Effects of pH on the Waste Activated Sludge Hydrolysis and Acidification under Mesophilic and Thermophilic Conditions

2009 ◽  
Author(s):  
Peng Zhang ◽  
Yinguang Chen ◽  
Qi Zhou
Keyword(s):  
Activated Sludge ◽  
Waste Activated Sludge ◽  
Thermophilic Conditions ◽  
Effects Of Ph ◽  
Sludge Hydrolysis

Anaerobic co-digestion of winery waste and waste activated sludge: assessment of process feasibility

2013 ◽  
Vol 69 (2) ◽  
pp. 269-277 ◽  
Author(s):  
C. Da Ros ◽  
C. Cavinato ◽  
F. Cecchi ◽  
D. Bolzonella
Keyword(s):  
Activated Sludge ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Waste Activated Sludge ◽  
Organic Loading ◽  
Operational Conditions ◽  
Loading Rates ◽  
Thermophilic Conditions ◽  
Soluble Chemical Oxygen Demand

In this study the anaerobic co-digestion of wine lees together with waste activated sludge in mesophilic and thermophilic conditions was tested at pilot scale. Three organic loading rates (OLRs 2.8, 3.3 and 4.5 kgCOD/m3d) and hydraulic retention times (HRTs 21, 19 and 16 days) were applied to the reactors, in order to evaluate the best operational conditions for the maximization of the biogas yields. The addition of lee to sludge determined a higher biogas production: the best yield obtained was 0.40 Nm3biogas/kgCODfed. Because of the high presence of soluble chemical oxygen demand (COD) and polyphenols in wine lees, the best results in terms of yields and process stability were obtained when applying the lowest of the three organic loading rates tested together with mesophilic conditions.

scholarly journals Microalgae as biological treatment for municipal wastewater – effects on the sludge handling in a treatment plant

2018 ◽  
Vol 78 (3) ◽  
pp. 644-654 ◽  
Author(s):  
J. Olsson ◽  
S. Schwede ◽  
E. Nehrenheim ◽  
E. Thorin
Keyword(s):  
Heavy Metals ◽  
Activated Sludge ◽  
Biological Treatment ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Waste Activated Sludge ◽  
Activated Sludge Process ◽  
Primary Sludge ◽  
Thermophilic Conditions ◽  
Mesophilic Conditions

Abstract A mix of microalgae and bacteria was cultivated on pre-sedimented municipal wastewater in a continuous operated microalgae-activated sludge process. The excess material from the process was co-digested with primary sludge in mesophilic and thermophilic conditions in semi-continuous mode (5 L digesters). Two reference digesters (5 L digesters) fed with waste-activated sludge (WAS) and primary sludge were operated in parallel. The methane yield was slightly reduced (≈10%) when the microalgal-bacterial substrate was used in place of the WAS in thermophilic conditions, but remained approximately similar in mesophilic conditions. The uptake of heavy metals was higher with the microalgal-bacterial substrate in comparison to the WAS, which resulted in higher levels of heavy metals in the digestates. The addition of microalgal-bacterial substrate enhanced the dewaterability in thermophilic conditions. Finally, excess heat can be recovered in both mesophilic and thermophilic conditions.

Acidification of Waste Activated Sludge during Mesophilic Phase in Two Phases Anaerobic Digestion System

2012 ◽  
Vol 610-613 ◽  
pp. 2416-2420 ◽  
Author(s):  
Xiu Yun Sun ◽  
Can Chen ◽  
Wei Wang ◽  
Jin You Shen ◽  
Jian Sheng Li ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Activated Sludge ◽  
Hydraulic Retention Time ◽  
Ph Value ◽  
Operating Conditions ◽  
Waste Activated Sludge ◽  
Optimal Conditions ◽  
Batch Experiments ◽  
Effects Of Ph ◽  
Two Phases

Waste activated sludge is always used to product methane by two phases anaerobic digestion, but fermenting to accumulate VFAs has seldom reported. This paper deals with the effects of pH value, adding ratio and hydraulic retention time (HRT) on WAS acidification during mesophilic phase in two phases anaerobic digestion (TPAD) system through batch experiments. In order to gain the most amount of VFAs for providing more carbon source, the optimal conditions for WAS mesophilic anaerobic digestion observed in this study are pH=7, adding ratio=12.5%, HRT=4d and TC/TNb value=1.7~2.0. Finally, we analyzed acid production kinetic under the optimal conditions. It can be inferred that the performance of WAS acidification is sensitive to operating conditions.

A new model with serial hydrolysis reactions for the anaerobic digestion of waste activated sludge under thermophilic conditions

2019 ◽  
Vol 5 (12) ◽  
pp. 2182-2192
Author(s):  
Yousif Hirmiz ◽  
Youngseck Hong ◽  
Younggy Kim
Keyword(s):  
Anaerobic Digestion ◽  
Activated Sludge ◽  
Numerical Simulations ◽  
Kinetic Models ◽  
Wastewater Sludge ◽  
Waste Activated Sludge ◽  
New Model ◽  
Thermophilic Conditions ◽  
Rate Limiting ◽  
Hydrolysis Reactions

Hydrolysis is one of the rate-limiting reactions in the anaerobic digestion (AD) of wastewater sludge; thus, reliable kinetic models for hydrolysis reactions are essential in numerical simulations of AD.

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