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Biodrying of dewatered secondary sludge: behavior of dynamic respiration index (DRI) and energy release under different operating conditions
Author(s) -
Huiliñir César,
Leiva Estefanía,
Stegmaier Francisco,
Castillo Antonio,
Cottet Luis,
Montalvo Silvio
Publication year - 2020
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.6210
Subject(s) - sewage sludge , water content , moisture , respiration , environmental science , oxygen , environmental engineering , degradation (telecommunications) , energy consumption , pulp and paper industry , chemistry , sewage , environmental chemistry , botany , geotechnical engineering , organic chemistry , engineering , biology , telecommunications , ecology , computer science
BACKGROUND Biological activity monitored through the dynamic respiration index (DRI) and the calculation of biological heat generation ( Q bio ) through O 2 consumption has been reported only scarcely in the case of biodrying. Therefore, the present work studies the DRI and Q bio for a dewatered secondary sewage sludge biodrying process under different operating conditions: airflow rate (AFR) and initial moisture content (IMC). RESULTS It was found that AFR has an important effect on oxygen consumption, with higher DRI (≤6 gO 2 kg VS –1 h –1 ) at higher AFR for different studied IMCs. IMC also affects the DRI, with higher values of DRI at higher IMC. Determination of the Q bio indicated that its calculation through O 2 consumption provided better explanations of the water removal of the process. AFR also affects water removal and volatile solids ( VS ) degradation, with greater water removal ( c . 30%) and lower VS degradation ( c . 3.6%) at lower AFR. CONCLUSIONS AFR strongly affects the DRI, with higher DRI at low AFR. The calculation of Q bio through O 2 consumption is recommended. © 2019 Society of Chemical Industry