NH4Cl recovery from high-ammonia organic waste liquor by electrolysis with aluminum soluble anode

High-ammonia organic waste liquor is regarded as highly toxic and non-biodegradable due to containing high concentration of ammonia and organic refractory compounds. Treating high-ammonia organic waste liquor could be costly in the need of large energy or chemical agent input. Recovery of ammonium is an alternative way because high ammonium waste liquor could act as a reservoir of nitrogenous fertilizer. In this study, NH4Cl was separated from waste liquor by electrolysis with aluminum-soluble anode. The white foamy substances with NH4Cl purity over 90 % were produced at a current density of 12.5 mA/cm2 with 100 min electrocution. The white foamy substance production rate was increased as pH rose, and NH4Cl purity increased from 82.44 % at pH 4 to 91.34 % at pH 6. The soluble aluminum from anode sacrifice promoted crystallization and separation of NH4Cl by participating in the formation of CGAs (Colloidal Gas Aphrons) and improving their stability. Organic substances in the liquor functioned as surfactant to generate of CGAs, CGAs carried NH4Cl crystals floated to the surface and formed the white foamy substance. The study proposes an efficient, sustainable method for the hazardous high-ammonia organic waste liquor resource utilization.