Acetate and ammonia recovery and enrichment from wastewater intended for single cell protein (SCP) production by electrodialysis-forward osmosis (ED-FO)

Acetate and ammonia were both recovered from anaerobic digestion (AD) effluent into the middle chamber of a three-chamber electrodialysis (ED) reactor. The recovery, containing 4.5 g/L acetic acid and 0.76 g/L ammonia, was utilized to feed the yeast strain Saccharomyces cerevisiae and obtained single cell protein (SCP) with 1.76 g/L biomass and 44% protein. Forward osmosis (FO) was applied to further enrich the recovery, but a coupled FO-ED reactor consumed much more energy than a single ED reactor, where it cost only 1 euro during ED recovery at 2 V, at the meantime recovered 42.2% acetate and 60.1% ammonia from 7143 L AD effluent wastewater.