Phosphate and nitrate enrichment largely impair aquatic ecosystem functions and services, thus comprising an emerging problem of environmental concern. The problem pertains to developing countries where phosphate and nitrate discharge to surface water is on the rise due to a rapid growth in population. Herein, these pollutants (phosphate and ammonia) were removed from real municipal wastewater using a simple, fast, and cost-effective process. Raw cryptocrystalline magnesite, a mineral abundant in South Africa, was simply milled and calcined (mechano-thermo processing) in order to produce the activated magnesite (feed). The feed was then used in batch processing for pollutants adsorption and precipitation from real wastewater. The process was optimised by varying the treatment or contact time, feed dosage, concentration, pH, and temperature. The feed and product mineral (produced sludge) were characterised using X-ray Diffraction (XRD), field emission scanning electron microscopy (FESEM) compatible with energy dispersive spectroscopy (EDS), and Fourier Transform Infrared Spectrometer (FTIR). It was identified that the optimal conditions differed for each pollutant, highlighting the importance of tailoring the process to fit the local wastewater characteristics and as part of a treatment train system. Specifically, maximum P removal was achieved after 5 min of mixing, using 1 g L-1 of feed, 123 mg L-1 initial phosphate concentration, pH 8-10, and was not affected by temperature variations; whereas, for ammonia removal, optimal conditions were 180 min, 16 g L-1 feed dosage, 80 mg L-1 initial concentration, pH 10 and temperature > 45 °C. The optimal conditions for the removal of both pollutants from real wastewater were 30 min, 8 g L-1 dosage, 7.5 pH, 35 o C. Furthermore, Mg and Ca concentration was found to influence the process. Reduction in total dissolved solids and electrical conductivity suggest an attenuation of chemical species. Characterisation revealed that the product mineral obtained under the optimal conditions for pollutants removal is rich in quartz, periclase, brucite, calcite, magnesite, and struvite. This was further supported by the FTIR results, which indicated the presence of Mg-O, PO 4 3− , N-H and-OH stretches. In addition, the EDS verified the presence of Mg, Ca and P in product mineral. Results are suggestive of the high efficiency of the mechano-thermo activated magnesite treatment process for P and N removal and struvite crystallization. Thus, this technology could valorise municipal wastewater effluents and open new horizons for the
