Removal of ammonium (NH4 +) as struvite from the wet scrubber wastewater of a composting plant was investigated. Magnesium salts and phosphate salts were added to the wastewater containing high concentration (29.33 mmol/L) of NH4 + for the precipitation of struvite. Two sets of chemicals, including reagent A (MgCl2 + K2HPO4) and reagent B (MgO + 85 % H3PO4) were used, respectively, at stoichiometric ratio ([Mg2+]:[NH4 +]:[PO4 3−] = 1:1:1) and at different pH ranging from 8 to 9. Experimental results showed that reagent A performed better than reagent B, and 73.3 % NH4 + was removed and recovered as struvite at pH 8.5. Removal efficiency of NH4 + did not improve when molar ratio became higher than stoichiometry. The formation of struvite was confirmed by field emission scanning electron microscope (FESEM), X-ray spectroscopy (EDX), X-ray diffractometer (XRD), and wet chemical analysis. Experimental results were compared with model predictions by PHREEQC. NH4 + removal efficiency was not affected by 5–10 mg/L of Fe(III). The study demonstrated that removal and recovery of NH4 + as struvite from the wet scrubber wastewater is feasible.