SYNTHESIS OF NANOSCALE ZERO VALENT IRON COATED WITH IRON SULFIDE PRECIPITATE ON SURFACE THEREOF BY MEANS OF HYDROGEN SULFIDE IONS AND METHOD FOR PURIFYING ENVIRONMENTAL POLLUTANTS IN CONTAMINATED SOIL AND GROUND WATER USING SAME

摘要

The present invention relates to nanoscale zero valent iron (nZVI) coated with iron sulfide precipitate on the surface thereof by means of hydrogen sulfide (HS^-) ions and to a method for purifying environmental pollutants in contaminated soil and ground water using same. More particularly, the present invention relates to the synthesis of nanoscale zero valent iron coated with iron sulfide precipitate on the surface thereof (hydrosulfide mediate-nZVI, H-nZVI) by adding HS^- ions to the conventional reduction method using sodium borohydride to prepare novel nZVI which is economical and has outstanding reactivity for the purification treatment of heavy metals and organic pollutants in soil/ground water, and to a method for purifying environmental pollutants using the H-nZVI. The H-nZVI of the present invention is applied to the dehalogenation of environmental pollutants present in soil and ground water, and to an immobilization process for heavy metals. According to the present invention, a novel nZVI can be synthesized which has a small amount of iron sulfide precipitate on the surface thereof as compared to that synthesized by conventional methods using dithionite. Also, the present invention exhibits improved treatment efficiency over the previously reported efficiency of D-nZVI in which dithionite is added, or of typical nZVI, in the purification treatment of organic substances such as TCE and environmental pollutants of heavy metals.