title: Immobilization of selenite in soil and groundwater using stabilized Fe-Mn binary oxide nanoparticles.
abstract: Stabilized Fe-Mn binary oxide nanoparticles were synthesized and tested for removal and in-situ immobilization of Se(IV) in groundwater and soil. A water-soluble starch or food-grade carboxymethyl cellulose (CMC) was used as a stabilizer to facilitate in-situ delivery of the particles into contaminated soil. While bare and stabilized nanoparticles showed rapid sorption kinetics, starch-stabilized Fe-Mn offered the greatest capacity for Se(IV). The Langmuir maximum capacity was determined to be 109 and 95 mg-Se/g-Fe for starch- and CMC-stabilized nanoparticles, respectively, and the high Se(IV) uptake was observed over the typical groundwater pH range of 5-8. Column breakthrough tests indicated that the stabilized nanoparticles were deliverable in a model sandy soil while non-stabilized particles were not. When a Se(IV)-spiked soil was treated in situ with the nanoparticles, >90% water leachable Se(IV) was transferred to the nanoparticle phase, and thereby immobilized as the particles were retained in the downstream soil matrix. The nanoparticle amendment reduced the TCLP (toxicity characteristic leaching procedure) leachability and the California WET (waste extraction test) leachability of Se(IV) by 76% and 71%, respectively. The technology holds the potential to fill a major technology gap in remediation of metals-contaminated soil and groundwater.
authors.affiliation: Environmental Engineering Program, Department of Civil Engineering, Auburn University, Auburn, AL 36849, USA; College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, PR China.
authors.forename: Wenbo
authors.initials: W
authors.lastname: Xie
authors.affiliation: Environmental Engineering Program, Department of Civil Engineering, Auburn University, Auburn, AL 36849, USA.
authors.forename: Qiqi
authors.initials: Q
authors.lastname: Liang
authors.affiliation: Environmental Engineering Program, Department of Civil Engineering, Auburn University, Auburn, AL 36849, USA; Institute of Environmental Science, Taiyuan University of Science and Technology, Taiyuan, Shanxi 030024, PR China.
authors.forename: Tianwei
authors.initials: T
authors.lastname: Qian
authors.affiliation: Environmental Engineering Program, Department of Civil Engineering, Auburn University, Auburn, AL 36849, USA; Institute of Environmental Science, Taiyuan University of Science and Technology, Taiyuan, Shanxi 030024, PR China. Electronic address: zhaodon@auburn.edu.
authors.forename: Dongye
authors.initials: D
authors.lastname: Zhao
mesh_terms: D002266:Carboxymethylcellulose Sodium / Q000737:chemistry; D005079:Excipients / Q000737:chemistry; D060587:Groundwater / Q000032:analysis; D007501:Iron / Q000737:chemistry*; D008345:Manganese / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry; D020887:Selenious Acid / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry*; D013213:Starch / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D005079:Excipients; D010087:Oxides; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D008345:Manganese; D013213:Starch; D007501:Iron; D020887:Selenious Acid; D002266:Carboxymethylcellulose Sodium
keywords: Fe–Mn binary oxide; Groundwater remediation; Immobilization; Selenium; Soil contamination; Stabilized nanoparticles