Abstract
Several chemical parameters were studied during a 100 days period in order to identify parameters that can be used as indicators of compost maturity. One treatment was a mixture of sewage sludge and sawdust (TS); another was a mixture of sewage sludge, pig manure and sawdust (TS-PM). The pH of water extracts increased during the thermophilic phase and then decreased in two treatments. While the electrical conductivity (EC) decreased throughout the composting time. The 4.99% in the change of volatile matter of TS-PM was higher than 1.73% in that of TS, at the same time, the change of organic carbon were 5.04% in TS-PM more than 3.82% of TS. Total nitrogen content in TS and TS-PM had a markedly increase tendence during composting, and the change in TS-PM was very more obvious than in TS, so reduction of C/N ratio in TS-PM was higher than in TS, C/N ratio of TS-PM and TS was 14.39 and 18.57 in mature production, respectively. Carbon content in HA plus FA and HA in two composts decreased from 0 to 100 day, but carbon content of FA decreased, so HA-C/FA-C ratio, HR, HI has a markedly increase in TS and TS-PM, and the parameters in TS-PM were higher than in TS. The points expressing maturity degree in TS-PM was more in TS. The nitrogen content of HA plus and HA showed a increased tendence in TS and TS-PM, the change of nitrogen of these fractions in TS-PM was higher than in TS, so C/N ratio of all fractions including HA plus FA, HA and FA, indicated a reduction tendence, and the refuction in FA was larger than in HA. E4/E6 ratio of HA plus FA and HA decreased during composting, and one FA was increase. E4/E6 ratio of HA plus FA and HA in TS-PM was very smaller than in TS, HA in TS-PM was a larger molecular size than HA in TS. The changes of organic matter compositions in composting: the crude fat and carbohydrates had a markedly reduction and cellulose plus hemicellulose had a slight decrease; crude protein and lignin content in TS and TS-PM had an increase tendence.
Original language | English |
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Pages (from-to) | 333-345 |
Number of pages | 13 |
Journal | Water, Air, and Soil Pollution |
Volume | 132 |
Issue number | 3-4 |
DOIs | |
Publication status | Published - 2001 |
Scopus Subject Areas
- Environmental Engineering
- Environmental Chemistry
- Ecological Modelling
- Water Science and Technology
- Pollution
User-Defined Keywords
- Chemical evaluation
- Composting
- Humification index
- Humification ratio
- Maturity degree
- Organic matter