Nutritive value and agricultural/horticultural uses of intra-process wastewater generated from anaerobic digestion of organic wastes
Modern societies continue to generate increasing volumes of waste, and nutrients in these wastes represent 'lost' resources if not re-used. Super Blue Box Recycling Corporation (SUBBOR) processes municipal wastes using anaerobic digestion technology, producing methane for electricity generation, an organic-rich peat-like product, and a plant nutrient-rich wastewater stream. This research evaluated the wastewater as a potential plant nutrient source by evaluating turfgrass growth and nutrient uptake in growth room and field experiments. The wastewater performed equal to a commercial fertiliser when used at nitrogen rates up to OMAFRA recommendations. Turfgrass and two nursery woody species were also grown hydroponically and supplied with wastewater and teas of spent mushroom and municipal composts. Amendment of these nutrient solutions with essential plant nutrients improved plant growth response. There is potential for use of anaerobic wastewater as a supplemental nutrient source for plant growth, providing adjustments are made to pH, EC and nutrient levels.