Differences in soluble COD and ammonium when applying ultrasound to primary, secondary and mixed sludge

Ultrasound treatment is often applied to enhance the anaerobic digestion of sludge. Optimal conditions for organic matter solubilisation of primary, secondary and mixed sludge were assessed by implementing ultrasound disruption at different specific energies (from 3,500 to 21,000 kJ/kgTS). The varia...

Full description

Saved in:
Bibliographic Details
Published in:Water science and technology 2015-01, Vol.71 (9), p.1398-1406
Main Authors: Negral, L, Marañón, E, Castrillón, L, Fernández-Nava, Y
Format: Article
Language:English
Subjects:
Ammonium
Ammonium compounds
Ammonium Compounds - analysis
Anaerobic conditions
Anaerobic digestion
Anaerobic treatment
Biological Oxygen Demand Analysis
Chemical engineering
Chemical oxygen demand
Conditioning
Disruption
Fermentation
Hydrolysis
Inoculum
Irradiation
Microorganisms
Nitrogen
Organic matter
Primary sludge
Radiation
Resource recovery
Sewage - chemistry
Sludge
Sludge digestion
Sludge treatment
Solubility
Ultrasonic imaging
Ultrasonics
Ultrasound
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Ultrasound treatment is often applied to enhance the anaerobic digestion of sludge. Optimal conditions for organic matter solubilisation of primary, secondary and mixed sludge were assessed by implementing ultrasound disruption at different specific energies (from 3,500 to 21,000 kJ/kgTS). The variation in soluble chemical oxygen demand (sCOD) and ammonium nitrogen (NH4+-N) was monitored following the treatment, and after a subsequent fermentation (24 h, 37 °C). The effect of the treatment was clearly more pronounced in secondary sludge than in the other types of sludge. Relatively minimal values in solubility were found when applying ultrasound at different energies depending on the sludge (3,500-7,000 kJ/kgTS in primary sludge and 10,500-14,000 kJ/kgTS in secondary sludge). This minimal value was not so noticeable in mixed sludge. The addition of inoculum was not required after ultrasound disruption in order to perform the subsequent fermentation. After this final stage, no general pattern in terms of sCOD was observed. Increases and decreases were conditioned by the coverage of the ultrasound irradiation; NH4+-N values increased notably during the fermentation.
ISSN:0273-1223
1996-9732
DOI:10.2166/wst.2015.113