
Toxicity Effects

An unusually severe case of toxicity accompanied by activated sludge filamentous bulking was observed at the wastewater treatment plant Sao Paulo-Barueri. Treatment efficiency of the plant, operated without major problems for more than five years before, was significantly hindered for almost six months. Occurrence of toxic shocks was confirmed partly directly but mostly indirectly by inhibition of nitrification and biological phenomena related to toxicity. Several measures adopted, including the recycled activated sludge chlorination, are described in the paper.

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