Selected Pesticide Remediation with Iron Nanoparticles: Modeling and Barrier Applications

摘要

Pesticide contamination of groundwater is a major concern in agricultural areas. Of the many remediation technologies developed in the last decade, zero-valent iron is among the most studied. Nanoscale zero-valent iron (nZVI), with its unique properties and high surface area, enhances many of the advantages of traditional iron remediation. Unfortunately, studies comprehensively examining the utility of iron nanoparticles for pesticide remediation are lacking. The intent of this work is to survey the effectiveness of iron nanoparticles for several common chlorinated pesticides and to comprehensively study the reaction kinetics.Specifically, this study examined the effectiveness of iron nanoparticles for the treatment of the herbicides alachlor, atrazine, dicamba and picloram. Iron nanoparticles were synthesized by the borohydride reduction method and characterized using transmission electron microscopy, X-ray diffraction and Brunauer-Emmett-Teller (BET) specific surface area analysis. The resulting particles had an average diameter of 35 nm and a N2-BET specific surface area of 25 m(2) g(-1). Of the compounds studied, only alachlor degraded in the presence of nZVI. The surface area normalized pseudo first-order rate constant (kSA) for alachlor dechlorination by nZVI was found to be 38.5 x 10(-5) L h(-1) m(-2) (R(2) = 0.999). The primary reaction by-product was identified as dechlorinated alachlor. The effect of ionic strength was also examined. The results suggested that nZVI might be a viable option for both site remediation and low volume, high concentration pesticide waste treatment.