التفاصيل البيبلوغرافية
| العنوان: |
NaHCO 3 -enhanced sewage sludge thin-layer drying: Drying characteristics and kinetics. |
| المؤلفون: |
Zhou, Jiazhen, Zhang, Ruina, Wang, Xing, Chen, Shanping, Luo, Anran, Niu, Dongjie, Chai, Xiaoli, Zhao, Youcai |
| المصدر: |
Drying Technology; 2017, Vol. 35 Issue 10, p1276-1287, 12p |
| مصطلحات موضوعية: |
SEWAGE, DRYING, SEWERAGE, EVAPORATION (Chemistry), ANALYTICAL mechanics |
| مستخلص: |
Drying sewage sludge is a highly energy-extensive process. For this reason, this work seeks to identify a reagent that can enhance the effectiveness of the drying process. In this study, drying experiments of sewage sludge were conducted at drying temperatures ranging from 100 to 160°C. NaHCO3was selected as the drying reagent, which was added to the sludge before drying. The thin-layer drying characteristics of the sludge and sludge/NaHCO3mixtures were later investigated and compared. Various mathematical models were used to simulate the sludge drying curves. It was found that adding 2 and 6% (wet basis) of NaHCO3to the sludge was effective in improving the moisture diffusion during the drying process, whereas the drying rate of the sludge/NaHCO3mixtures decreased when the addition of NaHCO3was further increased to 10% (wet basis). When the addition ratio was 2%, the increase in the maximum drying rate was the largest. With coefficients of determination (R2) over 0.9999, the modified Midilli model proposed in this study was observed to be the most suitable model to describe thin-layer drying of sludge relative to the other models examined in terms ofR2, reduced χ2, root mean square error, and residual sum of squares. The values of the diffusion coefficients at each temperature were obtained using Fick’s second law of diffusion, which varied from 3.700 × 10−9to 1.085 × 10−8 m2/s over the temperature range (i.e., 100–160°C). The activation energy of moisture diffusion was determined to be 27.57 kJ/mol. Scanning electron microscope images of the dried sludge and sludge/NaHCO3mixtures indicated that the porosity of the sludge after drying increased with an increase in the NaHCO3addition ratio. Overall, the results suggested that NaHCO3is a suitable reagent to improve the drying efficiency of the sludge. [ABSTRACT FROM PUBLISHER] |
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| قاعدة البيانات: |
Complementary Index |
