Magnetoactive Compound Based on Humic Acid and Magnetite as a Sorbent for Heavy Metals

In the process of in situ synthesis using ultrasound, a magnetoactive sorbent based on humic acid and magnetite was produced for the extraction of heavy metals from industrial wastewater by magnetic solid-phase extraction. When exposed to ultrasound, substances are dispersed, which results in an increase in the specific surface area of the studied sorbent and the opening of inaccessible pores on its surface. Humic acid, which is part of the magnetoactive sorbent, is a stabilizer of the size of magnetite nanoparticles. The composition and sorption properties of a magnetoactive compound with respect to heavy metal ions Pb(II), Cu(II), Zn(II), Sr(II), Fe(III), and Al(III) were investigated. The dependence of the sorption value of the studied metal ions on the temperature and pH of the waste water was examined, the sorption capacity of the magnetoactive compound and the degree of waste water purification were determined. It was found that the maximum extraction of metal ions Pb(II), Cu(II), Al(III), Zn(II), Sr(II), Fe(III) from wastewater occurs at 25°C and pH 6.5, after additional sorption post-treatment, the content of Pb(II), Cu(II) and Zn(II) ions decreases by more than 15 times, and of Al(III), Pb(II), and Fe(III) ions, more than 12 times. The maximum degree of water purification from metal ions Pb(II), Cu(II), Al(III), Zn(II), Sr(II), and Fe(III) is 98.8, 83.1, 81.5, 78.1, 69.5, and 42.5%, respectively.