An analysis of boron removal from water using modifed zero-valent iron nanoparticles

Considering the necessity of boron removal from water and its unexpected resistance against a majority of common processes, the use of efficient procedures for its removal seems more necessary than
ever. Therefore, the aim of the present study is to analyze boron removal from water using zero-valent
iron nanoparticles (nZVI) stabilized by two biopolymers. Modified nZVI was synthesized using the
method of ferrous sulfate reduction. Structural features, chemical mixture, and morphological characteristics of selected nanoparticles (starch-nZVI [S-nZVI]) were confirmed by X-ray diffraction and
scanning electron microscope. The function of S-nZVI in boron removal was examined under the influence of various factors including initial concentration of boron, S-nZVI dose, pH, and contact time
in batch conditions. Boron was measured by the standard carmine method. The results showed that
1 mg/L of S-nZVI can reduce up to 20 mg/L of boron to less than its maximum allowable concentration
in the pH of 8.5 and reaction time of 90 min. Kinetics of boron adsorption by S-nZVI follows pseudo-second-order (R2 = 0.999) upon which adsorption capacity of boron by S-nZVI at equilibrium time
fluctuates between 4.55 mg/g at initial concentration of 5 mg/L and 48.78 mg/g at initial concentration
of 50 mg/L. Furthermore, boron adsorption by S-nZVI is more compatible with Langmuir isotherm
(R2 = 0.93). Accordingly, the maximum adsorption capacity of boron by S-nZVI was determined as
128.2 mg/g. Hence, as an appropriate, eco-friendly reactant, nZVI modified by starch can be used in
boron removal from aquatic environments