Solubilization of waste activated sludge by alkaline pretreatment and biochemical methane potential (BMP) tests for anaerobic co-digestion of municipal organic waste

2003 ◽  
Vol 48 (8) ◽  
pp. 211-219 ◽  
Author(s):  
N.-H. Heo ◽  
S.-C. Park ◽  
J.-S. Lee ◽  
H. Kang
Keyword(s):  
Activated Sludge ◽  
Food Waste ◽  
Organic Waste ◽  
Waste Activated Sludge ◽  
Feed Mixture ◽  
Biochemical Methane Potential ◽  
Methane Recovery ◽  
Attractive Option ◽  
Methane Potential ◽  
Anaerobic Digestibility

Biochemical methane potential (BMP) tests have been carried out to determine the anaerobic digestibility of the waste activated sludge (WAS) and the sludge pretreated by NaOH (PWAS). The optimal NaOH dosage was determined to be 45 meq NaOH/L. The maximum SCOD solubilization was 27.7, 31.4 and 38.3% at the temperatures of 25, 35 and 55°C respectively after 4 hours reaction. The final methane yield of simulated food waste (SFW) was 430 ml CH4/g VSadded, and those of PWAS (25°C), PWAS (35°C) and PWAS (55°C) was 274, 286 and 310 ml CH4/g VSadded respectively after 20 days. The figures were 66%, 73% and 88% higher than that of WAS. The methane production in anaerobic co-digestion is considerably affected by the fraction of SFW and PWAS in the feed. The anaerobic digestibility of the feed mixture (SFW with PWAS) is higher than that of the feed mixture (SFW with WAS). Anaerobic co-digestion of food waste with the PWAS is found to be an attractive option to reduce the solid waste volume with improved methane recovery.

scholarly journals Pre-treatment of thickened waste activated sludge (TWAS) for enhanced biogas production via the application of a novel radial horn sonication technology

2017 ◽  
Vol 75 (9) ◽  
pp. 2179-2193 ◽  
Author(s):  
Sri Suhartini ◽  
Lynsey Melville ◽  
Tony Amato
Keyword(s):  
Activated Sludge ◽  
Biogas Production ◽  
Applied Pressure ◽  
Low Frequency ◽  
Waste Activated Sludge ◽  
Biochemical Methane Potential ◽  
Experimental Conditions ◽  
Working Volume ◽  
Methane Potential ◽  
Pre Treatment

The efficacy of sonication as a pre-treatment to anaerobic digestion (AD) was assessed using thickened waste activated sludge (TWAS). Efficiency was measured in relation to solubilisation, dewaterability, and AD performance. Eighteen experimental conditions were evaluated at low frequency (20 kHz), duration (2–10 s), amplitude (∼8–12 μm) and applied pressure (0.5–3.0 barg), using a sonix™ patented titanium sonoprobe capable of delivering an instantaneous power of ∼6 kW provided by Doosan Enpure Ltd (DEL). An optimised experimental protocol was used as a pre-treatment for biochemical methane potential (BMP) testing and semi-continuous trials. Four digesters, with a 2-L working volume were operated mesophilically (37 ± 0.5 °C) over 22 days. The results showed that the sonix™ technology delivers effective sonication at very short retention times compared to conventional system. Results demonstrate that the technology effectively disrupts the floc structures and filaments within the TWAS, causing an increase in solubilisation and fine readily digestible material. Both BMP tests and semi-continuous trials demonstrated that sonicated TWAS gave higher biodegradability and methane potential compared to untreated TWAS. Partial-stream sonication (30:70 sonicated to untreated TWAS) resulted in a proportionate increase in biogas production illustrating the benefits of full-stream sonication.

Reply to Comment on “Parameter Identification and Modeling of the Biochemical Methane Potential of Waste Activated Sludge”

2011 ◽  
Vol 45 (17) ◽  
pp. 7598-7599
Author(s):  
Lise Appels ◽  
Joost Lauwers ◽  
Geert Gins ◽  
Jan Degrève ◽  
Jan Van Impe ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Parameter Identification ◽  
Waste Activated Sludge ◽  
Biochemical Methane Potential ◽  
Methane Potential

Parameter Identification and Modeling of the Biochemical Methane Potential of Waste Activated Sludge

2011 ◽  
Vol 45 (9) ◽  
pp. 4173-4178 ◽  
Author(s):  
Lise Appels ◽  
Joost Lauwers ◽  
Geert Gins ◽  
Jan Degrève ◽  
Jan Van Impe ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Parameter Identification ◽  
Waste Activated Sludge ◽  
Biochemical Methane Potential ◽  
Methane Potential

Use of Combined NaOH-Microwave Pretreatment for Enhancing Mesophilic Anaerobic Digestibility of Thickened Waste Activated Sludge

2010 ◽  
Vol 113-116 ◽  
pp. 459-468 ◽  
Author(s):  
Yong Zhi Chi ◽  
Yu You Li ◽  
Min Ji ◽  
Hong Qiang ◽  
Heng Wei Deng ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Uniform Design ◽  
Oxygen Demand ◽  
Holding Time ◽  
Waste Activated Sludge ◽  
Methane Potential ◽  
Soluble Chemical Oxygen Demand ◽  
Anaerobic Digestibility ◽  
Relationship Of ◽  
The Mathematical Model

A combined NaOH-microwave (MW) pretreatment process was studied in order to investigate the effects of NaOH-MW pretreated thickened waste activated sludge (TWAS) on anaerobic digestion. In the NaOH-MW pretreatment studies, Uniform design was successfully applied to determine the relationship of TWAS solubilization to environmental conditions (NaOH dose, target temperature, and MW holding time) and to establish the mathematical model describing the solubilization degree to changes in these variables. The maximum solubilization ratio (85.1%) of volatile suspended solids (VSS) could be achieved at 210°C with 0.2 g-NaOH/g-SS and 35 min holding time. The biochemical methane potential (BMP) tests showed that all digesters fed with pretreated TWAS improved the methane production compared to control system, and the optimal conditions, at 170°C with 0.05 g-NaOH/g-SS and 1 min holding time, were suggested for NaOH-MW pretreatment of TWAS. In spite of the increase in the soluble chemical oxygen demand concentration and decrease in the dewaterability of digested sludge, the semi-continuous reacter fed with the pretreated TWAS without neutralization was stable and gave higher organics reductions and methane yields compared to the control.

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