| Autor: |
Kasmi, M., Djebali, K., Hamdi, M., Trabelsi, I. |
| Zdroj: |
International Journal of Environmental Science & Technology (IJEST); Apr2018, Vol. 15 Issue 4, p779-790, 12p |
| Abstrakt: |
Among dairy effluents, bactofugate (B) and decreaming racking water (D) were identified as the most polluting due to their organic load content expressed in the chemical oxygen demand (156-240 g·L−1). Joining the plant wastewater, such effluents contribute to the increase of the polluting load of the wastewater treatment plant input which disturbs the treatment performance. This work proposes an upstream segregation of those dairy effluents for combined physical-chemical and biological treatment. An experimental design was proposed to investigate initial pH, applied temperature and exposure time factor effects on the thermal coagulation process. The fermentation of the resulted supernatants using Lactobacillus lactis ssp. lactis was performed. The optimized thermal coagulation pretreatment was obtained at (pH; T(°C); t(min)): 6, 60 °C and 5 min, with both (B) and (D) effluents. Resulted clarified whey sugar, protein and fat contents were assessed. The physical-chemical treatment resulted in considerable organic matter removal: 45% for (B) samples and 31% for (D) samples of proteins content and almost the total fat content. However, there is no considerable effect on the sugar content reduction, which remains responsible for the major fraction of the whey residual chemical oxygen demand (COD). Clarified whey fermentation using Lactococcus lactis ssp. lactis strain induced important sugar consumption rates. Therefore, important sugar consumption rates were recorded and the COD removal efficiency was improved. The recorded global COD removal efficiency was of about 93%. The proposed combined physical-chemical and biological processes for dairy effluents pretreatment allowed not only to reduce the effluents polluting load, but also to valorize wheys by producing valuable components. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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