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.

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.

A full scale worm reactor for efficient sludge reduction by predation in a wastewater treatment plant

2011 ◽  
Vol 45 (18) ◽  
pp. 5916-5924 ◽  
Author(s):  
J. Tamis ◽  
G. van Schouwenburg ◽  
R. Kleerebezem ◽  
M.C.M. van Loosdrecht
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Full Scale ◽  
Sludge Reduction

Application of ozonation to reduce biological sludge production in an industrial wastewater treatment plant

2008 ◽  
Vol 58 (10) ◽  
pp. 1971-1976 ◽  
Author(s):  
J. S. Albuquerque ◽  
J. C. Domingos ◽  
G. L. Sant'Anna ◽  
M. Dezotti
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Industrial Wastewater ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Yield Coefficient ◽  
Experimental Conditions ◽  
Industrial Wastewater Treatment ◽  
Biological Sludge ◽  
Sludge Production

Biosolids production in the activated sludge process generates an additional cost to wastewater treatment plants due to the growing requirements for sludge treatment and disposal. This work focuses on the application of ozonation to reduce sludge production in an industrial wastewater treatment plant. The results show that ozonation was able to promote cell wall rupture, releasing intracellular matter into the liquid medium. This effect was observed by the increase in concentrations of DNA (1.14 to 7.83 mg/L) and proteins (0.5 to 45.602 mg/L) in the liquid phase, when ozonation was applied during 10 min, using 30 mg/L of ozone. Reduction of sludge production was assessed by calculating the observed sludge yield coefficient (Y) in bench-scale continuous experiments conducted with varying proportions of ozonated sludge in the recycle stream and recycle ratios. Reduction of sludge production ranged from 14 to 39%, depending on the experimental conditions. The best result in terms of sludge excess reduction was achieved when 20% of the recycle sludge was ozonated and the recycle ratio was 0.67.

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