Magnesium ammonium phosphate formation, recovery and its application as valuable resources: a review

Abstract

To address the issues of wastewater treatment and depleting phosphorus (P) resources, the present review focuses on the very wide interest in P recovery from wastewater, with scientific research underway in countries across the globe. The study describes the growing concern for diminishing P resources and then the chemical principle of magnesium ammonium phosphate (MAP) precipitation, factors influencing MAP crystallization, and various developments achieved through bench, pilot and full scale MAP reactors. A brief description is given of MAP purification and dissolution to economically exploit MAP as a phosphate and magnesium source. Experience in re‐use of recovered MAP as a sustainable agriculture fertilizer is discussed including pot and field trials. © 2012 Society of Chemical Industry

Effects of graphene oxide on the properties and microstructures of the magnesium potassium phosphate cement paste

“…It has been regarded as a good candidate to replace Portland cement and widely investigated in recent years due to its many advantages, such as rapid setting time, higher mechanical behavior and lower drying shrinkage [4][5][6]. In terms of civil engineering, MPC cement has widely been used as a repair material for many years, such as damaged runway and bridge piers, because it set rapidly with high early strength, low permeability and good durability.…”

Precipitation of organic arsenic compounds and their degradation products during struvite formation

“…The effluent of anaerobic reactors contains a high concentration of ammonium (NH 4 + -N) and phosphate (PO 4 3− -P), which could cause severe eutrophication in surface water after discharging into aquatic environments [14]. As a finite and non-renewable resource, phosphate has been widely used in industry and agriculture [15]. Therefore, the recovery of PO 4 3− -P and NH 4 + -N present in the anaerobic reactor effluent is of great significance.…”

Is nitrogen fixation (once again) “vital to the progress of civilized humanity”?

“…Therefore, even with the optimistic assumption of recovering all of the N from wastewater, it will be insufficient to meet demand. There is existing technology for recovering N and P simultaneously from wastewater through the production of struvite (MgNH 4 PO 4 Á6H 2 O), but it is feasible only for concentrated wastewater (Liu et al 2013).…”