Struvite Precipitation for Ammonia Nitrogen Removal in 7-Aminocephalosporanic Acid Wastewater

7-Aminocephalosporanic acid wastewater usually contains high concentrations of ammonium (NH(4)(+)-N), which is known to inhibit nitrification during biological treatment processes. Chemical precipitation is a useful technology to remove ammonium from wastewater. In this paper, the removal of ammonium from 7-aminocephalosporanic acid wastewater was studied. The optimum pH, molar ratio, and various chemical compositions of magnesium ammonium phosphate (MAP) precipitation were investigated. The results indicated that ammonium in 7-aminocephalosporanic acid wastewater could be removed at an optimum pH of 9. The Mg(2+):NH(4)(+)-N:PO(4)(3)(−)-P molar ratio was readily controlled at a ratio of 1:1:1.1 to both effectively remove ammonium and avoid creating a higher concentration of PO(4)(3)(−)-P in the effluent. MgCl(2)·6H(2)O + 85% H(3)PO(4) was the most efficient combination for NH(4)(+)-N removal. Furthermore, the lowest concentration of the residual PO(4)(3−)-P was obtained with the same combination. Struvite precipitation could be considered an effective technology for the NH(4)(+)-N removal from the 7-aminocephalosporanic acid wastewater.