Combined psychrophilic dry/wet anaerobic digestion - reverse osmosis processes for the valorisation of organic municipal solid waste into green energy, fertilizer and reusable wate

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Organic solids are present in very large quantities as products or waste from the food industry, agriculture and food markets. Approximately one third (1.3 billion tonnes) of the food produced globally for human consumption gets wasted every year. Organic waste makes up about 40% of the residential waste in Canada. Eliminating and reducing the organic solid waste without having any environmental effect is an internationally renowned challenge. Anaerobic digestion (AD) is considered to be an effective treatment method for the concentrated organic waste and exhibits great promise in bringing environmental and social sustainability by providing bioenergy from the renewable feed-stocks with recovery of nutrients to be used as fertilizer. Anaerobic digesters can be operated under liquid (wet), semi-solid, or solid-state (dry) conditions. Solid-state AD (DAD) using liquid inoculum recirculation-percolation method of operation at psychrophilic temperature could be a promising cost-effective option as it results in exportable dry organic fertilizer in addition to the green energy production. The effluent discharged from the liquid percolate DAD process will be further treated by the reverse osmosis (RO) process to produce high quality treated liquid and nutrient recovery for municipal food waste. The integration of the recovery of nutrients (as organic fertilizer) along with energy recovery through DAD will largely improve the bioenergy efficiency and fertilizer quality, and also provide solutions to reuse water for non-potable applications. The outcomes of this project will significantly add value for the Bio-Terre Systems Inc. and Canada in general. The DAD process operates at low temperature (20-25°C), resulting in year-round positive energy balance, even for cold weather countries like Canada. In effect, this project aims to develop energy efficient solutions for municipal food sectors, and preserve the quality of our environment by reducing greenhouse gas (GHG) emissions. In addition, the end-product can be used as a valuable organic fertilizer and treated the water can be reused for non-potable/industrial purposes.