Ammonium Nitrogen Removal from Urea Fertilizer Plant Wastewater via Struvite Crystal Production

3rd International Conference on Global Sustainability and Chemical Engineering

工业技术;化学工业

Machdar, I.^1 ; Depari, S.D.^1 ; Ulfa, R.^1 ; Muhammad, S.^1 ; Hisbullah, A.B.^1 ; Safrul, W.^1

Laboratory of Environmental Engineering, Chemical Engineering Department, Faculty of Engineering, Syiah Kuala University, Darussalam, Banda Aceh, Indonesia^1

关键词: Ammonium concentrations;    Ammonium nitrogen;    Batch crystallizer;    Crystal production;    First-order kinetic models;    Reactant molar ratio;    Slow release fertilizers;    Struvite formation;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/358/1/012026/pdf
DOI  :  10.1088/1757-899X/358/1/012026

学科分类：工业工程学

来源: IOP

【 摘 要 】

Elimination of ammonium concentration from urea fertilizer plant wastewater through struvite crystal (NH4MgPO4.6H2O) formation by adding MgCl2, KH2PO4, and KOH were studied. This method of elimination has two benefits, namely, reducing ammonium nitrogen content in the wastewater, as well as production of a valuable material (struvite crystal). Struvite is known as a slow-release fertilizer and less soluble. This report presents the ammonium removal efficiencies during struvite formation. The growth of struvite production under different molar ratios of Mg2+:NH4 +:PO4 3- and solution pH is also discussed. To find the efficiencies and measure the growth rates, lab-scale experiments were conducted in a batch crystallizer-reactor. SEM, XRD, and FTIR observation were also applied to investigate the characteristics of struvite. The reactant molar ratios of Mg2+:NH4 +:PO4 3- of 1.2:1:1, 1:1:1.2, and 1:1:1 were evaluated. Each of the molar ratios was treated at the solution pH of 8, 9, and 10. It was found that, the highest ammonium removal efficiency was 94.7% at the molar ratio of 1.2:1:1 and pH of 9. Primarily, the growth rate of struvite formation complied with a first-order kinetic model. The rate constants (k1) were calculated to be 2.6, 4.3, and 5.0 h-1 for solution pH of 8, 9, and 10, respectively. The findings of the study provide suggestion for an alternative sustainable recovery of ammonium nitrogen content in a urea fertilizer plant effluent.