Perchlorate Reduction by Nanoscale Iron Particles

Rapid and complete destruction of perchlorate in water and ion-exchange brine using stabilized zero-valent iron nanoparticles

“…These initial concentration values are within the range of reported perchlorate levels, especially in the source zones (USGAO, 2005) or in spent IX brine, and are comparable to those studied by other researchers (Cao et al, 2005;Hurley and Shapley, 2007;Moore et al, 2003;Oh et al, 2006a, b). In all cases, a ZVI dose of 1.8 g L À1 was tested, which required a stabilizer (CMC or starch) concentration of 0.9% (w/w) to maintain effective particle stabilization.…”

“…In another study, Oh et al (2006b) reported that perchlorate in wastewater was completely removed by iron at an elevated temperature of 150 1C in 6 h without pH control. Cao et al (2005) observed that non-stabilized iron particles were able to degrade perchlorate at temperatures from 25 to 75 1C.…”

“…It has been reported that decreasing the size of ZVI particles to the nanoscale can greatly enhance the reaction rates for perchlorate reduction (Cao et al, 2005) and nitrate removal (Yang and Lee, 2005). However, because nanoscale ZVI particles tend to agglomerate rapidly (in a few minutes) (He and Zhao, 2005;He et al, 2007), the ''nanoparticles'' without a stabilizer are actually agglomerates or flocs of ZVI particles in the micron scale.…”

“…In all cases, a ZVI dose of 1.8 g L À1 was tested, which required a stabilizer (CMC or starch) concentration of 0.9% (w/w) to maintain effective particle stabilization. The iron dose amounts to the lower end of the range (1.0-20.0 g L À1 of nonstabilized ZVI) tested by Cao et al (2005). Higher concentrations of ZVI were also prepared, but it would require the stabilizer concentration to be increased accordingly.…”

Effective Pb2+ removal from water using nanozerovalent iron stored 10 months

“…In the past few years, different methods were developed to synthesize iron nanoparticles (Brumfiel 2003;Hassan 2005;Zhang et al 2015;Su et al 2016), modify their surface properties (Mahfuz and Ahmed 2005;Karlsson et al 2004;Rajajayavel and Ghoshal 2015), and improve their efficiency for field delivery and reactions (Liu et al 2015;Glavee et al 1995;Khalil et al 2004;Xu et al 2005;Zhang et al 1998;Schrick et al 2002;Elliott and Zhang 2001). Extensive investigations reported that nanoscale iron particles are effective for the removal of a wide environmental contaminants such as heavy metal ions like As(III), Pb(II), Cu(II), Ni(II), and Cr(VI), chlorinated organic solvents, organochlorine pesticides, some inorganic compounds (Elliott and Zhang 2001;Liu et al 2005;Alowitz and Scherer 2002;Cao et al 2005;Kanel et al 2005), and organic dyes (Alowitz and Scherer 2002;Cao et al 2005;Kanel et al 2005).…”