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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

Magnesium ammonium phosphate (MAP) was recovered from swine wastewater and the feasibility of reutilizing it as a slowly-releasing fertilizer was evaluated. Maize growth was investigated with normal and high application rates of MAP and a fused super phosphate (FSP) fertilizer. A total of 5 treatments (T 0 = control, T 1 = MAP based on 30 kg P ha -1 , T 2 = FSP based on 30 kg P ha -1 + urea equivalent to nitrogen of MAP applied in T 1 , T 3 = MAP based on 40 kg P ha -1 , T 4 = FSP based on 40 kg P ha -1 +urea equivalent to nitrogen of MAP applied in T 3 ) were arranged with 3 replications. In the case of height and circumference, significant differences were found between controls and treated maize plants (p<0.01). However, no statistical differences were found between MAP-and FSP-urea treated maize. Leaf area and green biomass yield were significantly (p<0.01) higher in the treated group than control. Leaf area was also found significantly higher (p<0.01) in the higher MAP-treated group (2,374 cm 2 plant -1 ) than other treatments. N 2 O emission was found to be lower in MAP treated soil than that from FSP-urea treated soil, which might be due to the slow releasing pattern of MAP. It could be assumed from the results that MAP would be an eco-friendly sustainable fertilizer source for crop production.

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