1 SPECIALIZED ENGLISH – SEMTESTER 5 VAN LANG UNIVERSITY DEPARTMENT OF ENVIRONMENTAL TECHNOLOGY AND MANAGEMENT Chapter 24Chapter 24 FUNDAMENTALS OF BIOLOGICAL FUNDAMENTALS OF BIOLOGICAL Dr. Tran Thi My Dieu Sep. 2011 VAN LANG UNIVERSITY DENTEMA WASTEWATER TREATMENT & REUSEWASTEWATER TREATMENT & REUSE Bacterial growthBacterial growth CONTENTSCONTENTS Bacterial reproductionBacterial reproduction Bacterial growth patterns in a batch reactorBacterial growth patterns in a batch reactor VAN LANG UNIVERSITY DENTEMA Bacterial growth patterns in a batch reactorBacterial growth patterns in a batch reactor Bacterial growth and biomass yieldBacterial growth and biomass yield BACTERIAL REPRODUCTIONBACTERIAL REPRODUCTION Is it important in biological treatment?Is it important in biological treatment? Binary fission 1 ori g inal cel l becomes 2 new ones VAN LANG UNIVERSITY DENTEMA Bacteria re p roduce b y Asexual mode Budding new ones Generation time ~ 20 min - days Rapid change in biomass BACTERIAL REPRODUCTIONBACTERIAL REPRODUCTION Is it important in biological treatment?Is it important in biological treatment? Spherical-shaped bacteria VAN LANG UNIVERSITY DENTEMA Assume 1  m diameter Specific gravity of 1.0 Generation time ~ 30 min Estimate bacteria mass after 12 h? BACTERIAL REPRODUCTIONBACTERIAL REPRODUCTION Is it important in biological treatment?Is it important in biological treatment? Estimate bacteria mass after 12 h? Weight of 1 cell ~ 5.0 x 10 -13 g 6 VAN LANG UNIVERSITY DENTEMA Bacteria mass in 12 h ~ 8.4 x 10 - 6 g Number of cell is quite large compared to the mass In biological treatment systems, bacteria would not continue to divide indefinitely because of environmental limitations (substrate and nutrient) BACTERIAL GROWTH PATTERNS IN A BACTERIAL GROWTH PATTERNS IN A BATCH REACTORBATCH REACTOR i on Lag phase Exponential growth phase Stationary phase Dead phase Substrate To acclimate to new environment Multiplying at max rate VAN LANG UNIVERSITY DENTEMA Concentrat i Time Substrate Biomass Batch process biomass growth phases with changed in substrate and biomass versus time Amount of growth is offset by the death of cells No growth 2 BACTERIAL GROWTH AND BACTERIAL GROWTH AND BIOMASS YIELDBIOMASS YIELD Biomass yield Y = g biomass produced g substrate utilized g biomass/g COD removed VAN LANG UNIVERSITY DENTEMA g biomass/g BOD removed g biomass/g VFAs used g biomass/g N-NH 4 oxidized How to measure biomass?How to measure biomass? BACTERIAL GROWTH AND BACTERIAL GROWTH AND BIOMASS YIELDBIOMASS YIELD How to measure biomass?How to measure biomass? Increase in biomass can be measured by Volatile suspended solids (VSS) or pCOD VAN LANG UNIVERSITY DENTEMA Volatile suspended solids (VSS) or pCOD Protein content (growth relates to true microbial mass) DNA (if the reactor solids contain proteins) ATP (if the reactor solid contain proteins) Turbidity (if very low biomass concentration) Bacterial cell counts BACTERIAL GROWTH AND BACTERIAL GROWTH AND BIOMASS YIELDBIOMASS YIELD How to estimate biomass yield?How to estimate biomass yield? Estimating biomass yield and oxygen VAN LANG UNIVERSITY DENTEMA requirements from stoichiometry Estimating biomass yield from bioenergetics BACTERIAL GROWTH AND BACTERIAL GROWTH AND BIOMASS YIELDBIOMASS YIELD Estimating biomass yield from stoichiometryEstimating biomass yield from stoichiometry 3C3C 66 HH 1212 OO 66 + 8O+ 8O 22 + 2NH+ 2NH 33 2C2C 55 HH 77 OO 22 N + 8CON + 8CO 22 + 14H+ 14H 22 O O Substrate Oxygen Nutrient Biomass VAN LANG UNIVERSITY DENTEMA 3 x 180 8 x 32 2 x 17 2 x 113 The yield based on glucose consumedThe yield based on glucose consumed Y = g biomass produced g glucose used g C 5 H 7 O 2 N g C 6 H 12 O 6 = 2 x 113 3 x 180 = Y = 0.42 g cells/g glucose used BACTERIAL GROWTH AND BACTERIAL GROWTH AND BIOMASS YIELDBIOMASS YIELD Estimating biomass yield from stoichiometryEstimating biomass yield from stoichiometry In practice, used COD and VSS ~ organic & cells Determine COD of glucose C H O +6O 6CO +6H O VAN LANG UNIVERSITY DENTEMA C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O 180 6 x 32 COD of glucose = 6 x 32 180 = 1.07 g O 2 /g glucose Y = g C 5 H 7 O 2 N g (glucose as COD) = 0.39 g cells/g COD 2 x 113 3 x 180 x 1.07 = BACTERIAL GROWTH AND BACTERIAL GROWTH AND BIOMASS YIELDBIOMASS YIELD Estimating oxygen requirement from stoichiometryEstimating oxygen requirement from stoichiometry COD utilized = COD cells + COD of oxidized substrate Oxygen consumed VAN LANG UNIVERSITY DENTEMA C 5 H 7 O 2 N + 5O 2 5CO 2 + NH 3 + 2H 2 O COD cells = 5 x 32 113 = 1.42 gO 2 /g cells 3 BACTERIAL GROWTH AND BACTERIAL GROWTH AND BIOMASS YIELDBIOMASS YIELD Estimating oxygen requirement from stoichiometryEstimating oxygen requirement from stoichiometry Oxygen consumed = COD utilized –COD cells =107 gO /g glucose x 3 moles x 180 g glucose/mole VAN LANG UNIVERSITY DENTEMA = 1 . 07 gO 2 /g glucose x 3 moles x 180 g glucose/mole - 1.42 gO 2 /g cells x 2 moles x 113 g cells/mole = 577.8 g O 2 – 320.9 g O 2 = 256.88 g O 2 BACTERIAL GROWTH AND BACTERIAL GROWTH AND BIOMASS YIELDBIOMASS YIELD Estimating oxygen requirement from stoichiometryEstimating oxygen requirement from stoichiometry Oxygen consumed per unit of COD used: VAN LANG UNIVERSITY DENTEMA Ox yg en consumed Glucose as COD = 256.88 g O 2 3 moles x 1.07 gCOD/g glucose x 180 g glucose/mole = 0.44 g O 2 /g COD used BACTERIAL GROWTH AND BACTERIAL GROWTH AND BIOMASS YIELDBIOMASS YIELD Estimating oxygen requirement from stoichiometryEstimating oxygen requirement from stoichiometry Oxygen consumed per unit of COD used: 3C3C 66 HH 1212 OO 66 + 8O+ 8O 22 + 2NH+ 2NH 33 2C2C 55 HH 77 OO 22 N + 8CON + 8CO 22 + 14H+ 14H 22 O O VAN LANG UNIVERSITY DENTEMA 3 x 180 8 x 32 Oxygen consumed Glucose as COD = 8 x 32 3 x 180 x 1.07 = 0.44 g O 2 /g COD used ASSIGNMENT 2ASSIGNMENT 2 Estimate biomass yield in term of g cells/g Estimate biomass yield in term of g cells/g saccharosesaccharose used and g cells/g COD used ifused and g cells/g COD used if VAN LANG UNIVERSITY DENTEMA CC 1212 HH 2222 OO 1111 + O+ O 22 + NH+ NH 33 CC 55 HH 77 OO 22 N + CON + CO 22 + H+ H 22 O O . SEMTESTER 5 VAN LANG UNIVERSITY DEPARTMENT OF ENVIRONMENTAL TECHNOLOGY AND MANAGEMENT Chapter 24Chapter 24 FUNDAMENTALS OF BIOLOGICAL FUNDAMENTALS OF BIOLOGICAL Dr. Tran Thi My Dieu Sep. 2011 VAN