Treatment of Baker’s Yeast Wastewater by Combined coagulation and ultrafiltration membranes
Paper ID : 1256-MST2015-FULL
Authors:
1Hossein Nouri, 2Morteza Sadeghi *, 1Ahmad Moheb, 1Mohamadreza Rajaeieh
1Isfahan University of Technology
2isfahan university of technology
Abstract:
Baker’s yeast is used for producing bread that increases nutritional value, palatability and volume of bread. One of the main problems of baker’s yeast industries is its effluent that has high pollution in terms of environmental standards. Molasses is the main constituent of baker’s yeast, which is a byproduct of sugar production. Membrane Technology is one of the new methods of industrial wastewater treatment. In this study, a combined system coagulation-ultrafiltration membrane is employed for removal of chemical oxygen demand (COD) and turbidity from baker's yeast effluents. Membrane fouling is the most important problem of membrane technology so chemical coagulation is used as pre-treatment method to decrease fouling. Poly aluminum chloride (PACl), aluminum sulfate and lime used as coagulants. Our results indicate that PACl has higher removal efficiency than other coagulants. Furthermore combination of coagulants was investigated in this research. The obtained results show the combination of PACl-lime was more efficient in their optimal conditions. The removal efficiency of COD and turbidity reached 68% and 81% respectively by PACl-lime. Then effects of operating conditions in the ultrafiltration process for two types of hollow fiber membranes polyvinylidene fluoride (PVDF) and polypropylene (PP) on permeate flow rate, turbidity and COD removal of wastewater was investigated. The results showed that increasing the pressure and velocity increase permeate flow rate and decrease the removal efficiency. Under optimum condition, PVDF membrane show higher performance in comparison to PP membrane. The overall performance of PVDF membrane showed about 99% and 74.5% rejection in turbidity and COD respectively. Also with use of PVDF the flux was 59 L/m2 but this amount for PP was 81 L/m2. The removal efficiency of COD and turbidity reached 65% and 97% respectively for PP membrane.
Keywords:
Baker's Yeast Wastewater treatment, Ultrafiltration membrane, Coagulation, Fouling, COD removal, Turbidity removal
Status : Paper Accepted (Oral Presentation)