Resource recovery technology
Juliet Van Haudt
2022-2023
INHOUD
1. Anaerobic digestion ............................................................................................................................................ 4
1.1. Introduction ................................................................................................................................................. 4
1.2. Stoichiometry............................................................................................................................................... 4
1.3. Biochemistry & microbiology....................................................................................................................... 5
1.3.1. Hydrolysis ............................................................................................................................................. 5
1.3.2. Fermentation & acidogenesis ............................................................................................................... 5
1.3.3. Acetogenesis ........................................................................................................................................ 5
1.3.4. Methanogenesis ................................................................................................................................... 6
1.4. Thermodynamics ......................................................................................................................................... 6
1.5. Operational conditions ................................................................................................................................ 6
1.5.1. Substrates ............................................................................................................................................. 6
1.5.2. pH ......................................................................................................................................................... 6
1.5.3. Temperature......................................................................................................................................... 7
1.5.4. Ammonia toxicity ................................................................................................................................. 7
1.5.5. Sulphate and sulphide .......................................................................................................................... 7
1.6. Reactors technology for liquid streams ....................................................................................................... 7
1.6.1. Process design: single stage process .................................................................................................... 7
1.6.2. Process design: two-stage process ....................................................................................................... 7
1.6.3. Anaerobic lagoons ................................................................................................................................ 8
1.6.4. High-rate anaerobic digestion: biomass retention ............................................................................... 8
1.7. Solids digestion .......................................................................................................................................... 11
2. Bioproduction.................................................................................................................................................... 13
2.1. Carboxylate production ............................................................................................................................. 13
2.1.1. Introduction and rationale of the carboxylate platform .................................................................... 13
2.1.2. Fundamentals and pathways.............................................................................................................. 13
2.1.3. Operational conditions, reactor configurations and product recovery .............................................. 14
2.1.4. A couple of examples ......................................................................................................................... 16
2.1.5. Summary: key features ....................................................................................................................... 17
2.2. Biopolymer production .............................................................................................................................. 17
2.2.1. Bioplastics: definition and types......................................................................................................... 17
2.2.2. PHA & PLA .......................................................................................................................................... 18
3. Composting ....................................................................................................................................................... 20
3.1. General aspects ......................................................................................................................................... 20
1
, 3.2. The conversion process ............................................................................................................................. 20
3.2.1. Microorganisms active during composting ........................................................................................ 21
3.2.2. Phases of the composting process ..................................................................................................... 21
3.3. Factors affecting the composting process ................................................................................................. 22
3.3.1. Oxygen and aeration .......................................................................................................................... 22
3.3.2. Temperature....................................................................................................................................... 22
3.3.3. Moisture ............................................................................................................................................. 23
3.3.4. Balanced microorganism diet ............................................................................................................. 23
3.3.5. pH ....................................................................................................................................................... 23
3.3.6. Size does matter ................................................................................................................................. 24
3.3.7. When is the compost finished ............................................................................................................ 24
3.3.8. Summary ............................................................................................................................................ 24
3.4. Composting technologies .......................................................................................................................... 25
3.4.1. Preprocessing ..................................................................................................................................... 25
3.4.2. Windrow system................................................................................................................................. 25
3.4.3. Passively aerated static windrow ....................................................................................................... 25
3.4.4. Actively aerated static windrow ......................................................................................................... 25
3.4.5. Closed vessel composting ................................................................................................................... 26
3.4.6. How to choose the system? ............................................................................................................... 26
3.5. General evaluation..................................................................................................................................... 26
4. Sulfur management and recovery ..................................................................................................................... 27
4.2. Occurrence of sulfur compounds in wastewater treatment and waste gases .......................................... 27
4.2.1. Sewer systems .................................................................................................................................... 27
4.2.2. Biogas ................................................................................................................................................. 28
4.3. Treatment of sulfur-rich gas streams ........................................................................................................ 29
4.3.1. Physico-chemical sulfide removal ...................................................................................................... 29
4.3.2. Biological sulfide removal ................................................................................................................... 29
4.4. Bioreactors used for H2S removal .............................................................................................................. 29
5. Nutrient recovery .............................................................................................................................................. 31
5.1. Problems .................................................................................................................................................... 31
5.1.1. Nitrogen .............................................................................................................................................. 31
5.1.2. Phosphorus ......................................................................................................................................... 33
5.1.3. Important take home messages ......................................................................................................... 33
5.2. Solutions .................................................................................................................................................... 34
5.2.1. Role of the biogas process in optimizing nutrient & energy cycles .................................................... 35
5.2.2. Characterization bio-based fertilizers ................................................................................................ 35
6. Water reuse....................................................................................................................................................... 36
6.1. Motivation for water reuse........................................................................................................................ 36
6.2. Categories of water reuse .......................................................................................................................... 37
2
, 6.3. Management & risk assessment ................................................................................................................ 37
6.4. Water constituents to be considered ........................................................................................................ 38
6.4.1. Composition for water reclamation ................................................................................................... 38
6.5. Treatment technologies ............................................................................................................................. 39
6.5.1. Filtration ............................................................................................................................................. 39
6.5.2. Reversed osmosis ............................................................................................................................... 40
6.5.3. Disinfection ......................................................................................................................................... 40
6.5.4. Biological technologies ....................................................................................................................... 40
7. Recovery opportunities from sewage by source separation............................................................................. 41
7.1. Introduction ............................................................................................................................................... 41
7.2. New approaches ........................................................................................................................................ 41
7.3. Applications ............................................................................................................................................... 42
7.3.1. The Grove (Aus) .................................................................................................................................. 42
7.3.2. Lubeck (Germany) .............................................................................................................................. 42
7.3.3. Vacuum (low water) ........................................................................................................................... 43
7.3.4. Sneek (NL)........................................................................................................................................... 43
8. Resource recovery with microalgae .................................................................................................................. 44
8.1. Microalgae ................................................................................................................................................. 44
8.2. Photosynthesis........................................................................................................................................... 44
8.3. Microalgae photoreactors ......................................................................................................................... 46
8.4. Wastewater treatment with microalgae ................................................................................................... 46
9. Biometallurgy .................................................................................................................................................... 47
9.1. Introduction ............................................................................................................................................... 47
9.1.1. Basics and fundamentals .................................................................................................................... 47
9.1.2. Applications ........................................................................................................................................ 48
9.2. Bioleaching................................................................................................................................................. 48
9.2.1. Autotrophic bioleaching ..................................................................................................................... 48
9.2.2. Heap bioleaching ................................................................................................................................ 49
9.2.3. Examples............................................................................................................................................. 49
9.3. Biooxidation ............................................................................................................................................... 49
9.4. Biological wastewater treatment .............................................................................................................. 50
3
, 1. ANAEROBIC DIGESTION
1.1. Introduction
− Anaerobic digestion = process in which biomass either as a solid fraction, slurries or suspended material
is converted to biogas in the absence of oxygen
• Organic waste → CH4 & CO2 → renewable energy
− Advantages AD:
• Biogas production
• Organic waste stabilization
• Low cell yield
• High organic loading rate
• Limited nutrient demands
• Low costs for operation and maintenance
− Methane is a dangerous GHG
• For every kg CH4 emitted = 34 kg CO2 emitted
− Comparison anaerobic digestion vs aerobic digestion
− Energy recovery from AD:
• Heat: trough a boiler
▪ Lowest quality of energy
▪ Losses 15%
• Electricity: trough a CHP (combined heat and power)
▪ Best option at present
▪ Production of electricity and heat
▪ Smart grids
• Biogas: needs to be upgraded
▪ Complicated
▪ Efficiency is unknown
1.2. Stoichiometry
− Fermentation: no oxidant
• COD is preserved
− Anaerobic digestion: extreme fermentation
• CO2 is not oxidizable, CH4 not reducible
• Stable end products
• Gaseous end products: easy to harvest
− Buswell equation: assuming 100% degradation, how much CH4 can we produce?
4
Juliet Van Haudt
2022-2023
INHOUD
1. Anaerobic digestion ............................................................................................................................................ 4
1.1. Introduction ................................................................................................................................................. 4
1.2. Stoichiometry............................................................................................................................................... 4
1.3. Biochemistry & microbiology....................................................................................................................... 5
1.3.1. Hydrolysis ............................................................................................................................................. 5
1.3.2. Fermentation & acidogenesis ............................................................................................................... 5
1.3.3. Acetogenesis ........................................................................................................................................ 5
1.3.4. Methanogenesis ................................................................................................................................... 6
1.4. Thermodynamics ......................................................................................................................................... 6
1.5. Operational conditions ................................................................................................................................ 6
1.5.1. Substrates ............................................................................................................................................. 6
1.5.2. pH ......................................................................................................................................................... 6
1.5.3. Temperature......................................................................................................................................... 7
1.5.4. Ammonia toxicity ................................................................................................................................. 7
1.5.5. Sulphate and sulphide .......................................................................................................................... 7
1.6. Reactors technology for liquid streams ....................................................................................................... 7
1.6.1. Process design: single stage process .................................................................................................... 7
1.6.2. Process design: two-stage process ....................................................................................................... 7
1.6.3. Anaerobic lagoons ................................................................................................................................ 8
1.6.4. High-rate anaerobic digestion: biomass retention ............................................................................... 8
1.7. Solids digestion .......................................................................................................................................... 11
2. Bioproduction.................................................................................................................................................... 13
2.1. Carboxylate production ............................................................................................................................. 13
2.1.1. Introduction and rationale of the carboxylate platform .................................................................... 13
2.1.2. Fundamentals and pathways.............................................................................................................. 13
2.1.3. Operational conditions, reactor configurations and product recovery .............................................. 14
2.1.4. A couple of examples ......................................................................................................................... 16
2.1.5. Summary: key features ....................................................................................................................... 17
2.2. Biopolymer production .............................................................................................................................. 17
2.2.1. Bioplastics: definition and types......................................................................................................... 17
2.2.2. PHA & PLA .......................................................................................................................................... 18
3. Composting ....................................................................................................................................................... 20
3.1. General aspects ......................................................................................................................................... 20
1
, 3.2. The conversion process ............................................................................................................................. 20
3.2.1. Microorganisms active during composting ........................................................................................ 21
3.2.2. Phases of the composting process ..................................................................................................... 21
3.3. Factors affecting the composting process ................................................................................................. 22
3.3.1. Oxygen and aeration .......................................................................................................................... 22
3.3.2. Temperature....................................................................................................................................... 22
3.3.3. Moisture ............................................................................................................................................. 23
3.3.4. Balanced microorganism diet ............................................................................................................. 23
3.3.5. pH ....................................................................................................................................................... 23
3.3.6. Size does matter ................................................................................................................................. 24
3.3.7. When is the compost finished ............................................................................................................ 24
3.3.8. Summary ............................................................................................................................................ 24
3.4. Composting technologies .......................................................................................................................... 25
3.4.1. Preprocessing ..................................................................................................................................... 25
3.4.2. Windrow system................................................................................................................................. 25
3.4.3. Passively aerated static windrow ....................................................................................................... 25
3.4.4. Actively aerated static windrow ......................................................................................................... 25
3.4.5. Closed vessel composting ................................................................................................................... 26
3.4.6. How to choose the system? ............................................................................................................... 26
3.5. General evaluation..................................................................................................................................... 26
4. Sulfur management and recovery ..................................................................................................................... 27
4.2. Occurrence of sulfur compounds in wastewater treatment and waste gases .......................................... 27
4.2.1. Sewer systems .................................................................................................................................... 27
4.2.2. Biogas ................................................................................................................................................. 28
4.3. Treatment of sulfur-rich gas streams ........................................................................................................ 29
4.3.1. Physico-chemical sulfide removal ...................................................................................................... 29
4.3.2. Biological sulfide removal ................................................................................................................... 29
4.4. Bioreactors used for H2S removal .............................................................................................................. 29
5. Nutrient recovery .............................................................................................................................................. 31
5.1. Problems .................................................................................................................................................... 31
5.1.1. Nitrogen .............................................................................................................................................. 31
5.1.2. Phosphorus ......................................................................................................................................... 33
5.1.3. Important take home messages ......................................................................................................... 33
5.2. Solutions .................................................................................................................................................... 34
5.2.1. Role of the biogas process in optimizing nutrient & energy cycles .................................................... 35
5.2.2. Characterization bio-based fertilizers ................................................................................................ 35
6. Water reuse....................................................................................................................................................... 36
6.1. Motivation for water reuse........................................................................................................................ 36
6.2. Categories of water reuse .......................................................................................................................... 37
2
, 6.3. Management & risk assessment ................................................................................................................ 37
6.4. Water constituents to be considered ........................................................................................................ 38
6.4.1. Composition for water reclamation ................................................................................................... 38
6.5. Treatment technologies ............................................................................................................................. 39
6.5.1. Filtration ............................................................................................................................................. 39
6.5.2. Reversed osmosis ............................................................................................................................... 40
6.5.3. Disinfection ......................................................................................................................................... 40
6.5.4. Biological technologies ....................................................................................................................... 40
7. Recovery opportunities from sewage by source separation............................................................................. 41
7.1. Introduction ............................................................................................................................................... 41
7.2. New approaches ........................................................................................................................................ 41
7.3. Applications ............................................................................................................................................... 42
7.3.1. The Grove (Aus) .................................................................................................................................. 42
7.3.2. Lubeck (Germany) .............................................................................................................................. 42
7.3.3. Vacuum (low water) ........................................................................................................................... 43
7.3.4. Sneek (NL)........................................................................................................................................... 43
8. Resource recovery with microalgae .................................................................................................................. 44
8.1. Microalgae ................................................................................................................................................. 44
8.2. Photosynthesis........................................................................................................................................... 44
8.3. Microalgae photoreactors ......................................................................................................................... 46
8.4. Wastewater treatment with microalgae ................................................................................................... 46
9. Biometallurgy .................................................................................................................................................... 47
9.1. Introduction ............................................................................................................................................... 47
9.1.1. Basics and fundamentals .................................................................................................................... 47
9.1.2. Applications ........................................................................................................................................ 48
9.2. Bioleaching................................................................................................................................................. 48
9.2.1. Autotrophic bioleaching ..................................................................................................................... 48
9.2.2. Heap bioleaching ................................................................................................................................ 49
9.2.3. Examples............................................................................................................................................. 49
9.3. Biooxidation ............................................................................................................................................... 49
9.4. Biological wastewater treatment .............................................................................................................. 50
3
, 1. ANAEROBIC DIGESTION
1.1. Introduction
− Anaerobic digestion = process in which biomass either as a solid fraction, slurries or suspended material
is converted to biogas in the absence of oxygen
• Organic waste → CH4 & CO2 → renewable energy
− Advantages AD:
• Biogas production
• Organic waste stabilization
• Low cell yield
• High organic loading rate
• Limited nutrient demands
• Low costs for operation and maintenance
− Methane is a dangerous GHG
• For every kg CH4 emitted = 34 kg CO2 emitted
− Comparison anaerobic digestion vs aerobic digestion
− Energy recovery from AD:
• Heat: trough a boiler
▪ Lowest quality of energy
▪ Losses 15%
• Electricity: trough a CHP (combined heat and power)
▪ Best option at present
▪ Production of electricity and heat
▪ Smart grids
• Biogas: needs to be upgraded
▪ Complicated
▪ Efficiency is unknown
1.2. Stoichiometry
− Fermentation: no oxidant
• COD is preserved
− Anaerobic digestion: extreme fermentation
• CO2 is not oxidizable, CH4 not reducible
• Stable end products
• Gaseous end products: easy to harvest
− Buswell equation: assuming 100% degradation, how much CH4 can we produce?
4
