Microemulsion prepared magnetic nanoparticles for phosphate removal: Time efficient studies

•Microemulsion prepared magnetic nanoparticles (ME-MION) was employed for phosphate removal from sewage wastewater.•FT-IR technique confirms the phosphate bound on to the ME-MION surface.•Under laboratory condition, close to 100% phosphate removal was achieved within 20 min using ME-MION.•Magnetic nanoparticles were regenerated and reused with sewage wastewater for 5 consecutive times.

The present study investigates the effective removal of phosphate in sewage wastewater using magnetic iron oxide nanoparticles (MION). The microemulsion-prepared magnetic iron oxide nanoparticles (ME-MION) of around 7–10 nm was synthesized using water-in-oil microemulsion method. The interaction of ME-MION and phosphate was studied using In situ FT-IR technique. Batch experiments were carried out with wastewater to determine the conc. and time efficiency using ME-MION for removal of phosphate. The vibration peak at 1004 cm−1 and the presence of hydroxyl group (OH−) at 3673 cm−1 confirms the binding of phosphate to ME-MION. ME-MION with 0.44 g L−1 exhibited more than 95% phosphate reduction in 5 min and close to 100% in 20 min. Conversely the experimental data obtained has been fitted with Langmuir isotherm model and also exhibited high correlation coefficients. The ME-MION was regenerated and can be reused for minimum 5 consecutive times. Efficient and fast reduction of phosphate was attained while the recovery of nanoparticles was achieved by an external magnetic field. To the author's knowledge, this is the first report that underscores around 100% phosphate removal from wastewater using ME-MION in 20 min. The approach utilized in this study offers a potential technique in the reduction of phosphate in wastewater whilst, reducing the time and reuse of nanoparticles.

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