Pretreatment of Sewage Sludge by Low-frequency Ultrasound

2012 ◽  
Vol 15 (2) ◽  
Author(s):  
Basak Savun ◽  
Uwe Neis ◽  
Nilsun H. Ince ◽  
Orhan Yenigün
Keyword(s):  
Sewage Sludge ◽  
Activated Sludge ◽  
Low Frequency ◽  
Oxygen Demand ◽  
Short Wave ◽  
Waste Activated Sludge ◽  
Total Dissolved Nitrogen ◽  
Low Frequency Ultrasound ◽  
The Impact ◽  
Frequency Ultrasound

AbstractThe key point of waste activated sludge (WAS) pretreatment is to rupture the cell wall for allowing the release of intracellular matter that acts as a bioavailable substrate in anaerobic digestion processes. In this regard, ultrasonic irradiation has been one of the most effective tools owing to the unique properties of ultrasound to produce extreme conditions in heterogeneous liquids such as waste activated sludge. The present study investigates the impact of short-frequency ultrasound on disintegration, biodegradability and dewatering characteristics of sewage sludge by monitoring soluble chemical oxygen demand (sCOD), dissolved organic carbon (DOC), soluble proteins, total dissolved nitrogen, particle size and dewaterability of raw and sonicated sludge samples to optimize the operating parameters. The results showed that short wave ultrasound is a highly effective method of WAS treatment, because it provides high degrees of disintegration and biomass transfer from sludge solids to the aqueous phase, thus resulting in enhanced biodegradability.

scholarly journals Comparison of the impacts of thermal pretreatment on waste activated sludge using aerobic and anaerobic digestion

2018 ◽  
Vol 78 (8) ◽  
pp. 1772-1781 ◽  
Author(s):  
Hyungjun (Brian) Jo ◽  
Wayne Parker ◽  
Peiman Kianmehr
Keyword(s):  
Anaerobic Digestion ◽  
Activated Sludge ◽  
Oxygen Demand ◽  
Waste Activated Sludge ◽  
Thermal Pretreatment ◽  
Decay Products ◽  
Anaerobic Biodegradability ◽  
Pretreatment Conditions ◽  
The Impact ◽  
Aerobic And Anaerobic

Abstract A range of thermal pretreatment conditions were used to evaluate the impact of high pressure thermal hydrolysis on the biodegradability of waste activated sludge (WAS) under aerobic and anaerobic conditions. It was found that pretreatment did not increase the overall extent to which WAS could be aerobically biodegraded. Thermal pretreatment transformed the biodegradable fraction of WAS (XH) to readily biodegradable chemical oxygen demand (COD) (SB) (16.5–34.6%) and slowly biodegradable COD (XB) (45.8–63.6%). The impact of pretreatment temperature and duration on WAS COD fractionation did not follow a consistent pattern as changes in COD solubilization did not correspond to the observed generation of SB through pretreatment. The pretreated WAS (PWAS) COD fractionations determined from aerobic respirometry were employed in anaerobic modeling and it was concluded that the aerobic and anaerobic biodegradability of PWAS differed. It was found that thermal pretreatment resulted in as much as 50% of the endogenous decay products becoming biodegradable in anaerobic digestion. Overall, it was concluded that the COD fractionation that was developed based upon the aerobic respirometry was valid. However, it was necessary to implement a first-order decay process that reflected changes in the anaerobic biodegradability of the endogenous products through pretreatment.

scholarly journals Mathematical modelling of waste activated sludge thermal disintegration

2018 ◽  
Vol 23 ◽  
pp. 00027
Author(s):  
Sylwia Myszograj ◽  
Magdalena Wojciech
Keyword(s):  
Activated Sludge ◽  
Mixed Models ◽  
Treatment Time ◽  
Oxygen Demand ◽  
Repeated Measurements ◽  
Waste Activated Sludge ◽  
Disintegration Time ◽  
Random Factor ◽  
Factor Measurement ◽  
The Impact

Chemical Oxygen Demand (COD) solubilisation was used to evaluate the impact of thermal pretreatment on the transfer of sewage sludge from particulate to soluble phase. It was gathering the experimental data needed for building of empirical mathematical model describing the relation between applied temperature and time and rate of COD solubilisation and degradation. In view of repeated measurements, in order to describe the relationship between changes in the fraction of dissolved COD and the time and temperature, mixed models have been adopted where by fixed factor measurement conditions have been adopted: time and temperature, while the random factor changes the characteristics of waste activated sludge. Linear and logistic nonlinear mixed models were analyzed. The tests demonstrated that all variables are statistically significant in assessing their impact on the efficiency of liquefaction of sludge. On the basis of the estimated model, the temperature rise of 10°C increases degree of disintegration 1.7% above the average treatment time for 0.5h, by 2.6% for 1 hour, and by 3.9% for 2h. COD values decrease between 3 to 23% at temperatures in the range of 55 to 115°C. At higher temperatures COD was reduced in the range of 32 to 44%. Disintegration time did not have the significant impact on the degradation effect.

Application of low frequency ultrasound to stimulate the bio-activity of activated sludge for use as an inoculum in enhanced hydrogen production

RSC Advances ◽  
2013 ◽  
Vol 3 (44) ◽  
pp. 21848 ◽  
Author(s):  
Wan-Qian Guo ◽  
Shan-Shan Yang ◽  
Ji-Wei Pang ◽  
Jie Ding ◽  
Xian-Jiao Zhou ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Activated Sludge ◽  
Low Frequency ◽  
Low Frequency Ultrasound ◽  
Frequency Ultrasound

scholarly journals Low frequency ultrasound-assisted leaching of sewage sludge for toxic metal removal, dewatering and fertilizing properties preservation

2013 ◽  
Vol 20 (1) ◽  
pp. 109-117 ◽  
Author(s):  
Samuel de La Rochebrochard ◽  
Emmanuel Naffrechoux ◽  
Patrick Drogui ◽  
Guy Mercier ◽  
Jean-François Blais
Keyword(s):  
Sewage Sludge ◽  
Metal Removal ◽  
Low Frequency ◽  
Toxic Metal ◽  
Low Frequency Ultrasound ◽  
Ultrasound Assisted ◽  
Frequency Ultrasound

First results on biostimulation of denitrifying activated sludge using low frequency ultrasound

2017 ◽  
Vol 31 (4) ◽  
pp. 463-469
Author(s):  
Nabil Ben youcef ◽  
André Pauss ◽  
Claude-Olivier Sarde ◽  
Nabil Mameri ◽  
Hakim Lounici ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Low Frequency ◽  
Low Frequency Ultrasound ◽  
First Results ◽  
Frequency Ultrasound

Fate of micropollutants during sewage sludge disintegration by low-frequency ultrasound

2015 ◽  
Vol 280 ◽  
pp. 575-587 ◽  
Author(s):  
G. Rivas Ibáñez ◽  
B. Esteban ◽  
L. Ponce-Robles ◽  
J.L. Casas López ◽  
A. Agüera ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Low Frequency ◽  
Low Frequency Ultrasound ◽  
Frequency Ultrasound

Low-frequency ultrasound and photochromotherapy in the complex treatment of patients with chronic bacterial and viral rhinosinusitis

2020 ◽  
pp. 13-23
Author(s):  
Natalya Kornova ◽  
A. Krylov
Keyword(s):  
Chronic Rhinosinusitis ◽  
Low Frequency ◽  
Chronic Tonsillitis ◽  
Complex Treatment ◽  
Resonance Imaging ◽  
X Ray ◽  
Low Frequency Ultrasound ◽  
Viral Nature ◽  
Ig G ◽  
Frequency Ultrasound

The article presents results of a study on the effectiveness of using lowfrequency ultrasound and photochromotherapy in the complex treatment of patients with chronic bacterial and viral rhinosinusitis. The study involved 69 people aged 18 to 55 years: 39 (56.83 %) women and 30 (45.11 %) men with chronic rhinosinusitis during the period of clinical exacerbation and concomitant chronic tonsillitis without exacerbation. All patients included in the study underwent X-ray examination or computed tomography and magnetic resonance imaging of the paranasal sinuses. 100 % of the patients were examined for the presence of antibodies to Human gammaherpesvirus 4 (ELISA), had study of blood serum for IgM and IgG and test to determine the avidity of Ig G antibodies to γ-herpesviruses. The obtained data indicate the effectiveness of including low-frequency ultrasound and photochromotherapy in the complex treatment of patients with chronic rhinosinusitis and concomitant chronic tonsillitis of bacterial and viral nature without exacerbation.

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