ALGAE FOR ENERGY AND FEED: A WASTEWATER SOLUTION. A REVIEW (Project 4A-101 112) Report prepared for the Co-operative Research Centre for High Integrity Australian Pork By Buchanan1, AN, Bolton1, N, Moheimani2, N, Svoboda1, IF, Grant3, T, Batten4, D, Cheng1, NN, Borowitzka2, M, and Fallowfield1 HJ. Health and Environment Group1, School of the Environment, Flinders University, Adelaide, School of Biological Sciences & Biotechnology2, Murdoch University, Murdoch and Life Cycle Strategies Pty. Ltd3., Melbourne and The Temaplan Group4, Victoria. January 2013 Established and supported under the Australian Government’s Cooperative Research Centres Program Contents 1 Executive summary .......................................................................................... 1 2 Research Needs ............................................................................................... 2 2.1 Integration of treatment systems for wastewater treatment, biomass energy production and GHG abatement .............................................................................................. 2 2.2 Management of the animal and occupational health risk of reusing wastewater for flushing and wash-down ......................................................................................... 2 2.3 Growth of algae for pig nutrition .................................................................... 3 2.4 Anaerobic digestion .................................................................................... 3 2.5 Life cycle assessment .................................................................................. 3 3 Executive Overview .......................................................................................... 4 3.1 Review Objective ....................................................................................... 4 3.2 Current manure handing strategies ................................................................. 4 3.3 Deficiencies with current manure management in the pig industry .......................... 5 3.4 Manure as an energy source .......................................................................... 6 3.5 Production of microalgae for pig feed .............................................................. 6 3.6 Sub-clinical disease and the effect on profitability .............................................. 7 3.7 Manure as a fertiliser .................................................................................. 7 3.8 Greenhouse gases and life cycle assessment (LCA) ............................................... 8 3.9 Financial viability and investment risk & constraints ............................................ 9 3.10 References .............................................................................................. 13 4 The Australian Pork Industry: An Overview of Size, distribution and current manure Management practices ........................................................................................... 14 Neil Buchanan 4.1 Distribution of the Australian Pig industry (Aust_Pork 2010) ................................. 14 4.2 Changing demographics of pig production ........................................................ 17 4.3 Waste treatment: an overview ...................................................................... 19 4.3.1 Anaerobic lagoons .................................................................................. 19 4.3.2 Deep-Litter Systems ................................................................................ 20 4.3.3 Composting .......................................................................................... 21 4.3.4 Vermiculture ......................................................................................... 22 4.3.5 Carcass Disposal ..................................................................................... 23 4.4 Summary ................................................................................................. 23 4.5 References .............................................................................................. 24 5 Current Effluent Treatment Practice: ANAEROBIC Digestion ..................................... 25 Neil Buchanan & Ryan Cheng 5.1 Anaerobic digestion in livestock agriculture ...................................................... 25 5.1.1 Anaerobic digestion biochemical processes .................................................... 27 5.1.2 Hydrolysis & Acidogenesis ......................................................................... 28 5.1.3 Acetogenesis ......................................................................................... 29 5.1.4 Methanogenesis ..................................................................................... 29 5.1.5 Equilibrium ........................................................................................... 29 5.2 Factors Influencing Anaerobic Digestion ........................................................... 30 5.2.1 Temperature ......................................................................................... 31 5.2.2 pH ..................................................................................................... 32 5.2.3 Ammonia ............................................................................................. 32 5.2.4 Sulphides ............................................................................................. 33 5.2.5 Treatment time and organic loading ............................................................ 33 5.3 Advantages and disadvantages of anaerobic digestion (Table 5.1) .................... 34 5.3.1 Advantages of anaerobic digestion .............................................................. 34 5.3.2 Disadvantages of anaerobic digestion ........................................................... 34 5.4 Anaerobic lagoons ..................................................................................... 36 5.4.1 Facultative lagoons ................................................................................. 37 5.4.2 Stratified lagoons ................................................................................... 37 5.5 Anaerobic pond design – Prediction of manure composition. .................................. 37 5.5.1 DAMP model ......................................................................................... 38 5.5.2 Nutrient Mass Balance Models .................................................................... 38 5.5.3 DMDAMP model ...................................................................................... 39 5.5.4 Summary of manure prediction models currently used in Australia ....................... 39 5.6 Anaerobic digestion - Estimating methane production from volatile solids in the manure 40 5.6.1 Bo Factor .............................................................................................. 40 5.6.2 The methane conversion factor .................................................................. 41 5.7 Anaerobic digestion - Electricity generation from biogas ...................................... 42 5.8 Case studies ............................................................................................. 43 5.8.1 Case Study 1: Berrybank Farms, Windermere, Vic ............................................ 43 5.8.2 Case Study 2: Bears Lagoon Piggery, 60 km N of Bendigo, Vic ............................. 45 5.8.3 Case Study 3: Grantham Piggery, 100 km W of Brisbane, Qld .............................. 49 5.9 ANAEROBIC DIGESTION OF ALGAL BIOMASS ....................................................... 52 5.9.1 Co-digestion ......................................................................................... 55 5.10 Summary ................................................................................................. 57 5.11 Knowledge gaps ........................................................................................ 57 5.12 References .............................................................................................. 58 6 AEROBIC TREATMENT OF PIGGERY WASTEWATERS .................................................. 62 Dr Ivo Svoboda, Neil Buchanan & Prof. Howard Fallowfield 6.1 Introduction ............................................................................................. 62 6.2 The effect of aerating slurry on organic matter and nutrients ............................... 63 6.2.1 Oxidation of Carbon ................................................................................ 63 6.2.2 Heterotrophic oxygen demand ................................................................... 64 6.2.3 BOD & COD removal ................................................................................ 65 6.2.4 Oxidation of Ammonia ............................................................................. 66 6.3 Reduction of offensive odour ........................................................................ 69 6.4 The effect of aerobic treatment on pathogens and faecal indicators ....................... 70 6.5 Production of energy .................................................................................. 71 6.6 Aerobic treatment system design ................................................................... 73 6.6.1 Aerators .............................................................................................. 73 6.6.2 AT design variants .................................................................................. 73 6.6.3 Measuring and control equipment. .............................................................