oa Nanosorbents For The Selective Removal Of Boron From Seawater

The rejection efficiency of boron by RO membranes is poor, especially when a large proportion of boron in feedwater exists as uncharged boric acid which can diffuse through most of the available RO membranes.1,2 Among the methods suggested for boron removal from water and wastewater, adsorption is a very useful and economical technique. Magnetic adsorbents containing chelating precursors that are selective for boron have been used as a smart, fast and simple method for the separation and pre-concentration of boron3. After adsorption, the adsorbents can be isolated from the medium by simple magnetic separation. Here, we present novel magnetic nanocomposites for the selective removal of boron from seawater. The nanocomposites have been synthesized and fully characterized using scanning electron microscopy (SEM), tunneling electron microscopy (TEM), Fourier transformed infrared (FTIR) and powder x-rat diffraction (PXRD). This technology provides a simple method for the adsorption of boron and separation of magnetic nanoparticles from a solution using an easy magnetic procedure. The effect of different nanosorbents, sorbent amount and pH on the sorption of boron was studied. The magnetic sorbent that provided the highest boron sorption efficiency was used for the subsequent experiments investigating the most effective magnetic sorbent amount and pH for the sorption of boron. Experimental results indicate that boron sorption increases with increasing sorbent dosage up to a sorbent amount of approximately 0.6 g, after which the difference in removal efficiency was found to be negligible. The effect of pH on boron removal efficiency using the nanosorbents was studied at initial boron concentrations of 4-5 ppm, amounts commonly found in seawater. The sorption of boron was found to be highest at a pH range of 7-7.5 with a sorption efficiency of 77.6 ± 1%.