Influence of different mixing ratios on in-vessel co-composting of sewage sludge with horse stable straw bedding waste: maturity and process evaluation

Composting sewage sludge alone would reduce the decomposition efficiency due to free limited porosity in sludge. To alleviate this, the use of horse stable straw bedding waste (HSB) was evaluated as a co-composting material with sewage sludge in a 10 tonnes day−1 in-vessel composter for a period of...

Full description

Saved in:
Bibliographic Details
Published in:Waste management & research 2011-11, Vol.29 (11), p.1164-1170
Main Authors: Wong, Jonathan W. C., Selvam, Ammaiyappan, Zhao, Zhenyong, Yu, S. M., Law, Alex C. W., Chung, Patricia C. P.
Format: Article
Language:English
Subjects:
Animal Husbandry - methods
Animals
Composting
Decomposition
Horses
Housing, Animal
Humidity
Hydrogen-Ion Concentration
Organic Chemicals - analysis
Organic Chemicals - chemistry
Organic Chemicals - metabolism
Pathogens
Porosity
Sewage - analysis
Sewage - chemistry
Sewage disposal
Sludge
Soil Pollutants - analysis
Soil Pollutants - chemistry
Soil Pollutants - metabolism
Studies
Temperature
Time Factors
Waste Disposal, Fluid - methods
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Composting sewage sludge alone would reduce the decomposition efficiency due to free limited porosity in sludge. To alleviate this, the use of horse stable straw bedding waste (HSB) was evaluated as a co-composting material with sewage sludge in a 10 tonnes day−1 in-vessel composter for a period of 7 days before curing in a static aeration pile. Sludge was mixed with HSB at 1 : 1.5 (HSL) and 1 : 2.9 (LSL) on a fresh weight basis. After a composting period of 56 days, both mixing ratios demonstrated to be feasible with LSL having a better organic decomposition and a shorter time to reach maturity. The overall decomposition rates were 52.0 and 58.9% (dry weight basis) for HSL and LSL, respectively. In both treatments, temperature in the in-vessel composters could reach 65°C, which was sufficient to remove the pathogens. Although both products were free of pathogens, HSL exhibited a higher ammoniacal nitrogen contents but a lower seed germination index than that of LSL indicating a higher phytotoxicity and a longer curing period would be required. It can be concluded that HSB provided a better composting conditions at a mixing ratio of 1 : 2.9
ISSN:0734-242X
1096-3669
DOI:10.1177/0734242X11420600