Efficiency of autothermal thermophilic aerobic digestion and thermophilic anaerobic digestion of municipal wastewater sludge in removing Salmonella spp. and indicator bacteria

2003 ◽  
Vol 47 (3) ◽  
pp. 151-156 ◽  
Author(s):  
J. Zábranská ◽  
M. Dohányos ◽  
P. Jeníček ◽  
H. Ružičková ◽  
A. Vránová
Keyword(s):  
Anaerobic Digestion ◽  
Municipal Wastewater ◽  
Agricultural Land ◽  
Land Application ◽  
Wastewater Sludge ◽  
Indicator Bacteria ◽  
Salmonella Spp ◽  
Aerobic Digestion ◽  
Thermophilic Aerobic Digestion ◽  
Autothermal Thermophilic Aerobic Digestion

The study is focused on the comparison of autothermal thermophilic aerobic digestion, thermophilic and mesophilic anaerobic digestion, based on long term monitoring of all processes in full-scale wastewater treatment plants, with an emphasis on the efficiency in destroying pathogens. The hygienisation effect was evaluated as a removal of counts of indicator bacteria, thermotolerant coliforms and enterococci as CFU/g total sludge solids and a frequency of a positive Salmonella spp. detection. Both thermophilic technologies of municipal wastewater sludge stabilisation had the capability of producing sludge A biosolids suitable for agricultural land application when all operational parameters (mainly temperature, mixing and retention time) were stable and maintained at an appropriate level.

scholarly journals Inter-stage thermophilic aerobic digestion may increase organic matter removal from wastewater sludge without decreasing biogas production

2017 ◽  
Vol 77 (3) ◽  
pp. 721-726
Author(s):  
Sasha D. Hafner ◽  
Johan T. Madsen ◽  
Johanna M. Pedersen ◽  
Charlotte Rennuit
Keyword(s):  
Anaerobic Digestion ◽  
Methane Production ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Wastewater Sludge ◽  
Aerobic Digestion ◽  
Anaerobic Digesters ◽  
Stage System ◽  
Thermophilic Aerobic Digestion ◽  
Pre Treatment

Abstract Combining aerobic and anaerobic digestion in a two-stage system can improve the degradation of wastewater sludge over the use of either technology alone. But use of aerobic digestion as a pre-treatment before anaerobic digestion generally reduces methane production due to loss of substrate through oxidation. An inter-stage configuration may avoid this reduction in methane production. Here, we evaluated the use of thermophilic aerobic digestion (TAD) as an inter-stage treatment for wastewater sludge using laboratory-scale semi-continuous reactors. A single anaerobic digester was compared to an inter-stage system, where a thermophilic aerobic digester (55 °C) was used between two mesophilic anaerobic digesters (37 °C). Both systems had retention times of approximately 30 days, and the comparison was based on measurements made over 97 days. Results showed that the inter-stage system provided better sludge destruction (52% volatile solids (VS) removal vs. 40% for the single-stage system, 44% chemical oxygen demand (COD) removal vs. 34%) without a decrease in total biogas production (methane yield per g VS added was 0.22–0.24 L g−1 for both systems).

Improved alkaline stabilization of municipal wastewater sludge

2002 ◽  
Vol 46 (10) ◽  
pp. 139-146 ◽  
Author(s):  
J.M. Mendez ◽  
B.E. Jiménez ◽  
J.A. Barrios
Keyword(s):  
Municipal Wastewater ◽  
Treatment Plant ◽  
Physicochemical Process ◽  
Wastewater Sludge ◽  
The Other ◽  
Stabilization System ◽  
Municipal Wastewater Treatment ◽  
Faecal Coliforms ◽  
Salmonella Spp ◽  
Closed Systems

In Mexico, physicochemical sludge contains high levels of pathogens; and alkaline stabilization is an alternative for their control. However, the odours caused mainly by ammonia generation represent a disadvantage. On the other hand, the ammonia is known as an effective disinfectant. The aim of this study was to evaluate the disinfectant properties of ammonia in sludge, and use it in a closed alkaline stabilization system, which, not only copes with odours but also increases the efficiency of the process. Raw sludge from a municipal wastewater treatment plant using a physicochemical process was used. Ammonia was applied in doses from 10 to 50% w/w; also, doses from 5 to 40% of CaO were applied in open and closed systems and raw and treated sludge quality was evaluated. Results showed that ammonia removed 6 and 5 logs of faecal coliforms and Salmonella spp., respectively and up to 94% of viable helminth ova. The closed system was more efficient than the open system when applying doses from 5 to 20% of CaO. Finally, the results indicate that the ammonia represents an alternative to disinfecting wastewater sludge and it can be used to enhance alkaline stabilization processes.

scholarly journals Impact on degradation of antibiotics from poultry litter using Autothermal Thermophilic Aerobic Digestion (ATAD)

2021 ◽  
Vol 28 (1) ◽  
pp. 988-992
Author(s):  
Arivalagan Pugazhendhi ◽  
Sridevi Dhanarani Theivaraj ◽  
Gowri Manogari Boovaragamoorthy ◽  
Veerasamy Veeramani ◽  
Kathirvel Brindhadevi ◽  
...  
Keyword(s):  
Poultry Litter ◽  
Aerobic Digestion ◽  
Thermophilic Aerobic Digestion ◽  
Autothermal Thermophilic Aerobic Digestion
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