Ammonium removal from digested effluent of swine wastewater by using solid residue from magnesium-hydroxide flue gas desulfurization process

• Published in: Journal of industrial and engineering chemistry (Seoul, Korea) Vol. 58; pp. 148 - 154
• Main Authors: Lin, Huanjia, Lin, Yunqin, Wang, Dehan, Pang, Yuwan, Zhang, Fabao, Tan, Shuanhu
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 25.02.2018; 한국공업화학회
• Subjects: Ammonium removal; Digested effluent of swine wastewater; MAP precipitation; Solid residue from MFGD process; 화학공학; MAP precipitation; Ammonium removal; Solid residue from MFGD process; Digested effluent of swine wastewater
• ISSN: 1226-086X; 1876-794X
• DOI: 10.1016/j.jiec.2017.09.019

[Display omitted] •First report on ammonium removal using MFGD residue as a Mg source.•MAP optimally formed at pH 9.5, HRT 10min and n(PO43−):n(Mg2+):n(NH4+)=0.6:0.7:1.•Ammonium concentration was less than 200mgL−1 in DESW after MAP precipitation.•Total chemical cost was saved by 29.17% compared to MgCl2 application. This paper focused on the ammonium removal from the digested effluent of swine wastewater (DESW) via MAP precipitation using the residue from magnesium-hydroxide flue gas desulfurization (MFGD) process as a Mg source. The MAP precipitation was proceeded in a 500-mL beaker with a magnetic stirrer. It was found that around 60% of ammonium in the DESW was removed at pH 9.5, HRT 10min and the P:Mg:N molar ratio of 0.6:0.7:1. The NH4+ concentration (183.2mg/L) in the DESW after MAP precipitation was lower than 200mgL−1, being alternative for the downstream biological process. A low content of PO43− (3.64mgL−1) and a high concentration of Mg2+ (67.17mgL−1) were also observed in the solution. The main composition of the precipitate was proved to be MAP via XRD and SEM-EDX analysis. Besides, the total chemical cost was saved by 29.17% using the MFGD residue as a Mg source instead of the commercial MgCl2·6H2O. Hence, reusing MFGD residue as a Mg source to remove ammonium from the DESW was feasible with cost saving, resource recovery and environment protection.